全文获取类型
收费全文 | 1413篇 |
免费 | 68篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 40篇 |
综合类 | 8篇 |
化学工业 | 356篇 |
金属工艺 | 47篇 |
机械仪表 | 90篇 |
建筑科学 | 33篇 |
矿业工程 | 1篇 |
能源动力 | 172篇 |
轻工业 | 58篇 |
水利工程 | 10篇 |
石油天然气 | 2篇 |
无线电 | 99篇 |
一般工业技术 | 300篇 |
冶金工业 | 77篇 |
原子能技术 | 12篇 |
自动化技术 | 178篇 |
出版年
2023年 | 25篇 |
2022年 | 40篇 |
2021年 | 48篇 |
2020年 | 66篇 |
2019年 | 47篇 |
2018年 | 73篇 |
2017年 | 46篇 |
2016年 | 68篇 |
2015年 | 48篇 |
2014年 | 69篇 |
2013年 | 135篇 |
2012年 | 63篇 |
2011年 | 111篇 |
2010年 | 75篇 |
2009年 | 68篇 |
2008年 | 64篇 |
2007年 | 47篇 |
2006年 | 40篇 |
2005年 | 26篇 |
2004年 | 31篇 |
2003年 | 23篇 |
2002年 | 18篇 |
2001年 | 8篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 21篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 20篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 15篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 11篇 |
1980年 | 5篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有1483条查询结果,搜索用时 253 毫秒
51.
Dr. Lalit N. Goswami Dr. Tyson J. Olds Dr. Terri G. Monk Dr. Quinn L. Johnson Dr. James P. Dilger Dr. Mohammed A. Shanawaz Dr. Satish S. Jalisatgi Dr. M. Frederick Hawthorne Dr. George R. Kracke 《ChemMedChem》2019,14(11):1108-1114
We synthesized a family of neuromuscular blocking agents (NMB) based on decamethonium, but containing a carborane cluster in the methylene chain between the two quaternary ammonium groups. The carborane cluster isomers o-NMB, m-NMB, and p-NMB were tested in animals for neuromuscular block and compared with agents used clinically: rocuronium and decamethonium. All three isomers caused reversible muscle weakness in mice as determined by grip strength and inverted screen tests, with a potency rank of p-NMB > rocuronium > decamethonium > m-NMB > o-NMB. The mechanism of action of the compounds was determined by using the in vitro rat phrenic nerve hemi-diaphragm preparation and electrophysiologic measurements in cells. Neostigmine reversed hemi-diaphragm weakness caused by the three isomers and rocuronium, but not succinylcholine. In electrophysiologic recordings of currents through acetylcholine receptor channels, the carborane compounds did not activate channel activity but did inhibit channel activation by acetylcholine. These results demonstrate that the carborane neuromuscular blocking agents are non-depolarizers in contrast to the depolarizing action of the parent compound. 相似文献
52.
Raste Malhari N. Jagtap Rohidas M. Pardeshi Satish K. 《Journal of Materials Science: Materials in Electronics》2022,33(14):10785-10799
Journal of Materials Science: Materials in Electronics - The bisthiourea copper and cadmium adipate (BTCu/CdA), and their glycine-doped derivatives (BTCu/CdA-Gly) have been synthesized by simple... 相似文献
53.
David E. Meyer Venkata K. K. Upadhyayula 《Clean Technologies and Environmental Policy》2014,16(4):757-772
Nanotechnology is a broad-impact technology with applications ranging from materials and electronics to analytical methods and metrology. The many benefits that can be realized through the utilization of nanotechnology are intended to lead to an improved quality of life. However, numerous concerns have been expressed regarding the unchecked growth of nanotechnology and the unforeseen consequences it may bring. To address the concerns, nanotechnology must be examined under the microscope of sustainability. This work applies the life cycle perspective to provide an understanding of the challenges facing the development of sustainable nanotechnology. A discussion of the holistic tools used to assess the components of sustainability serves as the basis to examine how a harmony between policy and product development can be maintained using decision making for sustainability. This harmony will be most readily achieved using an enhanced risk management strategy for sustainability that combines sustainability assessment with sustainable chemical design. 相似文献
54.
