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1.
Corals, like many other coelenterates, contain fluorescent pigments that show considerable homology with the well known green fluorescent protein of the jellyfish Aequoria. In corals, unlike jellyfish, multiple proteins are present and the range of excitations and emissions suggest the possibility of energy transfer. The occurrence of F?rster resonant energy transfer (FRET) between fluorescent proteins in corals has already been reported and time-resolved spectra have shown the effect on fluorescent lifetime, but without any spatial resolution. Lifetime confocal microscopy offers lower time resolution but excellent spatial resolution. Lifetimes of the isolated A. millepora pigments amilFP490, amilFP504, and amilFP593 (names indicate emission peaks) were 2.8, 2.9, and 2.9 ns, respectively. In the coral sample, imaging the entire emission spectrum from 420 nm, the mean lifetime was reduced to 1.5 ns, implying that FRET was occurring. Looking just at the fluorescence from FRET donors the lifetime was even shorter, at 1.3 ns, supporting this interpretation. In contrast, no reduction in lifetime is seen in the coral Euphyllia ancora, where the pigment distribution also suggests that the pigments are unlikely to be involved in photoprotection. This study set out to determine the extent of FRET between pigments in two corals, Acropora millepora and Euphyllia, ancora which differ in the arrangement of their pigments and hence possibly in pigment function.  相似文献   
2.
李玲  张春丽  闫平  殷雷  康磊  赵倩  王荣福 《同位素》2012,25(3):165-170
合成了含8个CArG元件的放射敏感性启动子E8,将其连接于胞嘧啶脱氨酶(Cytosine Deaminase, CD)基因及GFP报告基因上游,构建了重组慢病毒载体pGC-FU-E8-codA-GFP。与慢病毒包装系统共转染293T细胞包装重组慢病毒颗粒E8-codA-GFP LV,研究重组慢病毒感染EJ细胞在不同剂量125I的电离辐射下绿色荧光表达情况及其将5-FC转化为5-FU的能力。结果显示:构建的含有E8启动子及CD基因的重组慢病毒载体,包装的重组慢病毒滴度为2×108TU/mL;经125I照射的重组慢病毒感染EJ细胞均可观察到绿色荧光,其细胞上清液均可检测到5-FC转化成的5-FU紫外峰,其中55.5 kBq及74.0 kBq 125I照射的细胞组绿色荧光明显,148 kBq 125I照射的细胞组,其5-FU紫外峰最为明显。以上结果表明:本工作所构建的放射敏感性启动子调控CD基因/5-FC自杀系统重组慢病毒载体具有电离辐射调控作用,可在125I的电离辐射作用下诱导下游基因表达,为放射性核素125I联合CD基因/5-FC自杀系统对肿瘤细胞的治疗作用研究提供了实验基础。  相似文献   
3.
Dendrimers are novel three dimensional, hyperbranched globular nanopolymeric architectures. Attractive features like nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery and cavities in the interior distinguish them amongst the available polymers. Applications of dendrimers in a large variety of fields have been explored. Drug delivery scientists are especially enthusiastic about possible utility of dendrimers as drug delivery tool. Terminal functionalities provide a platform for conjugation of the drug and targeting moieties. In addition, these peripheral functional groups can be employed to tailor-make the properties of dendrimers, enhancing their versatility. The present review highlights the contribution of dendrimers in the field of nanotechnology with intent to aid the researchers in exploring dendrimers in the field of drug delivery.  相似文献   
4.
5.
Optical properties of a green fluorescent protein (GFP) are examined using optical absorption, circular dichroism (CD), and circular polarized luminescence (CPL) spectroscopies. The GFP has chiroptical activity and exhibits green circular polarized emission, although the g em-factor is small. Poly(vinyl alcohol) (PVA)/GFP composite films are prepared to attempt long-term preservation of the GFP emission activity. After five years, the transparent PVA/GFP composite film still exhibits stable fluorescence that appears similar to the emission from the Aequorea jellyfish.  相似文献   
6.
