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61.
Quality control and screening of active substances in traditional Chinese medicines have been performed using fingerprint analysis. The spectrum-effect relationship between chromatography fingerprints and efficacy of herbal drugs is considered as a potentially useful method for determining active ingredients in complex mixtures. The study was designed to develop a method for determining the bioactive components of a compound Chinese medicine called Tiefeng based on spectrum-effect relationships between high-performance liquid chromatography (HPLC) fingerprints and anticoccidial activities. Four peaks of the established HPLC fingerprint indicate the main bioactive components of this medicine. In addition, pharrnacodynamic atlas was defined and used to assess the anticoccidial activity of Tiefeng from different sources for the first time. We found that the level of anticoccidial activity of Tiefeng was consistent with the degree of similarity between the pharmacodynamic atlas and chromatogram of any sample. Furthermore, effect of this medicine was related with the main active constituents, along with the origin and the harvesting time.  相似文献   
62.
Soil organic carbon (SOC) content and its spatial distribution in the Northern Gangetic Plain (NGP) Zone of India were determined to establish the cause–effect relationship between agro‐ecological characteristics, prevailing crop management practices and SOC stock. Area Spread Index (ASI) approach was used to collect soil samples from the NGP areas supporting predominant cropping systems. Exponential ordinary kriging was found most suitable geo‐statistical model for developing SOC surface maps of the NGP. Predicted surface maps indicated that 43.7% area of NGP had 0.5–0.6% SOC, while the rest of the area was equally distributed with high (0.61–0.75%) and low (< 0.5%) SOC content levels. Averaged across cropping systems, maximum SOC content was recorded in Bhabar and Tarai Zone (BTZ), followed by Central Plain Zone (CPZ), Mid‐Western Plain Zone (MWPZ), Western Plain Zone (WPZ) and South‐Western Plain Zone (SWPZ) of the NGP. The SOC stock was above the optimum threshold (> 12.5 Mg/ha) in 97.8, 57.6 and 46.4% areas of BTZ, CPZ and MWPZ, respectively. Only 9.8 and 0.4% area of WPZ and SWPZ, respectively, had SOC stock above the threshold value. The variation in SOC stock was attributed largely to carbon addition through recycling of organic sources, cropping systems, tillage intensity, crop or residue cover and land‐use efficiency, nutrient‐use pattern, soil texture and prevailing ecosystem. Adoption of conservation agriculture, balanced use of nutrients, inclusion of legumes in cropping systems and agro‐forestry were suggested for enhancing SOC stock in the region.  相似文献   
63.
为探索纯化的重组猪抑制素蛋白质毒素残留情况以及重组猪抑制素蛋白质稳定性,本研究利用鲎试剂、气相色谱和SDS-PAGE方法对重组猪抑制素蛋白质中的细菌内毒素、β-巯基乙醇的残留量及其蛋白质在不同温度、极端p H值和反复冻融条件下的稳定性进行检测。结果显示,经过3次等电点沉淀洗涤后,重组猪抑制素蛋白质中细菌内毒素和β-巯基乙醇的残留量大幅减少。通过在不同温度下的处理发现,重组猪抑制素蛋白质在4℃环境下较稳定,可以长期保存;但在37℃时,稳定性快速下降,随着温度上升而降解加速。通过极端p H值和反复冻融试验发现,重组猪抑制素蛋白质对极端p H值和反复冻融具有较好的耐受性。  相似文献   
64.
在全球变暖的气候背景下,近年来干旱频发且不断加剧,对人类的生产生活造成了严重的影响。目前,干旱监测已成为全球气候变化研究的一个热点课题。遥感技术以其客观、及时、经济、覆盖范围广、数据连续等优点,已被证明是干旱监测中最具前景的技术手段。本文基于遥感原理,介绍了归一化植被指数、温度状态指数、标准化降雨指数和标准化降雨蒸散指数等几种常见的干旱指数,综述了运用不同指数干旱监测的主要应用。最后针对目前研究中存在的问题,对今后研究的主要方向作出了展望。  相似文献   
65.
We analyzed the effects of glyphosate to the index of salinization and alkalization by simulation in soils collected from cotton fields in Anyang, Henan and Anqing, Anhui, China, in 2014. The results showed that application of glyphosate changed electrical conductivity (EC), total alkalinity (TAL), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR) and pH of soil in both regions,compared with the blank control. With increased frequency of glyphosate application and increased concentration applied, all indices increased in the Anqing cotton fields soil which were treated with concentrations of 2.5-20 g·L-1 . However, EC, TAL and ESP increased dynamically in Anyang soil to which high concentrations of 20 g·L-1 were applied only four consecutive times. After different glyphosate treatments, the soil pH value showed an upward trend but smaller changes. Therefore, after repeated use of glyphosate to soils of two different region soils, although the changes of all indices were within the range of non-saline and non-sodic soils, the soils affected by salt in the glyphosate aqueous solution tended towards saline-sodic soils.  相似文献   
66.
黄芪为豆科植物膜荚黄芪(Astragalus membranaceus(Fisch.)Bunge)或蒙古黄芪(A.membranaceus(Fisch.)Bunge var.mongholicus(Bunge)Hsiao)的干燥根。针对药用植物黄芪的农艺性状和栽培中遇到的主要问题,开发制备了黄芪专用型种衣剂,对黄芪种子进行包衣,通过田间试验,定期采样,对黄芪的根系活力、叶绿素质量分数、硝态氮、蛋白质、可溶性糖的质量分数进行测定,检验种衣剂对黄芪的这5种生理指标的影响。  相似文献   
67.
