General mechanisms of drought response and their application in drought resistance improvement in plants

Plants often encounter unfavorable environmental conditions because of their sessile lifestyle. These adverse factors greatly affect the geographic distribution of plants, as well as their growth and productivity. Drought stress is one of the premier limitations to global agricultural production due to the complexity of the water-limiting environment and changing climate. Plants have evolved a series of mechanisms at the morphological, physiological, biochemical, cellular, and molecular levels to overcome water deficit or drought stress conditions. The drought resistance of plants can be divided into four basic types-drought avoidance, drought tolerance, drought escape, and drought recovery. Various drought-related traits, including root traits, leaf traits, osmotic adjustment capabilities, water potential, ABA content, and stability of the cell membrane, have been used as indicators to evaluate the drought resistance of plants. In the last decade, scientists have investigated the genetic and molecular mechanisms of drought resistance to enhance the drought resistance of various crops, and significant progress has been made with regard to drought avoidance and drought tolerance. With increasing knowledge to comprehensively decipher the complicated mechanisms of drought resistance in model plants, it still remains an enormous challenge to develop water-saving and drought-resistant crops to cope with the water shortage and increasing demand for food production in the future.     

立窑窑面空气过剩系数与节能浅析

本文根据一些立窑水泥厂的热工测定数据,推导出了化学不完全燃烧热损失Q_(hb),废气带走热损失Q_f与窑面空气过剩系数之间的关系,阐述了产生化学不完全燃烧热损失的原因,并就如何降低热损失,节约能源提出了设想。     

固定支付利率的抵押贷款定价理论——限于在支付日提前支付或违约

建立限于在支付日提前支付或违约的固定支付利率抵押贷款的定价问题的数学模型,通过沿着利率特征线方向差分偏微分方程,建立模型的离散计算方法,同时根据一些计算实例所得的数字结果,分析和讨论它的风险特性与风险管理方法.     

浅析普通机床的数控改造

论述了普通机床数控改造的可行性、必要性和经济性，并对C620-1型普通机床的数控改造过程进行了较详细的总结和论述，对普通机床的数控改造具有实际的指导作用。     

商业市场信息随机预测模型的研究和计算机实现

本文针对商业市场信息的特点，选用了随机预测模型ＡＲＩＭＡ的基本模式；深入研究ＡＲＩＭＡ模型建立的全过程，开拓性地采用了功率谱估计方法，确定市场预测模型的阶数ｐ和ｑ；利用多种高级语言的混编程序技术，在微机上完全实现了商业市场信息预测系统；运行结果表明；该模型及其实现系统是可行的。     

矩阵的相似准直和与群逆

首先引入矩阵的相似准直和的定义,讨论了它和群逆的关系,得到了一些性质和应用。     

省道002线（分水岭—仲宫段）地层划分与岩土工程分类

详细阐述了省道002线分水岭到仲宫段跨越地带地层的时代、岩性,划分了岩、土的工程类别,为道路和桥梁设计、支挡物设置及工程概算提供了依据。     

采用NP催化剂的芥酸氢化制备山嵛酸工艺研究

本文制备了高效加氢ＮＰ催化剂,并讨论了芥酸采用该催化剂加氢制备山嵛酸时,催化剂浓度、氢气压力、反应温度、搅拌速度等因素对反应的影响。试验结果表明其适宜的工艺条件为：催化剂浓度０．６％,氢气压力８．１１×１０５Ｐａ,反应温度４１３Ｋ,脉冲式搅拌速度８０次／ｍｉｎ。     

辽宁沈北煤田早第三纪植物群的发现

辽宁沈北煤田位于沈阳市北郊３０余ｋｍ处,为第四纪冲积层广泛覆盖的平地,基岩出露极少．据辽宁省煤矿管理局地质勘探局的普查,煤田地层由老至新依次为：前震旦系、震旦系、侏罗系、白垩系、下第三系、上第三系和第四系．沈北煤田的煤层主要产于下第三系,下第三系自上...