全文获取类型
收费全文 | 6650篇 |
免费 | 574篇 |
国内免费 | 179篇 |
专业分类
电工技术 | 216篇 |
综合类 | 359篇 |
化学工业 | 1308篇 |
金属工艺 | 217篇 |
机械仪表 | 280篇 |
建筑科学 | 494篇 |
矿业工程 | 130篇 |
能源动力 | 166篇 |
轻工业 | 647篇 |
水利工程 | 109篇 |
石油天然气 | 140篇 |
武器工业 | 30篇 |
无线电 | 648篇 |
一般工业技术 | 920篇 |
冶金工业 | 500篇 |
原子能技术 | 82篇 |
自动化技术 | 1157篇 |
出版年
2024年 | 18篇 |
2023年 | 92篇 |
2022年 | 87篇 |
2021年 | 229篇 |
2020年 | 197篇 |
2019年 | 157篇 |
2018年 | 192篇 |
2017年 | 203篇 |
2016年 | 190篇 |
2015年 | 218篇 |
2014年 | 371篇 |
2013年 | 402篇 |
2012年 | 320篇 |
2011年 | 429篇 |
2010年 | 369篇 |
2009年 | 344篇 |
2008年 | 354篇 |
2007年 | 420篇 |
2006年 | 423篇 |
2005年 | 341篇 |
2004年 | 340篇 |
2003年 | 256篇 |
2002年 | 249篇 |
2001年 | 152篇 |
2000年 | 123篇 |
1999年 | 119篇 |
1998年 | 89篇 |
1997年 | 47篇 |
1996年 | 76篇 |
1995年 | 66篇 |
1994年 | 62篇 |
1993年 | 48篇 |
1992年 | 31篇 |
1991年 | 38篇 |
1990年 | 34篇 |
1989年 | 33篇 |
1988年 | 26篇 |
1987年 | 30篇 |
1986年 | 35篇 |
1985年 | 19篇 |
1984年 | 33篇 |
1983年 | 18篇 |
1982年 | 23篇 |
1981年 | 9篇 |
1979年 | 11篇 |
1978年 | 6篇 |
1976年 | 6篇 |
1966年 | 7篇 |
1956年 | 5篇 |
1955年 | 8篇 |
排序方式: 共有7403条查询结果,搜索用时 0 毫秒
11.
Reviews the book, Forms of feeling: The heart of psychotherapy by Robert F. Hobson. Robert Hobson calls this book his autobiography as a therapist. As such it provides interesting glimpses into some of his more meaningful sessions with clients, illuminating his approach to therapy and enabling the reader to see a master therapist at work. Hobson also presents a new method of therapy, which he calls the conversational model. On this level, his book is considerably less satisfying. Hobson succinctly outlines the general principles of the conversational model and basic skills required of the therapist, but in so doing offers essentially little new information, however valid the points may be. According to Hobson, the conversational model is designed for clients whose problems arise from disturbances in their significant relationships, and those problems are best solved not by talking about them but by being in a relationship such as therapy that provides "a special kind of friendship." Hobson puts great stress on the use of metaphorical language in therapy and learning how to use the language of art as well as of science. He relies heavily on literary quotations, prefacing each section with one or two, and liberally interspersing many more within the pages of text. The net result is not so much illuminating as it is wearisome, and the general tone is slightly pretentious and, when Hobson addresses his "dear Reader" directly, somewhat condescending. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
12.
Y.X. Li 《Materials Letters》2007,61(22):4366-4369
TiC/Al composite was successfully synthesized utilizing laser ignited self-propagating high-temperature synthesis (SHS) of Al-C-Ti system with the different C/Ti molar ratio. When the molar ratio of C to Ti is below 1:1 in the starting materials, in addition to fine TiC particulates, a large amount of Al3Ti phase was found in the composites; however, when the molar ratio of C to Ti is 1:1 in the starting materials, the Al3Ti phase was almost completely eliminated and the distribution of TiC particulates generally appeared to be more homogeneous throughout the products synthesized. 相似文献
13.
中国冷库的现状与发展趋势 总被引:8,自引:0,他引:8
张保生 《制冷与空调(四川)》2003,(2):21-24
本文从的设计建造、制冷工艺和管理维护这三个方面,介绍了近三年来中国冷库的现状,说明中国冷库正朝着灵活、自动化、节能和环保的方向进一步发展。 相似文献
14.
