全文获取类型
收费全文 | 329篇 |
免费 | 34篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 88篇 |
金属工艺 | 5篇 |
机械仪表 | 4篇 |
建筑科学 | 3篇 |
矿业工程 | 1篇 |
能源动力 | 22篇 |
轻工业 | 16篇 |
石油天然气 | 2篇 |
无线电 | 41篇 |
一般工业技术 | 88篇 |
冶金工业 | 5篇 |
原子能技术 | 3篇 |
自动化技术 | 81篇 |
出版年
2023年 | 11篇 |
2022年 | 13篇 |
2021年 | 18篇 |
2020年 | 20篇 |
2019年 | 23篇 |
2018年 | 18篇 |
2017年 | 16篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 23篇 |
2013年 | 26篇 |
2012年 | 17篇 |
2011年 | 17篇 |
2010年 | 12篇 |
2009年 | 19篇 |
2008年 | 24篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 12篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有364条查询结果,搜索用时 328 毫秒
1.
2.
Karishma Tiwari Pulak Sarkar Solagna Modak Harwinder Singh Sumit Kumar Pramanik Santanu Karan Amitava Das 《Advanced materials (Deerfield Beach, Fla.)》2020,32(8):1905621
Separation membranes with higher molecular weight cut-offs are needed to separate ions and small molecules from a mixed feed. The molecular sieving phenomenon can be utilized to separate smaller species with well-defined dimensions from a mixture. Here, the formation of freestanding polyimine nanofilms with thicknesses down to ≈14 nm synthesized via self-assembly of pre-synthesized imine oligomers is reported. Nanofilms are fabricated at the water–xylene interface followed by reversible condensation of polymerization according to the Pieranski theory. Polyimine nanofilm composite membranes are made via transferring the freestanding nanofilm onto ultrafiltration supports. High water permeance of 49.5 L m-2 h−1 bar−1 is achieved with a complete rejection of brilliant blue-R (BBR; molecular weight = 825 g mol−1) and no more than 10% rejection of monovalent and divalent salts. However, for a mixed feed of BBR dye and monovalent salt, the salt rejection is increased to ≈18%. Membranes are also capable of separating small dyes (e.g., methyl orange; MO; molecular weight = 327 g mol−1) from a mixed feed of BBR and MO. Considering a thickness of ≈14 nm and its separation efficiency, the present membrane has significance in separation processes. 相似文献
3.
Product optimization involves selecting design, manufacturing, and support attributes that can produce the best system. Producibility or manufacturability is the term often used to describe the relative ease of manufacturing a product. In complex systems, productibility optimization is a very difficult process, particularly when the values of many attributes are restricted by constraints. One challenge is to develop more universal producibility metrics for the conceptual design phase when design information is limited and drawings are nondimensional. This paper develops a new method for producibility optimization in conceptual design based on a combination of both decision theoretic and expert system techniques. Decision theoretic techniques provide the means to model the design for producibility problem in a manner that can deal with risk, uncertainty, and user (or corporate) preferences, and can effectively integrate diverse factors to provide a measure of the overall worth of a design. The particular decision theoretic approach employed is based on multi-attribute utility theory. An illustrative example of the methodology is applied to the conceptual design of a structural composite part. 相似文献
4.
Sinha Swati Shaw Siddharth Biswas Kunal De Debashis Das Samir Chandra Sarkar Angsuman Bandyopadhyay Jaya 《Microsystem Technologies》2021,27(11):4087-4100
Microsystem Technologies - Single-Walled Carbon Nanotubes (SWCNTs) are widely used as potential carriers in drug delivery systems. The objective of this work was to observe the effects of pristine,... 相似文献
5.
The effects of aging time of Cr(III) solutions on the structural, thermal, magnetic, and morphological properties of chromium polyacrylate complexes were studied. Chromium retention was found to increase with longer aging periods. IR spectra revealed the formation of polychelate structures with noticeable changes on aging. The interaction of multivalent, polynuclear Cr(III) species with the polymer backbone resulted in a decrease in thermal stability for the complexes prepared from olated chromium solutions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 490–493, 2005 相似文献
6.
