鸡树条荚蒾对干旱胁迫的生理响应

采用盆栽试验,测定鸡树条荚!扦插苗和播种苗在干旱胁迫下的生理指标.结果表明:鸡树条荚!嫩枝扦插苗、播种苗和硬枝扦插苗叶片相对含水量(RWC)均呈下降趋势,说明干旱胁迫下鸡树条荚!叶片保水能力较弱;3种鸡树条荚!幼苗叶片可溶性蛋白、游离脯氨酸(Pro)、丙二醛(MDA)、相对电导率和叶绿素含量均表现为先增加后降低的变化规律,各生理指标在第12天和第15天达到峰值.     

用户参与虚拟知识社区价值共创的机理研究

本文从自我决定理论出发,以知乎网和果壳网的用户为研究对象,实证分析了不同自我决定感对用户参与虚拟知识社区不同动机的影响,并探讨了这些动机对用户价值共创行为的作用。研究成果为厘清虚拟知识社区价值共创的轨迹提供了科学的理论依据。     

块体金属玻璃微磨削加工的温度场仿真

建立单颗磨粒微磨削的正交切削模型和玻璃金属的本构关系方程,采用有限元工艺仿真系统对块体金属玻璃进行微磨削加工的温度场仿真,从而得到块体金属玻璃在微磨削过程中的温度以及温度变化趋势,进而观察其磨削温度是否达到块体金属玻璃的玻璃转变温度.因此,对玻璃金属磨削加工过程的温度仿真可以有效预测非晶表面是否有晶化现象的发生.改变微磨削加工参数,对块体金属玻璃的各个磨削区的温度变化趋势进行观察.通过仿真实验发现,块体金属玻璃的最高磨削温度发生在磨粒前刀面与磨屑接触的区域,即第二变形区.     

An efficient identity-based key agreement protocol in a multiple PKG environment

Identity-based key agreement protocol affords a natural way to combine the participant’s identity with its public key.However,most of them just consider the key agreement in a single private key generator(PKG)environment.In addition,the existing key agreement protocols have a great computing overhead for mobile computing which is more and more popular today.This paper proposes a new identity based key agreement protocol.With the help of mathematical tools,we make our protocol applied in multiple PKG environment.It also satisfies all the security properties which is set for key agreement protocol.Moreover,some of its time-consuming operations can be delivered to untrusted public computation resources,so its computing complexity can be greatly reduced.     

一种简单窗口半透明方法的研究与实现

目前窗口半透明的应用越来越广泛,越来越多的窗口呈现出风格迥异的界面设计,如此别具一格的设计,提高了用户的体验.基于WPF实现了一种较为简单的窗口半透明方法,详细介绍了实现窗口半透明的原理和流程,提出并实现了窗口半透明且控件不透明的方法.算法运行结果表明,该方法效率较高、实现简单.     

回首之美——论席慕蓉《七里香》的情感特征

在《七里香》这部诗集里,席慕蓉以清新的笔调、低语式自白,回首青春年华,回溯生命历程,回望乡土乡愁,文本中充满着热烈的欣喜、深深的眷恋、淡淡的哀愁和超然的豁达等丰富多样而又清晰凝重的情感线条。席慕蓉在《七里香》中表现出的题材偏好和情感趋向,使其诗歌创作呈现出"回首之美"的独特艺术韵致,从而在中国诗坛引发"席慕蓉现象"。席慕蓉以"诗歌之力",唤起人们重铸爱情信仰、重新张扬理想风帆的人类崇高信念。     

Abnormal kynurenine pathway of tryptophan catabolism in cardiovascular diseases

Kynurenine pathway (KP) is the primary path of tryptophan (Trp) catabolism in most mammalian cells. The KP generates several bioactive catabolites, such as kynurenine (Kyn), kynurenic acid (KA), 3-hydroxykynurenine (3-HK), xanthurenic acid (XA), and 3-hydroxyanthranilic acid (3-HAA). Increased catabolite concentrations in serum are associated with several cardiovascular diseases (CVD), including heart disease, atherosclerosis, and endothelial dysfunction, as well as their risk factors, including hypertension, diabetes, obesity, and aging. The first catabolic step in KP is primarily controlled by indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO). Following this first step, the KP has two major branches, one branch is mediated by kynurenine 3-monooxygenase (KMO) and kynureninase (KYNU) and is responsible for the formation of 3-HK, 3-HAA, and quinolinic acid (QA); and another branch is controlled by kynurenine amino-transferase (KAT), which generates KA. Uncontrolled Trp catabolism has been demonstrated in distinct CVD, thus, understanding the underlying mechanisms by which regulates KP enzyme expression and activity is paramount. This review highlights the recent advances on the effect of KP enzyme expression and activity in different tissues on the pathological mechanisms of specific CVD, KP is an inflammatory sensor and modulator in the cardiovascular system, and KP catabolites act as the potential biomarkers for CVD initiation and progression. Moreover, the biochemical features of critical KP enzymes and principles of enzyme inhibitor development are briefly summarized, as well as the therapeutic potential of KP enzyme inhibitors against CVD is briefly discussed.     

成化初台阁派内部的一次政治、文艺斗争:“翰林四谏”事件分析

已经衰落的台阁派在成化二三年连续发生了被合称为"翰林四谏"的政治事件,翰林修撰罗伦上疏阻止内阁首辅李贤夺情起复,编修章懋、黄仲昭和检讨庄昶三人上疏谏阻举行元宵灯节,并拒绝应制撰作节庆诗词,先后被贬官外任。这是一场由政治道德而波及文艺思想领域的斗争,深刻反映了当时社会价值观念的趋于活跃和独立认真思考的力量,即使是受帝国意识形态训育和在体制内的人物,也有可能打破思想界和文艺界的沉闷气氛。