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- Abstract：The aim of this study was to analysis the quantitative and spatial characteristics of land use change in Beijing and provide scientific basis for Beijing's rational distribution of land use in future. Based on land use maps of Beijing in 1980, 1990, 1995, 2000, 2005 and 2010, the spatiotemporal disparity of regional land use quantitative structure and conversion change was quantitative analyzed combined with Major Function Oriented Zoning (MFOZ) in this study. The results demonstrated that:1) The area of arable land in Beijing sharply decreased by 1 462.11 km2 during the past 30 years, the construction land increased by 1 344.64 km2 significantly, and the forest change slightly, as well as the grassland. The change rate of all land use types area displayed a trend of "acceleration-deceleration" and 1990-1995 and 2000-2005 were two of the most typical phases of construction land expansion and arable land shrinkage. The conversion among forest, grassland and arable land was much more active before 2000 than after. The conversion from arable land to construction land existed throughout the study period and became the leading conversion type since 2000 with smaller conversion area than before. 2) The area of arable land in Urban Functional Development Zone and New Urban Development Zone decreased 61.75% and 22.28%, with the area of construction land increased 84.32% and 109.16% during the study period, which were much more active than other MFOZs. 3) The arable land shrinkage and construction land expansion mostly occurred in the region near the city center (<30 km) and gradually spread outward with time. Another tiny hotspot of arable land shrinkage and construction land expansion appeared in the distance of approximate 70 km from the city center, where the built up areas of Miyun, Pinggu and Yanqing located in. The structural imbalance of land use in Beijing with remarkable construction land expansion and arable land shrinkage indicated that the land use regulation of Beijing in future should lay emphasis on controlling the occupation of arable land by construction land. Other similar regions should also focus on coordinating the contradiction between the expansion of construction land and the protection of arable land as well as ecological space during the coming urbanization process in the future.Keywords：Beijing;land use change;regional disparity;major function oriented zone1|8|11<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The normal development of cotton fiber requires a lot of sucrose supply, and invertase is key enzyme involved in the body of sucrose metabolism. In this study, to obtain better understanding of the quantity and distribution of sucrose converting enzymes in cotton genome, the 17-invertase family genes was used as reference sequence in Arabidopsis to determine the cotton genome database in Gossypium barbadense, Gossypium hirsutum, Gossypium raimondii and Gossypium arboreum. The results showed that the number of sucrose invertase gene family contained in Gossypium barbadense was significantly higher than that in Gossypium hirsutum, while there was only one more in Gossypium raimondii than that in Gossypium arboreum. The numbers of invertase gene family members of these cultivars were 65, 46, 26 and 25, respectively. By analyzing the gene structure of members of the invertase gene family, α subgroup of neutral/alkaline invertases and acidic invertase gene were mostly consisted of 6 or 7 exons and β subgroup were consisted of 4 or 5 exons. In addition, a long UTR area was existed in the genetic structure of some Gossypium barbadense and Gossypium raimondii, but not in Gossypium hirsutum and Gossypium arboreum; The acidic invertase basically contained three conserved motifs, namely DNPNG, FRDP, and WECPD, indicating the evolutionary conservatism of the same gene family in different species. The clustering analysis inferred that the function of VIN subfamily genes might be related to cotton fiber development. These results laid a theoretical foundation for further research on cotton fiber development genes in invertase family.Keywords：cotton;cotton fiber;invertase gene family;bioinformatics analysis6|8|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This study explored the relationship between leaf photosynthetic characteristics and nitrogen use efficiency (NUE) of Coix cultivars. In early and late seasons of 2015, two pot experiments were conducted with four Coix cultivars with high NUE (XL and QY) and low NUE (LL and CU). Data were collected at tillering, heading and maturity stages to assess the relationship between leaf photosynthetic rate and chlorophyll fluorescence attribute. The photosynthetic rate and NUE of functional leaves (specify the leaf e.g. upper fully expanded leaf) were determined at heading stage. The results showed that the nitrogen uptake of high NUE cultivar LL and QL in the early and late seasons were respectively 125.5% and 96.0% higher by than those in low NUE cultivar XL and CU. Compared