绿色汽车的开发前景

绿色作为无污染、无公害和环境保护的标志，绿色汽车是汽车技术不断发展的必然产物，研究和开发新型的交通工具－绿色汽车是环境保护 迫切要求，是汽车工业可持续发展的需要，作者主要论述了开发与研究绿色汽车的重要性、绿色汽车技术在国际国内的发展现状及开发前景，并从绿色技术的理论体系出发来阐明绿色汽车与环境保护和能源的辨证关系，阐述了绿色汽车研究的主要内容，包括绿色汽车的设计及设计体系，绿色汽车的制造及工艺，绿色汽车的能源和绿色汽车的再制造工程等一列系问题，以及如何评价绿色汽车的生命周期及评价指标，指出绿色汽车的发展前景和开发绿色汽车的深远意义。     

黑龙江省森林火灾的时空分布

黑龙江省位于我国东北部边疆。省内森林资源丰富，是欧亚大陆北方森林带的重要组成部分，地带性植被属于寒温带针叶林和温带针阔混交林，拥有全国面积最大的天然林，主要分布在大兴安岭北部、小兴安岭和东部山地，全省森林面积共1919万hm^2，活立木总蓄积是150.亿m^3。作为一种自然现象，木林火灾在发挥有利作用的同时也在危害着我们宝贵的森林资源，因此，采取科学的方法预防和控制森林火灾的发生已迫在眉睫。本文通过对近三十年的林火资料分析，绘制了黑龙江省森林火灾的分布图，并根据不同的火灾发生原因分别制图，分析了森林火灾发生的原因，而且探讨了林火发生的时空规律。     

调整陕南农业产业结构的基本思路与对策

农业产业结构调整对促进农村发展，农民增收具有举足轻重的作用。本文通过对陕南自然生态条件，资源优势和农业现状的分析，指出传统农业产业结构是制约当前陕南农村农业经济发展的主要因素，并针对其问题提出了调整陕南农业产业结构的基本思路，方向及应采取的对策。     

盘形凸轮廓线圆弧拟合的曲率中心法

在盘形凸轮的加工过程中,只要保证凸轮廓线上每一点对应的曲率中心位置与理论计算结果相符,就可以保证从动件运动规律,准确地实现其二阶导数设计目标。本文以理论计算所得曲率中心轨迹为出发点,提出盘形凸轮廓线圆弧拟合的曲率中心法。     

热休克转录因子（σ^32）基因的克隆及其在大肠杆菌中的表达

用ＰＣＲ方法获得大肠杆菌热休克蛋白转录因子σ＾３２的编码基因ｒｐｏＨ，并将基克隆至含有Ｐｔａｃ启动子的表达载体ＰＵＨＥ中。     

大豆蛋白与乳蛋白质混合制造冰淇淋的研究

冰淇淋是以奶油和非脂乳固体为主体经搅拌凝冻而成的一类冷饮食品,组织细腻、香味浓郁、口味滋美、营养丰富、四季宜食。自于我国牛乳供应不足,奶油已部分由人造奶油替代,关于蛋白质取代物的研究,人们曾探讨过花生和大豆替代牛乳生产冰淇淋。取得了一定的成效,但还有许多问     

GCC box in<Emphasis Type="Italic">Arabidopsis PDF1.2</Emphasis> promoter is an essential and sufficient cis-acting element in response to MeJA treatment

The expression of Arabidopsis PDF1.2 gene isregulated by jasmonic acid (JA) and ethylene (ET). It also has been well documented that GCC box is an element responsive to ET, however, the responsive mechanism of JA in such plant defense gene expression is unclear. In this paper, the authors define the essential cis-acting element in PDF1.2 promoter responsive to methyl jasmonate (MeJA) through fragment deletions and site-directed mutageneses combiningAgrobacterium-mediated transient reporter gene expression in tobacco leaves. Firstly, the MeJA inducible expression o fPDF1.2 was confirmed by using the upstream -1.86 kb fragment of PDFI.2 gene. Secondly, the upstream -300— -243 bp fragment of the promoter was evidenced to respond to MeJA. To further characterize this promoter region, three point mutations were introduced into the -300— -243 bp fragment of the promoter. This result showed that the mutation of GCC box abolished MeJA induction, whereas the mutations of the G box-like and the imperfect palindrome sequence did not significantly decrease MeJA inducible effect, indicating that GCC box in PDFI.2 is essential for MeJA induction. The sufficient responsiveness to MeJA of this GCC box was further investigated by 4xGCC fused upstream to the CaMV 35S minimal promoter. This result suggested that the fused promoter was able to activate reporter gene expression in response to MeJA. Thus these results indicate that the GCC box in PDFI.2 is an essential and sufficient element to confer MeJA induction.     

VEGF links hippocampal activity with neurogenesis, learning and memory

An enriched environment is associated with hippocampal plasticity, including improved cognitive performance and increased neurogenesis. Here, we show that hippocampal expression of vascular endothelial growth factor (VEGF) is increased by both an enriched environment and performance in a spatial maze. Hippocampal gene transfer of VEGF in adult rats resulted in approximately 2 times more neurogenesis associated with improved cognition. In contrast, overexpression of placental growth factor, which signals through Flt1 but not kinase insert domain protein receptors (KDRs), had negative effects on neurogenesis and inhibited learning, although it similarly increased endothelial cell proliferation. Expression of a dominant-negative mutant KDR inhibited basal neurogenesis and impaired learning. Coexpression of mutant KDR antagonized VEGF-enhanced neurogenesis and learning without inhibiting endothelial cell proliferation. Furthermore, inhibition of VEGF expression by RNA interference completely blocked the environmental induction of neurogenesis. These data support a model in which VEGF, acting through KDR, mediates the effect of the environment on neurogenesis and cognition.     

论达·芬奇的"镜子说"

通过对达·芬奇"镜子说"的分析,揭示了艺术源于现实高于现实的深刻内涵。"镜子说"完美地表达了艺术和现实之 间的关系。根据此种理论,艺术家的艺术创作应该永远从生活中汲取灵感。     

川东高陡构造成因地质模式与含气性分析

川东高陡构造位于四川盆地东部 ,由一系列 NE-NNE向的隔档式褶皱组成。其构造变形经历了由隔槽式褶皱到“两背一断”,最终形成隔挡式褶皱的演化过程。在“两背一断”先存构造研究基础上 ,按继承发展的观点 ,综合运用伸展构造、反转构造、断层相关褶皱等构造新理论 ,系统探讨了川东高陡构造形成演化的成因地质模式 ,结合志留系主力生烃层的生气高峰期 ,对地腹不同成因类型的构造圈闭含气性进行了分析。