西北旱区喷灌条件下紫花苜蓿生长特征与品质指标的关系   总被引:1,自引:0,他引:1  
李岩  苏德荣  李宏韬 《草业学报》2018,27(10):54-65
西北旱区由于独特的气候条件,生产的苜蓿干草品质好,产量高。如何根据苜蓿的田间指标估测干草品质参数,对于苜蓿草产品生产销售具有重要意义。研究在喷灌条件下不同灌溉量对紫花苜蓿的生长品质的影响,并利用生长指标对紫花苜蓿的品质进行预测。试验于2014至2015年于中国农业大学石羊河流域生态节水试验站进行为期2年的田间试验。试验共设3个灌溉处理:A1灌溉量为100%紫花苜蓿蒸腾蒸散量(ETc),A2,A3的灌溉量分别为A1处理的66%,33%,以及一个不灌溉处理A4。结果表明,苜蓿生长指标如株高(H)和茎叶比(SLR)随生育期的推进呈上升趋势,而鲜干比(FDR)呈下降趋势;所有生长指标随着灌溉量的减少均呈下降趋势。在品质方面,随着生育期的推进,所有处理的粗蛋白(CP)呈下降趋势,而中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)则呈现上升趋势;随着灌溉量的降低,NDF与ADF呈下降趋势,而CP则呈上升趋势。各生长指标与品质指标的拟合结果表明,H和SLR均与各品质指标显著线性相关(P<0.001),且H与品质拟合结果相关系数最高(R2>0.900),而FDR则与各品质指标不显著。这些结果表明,在田间管理较好,长势良好,杂草与病虫害发生较少的情况下,可以用株高对苜蓿干草品质做出预测。  相似文献   
68.
Winter rye (Secale cereale L.) will be especially affected by drought induced yield losses in Central and Eastern Europe in the future because it is predominantly cultivated on low-fertile soils with a poor water-holding capacity. In order to examine the performance of winter rye under different drought conditions, field experiments were carried out during the years 2011, 2012, and 2013 near Braunschweig, Germany. Two sets of genotypes were tested under severe, mild, pre-anthesis, and post-anthesis drought stress in rain-out shelters as well as under rainfed and well-watered conditions. The grain, straw, and total above ground biomass yields, harvest index, grain yield components, leaf area index (LAI), and phenological characteristics were examined, as well as phenotypic correlations between grain yield and further characteristics. Drought induced grain yield reduction ranged from 14 to 57%, while straw yield and harvest index were lesser affected by drought than the grain yield. Under drought conditions, fully ripe was reached up to twelve days earlier than under non water-limited conditions. Pre-anthesis drought mainly reduced spikes m−2 and kernels spike−1 while drought during grain filling reduced the 1000-kernel weight (TKW) only. The grain yield was positively associated with straw yield, spikes m−2, and kernels spike−1 under water limited conditions while the TWK was only positively associated with grain yield under drought during grain filling. Consequently, high pre-anthesis biomass as well as high numbers of spikes m−2 and kernels spike−1 are especially important for obtaining high grain yields under water-limited conditions. Focusing on these traits is, therefore, recommendable for developing drought tolerant rye genotypes.  相似文献   
69.
本试验旨在根据肉鸡生长曲线及动态营养需要,研究动态细分饲粮营养供给对肉鸡生产性能、肉品质、氮、磷代谢率及血清生化指标的影响。选取1日龄爱拔益加(AA)肉鸡240只(公母各占1/2),随机分为3个组,分别为A组:每3.5 d 1个营养标准(1~7日龄1个营养标准);B组:每7 d 1个营养标准;C组:每14 d 1个营养标准。每组8个重复,每个重复10只鸡,试验期42 d。结果表明:1)C组肉鸡的平均日增重(ADG)显著高于A、B组(P0.05),料重比(F/G)显著低于A组(P0.05)。A、B组肉鸡生产性能指标差异均不显著(P0.05)。不同动态细分饲粮营养供给方式对肉鸡肉品质的影响无显著差异(P0.05)。2)不同动态细分饲粮营养供给方式对肉鸡氮、磷代谢率的影响无显著差异(P0.05)。3)肉鸡28日龄时,C组肉鸡血清尿素氮(UREA)含量显著高于A组(P0.05);42日龄时,C组肉鸡血清UREA含量显著高于A、B组(P0.05),但A、B组肉鸡血清UREA含量差异不显著(P0.05)。4)不同动态细分饲粮营养供给方式对肉鸡血清皮质酮(CORT)含量及总抗氧化能力(T-AOC)的影响差异不显著(P0.05)。综上所述,每14 d 1个营养标准可使肉鸡的生产性能达到最佳,从实际操作的复杂性考虑,每7 d 1个营养标准可更好地满足饲粮的氨基酸平衡。  相似文献   
70.
[目的]明确矮秆早熟高粱品种吉杂141在佳木斯地区的合理栽培密度。[方法]以吉杂141为研究对象,在大田生产试验条件下,采用平播的方式,设置15万、20万、25万、30万、35万株/hm2共5个栽培密度,研究不同栽培密度下,吉杂141的群体生理指标、产量及产量性状。[结果]随着栽培密度的增大,叶面积指数增加,叶绿素含量下降,群体光合势和总光合势增加,株高差异不显著,穗长、穗粗逐渐下降,生物产量上升,千粒重和单穗重下降。[结论]初步明确在佳木斯地区采用平播方式吉杂141最适栽培密度为20万株/hm2,产量可达9 203.36 kg/hm2。  相似文献   
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