低压管道输水在农田灌溉中的应用

低压管道输水是当前农田灌溉中的重要应用技术,就低压管道输水系统构建,建设原则以及建设管理注意事项进行重点阐述.     

水稻抗低温冷害栽培技术

通过对低温冷害对于水稻生产的影响程度、低温冷害的主要类型两方面的阐述,对水稻抗低温冷害栽培技术进行阐述、分析,并对水稻抗低温冷害栽培技术的大趋势做出预测。     

基于低碳经济视角的江西生态环境保护的思路

为了促进江西省经济、社会及生态的可持续发展,根据江西省生态环境及污染现状,遵循低碳经济的内涵及发展原则,探讨了江西省生态环境保护的思路,提出了发展对策,为更好地促进社会经济增长奠定良好的基础。     

低温弱光对西瓜幼苗生理特性的影响

以5个西瓜品种(系)为材料,研究低温(10℃)和弱光[200μmol·(m2·s)-1]对幼苗有关生理特性的影响。结果表明:各品种(系)的冷害指数、叶片主脉结构伤害程度、膜透性、MDA含量均随胁迫时间的延长而增加,光合速率随胁迫时间的延长而下降,而叶片SOD活性、CAT活性、SPAD值随着胁迫时间的延长先增加而后降低。综合评价各项生理指标,5个西瓜品种(系)耐低温弱光性由强到弱依次为鉴20、59046、扬9808、早春红玉、8424。     

低分子量有机酸对不同肥力土壤磷素的活化作用

针对石灰性土壤磷素固定累积问题,采用化学浸提方法,探讨低分子有机酸对不同肥力水平土壤磷素的活化作用,提高磷素的有效性.结果表明,对于低肥力和中肥力土壤,相同浓度下有机酸活化土壤磷的能力表现为草酸＞柠檬酸＞苹果酸;对于高肥力土壤,相同浓度下有机酸活化土壤磷的能力为柠檬酸＞草酸＞苹果酸.低浓度对有机骏对土壤磷的活化有抑制作...     

Statistical Analysis on High Strain and Low Cycle Fatigue Life of Rebars

High strain and low cycle fatigue(HSLCF)life of anti-seismic behaviors of rebars was investigaoted. Reliable theoretical basis was provided for data analysis on high strain and low cycle fatigue life of anti-seismic behaviors of rebars. The low cycle fatigue life of the HRB400 anti-seismic behaviors of rebars by quenching and self tempering (QST) process was tested. Because the low cycle fatigue life data was disperse, some kinds of mathematical statistics methods, such as Weibull double parameters probability function, normal distribution, lognormal distribution function and t-distribution function were used to statistically analyze the low cycle fatigue life data. The results indicate that in all of the probability functions, the low cycle fatigue life has the highest reliability by the t-distribution function method; the low cycle fatigue life has the lowest reliability by the normal distribution method; and the low cycle fatigue life has the highest safety by Weibull maximum likelihood method.     

Hierarchical control method of low voltage looped microgrid

The low voltage (LV) looped microgrid has high reliability of power supply and good accessibility of the DG. The medium voltage distribution network with single loop network and multi sectioned & multi linked is studied to analyze the wiring mode of the LV looped microgrid. A research on the two hierarchical control scheme of the looped microgrid is conducted, and the sub microgrid, which meets island operation requirements, is divided according to their segments. Then the incidence matrix is formed based on the connection relation of different segments and components, and the plan for switching the microgrid operation status is concluded from the reform of incidence matrix on the basis of the judgment of island and reconnection segments. A resynchronization strategy using microgrid central controller is proposed. The MATLAB/SIMULINK simulation software is used to analyze the dynamic characteristics of different operation status switching and synchronizing, and the results verify the effectiveness and correctness of the proposed control method.     

显性低酚棉新品系种仁营养品质与利用评价

 以自主选育的7个显性无腺体新品系为材料,通过种子性状考察,种仁游离棉酚、脂肪酸和氨基酸含量测定,研究了低酚棉种仁具有重要的油用、食用价值和保健功能。结果表明：4个新品系种仁棉酚含量低于国家食用标准,其中苏显无154、苏显无156棉酚占种仁质量低于3 mg·kg^-1,成为名副其实的无酚棉新种质。低酚新品系种仁粗脂肪含量高于有酚品种,不饱和脂肪酸总含量超过70%,油酸相对含量略低于有酚品种,亚油酸、亚麻酸、棕榈油酸相对含量以及不饱和脂肪酸总含量与有酚品种相同。低酚新品系种仁色氨酸含量高于常规有酚品种,其它必需氨基酸含量以及氨基酸总含量与有酚品种相近。低酚基因Gl₂^e对棉花种仁脂肪酸、氨基酸组成及其含量未产生负效应。     

低温胁迫对玉米幼苗光合特性的影响

以3个玉米品种为试材,研究低温胁迫下光合指标的变化。结果表明,随着低温胁迫处理时间的延长和程度的加强,3个品种表现出一致的规律。光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、PSⅡ最大光能转换效率(Fv/Fm)和光系统PSⅡ的潜在活性(Fv/Fo)呈下降趋势,胞间CO2浓度(Ci)在18℃/9℃、16℃/7℃低温处理下逐渐降低,14℃/5℃低温处理下呈先降低后升高的趋势。水分利用率(WUE)呈先升高之后趋于稳定。由此可知,低温胁迫使叶绿素所吸收的光能被用于光合作用的减少,叶光系统Ⅱ(PSⅡ)活性中心受损,植株通过调节气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、水分利用率(WUE)来进行自我调控。。