全文获取类型
收费全文 | 982篇 |
免费 | 15篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 11篇 |
化学工业 | 85篇 |
金属工艺 | 2篇 |
机械仪表 | 12篇 |
建筑科学 | 33篇 |
矿业工程 | 1篇 |
能源动力 | 7篇 |
轻工业 | 56篇 |
水利工程 | 10篇 |
石油天然气 | 2篇 |
无线电 | 54篇 |
一般工业技术 | 81篇 |
冶金工业 | 556篇 |
原子能技术 | 12篇 |
自动化技术 | 76篇 |
出版年
2022年 | 5篇 |
2021年 | 9篇 |
2019年 | 12篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 23篇 |
2012年 | 15篇 |
2011年 | 28篇 |
2010年 | 33篇 |
2009年 | 14篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 24篇 |
2005年 | 11篇 |
2004年 | 16篇 |
2003年 | 25篇 |
2002年 | 14篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 17篇 |
1998年 | 138篇 |
1997年 | 76篇 |
1996年 | 57篇 |
1995年 | 45篇 |
1994年 | 31篇 |
1993年 | 39篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 16篇 |
1989年 | 16篇 |
1988年 | 10篇 |
1987年 | 17篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 16篇 |
1983年 | 6篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 12篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 17篇 |
1976年 | 44篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 6篇 |
1965年 | 3篇 |
排序方式: 共有998条查询结果,搜索用时 187 毫秒
1.
Dr. Lina Liang Tong-You Wade Wei Pei-Yu Wu Wouter Herrebout Ming-Daw Tsai Prof. Stéphane P. Vincent 《Chembiochem : a European journal of chemical biology》2020,21(20):2982-2990
d -Glycero-d -manno-heptose-1β,7-bisphosphate (HBP) and d -glycero-d -manno-heptose-1β-phosphate (H1P) are bacterial metabolites that were recently shown to stimulate inflammatory responses in host cells through the activation of the TIFA-dependent NF-κB pathway. To better understand structure-based activity in relation to this process, a family of nonhydrolyzable phosphonate analogues of HBP and H1P was synthesized. The inflammation modulation by which these molecules induce the TIFA-NF-κB signal axis was evaluated in vivo at a low-nanomolar concentration (6 nM) and compared to that of the natural metabolites. Our data showed that three phosphonate analogues had similar stimulatory activity to HBP, whereas two phosphonates antagonized HBP-induced TIFA-NF-κB signaling. These results open new horizons for the design of pro-inflammatory and innate immune modulators that could be used as vaccine adjuvant. 相似文献
2.
Introduces the current issue of the American Psychologist, which examines the ramifications of the Brown vs. Board of Education decision and its sequelae over the last 50 years, with a special focus on the mixed role of psychological research and practice. Despite the great strides toward a more just society since May 17, 1954, inequities remain in schooling, in social relations, and in economic opportunity. How will history judge American psychology 50 years from now vis-a-vis the possibilities it helped create via Brown? The articles in this special issue suggest several important directions of research and action our field will need to take if the verdict of history is to be a positive one. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Two hundred thirty-three newly enrolled medical and nursing students at the American University of Beirut, Lebanon, were tested for antibodies to measles and mumps. Antibodies to measles were detected in 95% of the sample, and antibodies to mumps in 84% of the sample. Susceptible individuals were appropriately immunized. 相似文献
4.
Binder M. Mammone R.J. Wade W.L. Jr. Rondeau E. Lavene B. 《Electrical Insulation Magazine, IEEE》1992,8(4):16-19
It is shown that the electrical breakdown voltages of polycarbonate film/metal foil capacitors can be increased. This can be achieved by briefly exposing the metal foil in these spirally wound film foil sections to a low-pressure, low-temperature gas plasma. Exposure of tin/lead foil to a 96% CF4/4% O2 gas plasma for four min, for example, produced >500% increase in breakdown voltage of sealed polycarbonate capacitors 相似文献
5.