with LL and CU cultivars, the NUE on average of XL and QL were respectively 7.7% and 18.0% higher. The leaf photosynthetic rate and chlorophyll content of the high NUE cultivar were significantly higher than those of the low NUE variety at tillering, heading and maturity stage. At the same time, the photosynthetic rate and chlorophyll content of the high NUE cultivars were lower than those of nitrogen inefficient varieties after tillering stage. The chlorophyll fluorescence parameters and the photosynthetic rate of functional leaves at the full tillering, heading and maturity stages were not similar, but the variation pattern was not obvious. The photosynthetic rate and chlorophyll content of the functional leaves of the high-yielding cultivars were greater in the early growth stages but decreased later in the season. No significant relationship was observed between NUE and the chlorophyll fluorescence parameters and the change in photosynthetic rate of four functional leaves.0|7|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aims of this study were to clarify the advantages of the high-yield areas of two varieties and coordinate various factors to achieve specific results and conduct research by adjusting light and temperature in the future. This study investigated the agronomic traits of 2 millet varieities, Nongda 8 and Changnong 35, in 7 typical areas in Shanxi Province. The results showed that different regions displayed significant effects on the growth period, main stem height, density of seedlings, grain weight per spike and production of milet. The variety difference was the main factor causing 1 000-grain weight and spike length differences. The growth period of Nongda-8 was significantly shorter than that of Changnong 35. As the millet's tillering ability was automatically adjusted with the environment, the difference in the number of spike of millet in different regions was not significant, resulting in the correlation between the number of spike of millet and the density of seedlings in different regions was not obvious. In this study, the weight of spike and the spike grain weight were the main factors contributing on yield. The spike grain weight and the plant height of Nongda 8 were very sensitive to the local reaction and positively correlated with latitude. In terms of yield, 1 000-grain weight, number of spike and length of spike, Nongda 8 adapted all seven regions and the overall evaluation result of it was obviously better than those of the control varieties. The spike length of Changnong 35 performed best in Shanxi Wutai County. Changnong 35 was superior to Nongda 8 in the stress resistance of main stems. In addition to the main stem high, the stress resistance of Nongda 8 was higher than that of Changnong 35. During cultivation process, various factors could be coordinated to achieve the expected effect through the control and adjustment of the light and temperature.Keywords：region;millet;agronomic traits;resistance2|8|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to investigate the effect of planting density and nitrogen application on machine picking cotton canopy LAI transmittance and branch length index, using split plot design. The main area of 2 D18 planting density (180 thousand plants/hm2), D24 (240 thousand plant/hm2), deputy district with 4 nitrogen N0 (0 kg/hm2), N170 (170 kg/hm2), N320 (320 kg/hm2) and N470 (470 kg/hm2) were designed. The results showed that:Under the same nitrogen application amount, the boll number and boll weight, lint percentage decreased, canopy, canopy LAI increased with the increasing of planting density, and the branch length increased after the first dropping trend, DIFN decreased, boll, lower canopy weight gradually reduced. Under the same D18 planting density of condition, with the increase of nitrogen application amount, the boll number, boll weight and lint percentage, seed yield, canopy, LAI, branch length and DIFN increased, the performance of the N470 > N320 > N170 > N0. The planting density under the condition of D24 was increased after the first dropping trend, the performance was N320 > N470 > N170 > N0. The highest yield was the D18N470 treatment and followed by D24N320 treatment, and there was no significant difference between these two treatments. Although, the yield of D24N320 is 1.09% less than the D18N470, the amount of urea input (per hectare) 31.91% resulting in slightly lower yield, but caused lower the environmental harm. Therefore, when the planting density was 240 thousand/hm2 and the amount of nitrogen was 320 kg/hm2 were the optimum planting density and nitrogen application rate under the mode of machine harvest cotton planting in Southern Xinjiang.Keywords：planting density;nitrogen application rate;machine picking cotton;leaf boll spatial distribution;yield1|9|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to explore the physiological characteristics of leaves and grain yield of rice under different long-term fertilizer regimes in a double cropping rice system. The protective enzyme activities