首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1292篇
  免费   30篇
电工技术   6篇
综合类   2篇
化学工业   244篇
金属工艺   8篇
机械仪表   20篇
建筑科学   43篇
矿业工程   1篇
能源动力   23篇
轻工业   163篇
水利工程   31篇
石油天然气   6篇
无线电   52篇
一般工业技术   129篇
冶金工业   471篇
自动化技术   123篇
  2023年   11篇
  2022年   22篇
  2021年   37篇
  2020年   23篇
  2019年   23篇
  2018年   24篇
  2017年   17篇
  2016年   20篇
  2015年   20篇
  2014年   37篇
  2013年   55篇
  2012年   45篇
  2011年   75篇
  2010年   51篇
  2009年   48篇
  2008年   51篇
  2007年   54篇
  2006年   59篇
  2005年   43篇
  2004年   43篇
  2003年   28篇
  2002年   36篇
  2001年   18篇
  2000年   30篇
  1999年   21篇
  1998年   35篇
  1997年   23篇
  1996年   18篇
  1995年   25篇
  1994年   20篇
  1993年   18篇
  1992年   22篇
  1991年   9篇
  1990年   27篇
  1989年   15篇
  1988年   19篇
  1987年   12篇
  1986年   11篇
  1985年   24篇
  1984年   15篇
  1983年   9篇
  1982年   9篇
  1981年   16篇
  1980年   8篇
  1979年   10篇
  1978年   14篇
  1977年   7篇
  1976年   11篇
  1975年   10篇
  1973年   6篇
排序方式: 共有1322条查询结果,搜索用时 0 毫秒
71.
Designed a metacognitive intervention program to remediate the failures of 42 4th-grade boys in using metacognitive skills to aid their reading comprehension. The program consisted of 2 components: story grammar training, designed to increase comprehension monitoring; and attribution training, designed to increase awareness of effort in efficient reading. Ss were assigned to 3 groups: 1 group received both components and the other 2 groups each received one component alone. 14 skilled 4th-grade male readers served as a contrast group. Maintenance was assessed through free and probed recall; generalization was assessed through a metareading test and an error detection and correction task. Results indicate that strategy training produced dramatic gains in comprehension. Only Ss receiving attribution training alone showed poorer performance than skilled readers. Partial support was obtained for generalization on the metareading assessment. It is concluded that strategy training improved poor readers' comprehension by providing them with metacognitive skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
72.
The authors hypothesized that relations between temperature and assaults are stronger during evening hours than during other hours of the day and tested this hypothesis by obtaining 3-hr measures of assaults, temperature, and other weather variables for a 2-year interval. The hypothesis was confirmed by autoregression analyses that controlled for secular trends, seasonal differences, other weather variables, holidays, and other calendar events. In addition, as predicted by the negative affect escape model, assaults declined after reaching a peak at moderately high temperatures. The inverted U-shaped relation survived tests that controlled for secular trends, seasonality, autocorrelation, outliers, and heteroscedasticity. In addition, consistent with routine activity theory, moderator-variable regression analyses indicated that relations were strongest during evening hours and on weekends. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
73.
Responds to S. Garfield's (see record 1981-33210-001) article appraising the progress and claims of psychotherapy over the last 40 yrs. It is argued that Garfield failed to mention the impact and existence of the psychotherapeutic modality of family therapy and that his focus on the progress and claims of psychotherapy is thus incomplete. Garfield's exclusion of family therapy is seen as characteristic of the current interface between individual psychology and family theory. It is argued that it is possible to integrate individual psychology with systems theory and associated therapies and that such an integration and progression to systems thinking is a logical and necessary step in the development of psychotherapy. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
74.
Explored the applicability of laboratory findings of the effects of massed vs distributed practice to an applied situation. Using a hierarchical design, 4 types of groups were compared: massed practice, distributed practice, combination massed and distributed practice assertion-training groups, and no-treatment control groups. 66 college students participated. Assertiveness was assessed by self-report measures (e.g., College Self Expression Scale), a role-play test, and peer ratings before, immediately after, and 4 wks following assertion training. Results of analyses of covariance and preplanned comparisons indicate that although assertion training produced greater increases in assertiveness than no treatment, there were no differences between the different types of assertion-training groups. Data indicate that at least for the type of program and Ss involved in the study, scheduling of sessions can be guided by the convenience of group leaders and participants without loss of effectiveness. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
75.
