查询词典 precursor

Thus repairing the impaired myoideum. At present adult smooth muscle precursor cell uncertain yet. Sarcoblast my qua one smooth muscle precursor cell, is likely to treat copracrasia from rebuilding sphincter muscle of anus.

在目前成体内平滑肌前体细胞尚未明确的情况下，成肌细胞作为一种可能的平滑肌前体细胞，可被尝试用于重建肛门内括约肌治疗肛门失禁。

A direct method to prepare nanometre catalyst of positive electrode for methyl alcohol fuel battery is to add strong oxidant to a mixed solution of manganese nitrate and some other metal nitrate, to coat them on the graphite electrode to have catalyst precursor produced, then to prepare the non-platinum nanometre catalyst of metal ion-doped manganese dioxide with carbon as a carrier by thermolytic reaction of the in-situ precursor. The prepared catalyst has the advantages of high electrical catalytic activity of methyl alcohol, high performance to protect against CO poison and low price, and it can lower the battery manufacturing cost effectively as well as can raise the entire electrical property of the battery so that the price performance and the market competitive edge of the battery are enchnaced effectively.

一种直接甲醇燃料电池阳极纳米催化剂的制备方法是在硝酸锰和其它金属硝酸盐的混合溶液中加入强氧化剂，涂抹于石墨电极上制成催化剂先驱体，通过先驱体在原位的热分解反应来制备以碳为载体的金属离子掺杂二氧化锰非铂纳米催化剂；制得的催化剂具有高的甲醇电催化活性、高的抗CO毒化性能以及低廉的价格等优点，可以有效地降低电池的制造成本，提高电池的整体电性能，从而有效地提高直接甲醇燃料电池的性能价格比及市场竞争能力。

Research result indicated that the cooperative effect between swell and precursor is main factor for the nanoparticle loaded in Nafion, and moreover, polarity of solvent and water content in Nafion also affects the load largely. To improve away the surface concentration of CdS nanocrystal on two side of membrane for general preparation, thioacetamide was first used as a precursor instead of inorganic sulfur source(H2S and Na2S) in synthesis of CdS nanocrystal. The assembly mechanism for several sulfur source had been studied, and CdS/Nafion with the character of homogeneous disperse had been prepared, which is fit for mass transmission in photocatalitic reaction. Following the investigation of several crystallizing way, simple and reliable hydrothermal-crystallizing was found. According to this way, maximal TiO2 load in Nafion achieved 43%. Activity of TiO2/Nafion or CdS/Nafion as a photocatalyst was explored initially for disintegrating liquid contamination. Maximal decompose rate achieved 86% under condition of this research.

研究结果表明：Nafion膜对纳米粒子负载量的主要影响因素是溶胀作用与前驱体协同效应，同时溶剂极性和薄膜含水量对负载量也影响相当大；本课题首次使用硫代乙酰胺代替传统无机硫源（H2S、Na2S）合成CdS纳晶，研究了各种硫源的组装机理，克服了常规技术存在的CdS纳晶趋于膜表面富集的缺点，得到了有利于光催化传质需要的体相均匀分布CdS/Nafion；研究了多种Nafion膜内纳米粒子晶化途径，找到了简单可靠的水热晶化法，TiO2纳晶最高负载量达43％；初步探索了TiO2/Nafion、CdS/Nafion作为光催化剂降解水中模拟污染物的活性，在本实验条件下最高降解率达86％。

The amplified fragment was inserted into pRSET-A to generate the first double repeat of the precursor gene. By utilizing a pair of isocaudamer BamH I and Bgl II sites, and another downstream Hind III site of plasmid pRSET-A, following a series of simple double digestions and ligation of the resulted products, a series of repeat (3, 4 and 6) precursor peptide fragment genes were derived.

本实验设计一对两侧含编码疏水性氨基酸密码子的引物，经过扩增前导序列10~34aa基因序列，并重新克隆入质粒pRSET-A构建串联二聚体后，再利用质粒pRSET-A的BamH I / Bgl II同尾酶克隆位点，经一系列简单的酶切和连接，快速构建这一前导肽中不含组氨酸标签序列的串联多聚体基因，并成功表达其六聚体重组蛋白。

Iraq's procurement efforts include equipment that can filter and separate micro-organisms and toxins involved in biological weapons, equipment that can be used to concentrate the agent, growth media that can be used to continue producing anthrax and botulinum toxin, sterilization equipment for laboratories, glass-lined reactors and specialty pumps that can handle corrosive chemical weapons agents and precursors, large amounts of vinyl chloride, a precursor for nerve and blister agents, and other chemicals such as sodium sulfide, an important mustard agent precursor.