and photosynthetic characteristics of rice leaves, and grain yield of rice were analyzed by using conventional physiological and biochemical experimental analysis methods from 2015 to 2016 based on the long-term fertilizer experiment. The experiment included five different fertilizer treatments:Without fertilizer input (CK), mineral fertilizer alone (MF), rice residue and mineral fertilizer (RF), 30% organic matter and 70% mineral fertilizer (LOM), and 60% organic matter and 40% mineral fertilizer (HOM). The results showed that the activities of SOD, POD and CAT of rice leaves were increased under MF, RF, LOM, HOM treatments compared with those in CK at main different growth stages of early and late rice. Meanwhile, compared with CK, the MDA and Pro contents in rice leaves were decreased under MF, RF, LOM, and HOM treatments at main different growth stages of early and late rice. The Pn, Tr in rice leaves under different fertilizer treatments was decreased in the order of LOM > HOM > RF > MF > CK and RF > LOM > HOM > MF > CK at main different growth stages of early and late rice, respectively. Meanwhile, the Gs in rice leaves under different fertilizer treatments was decreased in the order of HOM > LOM > RF > MF > CK at main different growth stages of early and late rice. The grain yield of early rice with LOM and HOM treatments were higher than those of the other fertilizer treatments and the grain yield of late rice with RF and LOM treatments were higher than those of the other fertilizer treatments, respectively. In 2015 and 2016, the yield of early rice was increased by 3 582.5-3 650.0 kg/hm2 and 2 569.5-2 641.5 kg/hm2 under LOM and HOM treatments compared to the CK, respectively. The grain yield of late rice were increased by 2 480.0-2 757.5 kg/hm2 and 2 827.5-3 118.5 kg/hm2 with RF and LOM treatments in 2015 and 2016, respectively. In conclusion, the results indicated that the long-term combined application of chemical fertilizer with organic manure management was an effective way to improve protective enzyme activities and photosynthetic characteristics in rice leaves.Keywords：rice;fertilization regime;organic-inorganic fertilizer combination;protective enzyme;yield1|8|8<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the role of thymosin beta 10 (Tβ10) gene during the rapid growth process of antler, a prokaryotic Tβ10 gene expression vector was constructed by using Gateway technology to test Tβ10 fusion protein activities and produce polyclonal antibody. The results showed that:1) The complete open reading frame (ORF) of Tβ10 (190 bp) was inserted into the expression vector pDEST17 via LR cloning reaction which was named aspDEST17-Tβ10.2) The concentration of fusion Tβ10 protein could reach 0.5 mg/mL yielded from host cells BL21-SI under the induction with 0.3 mol/L NaCl for 2 hours. 3) The titer of Tβ10 polyclonal antibody researched 105 which could bind to natural or fusion Tβ10 protein in Western blot assay. 4) In vitro assay revealed that Tβ10 protein could promote proliferation of HUVEC but inhibited antler pre-cartilaginous cells'. In conclusion, the Tβ10 fusion protein and obtained high titer polyclonal antibody was purified, which would lay a solid foundation for the study of biological functions of Tβ10 gene.Keywords：sika deer;thymosin beta;10;prokaryotic expression;Antler;polyclonal antibody1|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the effects of feed additives on the early intestinal health of broiler chickens affected by coccidiosis, a total of 400 healthy 1-day-old AA broilers were randomly divided into 4 treatment groups consisting of 5 replicates with 10 in each. Four treatments were basal diet, basal diet + 0.08% antibiotics, basal diet + 0.05% probiotics and basal diet + 1% green tea powder. At 14 days old, each group was intragastrically administered with1 mL (5×104) Eimeria tenella and saline. The broiler's body weight was recorded every two weeks after 12 h fasting. Their feces were collected on day 4, 7 and 10 d after coccidial challenge for egg counting. One broiler from each replicate was sampled at the age of 19 and 25 d for intestine measurement, respectively. A total of 40 chickens were taken. and 2 cm of intestine was collected and fixed in 10% formalin. The egg number of broilers fed with diet containing antibiotics or probiotics was significantly lower than those fed with basal diet P<0.05 10 days after coccidial challenge. The egg number of broilers fed with diet containing green tea powder was significantly lower than those fed with basal diet (P>0.05). The broilers fed with diet containing green tea powder exhibited significant lower body weight at 14 d than those fed with basal diet or antibiotic supplementation (P<0.05). However, the body weight exhibited no significant difference among different groups of broilers at 28 d. The length of ileum of broilers fed diet containing probiotics was longer than those in other groups (P<0.05). And the thickness of ileum was significantly lower than those fed with basal diet or diet containing green tea