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Copyright of Research of Soil & Water Conservation is the property of Institute of Soil & Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Agrometeorology is the property of Editorial Board of Chinese Journal of Agrometeorology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electronic Communication & Computer Science is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Baiku Yao like to raise and eat local black pigs, and they are very good at collecting and managing forage plants. This study aimed to make an ethnobotanical inventory of forage plants and their related native knowledge in the Baiku Yao area, provide data support for the preservation of their traditional knowledge, and provide ideas for the development of modern new types of forage. From 2019 to 2021, we went to the local area for ethnobotanical investigation of forage plants, using key formant interviews, semi-structured interviews, and group discussions. Additionally, we had screened out the forage plants with high comprehensive utilization value according to scoring and ranking and their usage frequency. The results were as follows:(1)A total of 104 forage plant species were recorded, belonging to 42 families and 85 genera. The family with the most cited species was Asteraceae(16 species, accounting for 15.38% of the total species), followed by Urticaceae(13 species, accounting for 12.5% of the total species).(2)Branches and leaves(56.73%), whole plant(26.92%)and leaves(8.65%)were the main used parts of local forage plants, accounting for 92.30% of the recorded plants. Most forage plants were herbaceous plants(88.46%). There were adequate forage plants(accounting for 64.42% of the total)that could be collected to feed pigs in almost all seasons.(3)Chopping, crushing, and cooking feed plants were the main preparation methods of pig forage.(4)The most frequently cited local species were Zea mays, Broussonetia papyrifera, Ipomoea batatas, Morus alba, Fagopyrum dibotrys and Oryza sativa.(5)The local forage plants with high comprehensive evaluation were Broussonetia papyrifera, Ipomoea batatas, Morus alba, Fagopyrum dibotrys and Cucurbita moschata. The local people have rich traditional knowledge about the use and management of forage plants for pigs, which are very scientific and well preserved, and the related forage plant resources are also worthy of further development and promotion. [ABSTRACT FROM AUTHOR]

L-乳醛可以由L-乳酸甲酯经过一步硅保护，然后用二异丙基氢化铝溶液(DIBAl—H)还原制备得到.立体选择性化合物的制备是当代有机合成化学中非常重要而且具有挑战性的领域之一.高度立体选择性的各类化合物，包括立体高度选择性的烯烃化合物正在越来越频繁的运用在合成当中.本文系统地研究了L-乳醛与一系列不同类型的叶立德试剂在不同条件（改变温度、溶剂、碱）下发生Wittig反应的立体选择性，总结了一些基本规律，为今后得到立体专一的烯烃打下基础.

立体专一的手性烯酯(S)-3-（2，2-二甲基—1，3—二氧戊环基）-丙烯酸乙酯可以用来合成其它的一些具有光学活性的物质.笔者在研究(R)-甘油醛缩丙酮的合成及其Wittig反应选择性的过程中寻找这种立体专一性的手性烯酯的合成方法和条件，为今后得到更多立体专一的手性化合物打下一定的基础.