It has been found that there are two main factors complicating the preparation of CdxHg1–xTe. The marked difference between the liquidus and solidus curves of the CdTe-HgTe pseudo-binary system gives the expected problems of segregation of CdTe with respect to HgTe during growth but there are also problems due to the segregation of any excess Te in the melt. A 2% excess of Te can give rise to pronounced constitutional supercooling effects. To avoid this, careful control of melt stoichiometry is required. This is made difficult by the high vapour pressure of mercury over the melt, the value of which is not known with great accuracy.The conditions of melt stoichiometry required for crystal growth do not necessarily give material of the required type and resistivity and this must be adjusted after growth by annealing at a controlled mercury pressure at a fixed temperature.  相似文献   
76.
Infrared-visible sum frequency generation spectroscopy is used to investigate the corrosion inhibitor benzotriazole (BTAH) adsorbed on Cu(100) and Cu(111) in acidic solution. Potential-dependent in situ spectra indicate that the adsorbed molecule is the benzotriazole anion (BTA-) at all potentials investigated. The Cu(100) surface is shown to form an ordered adlayer at all potentials probed, while the Cu(111) face is shown to be disordered at negative potentials, but to order with applied positive potential. The ordered adlayer is shown to consist of the BTA- in two configurations, one coordinated to the surface and Cu+ ions in solution and the other coordinated only to the surface. The BTA- coordinated to Cu+ is shown to be more stable with respect to Cl- addition than BTA- coordinated to only the surface. This study demonstrates the viability of using sum frequency generation to study corrosion inhibition in situ.  相似文献   
77.
Biosensors function by reversibly linking bioreceptor-target analyte binding with closely integrated signal generation and can either continuously monitor analyte concentrations or be returned to baseline readout values by removal of analyte. We present an approach for producing fully reversible, reagentless, self-assembling biosensors on surfaces. In the prototype biosensor, quencher-dye-labeled biotin-linked E. coli maltose binding protein (MBP) bound in a specific orientation to a NeutrAvidin-coated surface is employed as a bioreceptor. To complete sensor formation, a modular tether arm consisting of a flexible biotinylated DNA oligonucleotide, a fluorescence resonance energy-transfer (FRET) donor dye, and a distal beta-cyclodextrin (beta-CD) analyte analogue is bound in an equimolar amount to the same surface by means of DNA-directed immobilization. After self-assembly, a baseline level of FRET quenching is observed due to specific interaction between the beta-CD of the flexible tether arm and the sugar binding site of MBP, which brings the two dyes into proximity. Addition of the target analyte, the nutrient maltose, displaces the linked beta-CD-dye of the DNA-based tether arm, and a concentration-dependent change in FRET results. Biosensor sensitivity and dynamic range can be controlled by either using MBP variants having different binding constants or by binding of modulator DNA oligonucleotides that are complementary to the flexible DNA tether. The sensor can be regenerated and returned to baseline quenching levels by washing away analyte. A complex set of interactions apparently exists on the sensing surface that may contribute to sensor behavior and range. This approach may represent a general way to assemble a wide range of useful biosensors.  相似文献   
78.
Multiplexed toxin analysis using four colors of quantum dot fluororeagents   总被引:1,自引:0,他引:1  
Quantum dots (QDs) have the potential to simplify the performance of multiplexed analysis. In this work, we prepared bioinorganic conjugates made with highly luminescent semiconductor nanocrystals (CdSe-ZnS core-shell QDs) and antibodies to perform multiplexed fluoroimmunoassays. Sandwich immunoassays for the detection of cholera toxin, ricin, shiga-like toxin 1, and staphylococcal enterotoxin B were performed simultaneously in single wells of a microtiter plate. Initially the assay performance for the detection of each toxin was examined. We then demonstrated the simultaneous detection of the four toxins from a single sample probed with a mixture of all four QD-antibody reagents. Using a simple linear equation-based algorithm, it was possible to deconvolute the signal from mixed toxin samples, which allowed quantitation of all four toxins simultaneously.  相似文献   
79.
Reviews the book, Behavioral approaches to medicine: Application and analysis edited by J. Regis McNamara (1979). In this book, McNamara has taken a different perspective, emphasizing the content of behavioral assessment and treatment as it applies to the activities of psychologists and other health professionals in medical settings. McNamara speaks of the interpenetration of behavior modification into medicine, much as one might speak of the use of behavior therapy in schools or of the application of behavioral psychology in prisons. Instead of involving the reader in a discussion of the nuances of definitions of fields such as health psychology or behavioral medicine, McNamara sticks with the idea of applying principles from a familiar area to particular problems that arise in a different area. Thus, the focus of the book is on practical problem-solving and on developing a behavioral conceptualization of health care problems. This book is very useful to the extent that it consistently presents this point of view. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号