powder. In conclusion, coccidial infection led to slower growth of jejunum and thickened cecum. The green tea powder addition alleviated the body weight loss caused by coccidiosis while exhibited no effect on the early growth promotion of broiler before the age of 14 days. The probiotics did not affect the weight gain of broilers from 15 to 28 days of age and reduced the number of eggs in feces after coccidia infection.Keywords：AA broiler;coccidiosis;green tea powder;intestinal health1|7|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to investigate the effects of growth differentiation factor 9 (GDF-9)on culture and the related gene mRNA expression of yak cumulus-oocyte complexes (COCs) in vitro. The healthy yak ovaries were collected and COCs were isolated for maturation culture in vitro. GDF-9 with final concentrations of 0, 200, 400, and 600 ng/mL was separately added to the maturation medium for yak COCs culture in vitro, and the oocyte maturation rate was separately counted. The mRNA expression levels of Smad 4 and cumulus cell extension related genes (HAS 2, PTX 3, PTGS 2) in COCs were detected by Real-time PCR. The results showed that there was no significant difference in the maturation rates of COCs treated with 0, 200, 400 and 600 ng/mL GDF-9 (P>0.05). The mRNA expression of Smad 4 gene and extension related genes (HAS 2, PTX 3, PTGS 2) were increased with the increasing of GDF-9 concentration. The mRNA expression of Smad 4 and PTX 3 in group treated with 600 ng/mL GDF-9 was the highest, which was significantly different from other treatments (P<0.05). Compared with group treated with 400 ng/mL GDF-9, the mRNA expression of HAS 2 and PTGS 2 in 600 ng/mL GDF-9 group had no significant difference (P>0.05), which was significantly different from other experimental groups (P<0.05). It was found that the maturation rates of yak COCs treated with GDF-9 showed no significant differences, but GDF-9 significantly increased the expression of Smad 4which was the downstream molecule gene of GDF-9 in the cell signaling pathway. GDF-9 also increased the mRNA expression of cumulus cell extension genes (HAS 2, PTX 3, PTGS 2). These results suggested that GDF-9 might play an important role in the extension of cumulus oocytes during culturing yak COCs in vitro, and the mechanism might be related to the activation of Smad signaling pathway, but its mechanisms remained to be further studied.3|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the effects of MRJPs (Major royal jelly proteins), the effects of the main water-soluble component of RJ on carbon tetrachloride (CCl4)-induced liver injury were investigated. The CCl4-induced acute liver injury model was established. Mice were randomly divided into six groups including negative control, positive control (CCl4 treated control group), Drug control, MRJPs (480 mg/kg) plus CCl4 treated group, MRJPs (320 mg/kg) plus CCl4 treated group and MRJPs (160 mg/kg) plus CCl4 treated group, respectively. The mice were pre-treated orally with MRJPs (480, 320 or 160 mg/kg) once daily for 28 days before CCl4 (10 mL/kg of 0.2% CCl4 solution in olive oil) injection. The hepato-protective effect of MRJPs was evaluated by the biochemical parameters related to hepatic damages, such as ALT, AST, SOD, MDA and TNF- α. The results showed that:MRJPs inhibited serum ALT and AST activities compared with positive group; MRJPs remarkably increased the levels of SOD and decreased MDA in liver; Histopathological test results showed that MRJPs effectively inhibited the acute liver injury induced by CCl4. Further investigation demonstrated that MRJPs markedly increased the gene expression of TNF- α in liver. In conclusion, MRJPs protected mouse from CCl4-induced acute liver injury.2|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to solve the problem recognizing stud rams' movement behaviors depends on feeders' observation is time consuming,a rams' movement behavioral identification system with acceleration sensor was designed. In the system, atriaxial acceleration sensor was employed to collect the rams' movement data in real time, and the data was wirelessly transmited. The system also could obtain the characteristics of movement behaviors by analyzing the data collected under four deployment schemes of sensor (the sensor fixed on the back, neck, foreleg and hindleg of ram), and classify the movement behaviors by K-means clustering algorithm and interval threshold algorithm. The results showed that the sensor fixed on the back near the forelegs of ram could obtain the most stable acceleration data in four deployment scenarios. The average recognition rate of K-means clustering algorithm was 77.05% and its recognition was not good. So this research presented interval threshold algorithm. The interval threshold was obtained by indentifying and testing the acceleration data. The recognition rates of standing, walking and running were 95.96%, 95.78% and 96.89%, respectively. The average recognition rate for the three movement behaviors reached 96.21%, showing that the movement behaviors