Copyright of Shanghai Land & Resources / Shanghai Guotu Ziyuan is the property of Editorial Board of Shanghai Land & Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Education Theory & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plastic film residues have posed a great threat to crop root growth and distribution in soil. The accumulation of agricultural wastes in the soil can also hinder the water and fertilizer migration in the farmland. Therefore, it is of great significance to clarify the effects of different Residual Plastic Film (RPF) amounts in soil on root growth and distribution. In this study, five levels of agricultural film residues were set at the Jiuzhuang Agricultural Comprehensive Water-Saving Experimental Station in Hetao Irrigation District from 2019 to 2020, including the control group, CK (0 kg/hm²), T1 (150 kg/hm², plastic film covering for about 18 years), T2 (300 kg/hm², plastic film covering for about 45 years), T3 (450 kg/hm², plastic film covering for about 72 years), and T4 (600 kg/hm², plastic film covering for about 100 years). A systematic investigation was also made on the effects of various RPF amounts on the Root Length Density (RLD) and the distribution of diameter classes for the maize roots. The RPF amount was then introduced to establish a root distribution model suitable for the farmland with the agricultural film residues. The results showed that the RPF effectively reduced the dense range of maize roots in the horizontal distribution, where the degree of reduction increased with the increase of RPF. The distribution of roots in the horizontal direction was divided into the main and the lateral root zone. The effect of RPF on the root system in the lateral root zone was greater than that in the main root zone, indicating a significant indigenous level (P＜0.05). Specifically, the RLD decreased sharply, when the RPF amount was 300 kg/hm² (T2), 75.98% lower than that in the 0 kg/hm² (CK) treatment. In the vertical distribution, the root system showed a significant downward trend with the increase of RPF. The maize root system was more affected by the RPF in the 0-30 cm soil layer than in the 30-80 cm soil layer. Furthermore, the RLD decreased by 50.02%, when the RPF reached 450 kg/hm². In addition, the RPF treatment reduced the coarse root ratio of maize (d＞2 mm), decreased by 29.25% on average. The proportion of fine roots (d≤2 mm) increased, with an average increase of 4.80%. A relative root length density (RPF-NRLD, Residual Plastic Film-Normalized Root Length Density) distribution model considering the RPF content presented a higher accuracy, in which the determination coefficient (R²) was 0.961, the Root Mean Square Error (RMSE) was 0.282, and the Mean Relative Error (MRE) was 18.87%, thereby to accurately simulate the distribution of maize roots under different residual film amounts. Meanwhile, the RPF-NRLD distribution model was also considered the different diameter classes of roots. Specifically, the simulated values for very fine roots and fine roots of maize were highly consistent with the measured values, where the MRE of 14.91% and 14.96%, respectively, and the MRE of very coarse roots of 35.41%. Correspondingly, the relative root length density distribution of very fine roots (d≤0.5 mm) and fine roots (0.5 mm＜d≤2 mm) followed the quadratic function, whereas, the coarse roots followed the exponential function. A field experiment was also conducted to verify the RPF-NRLD distribution model. It was found that the root system maintained normal growth, especially the very fine root and fine root, when the amount of RPF in the farmland was controlled in the range of 0-100 kg/hm². This finding can offer a scientific significance for the numerical simulation of crop growth and decision-making in the RPF-contaminated areas. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The North China Plain (NCP) is an important wheat-maize production region in China with limited water resource. Drought is one of major agro-meteorological disasters for the local agricultural production. This study introduced crop coefficient Kc into calculation of Standardized Precipitation Evapotranspiration Index (SPEI) to analyze drought condition. The method was compared with the two methods including SPEI based on Thornthwaite (SPEI_TW) and Penman-Monteith (SPEI_PM). Multi-year meteorological data in the North China Plain were obtained. The applicability of these three SPEI indexes in the annual drought assessment of wheat-maize was assessed based on historical disaster data. The spatial and temporal distributions and variations of annual drought during both winter wheat and summer maize growth season from 1961 to 2017 were analyzed. To understand the effect of climate change on wheat-maize, the study further analyzed the results at the key growth period scale and the annual scale. The results showed that SPEI_KC could be a better index than SPEI_TW and SPEI_PM to evaluate crop drought. Compared with the observed actual disaster data, SPEI_KC had the best applicability to assess annual scale of wheat-maize drought among the SPEI_TW index and SPEI_PM index in the North China Plain. For the condition with right evaluation when the drought was present, the average accuracy of SPEI_KC index in representing