全文获取类型
收费全文 | 115篇 |
免费 | 6篇 |
国内免费 | 22篇 |
专业分类
化学 | 111篇 |
力学 | 3篇 |
综合类 | 2篇 |
物理学 | 27篇 |
出版年
2022年 | 5篇 |
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 2篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有143条查询结果,搜索用时 734 毫秒
1.
2.
Zhang-Run Xu 《Analytica chimica acta》2004,507(1):129-135
A three-layer poly(dimethylsiloxane) (PDMS)/glass microfluidic system for performing on-chip solid-phase enzymatic reaction and chemiluminescence (CL) reaction was used for the determination of glucose as a model analyte. A novel method for the immobilization of controlled-pore-glass based reactive particles on PDMS microreactor beds was developed, producing an on-chip solid-phase reactor that featured large reactive surface and low flow impedance. Efficient mixing of reagent/sample/carrier streams was achieved by incorporating chaotic mixer structures in the microfluidic channels. A conventional sequential injection (SI) system was adapted for direct coupling with the microfluidic system, and combined with hydrostatic delivery of reagents to achieve efficient and reproducible sample introduction at 10 μl levels. A detection limit of 10 μM glucose (3σ), and a precision of 3.1% RSD (n=7, 0.2 mM glucose) were obtained using the SI-microfluidic-CL system integrated with a glucose oxidase (GOD) reactor. Carryover was <5% at a throughput of 20 samples/h. 相似文献
3.
Xiaowen Ou Peng Chen Xizhi Huang Shunji Li Bi‐Feng Liu 《Journal of separation science》2020,43(1):258-270
Microfluidic chip electrophoresis has been widely employed for separation of various biochemical species owing to its advantages of low sample consumption, low cost, fast analysis, high throughput, and integration capability. In this article, we reviewed the development of four different modes of microfluidics‐based electrophoresis technologies including capillary electrophoresis, gel electrophoresis, dielectrophoresis, and field (electric) flow fractionation. Coupling detection schemes on microfluidic electrophoresis platform were also reviewed such as optical, electrochemical, and mass spectrometry method. We further discussed the innovative applications of microfluidic electrophoresis for biomacromolecules (nucleic acids and proteins), biochemical small molecules (amino acids, metabolites, ions, etc.), and bioparticles (cells and pathogens) analysis. The future direction of microfluidic chip electrophoresis was predicted. 相似文献
4.
5.
6.
Cluster Analysis of Gene Expression Data 总被引:1,自引:0,他引:1
Eytan Domany 《Journal of statistical physics》2003,110(3-6):1117-1139
The expression levels of many thousands of genes can be measured simultaneously by DNA microarrays (chips). This novel experimental tool has revolutionized research in molecular biology and generated considerable excitement. A typical experiment uses a few tens of such chips, each dedicated to a single sample—such as tissue extracted from a particular tumor. The results of such an experiment contain several hundred thousand numbers, that come in the form of a table, of several thousand rows (one for each gene) and 50–100 columns (one for each sample). We developed a clustering methodology to mine such data. In this review I provide a very basic introduction to the subject, aimed at a physics audience with no prior knowledge of either gene expression or clustering methods. I explain what genes are, what is gene expression and how it is measured by DNA chips. Next I explain what is meant by clustering and how we analyze the massive amounts of data from such experiments, and present results obtained from analysis of data from colon cancer, brain tumors and breast cancer. 相似文献
7.
Trusch M Ehlert S Bertsch A Kohlbacher O Hildebrand D Schlüter H Tallarek U 《Journal of separation science》2010,33(21):3283-3291
The influence of packing process parameters (packing pressure, application of ultrasound) and the stationary phase particle size (3.5 and 5 μm) on the chromatographic performance of HPLC/MS chips was systematically investigated for proteomic samples. First, reproducibility and detection limits of the separation were evaluated with a low‐complexity sample of tryptic BSA peptides. The influence of adsorbent packing quality on protein identification was then tested with a typical proteomics sample of high complexity, a human plasma protein fraction (Cohn fraction IV‐4). All HPLC/MS chips provided highly reproducible separations of these proteomic samples, but improved packing conditions and smaller particle sizes resulted in chromatograms with narrower peaks and correspondingly higher signal intensities. Improved separation performance increased the peak capacity, the number of identified peptides, and thus the sequence coverage in the proteomic samples, particularly for low sample amounts. 相似文献
8.
M.F. Nonier N. Vivas N. Vivas de Gaulejac C. Vitry 《Journal of Analytical and Applied Pyrolysis》2011,91(1):134-139
Analytical pyrolysis was applied to oak wood to provide useful information concerning the structure of oak wood components and the effect of different treatments on the chemical structure of wood components. We have studied the influence of DMSO, H2O2, H2O, acetic acid, and enzymatic treatments focusing on the qualitative and quantitative aspects. We studied the evolution of syringyl (S) and guaiacyl (G) compounds (main thermal degradation products of lignins) and the evolution of mallard reaction products, and main thermal degradation products of cellulose and hemicellulose. 相似文献
9.
Traditional mathematical models of multiphase flow in porous media use a straightforward extension of Darcys equation. The key element of these models is the appropriate formulation of the relative permeability functions. It is well known that for one-dimensional flow of three immiscible incompressible fluids, when capillarity is neglected, most relative permeability models used today give rise to regions in the saturation space with elliptic behavior (the so-called elliptic regions). We believe that this behavior is not physical, but rather the result of an incomplete mathematical model. In this paper we identify necessary conditions that must be satisfied by the relative permeability functions, so that the system of equations describing three-phase flow is strictly hyperbolic everywhere in the saturation triangle. These conditions seem to be in good agreement with pore-scale physics and experimental data. 相似文献
10.
木屑是一种在各种案件现场中出现几率较高的微量物证,但由于其化学组成复杂、难溶,高分子组分之间的差异不显著,所以一直未建立有效的鉴定方法.采用裂解-气相/质谱技术(PY-GC/MS)对不同树种木屑难溶物进行分析,结果发现:不同树种木屑难溶物的总离子流图特征相似,即每种木屑难溶物的总离子流图中都有一组特征峰.但个别组分有差异. 相似文献