data obtained by analysis could be applied to guidance in supplement of stud rams' exercise and monitor their health condition.Keywords：stud ram;movement behaviors;acceleration sensor;K;-means clustering algorithm;interval threshold algorithm4|9|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To research the soil micromorphological features of sandy land after applying clay and explore the effect of the ameliorative measures from the aspects of soil micromorphology, soil collected from Horqin Sandy Land of Inner Mongolia were made into soil thin sections,the analysis was proceeded by observing the soil thin sections and collecting the quantitative data of soil matrix,pores and skeleton grains by using the soil slice image processing and analysis system and the software of Image-Pro Plus 6.0.The results showed that:The soil microstructure was improved after applying clay,blocky microstructure and cambic aggregate were found; In terms of matrix ratio and capillary pore ratio,the effect of subsoil application was better,the matrix ratio was increased by 8.8% at the level of C2 (3×105kg/hm2), and the capillary pore ratio was increased by 15% at the level of C3 (6×105kg/hm2);However in terms of total soil porosity,roundness,the ratio of silt area and average diameter,the effect of surface application was better. All were improved significantly at the level of C1(1.5×105kg/hm2) and C2(3×105kg/hm2).In conclusion1)the sandy soil structure has improved after applying clay. 2) In the short term at subsoil application,the matrix ratio was increased at the levels of C1 and C2,the capillary pore ratio was increased with the increase of clay amount.And the effect of surface application was better as for skeleton grains;3) In the short term after the amelioration,there was no great improvement in soil microstructure,which was dominated by skeleton grains and with small amount of cambic aggregate,and all quantitative index were improved to some extent.Keywords：clay;sandy soil;improvement;soil micromorphology;Horqin Sandy Land of Inner Mongolia1|11|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the influence of organic wastes and soil fertility on nutrition contents in soil, twelve treatments were designed with 4 types of organic wastes (pig manure, straw, woody peat and molasses) and two types of soil (low-fertility soil and high-fertility soil), supplied with same chemical fertilizer (diammonium phosphate). The results showed that both waste and soil influenced soil nutrition content in soil after 90 d incubation without plant. For the low-fertility soil, all organic wastes affected its nitrogen contents, with the ratio ranged 25.78%-63.92%. When used together with chemical fertilizer, only the woody peat and molasses significantly increased the nutrition contents, at the ratio of 27.18%, 53.53%and 24.04%, 56.15% for organic carbon and nitrogen, respectively. The soil nitrogen was more easily to be transferred to nitrate-N from ammonium-N in high-fertility soil afterwards. The effects of woody peat and molasses were better to transfer ammonium-N into nitrate-N, and activate phosphorous. The contents of Olsen-P were respectively increased by 65.98% and 130.13% in low-fertility, and 50.25% and 74.84% in high-fertility soil in the treatments used woody peat and molasses. In conclusion, the nutrition management should be set based on the soil fertility. The organic wastes could increase the chemical fertilizer efficiency and activate the phosphorous. The woody peat and molasses were the two better organic wastes.Keywords：organic wastes;soil fertility;nutrition;incubation4|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the optimal regulation combination of water and composite soluble fertilizers supplied with drip irrigation system beneath mulched film, a field drip fertigation experiment was conducted in a cherry orchard at three irrigation levels (W1, W2 and W3, i.e. 70%, 85% and 100% of designed irrigation quota) and three fertilizer levels (F1, F2 and F3, i.e. 60%, 80% and 100% of recommend dose of fertilizers for drip irrigation) were designed. Conventional border irrigation and fertilization method was set as control (CK). The results showed that the amount of irrigation and soluble fertilizers showed significant effects on the cherry yield, quality, irrigation water use efficiency (IWUE), partial factor productivity (PFP) and main nutrients content at the 0-100 cm soil layer. The drip fertigation beneath mulched film with reasonable regulation of water and fertilizer obtained better yield, quality and soil fertility than those of conventional method. IWUE and PFP were both improved effectively. The treatment with medium water deficit and enough fertilizer (W2F3) was considered as the best combination for cherry tree, which obtained the highest yield (3174.61 kg/hm2), vertical diameter (23.15mm), total soluble sugar content (17.82%) and IWUE (9.69 kg/kg), the lowest titratable acid (0.41%). Other quality indicators and soil nutrients such as the content of total nitrogen, available nutrients and