基于有限元法的发光二极管光学传播模型

应用有限元电磁场分析方法对发光二极管(LED)芯片的光学传播进行模拟.对光子晶体结构的外量子效率进行了计算.特别的是,对光源的处理上,使用了点光源球面波来进行分析并且考虑了光源的相干性.由于计算的复杂程度,对模型进行了简化处理.把光子晶体结构的实验数据与仿真结果进行了对比,验证了模型的正确性.     

人工神经网络在热轧宽厚板性能预测中的应用

建立了神经网络预测热轧管线钢力学性能的网络模型.在此基础上,利用神经网络对热轧管线钢力学性能进行了预测,并对预测结果与生产数据进行了比较.此外,还利用神经网络对生产工艺参数进行了优化.结果表明,将神经网络应用于热轧生产进行力学性能预测和工艺参数优化具有一定现实意义.     

新疆阿勒泰海新区绿化灌溉方案的研究

根据实际的地理及生态环境,确定该灌溉工程采用微灌系统进行灌溉.根据其生态环境,进行了灌溉分区的划分,喷头的布置.在充分地进行了理论方案分析的基础上,确定了该灌溉工程的相应的参数.对灌溉的喷头的型号及数量、管材的选择,管径的确定,水头损失的计算,进行了参数确定.并对其施工措施进行了设计.通过对该灌溉系统的计算分析,能够使该区的绿化园艺工作得以顺利进行,营造一个风景秀美的新区.     

几种可溶性有机半导体材料的合成与器件表征

以6,13-并五苯二酮为原料,利用Grignard试剂进行加成反应,合成了4种6,13-取代的并五苯衍生物.产物经IR和MS进行了结构鉴定.产物进行了器件表征,对它们的迁移率和开关电流比因素进行了探讨.     

河南省高等院校离退休教职员工的血脂、血糖分析

作者采集了河南省高等院校部分离退休教职员工的血样数据,并进行了分析.围绕胆固醇、甘油三酯、血糖、血压和心率五项指标,按照正常值标准进行了判别.采用SPSS12.0进行了统计分析,进行了性别、年龄组间的差异显著性检验,并进行了血脂、血糖与血压、心率相关性分析.发现胆固醇和甘油三酯与收缩压和舒张压之间存在相关性.     

红外水份测量仪的改进

对传统的红外水份测量仪进行了改进 .采用二级半导体制冷代替传统的一级半导体制冷加水冷的结构对红外探测器进行精密的温度控制 ,有效地抑制了探测器的热噪声 ,增强了测量信号 ,提高了信噪比 .系统的成本大为降低 ,效率和可靠性也得到提高 .同时采用Boxcar积分器对测量信号进行多次累加平均 ,进一步有效地提高了信噪比 .水份测量精度控制在 0 .3%以内 .     

Windows VFW技术在计算机培训管理系统中的应用

计算机培训管理系统要实时对缴费人的信息进行采集,其中包括照片,若想进行图像处理就要先进行视频捕获.鉴于此.文章对windows系统下的VFW体系结构进行了论述,给出了视频开发的相关windows API函数,分析了视频捕获的工作流程以及图片处理流程,并用Ⅶ来设计和实现视频捕捉以及图像处理程序,给出了程序的部分代码,并进行了程序测试.实验测试效果较好,实现了视频的实时捕捉及其处理.     

信道传输低通滤波器的最优化设计

本文采用Pspice对有源滤波器的最优化设计进行了讨论.以4阶巴特沃思(Butterworth)低通滤波电路为例,进行了电路性能、参数扫描分析,对滤波器电路结构和参数设定进行了最优化处理.采用蒙特卡洛分析方法对电路参数的容差进行了估计并在此基础上进行了400次统计分析,绘制出直方图对该电路设计投入生产时的成品率进行了预估计.结果证明了该方法的有效性及电路可靠性.     

空间对接整体动力学仿真系统稳定性分析

为了在地面模拟空间对接的动力学过程,对其动力学仿真系统进行了研究.描述了动力学综合实验台的工作原理,提出能模拟空间对接过程的动力学仿真问题.对空间对接整体动力学仿真系统的物理参数进行了合理配置,并对其稳定性进行了分析.试验结果验证了相应结论的有效性.     

超声刨削弯曲振动刀座的设计与测试

为了得到超声刨削弯曲振动刀座,对刀座进行了设计及研究.运用弯曲振动的相关理论,结合超声刨削的使用要求,进行了刀座的初步设计和计算.在初步计算的基础上,运用有限元分析方法,对阶梯形超声弯曲振动刀座进行了优化设计,得到了能满足振型和频率要求的刀座模型.并进行了频率和振幅测试.结果显示,刀座频率满足设计要求,具有一定的振幅放大倍数.     