Green fluorescent protein (GFP) has many applications as a marker in living cells, and has become widely used as a reporter gene in microbial, plant and animal cells. Screening microbial colonies for GFP expression enables various types of assays (e.g. for secretory mutations). However, this is laborious, non-quantitative and potentially hazardous to the operator (due to UV illumination) when performed manually. In order to address this the GloPix robot was developed. The imaging system discriminates between colonies based on the level of fluorescence activity and the picking function automatically transfers cells to microplate wells. Measuring fluorescent activity allows quantitation of fluorescent tag concentration/expression.  相似文献   
7.
The use of PCR-based techniques for directed gene alterations has become a standard tool in Saccharomyces cerevisiae. In our efforts to increase the speed of functional analysis of Candida albicans genes, we constructed a modular system of plasmid vectors and successfully applied PCR-amplified functional analysis (FA)-cassettes in the transformation of C. albicans. These cassettes facilitate: (a) gene disruptions; (b) tagging of 3'-ends of genes with green fluorescent protein (GFP); and (c) replacements of endogenous promoters to achieve regulated expression. The modules consists of a core of three selectable marker genes, CaURA3, CaHIS1 and CaARG4. Modules for C-terminal GFP-tagging were generated by adding GFP-sequences flanked at the 5'-end by a (Gly-Ala)3-linker and at the 3'-end by the S. cerevisiae URA3-terminator to these selection markers. Promoter exchange modules consist of the respective marker genes followed by the regulatable CaMAL2 or CaMET3 promoters at their 3'-ends. In order to ensure a reliably high rate of homologous gene targeting, the flanking homology regions required a size of 100 bp of gene-specific sequences, which were provided with the oligonucleotide primers. The use of shorter flanking homology regions produced unsatisfactory results with C. albicans strain BWP17. With these new modules only a minimal set of primers is required to achieve the functional analysis of C. albicans genes and, therefore, provides a basic tool to increase the number of functionally characterized C. albicans genes of this human pathogen in the near future.  相似文献   
8.
MSTP多业务传送平台基于SDH技术,同时实现TDM、ATM、以太网等业务的接入、处理和传送,并提供统一的网管,它具有SDH,ATM以及以太网/IP处理功能,通过将多业务汇聚并高效适配的方式可以实现多种业务的综合传送。论文首先回顾了MSTP发展、接着报告了MSTP相关的主要技术,从中可以大致了解MSTP的原理和其今后相关技术发展的趋势。  相似文献   
9.
陈海琴,徐志南,汪诚,廖玉华,岑沛霖在近几年来被广泛研究和应用的大肠杆菌无细胞蛋白质合成系统中,大肠杆菌抽提物的制备、底物浓度的配比以及能量再生体系的选择是最关键的几个因素.以绿色荧光蛋白(GFP)为报导基因,以缺失核酸酶I基因的大肠杆菌A19为实验菌株,通过对大肠杆菌无细胞抽提物制备过程中菌体收集时间、细胞破碎压力、后处理条件等参数的摸索和确定、无细胞蛋白质合成系统中底物浓度配比的正交实验优化以及系统中能量再生体系的比较和选择,制备得到了GFP表达量为154 μg/mL的大肠杆菌无细胞蛋白质合成系统,与优化前相比产量提高了29倍.  相似文献   
10.
基于静态小波变换的变透明度法融合GFP荧光与相衬图像   总被引:1,自引:0,他引:1  
李添捷  汪源源 《光学精密工程》2009,17(11):2871-2879
绿色荧光蛋白荧光图像与相衬图像的融合对蛋白质功能的研究和亚细胞结构的定位有重要价值。针对成功用于遥感图像融合的ARSIS概念下多尺度融合算法融合荧光图像与相衬图像时易产生伪像的缺点,提出变透明度的概念,根据直观视觉效果设计一组函数,为融合图像的每一像素分配尺度透明度,并基于静态小波变换的分解结果对源图像进行融合。先通过30组图像的融合实验,估计出所设计函数的相应参数,然后用于对另外117组图像的融合测试,分别计算融合结果的荧光区和非荧光区与荧光图像、相衬图像的质量指数Q和高频相关系数HPCC这两个表征融合效果的特征参数。结果表明,相比常用的融合算法--透明度法、棋盘格法和静态小波替换法,本方法在保持交互可变透明度的同时,提高了融合结果细节的清晰程度,降低了荧光图像背景对融合结果的影响。  相似文献   
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