organic matter at the 20-40 cm soil layer were relatively better. This study provided scientific data supports for the effective and productive water and fertilizer-saving system in orchard.Keywords：drip fertigation beneath mulched film;yield and quality;irrigation water use efficiency;partial factor productivity;soil fertility10|13|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To solve the problems of low water and fertilizer use efficiency and low yield of rice caused by cold well water irrigation in northern cold regions, warming well water irrigation field experiments were conducted in 2015 and 2016 at 852 Farm in Heilongjiang Province. Rice variety "Kendao24" was used as study material. The results indicated that increasing the temperature of well water irrigation had a significant effect on rice plant morphology, photosynthetic characteristics, yield, and water and fertilizer utilization efficiency. Compared with normal temperature well water irrigation mode, the warming well water irrigation mode significantly promoted the growth of rice plants and the roots grow downward. The leaf area index, the number of adventitious roots, the total root length, the total surface area and the total volume of the rice increased by 14.7%, 14.5%, 11.6%, 33.1% and 17.0%, respectively. The warming well water irrigation mode also significantly enhanced photosynthesis at full heading stage of rice and increased photosynthetic rate and net photosynthetic rate of rice by 19.5% and 22.2%, respectively. And the number of grains per spike, theoretical yield and the actual yield increased by 11.1%, 25.6% and 4.8%, respectively. The average annual pure income reached 6 749.6 yuan/hm2 and increased by 13.98%. At the same time, the warming well water irrigation mode significantly improved the water and fertilizer utilization efficiency and saved the production cost. The water use efficiency, nitrogen fertilizer use efficiency, seeds absorption nitrogen, grain yield and nitrogen harvest index increased by 8.5%, 5.4%, 9.2%, 4.9% and 3.8%, respectively. The direct irrigation mode caused the cold water damage to the rice seedlings, which led to the delay of rice development and significantly inhibited rice morphological characteristics, photosynthetic characteristics, yield, and water and fertilizer use efficiency. In conclusion, the warming well water irrigation mode is the optimized irrigation mode in this study, and it is also one of the technical measures for rice water saving, fertilizer saving, high yield and suitable for promotion in northern China.Keywords：rice;increasing well water temperature;biological characteristics;water use efficiency;nitrogen use efficiency10|10|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem of groundwater overexploitation in North China Plain, a case of water-saving demonstration area in Fangshan, where the situation of groundwater overexploitation is serious, is investigated using the method of the water supply quota management of well. A groundwater simulation software GMS was used to simulate groundwater in water-saving demonstration area. The results showed that:After the water supply quota management, the simulated groundwater level in the demonstration area in 2020 would be recovered to 3.34 m, which is 1.49 m higher than the current management simulated groundwater level. Quota management can improve the strength of underground water level recovery and is one of the effective measures of groundwater dynamic balance.Keywords：groundwater overexploitation;hydrogeological model;water quota management;groundwater level recovery14|20|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to classify the cotton disease images accurately under natural conditions, a disease identification method based on the improved VGG-16 convolution neural network is proposed. Based on the VGG-16 network model, this method replaces the original three fully connected layers with two fully connected layers, and replaces the SoftMax classifier in the original VGG-16 network with the 6-tag SoftMax classifier. These changes can optimize the model structure and parameters, and it can share the weight parameters of the convolutional layer and the pooling layer in the pre-training model through the mini-migration learning. From the constructed image database of cotton diseases, the images of disease images were randomly taken as training set and test set to test the performance of the method. The experimental results show that this method can effectively extract multi-layer feature images of cotton leaf disease images, and it can highlight the edge information and texture information from cotton disease feature map through the Relu activation function. In the four kinds of resolution image samples training and verification, 512 pixels×512 pixels resolution images are the best fit for testing. Compared with BP neural network, support vector machine, AlexNET, GoogleNET and VGG-16NET, the proposed method has the best performance in average recognition accuracy of 89.51%. It is better to distinguish Cercospora