隧洞掘进机(TBM)的洞外组装

概述了隧洞掘进机(TBM)的洞外组装,包括开敞式TBM的设备组成、组装前的准备工作、组装程序及关键性的技术措施。由于场地、机具、材料、人员和技术准备充分,TBM的洞外组装十分顺利。辽宁省水利水电工程局组织国内焊工,将国外焊接技术转化为国内严寒地区的焊接技术,成功地进行了刀盘焊接,基本实现了刀盘焊接的国产化,并在国内首次采用方便快捷的TBM滚轮(Dolly)步进技术。     

多孔基定型相变材料的研究进展

硅藻土、膨胀珍珠岩、膨胀石墨和高岭土等多孔材料能通过毛细管和表面张力的作用将相变材料定型,并为相变材料提供机械强度以阻止其在相变过程中发生泄漏.文章对多孔基定型相变材料的发展现状及其在建筑节能上的应用进行了综述,并对其今后在建筑节能上的应用研究及发展趋势进行了展望.     

考虑形位误差的装配尺寸链计算探讨

通过计算光滑圆柱体的配合间隙，分析了形位公差对加工装配精度的影响，给出包括形位公差在内的有关装配尺寸链的解法，并得出考虑形位误差在内孔轴配合间隙变大的结论。     

Packaged organic materials as monitoring tools for radionuclides

Pint-size perforated polyethylene bags were used as containers to test preserved tea, spinach, ion-exchange resin, live filamentous green algae, and dead filamentous green algae for the sorption and concentration of radionuclides from natural aquatic habitats and from a variety of laboratory controlled nutrient media. These packaged materials have been used to detect trace levels of radionuclides not found by the usual methods of analysis of the raw water itself for dissolved radionuclides.     

具有形位误差的装配尺寸链的分析计算

研究了形位误差对装配精度的影响，通过分析把形位误差作为一个减环纳入装配尺寸链内，并用表格法进行计算，保证了装配尺寸链的计算精度，为进一步提高机械产品质量提供了理论依据。     

产业集聚的创新力和竞争力研究

产业集聚具有群体竞争优势和集聚发展的规模效益。产业集聚拥有较强的竞争力来源于其区域内部的竞争和合作，进而形成一个区域创新系统，提升整个集聚企业的创新力。     

Double perovskites as anode materials for solid-oxide fuel cells

Extensive efforts to develop a solid-oxide fuel cell for transportation, the bottoming cycle of a power plant, and distributed generation of electric energy are motivated by a need for greater fuel efficiency and reduced air pollution. Barriers to the introduction of hydrogen as the fuel have stimulated interest in developing an anode material that can be used with natural gas under operating temperatures 650 degrees C < T < 1000 degrees C. Here we report identification of the double perovskites Sr2Mg(1-x)MnxMoO(6-delta) that meet the requirements for long-term stability with tolerance to sulfur and show a superior single-cell performance in hydrogen and methane.     

Mitochondrial DNA as a genomic jigsaw puzzle

In mitochondria of the unicellular eukaryote Diplonema, genes are systematically fragmented into small pieces that are encoded on separate chromosomes, transcribed individually, and then concatenated into contiguous messenger RNA molecules.     

Reaction of the antitumor antibiotic CC-1065 with DNA: structure of a DNA adduct with DNA sequence specificity

Sequence-dependent variations in DNA revealed by x-ray crystallographic studies have suggested that certain DNA-reactive drugs may react preferentially with defined sequences in DNA. Drugs that wind around the helix and reside within one of the grooves of DNA have perhaps the greatest chance of recognizing sequence-dependent features of DNA. The antitumor antibiotic CC-1065 covalently binds through N-3 of adenine and resides within the minor groove of DNA. This drug overlaps with five base pairs for which a high sequence specificity exists.     