Pablo F. Salazar Satish Kumar Baratunde A. Cola 《Journal of Applied Electrochemistry》2014,44(2):325-336
Thermo-electrochemical cells (or thermocells) convert thermal energy to electricity in continuous operation based on a balance of ion conduction and redox reactions at hot and cold electrodes. In this study, the fundamental governing equations for mass and heat transfer, fluid dynamics, and electrokinetics in thermocells are presented and solved numerically using COMSOL. A parametric study is performed to explore the limitations and optimal cell dimensions for maximum energy conversion efficiency in thermocells. Series-stacking designs are demonstrated to have the potential to increase conversion efficiency by 100 % compared to a single cell configuration. Natural convection is shown to significantly increase the conversion efficiency of thermocells with conventional aqueous electrolyte (0.4 M potassium ferri/ferrocyanide), by compressing the diffusive boundary layers. A flow cell thermocell design is also considered. Results reveal that the ohmic resistance of the electrolyte limits the energy conversion efficiency of this design. 相似文献
55.
Polyacrylonitrile solution homogeneity study by dynamic shear rheology and the effect on the carbon fiber tensile strength
下载免费PDF全文
![点击此处可从《Polymer Engineering and Science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bradley A. Newcomb Prabhakar V. Gulgunje Yaodong Liu Kishor Gupta Manjeshwar G. Kamath Chandrani Pramanik Sushanta Ghoshal Han Gi Chae Satish Kumar 《Polymer Engineering and Science》2016,56(3):361-370
Poly(acrylonitrile‐co‐methacrylic acid) (PAN‐co‐MAA)/N,N‐dimethylformamide (DMF) solutions were prepared and dynamic shear rheology of these solutions were investigated. With increasing stirring time up to 72 h at 70°C, the polymer solution became less elastic (more liquid‐like) with a ~60% reduction in the zero‐shear viscosity. Relaxation spectra of the PAN‐co‐MAA/DMF solutions yield a decrease in relaxation time (disentanglement time, τd), corresponding to an about 8% decrease in viscosity average molecular weight. The log‐log plot of G′ (storage modulus) versus G″ (loss modulus) exhibited an increase in slope as a function of stirring time, suggesting that the molecular level solution homogeneity increased. In order to study the effect of solution homogeneity on the resulting carbon fiber tensile strength, multiple PAN‐co‐MAA/DMF solutions were prepared, and the precursor fibers were processed using gel‐spinning, followed by continuous stabilization and carbonization. The rheological properties of each solution were also measured and correlated with the tensile strength values of the carbon fibers. It was observed that with increasing the slope of the G′ versus G″ log‐log plot from 1.471 to 1.552, and reducing interfilament fiber friction during precursor fiber drawing through the addition of a fiber washing step prior to fiber drawing, the carbon fiber strength was improved (from 3.7 to 5.8 GPa). This suggests that along with precursor fiber manufacturing and carbonization, the solution homogeneity is also very important to obtain high strength carbon fiber. POLYM. ENG. SCI., 56:361–370, 2016. © 2016 Society of Plastics Engineers 相似文献
56.