Mueser Kim T.; Bellack Alan S.; Wade Julie H.; Sayers Steven L.; Tierney Ann; Haas Gretchen 《Canadian Metallurgical Quarterly》1993,102(3):339
Examined social skills and social perception of 48 schizophrenia/schizoaffective disorder patients (aged 18–55 yrs) in response to negative affect as a function of family expressed emotion (EE). Ss participated in a role-play test, a social perception test, and a problem-solving discussion with a family member and were assessed on several measures of symptomatology. EE of family members was evaluated with the Camberwell Family Interview. On the role-play test, Ss with less critical relatives became more assertive in response to increased negative affect from a confederate portraying either a family member or friend, but Ss with highly critical relatives did not. Ss with highly critical relatives were also less assertive when confronted with negative affect from a confederate portraying a family member rather than a friend. The behaviors of both relatives and Ss during a family problem-solving interaction were related to the EE dimensions of criticism, emotional overinvolvement, and warmth. Patient gender was also related to family problem solving but was independent of EE. S's ratings of affect on a videotaped social perception task were not related to family EE, and there were few differences in psychopathology between Ss with high and low EE relatives.… (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
7.
Kinicki Angelo J.; Hom Peter W.; Trost Melanie R.; Wade Kim J. 《Canadian Metallurgical Quarterly》1995,80(3):354
Two studies examined whether the accessibility of performance prototypes influences performance appraisals. Pilot studies revealed students used performance prototypes when rating instructor performance. Study 1 manipulated the accessibility of these prototypes and the time delay of performance ratings. Results showed no effect of the prime on rating error and accuracy; however, discrimination accuracy decreased over time and recognition bias became more conservative. Study 2 manipulated prototype accessibility and type of rating stimuli (videotape vs. vignette). Rating accuracy and recall were higher for vignette than videotape stimuli, and only those participants exposed to the vignette exhibited priming effects. Results supported transfer-appropriate processing and implied that cognitive primes may have a stronger effect on performance ratings based on "paper-people" than videotaped stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
9.
Serdean C.V. Ambroze M.A. Tomlinson M. Wade J.G. 《Vision, Image and Signal Processing, IEE Proceedings -》2003,150(1):51-58
The paper describes a high-capacity blind video watermarking system invariant to geometrical attacks such as shift, rotation, scaling and cropping. A spatial domain reference watermark is used to obtain invariance to geometric attacks by employing image registration techniques to determine and invert the attacks. A second, high-capacity watermark, which carries the data payload, is embedded in the wavelet domain according to a human visual system model. This is protected by a state-of-the-art error correction code (turbo code). For a false detection probability of 10/sup -8/, the proposed system is invariant to scaling up to 180%, rotation up to 70/spl deg/, and arbitrary aspect ratio changes up to 200% on both axes. Furthermore, the system is virtually invariant to any shifting, cropping, or combined shifting and cropping. The system is also robust to MPEG2 compression, even when combined with shifting and cropping. 相似文献
10.
To determine if recombinant human Cu-Zn superoxide dismutase (rhSOD) would prevent acute lung injury caused by hyperoxia and barotrauma, 26 newborn piglets were studied. Ten piglets were hyperventilated (arterial PCO2 15-20 Torr) with 100% O2 for 48 h. A second group received identical treatment for 4 h (n = 2) or 48 h (n = 8) but was given 5 mg/kg of rhSOD intratracheally at time 0. Six piglets were normally ventilated (arterial PCO2 40-45 Torr) for 48 h with 21% O2. Pulmonary function and tracheal aspirates were examined at time 0 and at 24 and 48 h, and bronchoalveolar lavage was performed at 48 h. In piglets treated with hyperoxia and hyperventilation, lung compliance decreased 42%, and tracheal aspirates showed an increase in neutrophil chemotactic activity (32%), total cell counts (135%), elastase activity (93%), and albumin concentration (339%) over 48 h (P < 0.05). All variables were significantly lower in rhSOD-treated piglets and comparable to normoxic control values. Surfactant remained active in all groups. Immunohistochemistry demonstrated that at 48 h significant rhSOD was distributed homogeneously in terminal airways. Adding rhSOD to tracheal aspirates of hyperoxic hyperventilated piglets did not alter neutrophil chemotaxis, suggesting that rhSOD protected the lung by reducing the production of chemotactic mediators. Results indicate that acute lung injury caused by 48 h of hyperoxia and hyperventilation is significantly ameliorated by prophylactic intratracheal administration of rhSOD. 相似文献