全文获取类型
收费全文 | 379篇 |
免费 | 7篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 54篇 |
金属工艺 | 1篇 |
机械仪表 | 4篇 |
建筑科学 | 6篇 |
矿业工程 | 1篇 |
能源动力 | 10篇 |
轻工业 | 32篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 45篇 |
一般工业技术 | 47篇 |
冶金工业 | 115篇 |
原子能技术 | 3篇 |
自动化技术 | 58篇 |
出版年
2023年 | 2篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 17篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 12篇 |
2007年 | 13篇 |
2006年 | 13篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 13篇 |
2002年 | 7篇 |
2001年 | 7篇 |
1999年 | 10篇 |
1998年 | 36篇 |
1997年 | 20篇 |
1996年 | 20篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 9篇 |
1992年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 12篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
排序方式: 共有386条查询结果,搜索用时 31 毫秒
1.
Jones Enrico E.; Ghannam Jess; Nigg Joel T.; Dyer Jennifer F. 《Canadian Metallurgical Quarterly》1993,61(3):381
Articulates a paradigm for single-case research in psychotherapy. A patient diagnosed as having major depressive disorder was seen in an intensive, twice-weekly psychodynamic psychotherapy for 2.5 years. Each session was videotaped, and assessments of patient change were obtained at regular intervals. A time-series analysis was used to model fluctuations in the therapy process to take into account time and the effect of previous events on subsequent changes, thereby preserving the context-determined meaning for therapist and patient actions. A bidirectional analysis of causal effects shows that the influence processes between therapist and patient are mutual and reciprocal and suggests that the effect of the patient on the therapist and on the process has not been made sufficiently explicit in previous models of process and change. The potential of intensive single-case designs for uncovering causal effects in psychotherapy is demonstrated. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Hurst P.J. Lewis S.H. Keane J.P. Aram F. Dyer K.C. 《IEEE transactions on circuits and systems. I, Regular papers》2004,51(2):275-285
Several Miller compensation schemes using a current buffer in series with the compensation capacitor to modify the right-half-plane zero in fully differential two-stage CMOS operational amplifiers are analyzed. One scheme uses a current mirror as a current buffer, while the rest use a common-gate transistor as a current buffer. The gain transfer functions are derived for each topology, and approximate transfer-function coefficients are found that allow accurate estimation of the zero(s) and poles. 相似文献
3.
4.
HS Keirstead JK Dyer GN Sholomenko J McGraw KR Delaney JD Steeves 《Canadian Metallurgical Quarterly》1995,15(10):6963-6974
Transections of the chicken spinal cord after the developmental onset of myelination at embryonic day (E) 13 results in little or no functional regeneration. However, intraspinal injection of serum complement proteins with complement-binding GalC or 04 antibodies between E9-E12 results in a delay of the onset of myelination until E17. A subsequent transection of the spinal cord as late as E15 (i.e., during the normal restrictive period for repair) results in neuroanatomical regeneration and functional recovery. Utilizing a similar immunological protocol, we evoked a transient alteration of myelin structure in the posthatching (P) chicken spinal cord, characterized by widespread "unravelling" of myelin sheaths and a loss of MBP immunoreactivity (myelin disruption). Myelin repair began within 7 d of cessation of the myelin disruption protocol. Long term disruption of thoracic spinal cord myelin was initiated after a P2-P10 thoracic transection and maintained for > 14 d by intra-spinal infusion of serum complement proteins plus complement-binding GalC or 04 antibodies. Fourteen to 28 d later, retrograde tract tracing experiments, including double-labeling protocols, indicated that approximately 6-19% of the brainstem-spinal projections had regenerated across the transection site to lumbar levels. Even though voluntary locomotion was not observed after recovery, focal electrical stimulation of identified brainstem locomotor regions evoked peripheral nerve activity in paralyzed preparations, as well as leg muscle activity patterns typical of stepping in unparalyzed animals. This indicated that a transient alteration of myelin structure in the injured adult avian spinal cord facilitated brainstem-spinal axonal regrowth resulting in functional synaptogenesis with target neurons. 相似文献
5.