meteorological stations was up to 76.13%, which was 11.11 and 5.55 percent points higher than SPEI_TW index and SPEI_PM index, respectively. For the condition with right evaluation when the drought was not found, the accuracy of SPEI_KC index was 85.67%, which was 1.36 and 0.13 percent point higher than SPEI_TW index and SPEI_PM index, respectively. Spatial distribution of drought during the key growing period and the growth season of wheat and maize showed highly similar rules: light drought frequency at the key growing period and the growth season of wheat was high in the north of Heibei Province and serve drought frequency was high in the North China Plain; moderate drought frequency at the key growing period and the growth season of wheat was high in the north of Heibei Province. The drought intensity was strong in the northwest of the North China, weak in the southeast, mainly in the Henan. The average frequency of light drought was higher than 33.08%, the frequency of moderate drought was 10.08%, the average frequency of severe drought was higher than 6.14%. The drought frequency in the North China Plain showed a slight decreasing trend. The frequency of light drought increased at majority timescale and moderate drought and severe drought decreased at all of time scale. Moreover, the drought frequency decreased during the key growing period of wheat and the growing season of wheat and maize, and increased during the key growing period of maize and wheat-maize rotation. Our study revealed the temporal and spatial variation and the characteristics and causes of meteorological drought in North China Plain, and provided reasonable measures to deal with climate change. [ABSTRACT FROM AUTHOR]

Copyright of Studia Poliana is the property of Studia Poliana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Evaluation & Analysis of Drug-Use in Hospitals of China is the property of Evaluation & Analysis of Drug-Use in Hospitals of China Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Xinjiang is a main producing area of cotton in China. This study investigated the effects of global warming and plastic mulching on cotton-planting zoning of different matures in Xinjiang. The climatic data were from 173 meteorological stations during 1960-2015 in temperate zone around Xinjiang within a range of 200 km. The digital elevation mode data were from the United States Geological Survey, which had the resolution about 900 m. We analyzed the spatio-temporal variation of accumulated temperature not less than 10 °C, frost-free period and mean temperature in July with the aid of ANUSPLIN interpolation software. The cotton-growing area was classified based on these 3 parameters. In addition, the change of planting boundaries and area of different cotton matures were studied with climate change and the compensation effect of plastic mulching. The main results included: 1) the accumulated temperature not less than 10 °C, frost-free period and mean temperature in July showed an increasing trend in 1960-2015. Regional differences on thermal resources were obvious in Xinjiang. The accumulated temperature not less than 10 °C, frost-free period and mean temperature in July were closely related to the terrain elevation. The thermal resources was richer in the southern Xinjiang than those the northern Xinjiang and richer in plain areas than in mountain areas. 2) under global warming, the ratio of planting areas of middle mature and early-middle mature cotton all increased. The area of middle mature cotton region increased by 3.82×104 km2, and the main increase areas were located in the eastern part of tarim basin. The increased area of early-middle mature cotton was widely distributed in the eastern Junggar Basin, the southern Turpan Basin, the southern Hami Basin and the western Tarim Basin. But the proportion of planting area of early maturing cotton did not change significantly and exceptional early-mature and unsuitable areas decreased. 3) the accumulated temperature not less than 10 oC and mean temperature in July were the main limiting factors in unsuitable planting areas, besides the areas near Tianshan, Altai and Kunlun Mountains were also restricted by frost-free period. The main thermal limiting factors in early-middle mature cotton areas (Taha), early mature cotton areas and most regions of exceptional early-mature were limited by the accumulated temperature not less than 10 °C. 4) cotton plastic mulching had no significant influence on the planting boundaries of middle mature, early mature and unsuitable planting areas. But it had a significant influence on the planting boundaries of cotton areas in the area of the Junggar basin. With plastic mulching, the planting boundary of early-middle mature cotton extended 65 km to the east approximately, and that of early mature cotton areas extended 0-300 km to the east. With the plastic mulching, the planting area of early-middle mature cotton (Yeta) increased by 5.47×104 km2, some of which was from the former Taha cotton area. In addition, the planting areas of early mature and exceptional early-mature cotton decreased by 1.4% and 1.6% respectively. This study provide an effective method for cotton-planting zoning of different matures in Xinjiang. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)