技术效应、资本深化、规模效应和收入效应对环境影响的研究——基于1985—2008年第二产业数据的实证分析

本文将环境变量引入柯布-道格拉斯生产函数,对1985--2008年中国第二产业相关数据进行分析,在统一框架下探讨资本深化、人均收入、经济规模以及全要素生产率对环境污染和环境污染密度的影响,研究结果表明:技术效应是促使污染和污染密度降低的最重要因素,资本深化位居第二位,规模效应为促使污染降低的第三位因素,而收入效应在对污染和污染密度降低重要性方面分别居第四位和第三位.发展模式的差异导致了各因素对污染的影响程度具有阶段性.最后提出有关政策建议.     

A switched system approach to H∞ control of networked control systems with time-varying delays

This paper is concerned with the H_∞ control problem for a class of networked control systems (NCSs) with time-varying delay that is less than one sampling period. By applying a new working mode of the actuator and considering state feedback controllers, a new discrete-time switched system model is proposed to describe the NCS. Based on the obtained switched system model, a sufficient condition is derived for the closed-loop NCS to be exponentially stable and ensure a prescribed H_∞ performance level. The obtained condition establishes relations among the delay length, the delay variation frequency, and the system performances of the closed-loop NCS. Moreover, a convex optimization problem is formulated to design the H_∞ controllers which minimize the H_∞ performance level. An illustrative example is given to show the effectiveness of the proposed results.     

Transgenic barley with overexpressed PTrx increases aluminum resistance in roots during germination

A transgenic barley line (LSY-11-1-1) with overexpressed Phalaris coerulescens thioredoxin gene (PTrx) was employed to measure the growth, protein oxidation, cell viability, and antioxidase activity in barley roots during germination on the presence of 2 mmol/L AlCl₃ on filter paper. The results show that (1) compared with the non-transgenic barley, LSY-11-1-1 had enhanced root growth, although both were seriously inhibited after AlCl₃ treatment; (2) the degree of protein oxidation and loss of cell viability in roots of LSY-11-1-1 were much less than those in roots of non-transgenic barley, as reflected by lower contents of protein carbonyl and Evans blue uptakes in LSY-11-1-1; (3) activities of catalase (CAT), glutathione peroxidase (GPX), ascorbate peroxidase (APX), and glutathione reductase (GR) in LSY-11-1-1 root tips were generally higher than those in non-transgenic barley root tips, although these antioxidase activities gave a rise to different degrees in both LSY-11-1-1 and non-transgenic barley under aluminum stress. These results indicate that overexpressing PTrx could efficiently protect barley roots from oxidative injury by increasing antioxidase activity, thereby quenching ROS caused by AlCl₃ during germination. These properties raise the possibility that transgenic barley with overexpressed PTrx may be used to reduce the aluminum toxicity in acid soils.     

中国新诗史中不应缺失的名字——邵洵美

邵洵美的新诗创作深受波德莱尔、魏尔伦和乔治.莫尔等人的影响,诗歌风格带有明显的象征诗派死亡、阴郁、颓废和放荡的基调,致使邵洵美的名字长期被排斥在主流的文学史书写之外。新时期以来,文学史的建构是以文学性和审美性作为视野的。邵洵美诗歌颓废的诗美特征及独特的诗体建设,使他有理由成为新诗建设中颓废诗派的代表,邵洵美也应成为一个被书写的名字。     

“艺术兴学”与地方音乐文化相结合的研究

桂林师专＂艺术兴学＂的办学理念与桂林地方民间音乐文化相结合的研究是高校艺术教育教学改革的一项重要举措。它不仅是地方高校寻求自身发展的一个重要契机,探寻一条具有本土特色的艺术教育之路,使之成为一种融多元化与个性化于一体的办学特色。同时,也是时代赋予地方高校文化资源保护与传承的责任和义务。     

一类拟线性奇摄动边值问题

利用奇摄动理论,讨论了一类拟线性奇摄动边值问题。首先分别求得问题的外部解和内部解,再进行变量间的变换,得到外部解的内展开式和内部解的外展开式,利用边值条件和匹配原则,得出了该问题解的渐近展开式,推广了相应结论,并将所得结果应用于例子的求解。比较所得的渐近解和用边界层校正法求的解,可知所得到的渐近解达到了较高的精度。     

创新思路遵循规律扎实推进高校优势学科建设

江苏高校优势学科建设工程的实施,标志着江苏高等教育学科建设呈现出"高峰"学科建设与"高原"学科建设统筹并举的新格局.高校优势学科建设,需要在瞄准学科前沿、"项天攀高"上下功夫;在围绕重大需求、"立地贡献"上下功夫;在科学聚才用才、发挥"团队合力"上下功夫;在创新管理模式、建设"学科特区"上下功夫;在深化内外合作、建立"战略联盟"上下功夫;在遵循学科规律、营造"创新环境"上下功夫.     

轻声唱法对花腔演唱的意义

轻声唱法作为一种声音训练手段,对花腔演唱技能的掌握具有重要的意义。它贯穿花腔实践和教学历史,体现时代美学原则;它能够使声乐学习者较快掌握头腔共鸣的技巧,扩展音域,使嗓音逐步向全声发展,增强演唱者对于作品的表现和驾驭能力,是进入花腔演唱殿堂的重要路径。     

电磁感应透明物理机制的解释

利用半经典理论,以A型三能级原子系统为例,研究了电磁感应透明的物理机制．通过暗态、缀饰态和密度矩阵方程三种理论,解释了当激光场与原子系统相互作用时,原子在光场诱导的跃迁通道间发生量子相干效应是出现电磁感应透明的原因．     

论提升大学生就业指导课课堂教学效果的对策

提升大学生就业指导课课堂教学效果,必须在教学中让大学生认识到就业指导课对社会、对个人的重要意义和价值,提高大学生学习就业指导课的认识;树立科学的教学理念;运用问题式教学、专题式教学、讲座式教学、行为导向式教学等多种教学方式方法,并改变考核方式;加强师资队伍建设,提高教师的业务能力。