柴达木盆地北缘冷湖-南八仙构造带油气成藏条件及成藏模式

冷湖-南八仙构造带是柴达木盆地油气勘探的重点地区之一。综合地质、地震和分析化验等资料,应用现代油气成藏、地球物理学、地球化学等理论和方法,对该地区油气成藏的地质条件及成藏模式进行了分析。结果表明,该区带油源丰富,储集条件好,发育多套有效的储盖组合,多种类型圈闭（尤其是构造圈闭）发育且成排成带分布,各成藏要素配置良好,具有形成大中型油气田的有利条件。在此基础上,提出了该区带油气有近源断层输导纵向成藏、远源不整合输导侧向成藏、近源不整合输导纵向成藏和近源混合输导成藏4种模式。其中,近源断层输导纵向成藏模式和近源混合输导成藏模式是本区主要的油气成藏模式,而近源不整合输导纵向成藏模式的油藏可作为本地区下一步勘探的方向。     

猪瘟强毒株与兔化弱毒疫苗株的LAMP鉴别检测

为了鉴别猪瘟病毒（CSFV）野毒感染和疫苗接种,系统比较分析CSFV标准强毒株、疫苗株、不同基因亚型的野毒株的全基因组序列差异,设计一套分别针对猪瘟强毒与弱毒NS5B基因的环介导等温扩增（LAMP）引物,建立特异性的猪瘟强毒株与疫苗株的LAMP检测方法.LAMP扩增产物用罗丹明B指示剂或者琼脂糖凝胶电泳进行检测.该方法特异性好,比RT-PCR灵敏度高出1 000倍,且重复性稳定性良好,为快速准确地鉴别CSFV野毒感染和疫苗接种提供了有效的方法.     

Screening of HLA-A2 restricted CTL epitopes using molecular simulation

Immunity is one of the functions a body has to iden-tify and eliminate foreign antigens. As one of the surfacemolecules of antigen presenting cells, major histocom-patibility complex (MHC) will exert essential effects dur-ing the antigen presenting procession, and the presenting of MHC-Ⅰ peptide complex is regarded as the prelude to activate the cytotoxic T lymphocytes (CTL) which play an important role in the anti-tumor and anti-virus responses. As we know, CTLs can only identify the co…     

网络环境下的高校图书馆采访工作

文章将高校图书馆传统的采访工作与网上采访做比较,探讨了网络环境下的高校图书馆采访工作,认为两者并非替代关系,而是相互竞争,又按一定比例相互并存,在未来的采访中发挥各自长处,互相弥补不足,形成相辅相成协调互补的格局。同时指出网络环境下采访工作应关注的问题．“细水长流”是图书馆采购常态．     

Evaluation and characterization of an endosperm-specific sbeⅡa promoter in wheat

Starch,the main component of the wheat grain,is the product of a complex biochemical pathway. The sbeⅡα gene plays a key role in controlling the synthesis of starch, in particular, the biosynthesis of amylopectin,in maturing wheat grain.To investigate its regulatory mechanisms and endosperm-specific expression pattern, the sbeⅡα promoter (3094 bp in length) was cloned using APCR and sequenced.The effect of a series of deletions was studied using a GUS transient assay system. Results showed that the 3094 bp sequence (sbe.g construct) exhibited full stable promoting activity and that the activities of 5′ or 3′ deletions reduced levels of GUS expression. Some constructs with internal deletions showed only weak activity, however,sbe.e, with a deletion from -1579—--1210 bp resulted in higher levels of expression than the full-length promoter sequence, sbe.g. This indicates that motifs such as the -300 bp element, G-box and/or P-box act as positive elements and are necessary in determining the promoter‘s endosperm-specific pattern and that negative repressor elements or motifs may also be present within the -1579—-1210 bp sequence. The age of wheate ndosperm tissue used in the GUS-transient assay system is shown to be of significant importance.     

Polarizing activity and retinoid synthesis in the floor plate of the neural tube

In many developing organisms the establishment of axial polarity and the patterning of cells depend on local signals that derive from restricted regions of the embryo. In vertebrate embryos, the origins of tissue polarity have been examined extensively in the developing limb. The anteroposterior pattern of the chick limb seems to be controlled by a morphogen, possibly retinoic acid, that is enriched in a region of the limb known as the zone of polarizing activity (ZPA). Certain tissues other than the ZPA have also shown polarizing activity experimentally in the chick limb, raising the possibility that signalling molecules involved in pattern formation in different embryonic tissues are conserved. Here we provide evidence that a similar polarizing activity is also present in a restricted region of the developing central nervous system (CNS). We show that a specialized group of neural cells termed the floor plate, but not other regions of the CNS, mimics the ZPA in respecifying the digit pattern in the developing chick limb. In addition, using an in vitro biochemical assay, we show that the floor plate can synthesize retinoic acid and 3,4-didehydroretinol, the precursor of a second morphogenetically active retinoid, 3,4-didehydroretinoic acid. These results show that the floor plate is a local source of a ZPA-like polarizing signal, possibly a retinoid, which may regulate the pattern of cell differentiation in the developing CNS.     