伊拉克采购的设备包括可过滤和分离生化武器中微生物和毒素的设备；可用于为炭疽病毒和肉毒菌病毒集中药剂和生长媒体的设备；实验室杀菌设备；可处理腐蚀性化学武器药剂、前体、乙烯基氯化物及其他化学药剂(如钠硫化物，芥子气药剂的前体)的玻璃线纹反应堆和专业水泵。

Preparation of ultra fine MgNi2 powder via reduction of the oxide precursor was systematically studied.The precursor was prepared with nickel nitrate,magnesium nitrate and glycin as start materials by combustion method.

以Mg(NO3)2和Ni(NO3)2为原料，用甘氨酸作为氧化剂，采用燃烧法制备约50 nm的混合金属氧化物前躯体，再在H2气氛保护下的管式炉中用CaH2还原制备MgNi2合金。

Many introns are contained in precursor mRNAs of eukaryotic cells, which are usually cut off in the processing of precursor mRNAs.

真核细胞的前体mRNA中一般都含有大量的内含子，它们在前体mRNA的加工过程中将被剪除。

The millimetersized tubular crystal selenium was first prepared. By studying the process of treating selenium in ethylenediamine, we proposed the mechanism of the preparation of selenides under solvothermal condition. The selenides came into being from the reaction of metal ions with Se〓, which was obtained by the amine attacking selenium. Moreover, a new precursor to prepare nanocrystalline selenides at room temperature was obtained. From this precursor, we have prepared nanocrystalline silver selenides, copper selenides, lead selenides and cadmium selenides nanorods.

首次报道了采用溶剂热处理的方法制备出厘米尺度的管状结构硒晶体；通过对硒粉在乙二胺中的溶剂热研究，初步探讨了以单质硒为硒源的溶剂热合成硒化物的反应机理应是硒受胺类的亲核进攻变成Se〓而进一步形成相应的硒化物；获得了合成硒化物纳米晶的前驱物，并在室温条件下合成了硒化银、硒化铜、硒化铅纳米晶和硒化镉纳米棒等。

In this paper, a turbostratic CN precursor was prepared by means of pyrolysis of melamine, then it was treated by high temperature and high pressure. The pyrolysis process of melamine, mechanism of hydrogen elimination and the effect of catalysts on pyrolysis of melamine were studied. The crystal structures, bonding states and chemical compositions of CN precursor obtained by pyrolyzing melamine are analyzed by X ray diffraction, burning spectrum, scanning elecron microscope and Fourier transform infrared Spectroscopy.

本文采用三聚氰胺热解法制备了乱层石墨结构的碳氮前驱物并进行了探索性的高温高压实验；研究了三聚氰胺热解的工艺、去氢机理以及催化剂对三聚氰胺热解过程的影响规律；借助 X 射线衍射、燃烧谱、透射电镜和红外光谱等手段，对获得的碳氮前驱物进行了成分、晶体结构、价键结构的分析。

But when Fe/D113 precursor is pyrolysed in the range of 400-700℃, the crystal structure of the iron particle is different. The products are mainly iron oxides andα-Fe as Fe/D113 precursor pyrolysed at 500℃, and as the pyrolytic temperature increases to the range of 600-700℃,α-Fe and Fe_3C are observed. Meanwhile, Al_2O_3、MgO、MgAl_2O_4 were observed in Al/C, Mg/C, Al-Mg/C which were prepared from D113 resin at 1000-1300℃.

而在同样的条件下热解载铁树脂(Fe／D113)，热解产物中铁的晶体结构与热解温度有关，400℃热解产物为铁的氧化物；500℃热解产物为体心立方结构的单质铁；600-700℃的热解产物为bcc单质铁和铁的碳化物(Fe_3C)。1000-1300℃热解含Al、Mg及Al-Mg的D113树脂制得的Al／C、Mg／C、Al-Mg／C材料中Al、Mg主要以Al_2O_3、MgO、MgAl_2O_4形式存在。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失