《Drying Technology》2007,25(6):959-969
Three major aspects of food powder are described and discussed. Stickiness is one issue that can cause production and product handling difficulties. Stickiness has been interpreted in a number of ways and thus measured differently. Functionality of the primary (single) particles or agglomerated powders is of practical interest to the consumers. The desired quality will have to be matched or exceeded by the powder manufacturers. Finally, microstructure provides a key linkage between the production and the functionality. Its formation has impacts on both the stickiness and functionality. 相似文献
15.
16.
该文分析了应用袋装炸药装填水孔爆破产生拒爆、"冲天炮"、根底偏高和爆破效果差等问题,然而应用乳化炸药混装车装填水孔可以解决这些问题,并且爆破后具有根底平整、大块率低、毒气少和综合效益高等优点.以三峡永久船闸旁侧泄水箱涵工程和江苏田湾核电站工程为例进行了分析. 相似文献
17.
Wolfgang Appelt 《Computer Standards & Interfaces》1988,7(4):377-385
The Office Document Architecture (ODA) is an International Standard which is developed by TC 97/sc 18 of the International Organization for Standardization (ISO) in close collaboration with CCITT's Study Group VIII and with ECMA. This paper describes the current state of a formal specification of the ODA document structures by mathematical means and its use for conformance specification and conformance testing. 相似文献
18.
A novel mixed‐mode expanded bed adsorbent with anion‐exchange properties was explored with benzylamine as the functional ligand. The cellulose composite matrix, densified with stainless steel powder, was prepared with the method of water‐in‐oil suspension thermal regeneration. High activation levels of the cellulose matrix were obtained with allyl bromide because of the relative inertness of the allyl group under the conditions of the activation reaction. After the formation of the bromohydrin with N‐bromosuccinimide and coupling with benzylamine, the activated matrix was derived to function as a mixed‐mode adsorbent containing both hydrophobic and ionic groups. The protein adsorption capacity was investigated with bovine serum albumin as a model protein. The results indicated that the prepared adsorbent could bind bovine serum albumin with a high adsorption capacity, and it showed salt tolerance. Effective desorption was achieved by a pH adjustment across the isoelectric point of the protein. The interactions between the cell and adsorbent were studied, and the bioadhesion was shielded by the adjustment of the salt concentration above 0.1M. Stable fluidization in the expanded bed was obtained even in a 2% (dry weight) yeast suspension. The direct capture of target proteins from a biomass‐containing feedstock without extra dilution steps could be expected with the mixed‐mode adsorbent prepared in this work, and this would be especially appropriate for expanded bed adsorption applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
19.
Min-Max MPC (MMMPC) controllers [P.J. Campo, M. Morari, Robust model predictive control, in: Proc. American Control Conference, June 10–12, 1987, pp. 1021–1026] suffer from a great computational burden which limits their applicability in the industry. Sometimes upper bounds of the worst possible case of a performance index have been used to reduce the computational burden. This paper proposes a computationally efficient MMMPC control strategy in which the worst case cost is approximated by an upper bound based on a diagonalization scheme. The upper bound can be computed with O(n3) operations and using only simple matrix operations. This implies that the algorithm can be coded easily even in non-mathematical oriented programming languages such as those found in industrial embedded control hardware. A simulation example is given in the paper. 相似文献
20.
The broadband integrated services digital networks (B-ISDN) based on asynchronous transfer mode (ATM) technology can support
a wide range of applications such as voice, video, still images, and data. Compression techniques increase the effective bandwidth
utilization, but the bursty and asynchronous nature of the traffic can still lead to congestion in the network, and degradation
of image quality and quality of service (QOS). Some of the features to provide better coding schemes for ATM networks are
layered coding, resynchronization, buffering, interleaved schemes, constrained bit rate due to buffers, encapsulation with
the RTP or AAL1 for clock recovery, lapped transforms, motion compensation, and optimal bit allocation for coders based on
wavelet transforms. We review various techniques forimage and video coding such as transforms, motion compensation, vector
quantization, and subband coding. We outline the impact of the cell loss ratio (CLR), delay and cell delay variation (CDV)
on video coding: blocking effects, loss of frame synchronization, motion vectors, and vector quantization codewords. The open
problems include tuning coding parameters to the available QOS provided by the network. 相似文献