适于SSR-PCR的农作物基因组总DNA高通量提取方法的建立

[目的]建立一种新的、通用、快速的农作物基因组总DNA提取方法,为应用分子标记技术研究遗传多样性及变异提供方便.[方法]分别从甘蔗、水稻、玉米、花生和大豆5种作物中提取基因组DNA,用琼脂糖凝胶电泳对所提取的DNA质量进行检测,然后每种作物分别选取两对SSR引物进行PCR扩增,用聚丙烯酰胺凝胶电泳检测扩增结果.[结果]采用该提取方法,不同作物产生的纯DNA在100.0~160.0 g/g,提取DNA的A260/A280比率在1.80~1.95.此外,电泳凝胶未出现可见的RNA污染,每个作物基因组DNA单一条带非常清晰,DNA结构完整,质量较高,适用于分子标记的研究.应用SSR分子标记进行PCR扩增,重复性、稳定性好,经琼脂糖凝胶电泳检测,条带清晰且分辨率较高.[结论]建立的DNA提取方法为直接将叶片剪碎后装入EP管中,加入提取缓冲液进行DNA提取,省去了用液氮研磨的过程.与传统的DNA分离方法相比,新建立的DNA提取方法具有高通量、简单、快速、经济效益高等优点.     

Plant crops as a source of fuel and hydrocarbon-like materials

Chemical analyses have been made of a number of plant species in order to assess their suitability as renewable sources of hydrocarbon-like photosynthetic products. Yields of rubber and wax, glycerides, isoprenoids, and other terpenoids were estimated. Individual sterols were identified in latex from some species.     

Mutant of Bacterium paracoli 5099 with an altered DNA: identification as a Flavobacterium

A difference in the base composition of the DNA of Bacterium paracoli 5099 and of a "mutant" (No. 1975) derived from it was found. This is in accordance with the finding of others. However, biochemical tests revealed that the "mutant" was a Flavobacterium, whereas the parent strain belonged to a species of Escherichia. The base composition of the DNA of the "mutant" is similar to that reported for the DNA of Flavobacterium.     

微卫星DNA标记技术及其应用

微卫星DNA是高等真核生物基因组中种类多、分布广、具有高度的多态性和杂合度的分子标记,由于其具有多态性检出率高、信息含量大、共显性标记、实验操作简单、结果稳定可靠等优点,已经成为种群遗传学研究中被广泛应用的分子遗传标记．微卫星DNA标记技术在动物亲缘关系的鉴定、特定基因定位、群体遗传结构的分析、物种的进化和系统发生以及遗传基因连锁图谱的构建等方面已得到了广泛的应用．因此,就微卫星DNA遗传标记的原理、特点及应用等方面进行综述。     

浮顶油罐的装配式三防浮顶

石油储罐通常采用钢盘式钢制浮顶，组装式铝制浮顶以及金属骨架泡沫塑料浮子式浮顶，实践表明，这三类浮顶都有各自的优缺点。浮顶油罐的装配式三防浮顶在以上三类浮顶的基础上，作了进一步的改进，特别是在整体结构上采用了蜂窝，桁架或网架等设计形式，选和高强度防锈铝合金或不锈钢材料。     

ITS序列作为DNA条形码在虫草鉴定及系统发育关系中的研究与应用

冬虫夏草具有重要的药用价值,随着天然虫草资源的日益紧张,急需开发虫草尤其是冬虫夏草资源,首要任务便是准确快速地鉴别虫草及无性型菌种、确认虫草的系统发育地位及与其他种属的亲缘关系。由于虫草复性生活史复杂,运用传统的分类学方法并不能很好地对它进行鉴定[1]。DNA指纹技术为探讨真菌的系统发育及其进化地位提供了新的途径,近年来已成为分类研究领域的热点[2]。它是通     

土壤微生物总DNA的V_3可变区PCR反应体系优化

为了优化以土壤微生物DNA为模板的PCR反应条件,采用E.Z.N.A.soil DNA kit试剂盒提取土壤微生物总DNA,对16SrDNA V3可变区的PCR反应体系和反应条件进行优化。主要从DNA模板用量、引物浓度、退火温度、热启动方式4个方面进行筛选试验,最后得出最适宜的土壤DNA扩增体系为:10.5ng模板DNA、5μL 10×buffer、4μL 2.5mmol/L dNTP、10μmol/L引物各1.5μL,2.5UTaq酶,加无菌ddH2O补足至50μL;PCR循环程序为:94℃预变性5min;94℃变性1min,52℃退火1min,72℃延伸70s,29个循环;72℃延伸5min。试验结果表明:选择热启动方式和合适的退火温度是获得高质量PCR产物的关键。