Addition of adenosine triphosphate (ATP) to [14C]ethanolamine-prelabeled NIH 3T3 fibroblasts resulted in rapid formation of [14C]ethanolamine from the prelabeled cellular phosphatidylethanolamine (PtdEtn) pool. After 2-min exposure, 10 μM ATP had near
maximal effects on PtdEtn hydrolysis. Several other nucleotides, including UTP, ITP, and the stable ATP analog adenosine 5′-O-(3-thiotriphosphate) (ATPγS), also had stimulatory effects on PtdEtn hydrolysis with a potency comparable to that observed
with ATP. The same nucleotides which acted on PtdEtn hydrolysis also had similar stimulatory effects on the hydrolysis of
phosphatidylcholine (PtdCho) in [14C]choline-labeled cells. In isolated membranes, Mg2+ greatly enhanced the stimulatory effects of ATP and ATPγS, but not of other nucleotides, on the hydrolysis of PtdEtn and
PtdCho. Results indicate that in isolated membranes, both ATP and ATPγS stimulate phospholipid hydrolysis by two different
mechanisms, but in intact cells only one of these mechanisms appears to be responsive to externally added nucleotides. 相似文献
7.
Nishanta Barman Arpita Shome Saurav Kumar Priyam Mondal Karan Jain Mizuki Tenjimbayashi Uttam Manna 《Advanced functional materials》2023,33(22):2214840
Non-sticking droplets wrapped with fine hydrophobic particles, namely liquid marbles, can be transported both on solid and water pool without an undesired spill of the inner encapsulated liquid. While the stimuli-responsive release of the inner liquid in the target area is proposed, the time-programmed release is not yet achieved. Herein, the hydrophobicity of nanoclay is modulated via a catalyst-free 1,4-conjugate addition reaction to form liquid marbles. This nanoclay liquid marble is robust and stable in air but collapses on the liquid pool with a specific lifetime. The lifetime of the liquid marble can be modulated over seconds to hours scale depending on the selection of chemically modulated wettability of the nanoclay. The critical mechanism of lifetime modulation is responsible for controlling the coalescence kinetics between the water pool and inner liquid by nanoclays’ high diffusion length and chemically varied water spreading potential. The NC liquid marble's programmable lifetime to ‘time-bomb’ type drug release and cascade chemical reaction is applied—without requiring any external intervention. 相似文献
8.
The Journal of Supercomputing - Hpcfolder is a user-friendly high-performance computing tool that can be used to analyze the performance of algorithms parallelized using MPI. It is possible to view... 相似文献
9.
Kang Cui Kunal S. Mali Klaus Müllen Michael Walter Steven De Feyter Stijn F. L. Mertens 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(46)
Ionic self‐assembly of charged molecular building blocks relies on the interplay between long‐range electrostatic forces and short‐range, often cooperative, supramolecular interactions, yet has been seldom studied in two dimensions at the solid–liquid interface. Here, we demonstrate anion‐driven switching of two‐dimensional (2D) crystal structure at the Au(111)/octanoic acid interface. Using scanning tunneling microscopy (STM), three organic salts with identical polyaromatic cation (PQPC6+) but different anions (perchlorate, anthraquinonedisulfonate, benzenesulfonate) are shown to form distinct, highly ordered self‐assembled structures. Reversible switching of the supramolecular arrangement is demonstrated by in situ exchange of the anion on the pre‐formed adlayer, by changing the concentration ratio between the incoming and outgoing anion. Density functional theory (DFT) calculations reveal that perchlorate is highly mobile in the adlayer, and corroborate why this anion is only resolved transiently in STM. Surprisingly, the templating effect of the anion persists even where it does not become part of the adlayer 2D fabric, which we ascribe to differences in stabilization of cation conformations by the anion. Our results provide important insight into the structuring of mixed anion–cation adlayers. This is essential in the design of tectons for ionic self‐assembled superstructures and biomimetic adaptive materials and valuable also to understand adsorbate–adsorbate interactions in heterogeneous catalysis. 相似文献
10.
Kunal Sain Abhishek Dasgupta Utpal Garain 《International Journal on Document Analysis and Recognition》2011,14(1):75-85
Performance evaluation of mathematical expression recognition systems is attempted. The proposed method assumes expressions
(input as well as recognition output) are coded following MathML or TEX/LaTEX (which also gets converted into MathML) format. Since any MathML representation follows a tree structure, evaluation of
performance has been modeled as a tree-matching problem. The tree corresponding to the expression generated by the recognizer
is compared with the groundtruthed one by comparing the corresponding Euler strings. The changes required to convert the tree
corresponding to the expression generated by the recognizer into the groundtruthed one are noted. The number of changes required
to make such a conversion is basically the distance between the trees. This distance gives the performance measure for the
system under testing. The proposed algorithm also pinpoints the positions of the changes in the output MathML file. Testing
of the proposed evaluation method considers a set of example groundtruthed expressions and their corresponding recognized
results produced by an expression recognition system. 相似文献