谈谈语文教学如何培养学生的观察能力

观察是认识的先导,是获得写作材料的基本途径,重视提高学生观察能力,是提高学生写作水平的有效方法,是语文素质教学成败的关键.但学生在观察认识对象特征时常感到困惑,常常在写作上无从下手,表达上语无伦次,杂乱无章,面对这一现状,本文从空间位置、形状与形态、颜色、神情与神态等四方面引导介绍,使学生更为容易地掌握观察的方法,提高观察能力,以达到提高写作水平的目的.     

论警察战术发展的一般规律

研究警察战术的发展,应从警察执法战斗实践的需要出发,重点研究警察战术发展的基本动力、科学技术进步对警察战术发展的影响、警察战术思想与警用技术发展的关系、警察战术产生发展的一般循环过程、警察战术学术理论发展的必备条件以及警察战术发展的多重制约条件,从中概括出警察战术发展的一般规律,对于探索警察战术的发展趋势,研究新的战术形式,指导警察执法战斗实践有着重要意义。     

固体潮力触发地震的可能性

为验证固体潮力触发地震的可能性,通过理论推导计算了太阳和月球对地球的固体潮力及其作用范围。结果显示:太阳和月球对地球的固体潮力远远小于地壳岩石强度,单一的固体潮力不能使岩石破裂而引发地震;太阳和月球对地球的加卸载作用主要集中在低纬度地区,与地球地震带范围基本吻合。岩石力学实验结果表明,岩石在外力作用下达到非线性时,固体潮力的扰动也可以触发地震。该结果为地震预报研究奠定了基础。     

对开发教育旅游的思考

在分析教育旅游的涵义、现状和特点的基础上,提出教育旅游开发应当坚持安全第一、突出教育特色、因势利导和效益兼顾的原则.发展教育旅游业应当规范教育旅游市场;深入挖掘和丰富教育旅游产品内涵;开发短线旅游;利用"黄金周"开发家长携子游;促进夏令营的健康发展;实行高校优秀生互访制度;完善、丰富高校旅游;出国(境)修学旅游市场的拓展;加强区域协作等.     

乳糖对小鼠运动能力的影响研究

以糖作为能量补充的基点,昆明小鼠作为实验对象,将小鼠分为对照组(C)、空白运动组(B)和服用乳糖组(L),研究补充乳糖对减缓昆明小鼠运动性疲劳的作用,以提高小鼠的运动能力.结果表明:(1)在小鼠运动前补充乳糖能减少血液中的乳酸;(2)游泳力竭运动后,空白运动组的小鼠的血糖浓度有一定程度的下降,且下降趋势明显,而服用乳糖组小鼠的血糖浓度下降不大.说明补充乳糖后,可以提高小鼠的运动能力.     

A mutant protein kinase C that can transform fibroblasts

Expression of normal protein kinase C (PKC) isoenzymes in fibroblasts has been shown to alter growth regulation but has failed to induce complete transformation of the recipient cells. Here we report on a murine ultraviolet-induced fibrosarcoma cell line which has an unusual PKC subcellular distribution with 87% of the PKC activity associated with the membrane. We have cloned and sequenced the alpha-PKC complementary DNA from ultraviolet-induced-fibrosarcoma cells and from mouse Balb/c brain and found four point mutations in the fibrosarcoma PKC, of which three are in the highly conserved regulatory domain and one is in the conserved region of the catalytic domain. Expression of this mutant alpha-PKC gene in normal Balb/c 3T3 fibroblasts results in a fibrosarcoma-like PKC membrane localization and in cell transformation, as judged by their formation of dense foci, anchorage-independent growth and ability to induce solid tumours when inoculated into nude mice. By contast, transfectants expressing the normal alpha-PKC cDNA do not display a morphology typical of malignant transformed cells and fail to induce tumours in vivo. These findings demonstrate that point mutations in the primary structure of PKC modulate enzyme function and are responsible for inducing oncogenicity.     

Evidence that sensory traps can evolve into honest signals

Conventional models explaining extreme sexual ornaments propose that these reflect male genetic quality or are arbitrary results of genetic linkage between female preference and the ornament. The chase-away model emphasizes sexual conflict: male signals attract females because they exploit receiver biases. As males gain control of mating decisions, females may experience fitness costs through suboptimal mating rates or post-copulatory exploitation. Elaboration of male signals is expected if females increase their response threshold to resist such exploitation. If ornaments target otherwise adaptive biases such as feeding responses, selection on females might eventually separate sexual and non-sexual responses to the signal. Here we show that the terminal yellow band (TYB) of several Goodeinae species evokes both feeding and sexual responses; sexual responsiveness phylogenetically pre-dates the expression of the TYB in males and is comparable across taxa, yet feeding responsiveness decreases in species with more elaborated TYBs. Displaying a TYB is costly, and thus provides an example where a trait arose as a sensory trap but has evolved into an honest signal.     

论死亡出诗人

古人对死亡的最基本态度是执著悲观,由此产生两种基本的人生态度:及时享乐;奋发有为。后者在文学上就是"立言",这类文学有不朽式、忧生式、游仙式和哀祭式等。本文是对"悲愤出诗人"这一传统理论的重大修正的补充。     

用Delphi开发OA软件的一种方法

以开发文书管理程序为例 ,讨论了Delphi如何与word 97结合来实现基本的公文管理功能 .     

基于PowerBuilder开发WEB应用研究

介绍了基于PowerBuiler开发WEB应用的几种方法，分析其原理和结构，并给出了用WEB．PB开发简单的网上应用的实例。     

A cell line that can induce thymocyte positive selection.

The thymus positively selects thymocytes that bear T-cell receptors which recognize antigen presented by self major histocompatibility complex (MHC) proteins. Positive selection is usually driven by MHC products on radiation-resistant cortical epithelial cells. It is unknown whether positive selection is mediated by all thymic epithelial cells or by some specialized subsets. Here we introduce an H-2b-expressing thymic epithelial cell line into the thymuses of lethally irradiated H-2k animals reconstituted with H-2b/k F1 BM or fetal liver cells. I-Ab-restricted T cells are found in these animals, demonstrating that selection occurs on the introduced epithelial cells.