全文获取类型
收费全文 | 287篇 |
免费 | 19篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 78篇 |
金属工艺 | 5篇 |
机械仪表 | 11篇 |
建筑科学 | 8篇 |
矿业工程 | 1篇 |
能源动力 | 12篇 |
轻工业 | 60篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 35篇 |
一般工业技术 | 39篇 |
冶金工业 | 18篇 |
自动化技术 | 34篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 16篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 26篇 |
2012年 | 20篇 |
2011年 | 21篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 16篇 |
2007年 | 15篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有306条查询结果,搜索用时 0 毫秒
1.
2.
A. Jokic N. Ristic M. M. Jaksic M. Spasojevic N. Krstajic 《Journal of Applied Electrochemistry》1991,21(4):321-326
A new electrocatalytic process for simultaneous electrolytic production of xylitol and xylonic acid or the corresponding xylonate salts directly from -d-xylose in alkaline solutions of neutral salt as supporting electrolyte has been developed and presented. An electrocatalytically active cathode coating with essentially hydridic features has been employed to enhance Faradaic yields in xylitol production at low current densities by heterogeneous reaction of hydrogenation with H-adatoms, and the entire mechanism has been proved by experimental evidence. An anionic selective anodic coating for titanium substrate was also used to suppress oxygen evolution and optimize the xylonic acid production by direct oxidation with anodically generated bromine, and to carry out the electrode process at almost equilibrium potential. The kinetic effect of specifically adsorbable anions for decreasing cathodic current yields in xylitol production and the resulting necessity for membrane separation of catholyte from anolyte, with proper optimization of the supporting neutral salt composition, has also been emphasized.Paper partly presented at 39th and 40th ISE-Meetings at Glasgow UK, 1988 and Kyoto, Japan, 1989. 相似文献
3.
Mirjana Mazuran Edoardo Serra Carlo Zaniolo 《The VLDB Journal The International Journal on Very Large Data Bases》2013,22(4):471-493
Supporting aggregates in recursive logic rules represents a very important problem for Datalog. To solve this problem, we propose a simple extension, called Datalog $^{FS}\,$ (Datalog extended with frequency support goals), that supports queries and reasoning about the number of distinct variable assignments satisfying given goals, or conjunctions of goals, in rules. This monotonic extension greatly enhances the power of Datalog, while preserving (i) its declarative semantics and (ii) its amenability to efficient implementation via differential fixpoint and other optimization techniques presented in the paper. Thus, Datalog $^{FS}\,$ enables the efficient formulation of queries that could not be expressed efficiently or could not be expressed at all in Datalog with stratified negation and aggregates. In fact, using a generalized notion of multiplicity called frequency, we show that diffusion models and page rank computations can be easily expressed and efficiently implemented using Datalog $^{FS}\,$ . 相似文献
4.
A triple-product acousto-optic processor output was studied analytically and numerically. The processor is capable of detecting the carrier frequency and the modulation envelope of a signal. 相似文献
5.
H Ristic S Srinivasan KE Hall AA Sima JW Wiley 《Canadian Metallurgical Quarterly》1998,80(3):1236-1244
We examined the hypothesis that exposure of nondiabetic rat dorsal root ganglion (DRG) neurons to sera from diabetic BB/W rats would produce an increase in calcium currents associated with impaired regulation of the inhibitory G protein-calcium channel complex. Acutely dissociated rat DRGs were incubated for 18-24 h in medium supplemented with sera (10% vol/vol) from either diabetic rats with neuropathy or age-matched, nondiabetic controls. Exposure of DRG neurons to sera from diabetic BB/W rats resulted in a surface membrane immunofluorescence pattern when treated with an anti-rat light-chain antibody that was not observed in neurons exposed to control sera. Calcium current density (IDCa) was assessed with the use of the whole cell variation of the patch-clamp technique. IDCa in neurons exposed to diabetic sera was significantly increased compared with neurons exposed to control sera. Guanine nucleotide-binding (G) protein regulation of calcium channel function was examined with the use of a two-pulse "facilitation" or IDCa enhancement protocol in the presence of activators [guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S)] or antagonists [guanosine 5'-O-(2-thiodiphosphate) (GDP beta S) and pertussis toxin (PTX)] of G protein function. Facilitation was significantly decreased in neurons exposed to diabetic sera. Intracellular diffusion of neurons with GDP beta s blocked facilitation, whereas dialysis with GTP gamma s increased facilitation to a similar magnitude in neurons exposed to either diabetic or control sera. Treatment with PTX resulted in a significant increase in IDCa and approximately 50% decrease in facilitation in neurons treated with control sera but no significant changes in neurons exposed to diabetic sera. We conclude that serum from diabetic BB/W rats with neuropathy contains an autoimmune immunoglobulin that impairs regulation of the inhibitory G protein-calcium channel complex, resulting in enhanced calcium influx. Regulation of the inhibitory G protein-calcium channel complex involves PTX-sensitive and -insensitive G proteins. 相似文献
6.