leaf spot, Anthracnose, Verticillium wilt, Fusarium wilt, wheel disease and health leaf. The results show that the method has good classification performance in the field of cotton disease identification, and can realize accurate identification of cotton diseases under natural conditions.Keywords：cotton;convolution neural network;VGG network;diseases;image recognition47|34|39<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to solve the problems of existing potato seedling killing machine including high resistance to seedling, low rate of breaking length, high tuber rate and low operation efficiency, a Box-Behnken experimental design with three factors and three levels was performed. Parameters influencing cutting vine efficiency such as cutting type, cutting speed and cutting height were selected as independent variables. A mathematical model was established, and the effects of various parameters and their interactions were analyzed as well. The results of multi-factor test showed that the cutter and the cutting type had very significant effect on the cutting strength of potato vine (P<0.01), the cutting strength with serrated blade was smaller than smooth blade in the way of slide cutting; cutting type and cutting height had a highly significant effect on the cutting strength of potato vine (P<0.01). The cutting speed also had significant influence on the cutting strength. The interaction of the three factors was not significant(P>0.05), The order of influence on cutting strength was cutting type, cutting height and cutting speed.Keywords：potato;cutting strength;mechanical properties;cutting experiment12|13|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the collision damage during grapes harvest, storage and transportation, drop collision tests at different heights were carried out. A high-speed camera was used to record the collision process, and the relationship between the speed of collision and collision damage was analyzed. Stress relaxation test was carried out; a collision mechanics model of grape fruit based on ABAQUS was established, and the drop simulation tests were conducted and the finite element analysis was performed. The result of finite element analysis was compared with the result of collision test. The results showed that when the velocity of the grape increased from 0.5 to 3 m/s, the deformation amount increased from 1.1 mm to 4.2 mm, and the recovery coefficient decreased from 0.5 to 0.4; When the collision speed of the grape reached 1.5 m/s, its interior began to cause great damage, at this time, the maximum internal collision stress is 0.19 MPa; When the collision was no more than 1.5 m/s, the established grape fruit collision mechanics model had high accuracy with an error of 8%.Keywords：grape;drop collision;viscoelasticity;finite element;mechanical damage13|11|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the influence of corn storage system reform on the households' willingness of planting structure adjustment, based on the data of 359 households in Jilin Province, a Binary Logit Discrete Choice Model applied to study the effects of the corn storage system reform on the households' income and willingness of planting structure adjustment in main production areas of Northeast China. The results showed that:1)Because of far higher corn yield, quality and corn producer subsidy level in advantageous areas than those in non-advantageous areas, Households in advantageous areas still made reasonable profit, while those in non-advantageous areas generally got a loss; 2)The factors affecting the households' planting structure adjustment with lower willingness in advantageous areas were mainly corn sale price (positive correlation), land transfer difficulty degree (negative correlation) and satisfaction degree with corn producer subsidy standards (positive correlation). Those affecting the farmers' planting structure adjustment with stronger willingness in non-advantageous areas were mainly the quantity of agricultural labors (positive correlation), the cultivated land (negative correlation), the loan condition (positive correlation), the corn sale price (negative correlation) and whether to know the specific content of corn storage system reform (positive correlation).2|8|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to analyze the characteristics and mechanism of hog price volatility, a structural break was identified by means of non parametric Mann-kendall from the perspective of structural breaks in this study by using the data obtained from January 2000 to March 2017. On this basis, Census-X12 and covariance analysis were used to explore the heterogeneity of three factors' contribution to hog price at three stages. A Log-linear model was constructed to study the causes and differences of influence degrees. The results showed that the volatility for hog price mutated in May 2007 from January 2000 to March 2017. Compared to the previous stage, the impact of irregular components was increasing and seasonality was getting more and more obvious from June 