米非司酮对JAR细胞凋亡的诱导作用

米非司酮是一类抗孕激素和抗糖皮质激素药物,在临床被广泛用于早孕的终止．发现米非司酮能抑制人滋养层瘤细胞（ＪＡＲ）的生长．药物处理使细胞形态出现典型的凋亡特征．被处理细胞的ＤＮＡ经琼脂糖电泳呈凋亡细胞特有的云梯状条带．原位凋亡检测也证实了凋亡细胞的存在．临床样品分析证明,米非司酮药物流产的人绒毛组织也发生了明显的细胞凋亡．说明米非司酮诱导流产的机制除了对子宫蜕膜的作用外,还可能与诱导滋养层细胞凋亡有关     

玉米渣纤维降解菌LMPQ39菌丝原生质体诱变的研究

对担子菌ＬＭＰＱ３９菌丝原生质体进行了紫外光──ＬｉＣｌ复合处理后，得到突变株Ｕ３９，再将其分别用６０Ｃｏ、ＨＮＯ２两种方法处理，各获得突变株ＵＣｏ３９和ＵＮ３９，它们的ＣＭＣ酶活由原来ＬＭＰＱ３９的０．３１ｕ分别提高到０．４６ｕ和０．５７６ｕ．酯酶同功酶电泳表明，ＵＣｏ３９、ＵＮ３９和母株ＬＭＰＱ３９的酶谱出现了６条共同的谱带，同时也出现差异．突变株和母株的拮抗试验呈阳性。     

重瓣百合LiSEP3基因克隆与表达分析

【目的】克隆百合LiSEP3基因并确定其在百合不同地上器官及不同花瓣中的表达差异,探讨SEP3基因在重瓣花中的表达模式。【方法】利用RACE方法从重瓣百合品种‘比罗尼卡’中克隆得到LiSEP3基因核苷酸序列,利用SMART软件对其蛋白结构进行分析,以MEGA 5.0软件进行系统进化树分析,用基因枪轰击法进行亚细胞定位分析,采用荧光定量PCR进行不同地上器官及不同花瓣中LiSEP3基因表达差异分析。 【结果】LiSEP3基因属于MADS-box家族E类基因,其开放阅读框为729 bp,共编码242个氨基酸; LiSEP3基因编码的蛋白具有典型的MADS结构域、K-box区及2个SEP基序; LiSEP3与同为单子叶植物的六出花的SEP3亲缘关系最近; LiSEP3蛋白定位于细胞核中; LiSEP3基因在花中的相对表达量最高,在茎、叶中几无表达; 在1～7轮花瓣中均能检测到LiSEP3表达,且位于最内侧的第7轮花瓣中相对表达量最高。 【结论】LiSEP3基因属于MADS-box家族E类基因,主要在花中表达,其中在最内侧花瓣中表达量最高,其表达模式与双子叶植物花中SEP3基因表达模式存在不同。     

Conversion by retinoic acid of anterior cells into ZPA cells in the chick wing bud

In recent years there has been considerable interest in the role of retinoic acid (RA) in vertebrate-limb pattern formation. When RA is applied to the anterior of the chick wing bud, a mirror-image duplication of the limb pattern develops that is identical to the pattern resulting from grafts of posterior tissue (zone of polarizing activity, or ZPA). It has been proposed that position along the anterior-posterior axis in the chick limb is specified by a gradient of a diffusible factor produced by the ZPA. The ZPA-mimicking action of RA has led to the hypothesis that exogenously applied RA acts by providing graded spatial information across the anterior-posterior limb axis. An alternative interpretation is that RA changes anterior cells into ZPA cells, which in turn provide the actual pattern-duplicating stimulus; there is already some preliminary evidence that this occurs. A hybrid interpretation has also been suggested whereby ZPA cells are formed in response to RA exposure and then begin to release retinoids that act as graded spatial cues. We have used a functional assay to test anterior chick wing-bud cells for ZPA activity after exposure to RA. The results of our studies indicate that the action of RA is to change anterior cells into ZPA cells. Further, our results indicate that it is unlikely that RA-treated anterior cells then begin producing RA in such a way as to provide a graded positional signal.