7.
CAD based shape optimization for gas turbine component design 总被引:1,自引:0,他引:1
Djordje Brujic Mihailo Ristic Massimiliano Mattone Paolo Maggiore Gian Paolo De Poli 《Structural and Multidisciplinary Optimization》2010,41(4):647-659
In order to improve product characteristics, engineering design makes increasing use of Robust Design and Multidisciplinary
Design Optimisation. Common to both methodologies is the need to vary the object’s shape and to assess the resulting change
in performance, both executed within an automatic loop. This shape change can be realised by modifying the parameter values
of a suitably parameterised Computer Aided Design (CAD) model. This paper presents the adopted methodology and the achieved
results when performing optimisation of a gas turbine disk. Our approach to hierarchical modelling employing design tables
is presented, with methods to ensure satisfactory geometry variation by commercial CAD systems. The conducted studies included
stochastic and probabilistic design optimisation. To solve the multi-objective optimisation problem, a Pareto optimum criterion
was used. The results demonstrate that CAD centric approach enables significant progress towards automating the entire process
while achieving a higher quality product with the reduced susceptibility to manufacturing imperfections. 相似文献
8.
Mirjana D. Timotijevi Tanja Ili Bojan Markovi Danijela Randjelovi Neboja Ceki Ines Nikoli Sneana Savi Ivana Panteli 《International journal of molecular sciences》2022,23(11)
Polymeric film-forming systems have emerged as an esthetically acceptable option for targeted, less frequent and controlled dermal drug delivery. However, their dynamic nature (rapid evaporation of solvents leading to the formation of thin films) presents a true characterization challenge. In this study, we tested a tiered characterization approach, leading to more efficient definition of the quality target product profiles of film-forming systems. After assessing a number of physico-chemico-mechanical properties, thermal, spectroscopic and microscopic techniques were introduced. Final confirmation of betamethasone dipropionate-loaded FFS biopharmaceutical properties was sought via an in vitro skin permeation study. A number of applied characterization methods showed complementarity. The sample based on a combination of hydrophobic Eudragit® RS PO and hydroxypropyl cellulose showed higher viscosity (47.17 ± 3.06 mPa·s) and film thickness, resulting in sustained skin permeation (permeation rate of 0.348 ± 0.157 ng/cm2 h), and even the pH of the sample with Eudragit® NE 30D, along with higher surface roughness and thermal analysis, implied its immediate delivery through the epidermal membrane. Therefore, this study revealed the utility of several methods able to refine the number of needed tests within the final product profile. 相似文献
9.
Construction and operation of plants that produce energy from renewable energy sources is the subject for discussion in all the countries that have accepted the sustainable development concept and Kyoto protocol as their own development direction. Enlargement of the renewable energy production is clearly an imperative, but only economically viable construction and operation can result in long-term sustainability, which is initially the goal when deciding upon such investments. In line with this goal, this paper presents the estimation of the economic viability of constructing and operating biogas electricity plant on the farm Vizelj in Serbia. The timeframe for this estimation is from 2011 until 2020. This paper also presents all parameters which are necessary for performing this estimation, respectively, analysis of revenues and expenditures, projection of economic and financial flow, ratio analysis, dynamic and static analysis, and analysis of sensitivity of the project, i.e. impact of the changes in prices and raw material on the overall performance of the project. The observed investment is predicted to be financed from the EBRD's credit line for renewable energy in Western Balkans, while the total investment is estimated at Euro 958,000.00. After the performed economic assessment, the conclusion is that the observed investment in biogas electricity plant is very acceptable and it can serve as a role model for similar investments in the region. 相似文献
10.
Milica Jovanovi Krivokua Aleksandra Viloti Mirjana Nacka-Aleksi Andrea Pirkovi Danica uji Janko Legner Dragana Dekanski
anka Boji-Trbojevi 《International journal of molecular sciences》2022,23(1)
Galectins are a family of conserved soluble proteins defined by an affinity for β-galactoside structures present on various glycoconjugates. Over the past few decades, galectins have been recognized as important factors for successful implantation and maintenance of pregnancy. An increasing number of studies have demonstrated their involvement in trophoblast cell function and placental development. In addition, several lines of evidence suggest their important roles in feto-maternal immune tolerance regulation and angiogenesis. Changed or dysregulated galectin expression is also described in pregnancy-related disorders. Although the data regarding galectins’ clinical relevance are still at an early stage, evidence suggests that some galectin family members are promising candidates for better understanding pregnancy-related pathologies, as well as predicting biomarkers. In this review, we aim to summarize current knowledge of galectins in early pregnancy as well as in pregnancy-related pathologies. 相似文献