Abhishek Arun Barry Haddow Philipp Koehn Adam Lopez Chris Dyer Phil Blunsom 《Machine Translation》2010,24(2):103-121
Recent advances in statistical machine translation have used approximate beam search for NP-complete inference within probabilistic
translation models. We present an alternative approach of sampling from the posterior distribution defined by a translation
model. We define a novel Gibbs sampler for sampling translations given a source sentence and show that it effectively explores
this posterior distribution. In doing so we overcome the limitations of heuristic beam search and obtain theoretically sound
solutions to inference problems such as finding the maximum probability translation and minimum risk training and decoding. 相似文献
6.
Building the IBM 4758 secure coprocessor 总被引:1,自引:0,他引:1
Meeting the challenge of building a user-configurable secure coprocessor provided several lessons in hardware and software development and continues to spur further research. In developing the 4758, we met our major research security goals and provided the following features: (1) a lifetime-secure tamper-responding device, rather than one that is secure only between resets that deployment-specific security officers perform; (2) a secure booting process in which each layer progressively validates the next less-trusted layer, with hardware restricting access to its secrets before passing control to that layer; (3) an actual manufacturable product - a nontrivial accomplishment considering that we designed the device so that it does not have a personality until configured in the field; (4) the first FIPS 140-1 Level 4 validation, arguably the only general-purpose computational platform validated at this level so far; and (5) a multipurpose programmable device based on a 99-MHz 486 CPU internal environment, with a real operating system, a C language development environment and relatively high-speed cryptography 相似文献
7.
This paper introduces a generalization of cellular automata in which each celi is a tape-bounded Turing machine rather than a finite-state machine. Fast algorithms are given for performing various basic image processing tasks by such automata. It is suggested that this model of parallel computation is a very suitable one for studying the advantages of parallelism in this domain. 相似文献
8.
A. Norman J. Berman K. Brehm M. Drake A. Dyer J. Frisby C. Govil C. Hinchey L. Heuer J. Ke S. Kejriwal K. Kuang S. Keyburn S. Ler K. Powers A. Robertson J. Sanghai C. Schulze J. Schieck J. Sussman L. Tan A. Tello R. Wang K. Yan T. Zeinullayev 《Computational Economics》2012,39(3):243-257
Consumers check few sites in online purchases. Previous research and experiments we perform demonstrate that consumers can not calculate the optimal strategy for price search. They use heuristics whose performance is better than random and less than optimal. To investigate online price search performance we survey student online textbook purchases. Students achieve good performance because they start with a good strategy and online market organization of marketplace and meta-search sites. An important factor is that algorithms at sites searched perform calculations that reduce the computational complexity of the search. 相似文献
9.
Elongated black objects in black-and-white pictures can be ``thinned' to arcs and curves, without changing their connectedness, by (repeatedly) deleting black border points whose deletion does not locally disconnect the black points in their neighborhoods. This technique generalizes to gray-scale pictures if we use a weighted definition of connectedness: two points are ``connected' if there is a path joining them on which no point is lighter than either of them. We can then ``thin' dark objects by changing each point's gray level to the minimum of its neighbors' gray levels, provided this does not disconnect any pair of points in its neighborhood. Examples illustrating the performance of this technique are given. 相似文献
10.
The relationship of education to blood pressure: findings on 40,000 employed Chicagoans 总被引:3,自引:0,他引:3
The relationship of education to both actual blood pressure and the prevalence of high blood pressure, based on a systolic pressure of 160 mm Hg or greater or a diastolic pressure of 95 mm Hg or greater, was analyzed among 27,033 men and women, white and black, age 25-44 and 45-64, from the Chicago Heart Association Detection Project in Industry. The educational status of each individual was categorized as not a high school graduate, high school graduate, some college, or college graduate. A statistically significant inverse association between education and high blood pressure was present in all groups of whites. This association could not be "accounted for" by differences in age, relative weight, and heart rate among the educational strata. Controlling for these variables did, however, lessen the association. Among black males a significant inverse association between education level and blood pressure was found for the younger group. For the older black males there was a clear inverse association although with the small numbers it did not achieve statistical significance. For black females there was no clear association. 相似文献