2007 to March 2017. The non-linear effect of factors was more prominent after May 2007. In addition, the contribution of irregular factors increased from 0.004 in the first stage to 0.014 in the second stage, and contribution of seasonal factors increased from 0.029 to 0.065, while the contribution of trend factors decreased from 0.967 to 0.921. Overall, the influence of pork price and piglet were greater. The effects of size and direction on hog price were different at different stages and the cost of breeding cost and epidemic were becoming new influencing factors.Keywords：hog price;structural breaks;volatility characteristics;Mann-kendall test6|9|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study is to investigate the problems and causes of quality and safety in each link of the pig industry chain, under the framework of tracing responsibility and applying the concept of social governance. analyzes The present situation of pork quality and safety problems and the logic mechanism and countermeasures from the perspective of industry chain is analyzed based on the investigation of the main interests of pig breeding and circulation, pig slaughter and processing, as well as pork sale in Beijing. The results show that the overall situation of quality and safety of pork in Beijing is in good condition despite the fact that there are also some hidden threats including directly throwing away dead pigs are, the use of the banned drugs are still in use, the not strictly enforced of drug withdrawal period, the increase in the dosage of veterinary drugs and the selling of water injected pig. Hidden problems also exist in the quality and safety inspection sections. Slaughtering and processing enterprises also face the pressure of sustainability of harmless treatment. Both the wholesale market and the farmers' market have problems such as the sale of water injected meat and the sale of stale pork. According to the causes of pork quality safety problems, suggestions on strengthening the source control and legal publicity, making effort to increase the detection and punishment, establishment of registration system and credit evaluation system for pig buying and selling dealers, improving the subsidy policy of slaughtering and harmless treatment of dead pigs, establishing a comprehensive traceability system of pork distribution and strengthen traceability, accountability and publicity are proposed in the end of this study.Keywords：traceability and accountability;pig industry chain;quality and safety;logic mechanism and countermeasures;social governance1|9|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the relationship between egg futures market and spot market, the spillover effects and dynamic correlations was analyzed based on the data of the domestic egg market obtained through the BEKK-GARCH model and DCC-MGARCH model. The result showed that there was significant mean spillover effect between the two markets and a significant price guidance relationship. The futures market had more significant price guidance to the spot market. The egg futures market displayed better price discovery function to the spot market. In addition, there was significant two-way volatility spillover effect between egg futures market and spot market. The correlation between two markets displayed obvious time-varying characteristic, and the overall performance was positively correlated.Keywords：egg;futures price;spot price;spillover effect;dynamic relationship1|11|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the micro survey data of 937 rice farmers in Anhui, Jiangxi, Hunan and Hubei provinces located in the middle reaches of the Yangtze River, a three stage DEA model was adopted to measure the farmers' production efficiency, and analyze the influence degree and direction of agricultural socialization services on agriculture production efficiency. The results showed that:There are significant differences in the production efficiency of farmers' among the four provinces, and the level of efficiency was generally low, among which Jiangxi Province was the lowest. Financial services, agro-technical services and mechanical services had a significant positive impact on agriculture productivity. However, due to the maintenance and management deficiencies of the government or the village committee, good infrastructure had a significant negative impact effect on farmers' production efficiency. In addition, the individual characteristics and family characteristics of the farmers had significant effects on their production efficiency. In conclusion, it is necessary to construct an inclusive financial system, targeted agricultural technology services to farmers and pay attention to the quality of mechanical services so as to improve the level of agricultural socialization services and the agricultural socialization service system, and realize the agricultural modernization.Keywords：agricultural socialization services;agricultural production efficiency;three stage DEA model1|9|15<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