Janish Desai Dr. Yang Wang Dr. Ke Wang Dr. Satish R. Malwal Prof. Eric Oldfield 《ChemMedChem》2016,11(19):2205-2215
We synthesized potential inhibitors of farnesyl diphosphate synthase (FPPS), undecaprenyl diphosphate synthase (UPPS), or undecaprenyl diphosphate phosphatase (UPPP), and tested them in bacterial cell growth and enzyme inhibition assays. The most active compounds were found to be bisphosphonates with electron‐withdrawing aryl‐alkyl side chains which inhibited the growth of Gram‐negative bacteria (Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa) at ~1–4 μg mL?1 levels. They were found to be potent inhibitors of FPPS; cell growth was partially “rescued” by the addition of farnesol or overexpression of FPPS, and there was synergistic activity with known isoprenoid biosynthesis pathway inhibitors. Lipophilic hydroxyalkyl phosphonic acids inhibited UPPS and UPPP at micromolar levels; they were active (~2–6 μg mL?1) against Gram‐positive but not Gram‐negative organisms, and again exhibited synergistic activity with cell wall biosynthesis inhibitors, but only indifferent effects with other inhibitors. The results are of interest because they describe novel inhibitors of FPPS, UPPS, and UPPP with cell growth inhibitory activities as low as ~1–2 μg mL?1. 相似文献
57.
Barlev R. Nagawkar Venkata P. Kotrike Alberto Passalacqua Shankar Subramaniam 《American Institute of Chemical Engineers》2022,68(6):e17639
A mixing index based on solid volume fraction fields is developed for gas-solid flows. Conventional mixing indices are based on particle realizations of granular mixing and are applicable to experimental data or discrete element method simulations. However, these indices cannot be used as-is for multifluid models, and an index for characterizing mixing in gas-solid flows from continuous fields is needed. The performance of the new mixing index is tested in two applications. The first is a 3D simulation of the mixing of biomass and sand in a fluidized bed reactor, and the second is a 2D simulation of binary particle segregation in a fluidized bed. The simulations are performed using OpenFOAM®. The mixing index is used to quantify gas-solid mixing using solid volume fractions and solid-solid mixing using solid fractions. The formulation of conventional mixing indices is extended to be used with solid volume fractions fields, and methods for performance improvement are presented. 相似文献
58.
Venkata Sundeep Seesala Santanu Dhara 《Journal of the American Ceramic Society》2022,105(8):5131-5139
For successful osseointegration of load-bearing implants, an improved bone–implant contact area through a trabecular porous surface resulting in minimized stress shielding effect is highly desirable. We propose a novel strategy of green net shaping a ceramic dough, combined with a reticular foam replica method and gradient coating, to fabricate biomimetic porosity in a customizable ceramic dental implant for the first time. About 85 vol% porosity and 300–600-μm pore size were evident in microCT and electron microscopy of the sintered samples, suitable for bone ingrowth. Excellent integrity at the interface along with homogeneous distribution of secondary alumina phase in zirconia matrix was achieved, despite the difference in the green state powder loading between the dough and the slurry. 相似文献
59.
Surya Prakasarao Chodisetti V. K. Malik B. Venkata Manoj Kumar 《International Journal of Applied Ceramic Technology》2022,19(3):1367-1378
Highly dense electrically conductive silicon carbide (SiC)–(0, 10, 20, and 30 vol%) titanium boride (TiB2) composites with 10 vol% of Y2O3–AlN additives were fabricated at a relatively low temperature of 1800°C by spark plasma sintering in nitrogen atmosphere. Phase analysis of sintered composites reveals suppressed β→α phase transformation due to low sintering temperature, nitride additives, and nitrogen sintering atmosphere. With increase in TiB2 content, hardness increased from 20.6 to 23.7 GPa and fracture toughness increased from 3.6 to 5.5 MPa m1/2. The electrical conductivity increased to a remarkable 2.72 × 103 (Ω cm)–1 for SiC–30 vol% TiB2 composites due to large amount of conductive reinforcement, additive composition, and sintering in nitrogen atmosphere. The successful electrical discharge machining illustrates potential of the sintered SiC–TiB2 composites toward extending the application regime of conventional SiC-based ceramics. 相似文献
60.
Das Satish K. Nanda Umakanta Biswal Sudhansu M. Pandey Chandan Kumar Giri Lalat Indu 《SILICON》2022,14(6):2965-2973
Silicon - Short channel effects (SCEs) along with mobility degradation has a great impact on CMOS technology below 100 nm. These effects can be overcome by using gate and channel... 相似文献