全文获取类型
收费全文 | 1187篇 |
免费 | 28篇 |
国内免费 | 4篇 |
学科分类
工业技术 | 1219篇 |
出版年
2022年 | 10篇 |
2021年 | 28篇 |
2020年 | 10篇 |
2019年 | 14篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 23篇 |
2015年 | 14篇 |
2014年 | 33篇 |
2013年 | 91篇 |
2012年 | 34篇 |
2011年 | 63篇 |
2010年 | 45篇 |
2009年 | 42篇 |
2008年 | 38篇 |
2007年 | 53篇 |
2006年 | 37篇 |
2005年 | 42篇 |
2004年 | 35篇 |
2003年 | 35篇 |
2002年 | 30篇 |
2001年 | 31篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 21篇 |
1997年 | 10篇 |
1996年 | 17篇 |
1995年 | 17篇 |
1994年 | 13篇 |
1993年 | 13篇 |
1992年 | 20篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 18篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 21篇 |
1985年 | 23篇 |
1984年 | 24篇 |
1983年 | 14篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1980年 | 17篇 |
1979年 | 18篇 |
1977年 | 16篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1974年 | 10篇 |
1973年 | 11篇 |
1972年 | 11篇 |
排序方式: 共有1219条查询结果,搜索用时 828 毫秒
11.
Following a single shock presentation, fear conditioning to an auditory cue and to the experimental context was assessed by measuring the rat's tendency to freeze. On the conditioning day, 18-day-old rats showed as much freezing to the auditory cue as older rats. However, 18-day-old pups displayed much less freezing to the training context than did pups 21–27 days old. The developmental dissociation between contextual and auditory cue conditioning parallels the dissociation produced by damage to the adult rat's hippocampal system (J. J. Kim and M. S. Fanselow, 1992; R. G. Phillips and G. E. LeDoux, 1992). The dissociation is also consistent with the developmental hypothesis that the configural association system develops late in comparison with the elemental association system (J. W. Rudy, 1991, 1992). The implications of the findings for the maturation of the neural components of the fear-conditioning circuit also are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
12.
Hanggi Evelyn B.; Ingersoll Jerry F.; Waggoner Terrace L. 《Canadian Metallurgical Quarterly》2007,121(1):65
In the past, equine color vision was tested with stimuli composed either of painted cards or photographic slides or through physiological testing using electroretinogram flicker photometry. Some studies produced similar results, but others did not, demonstrating that there was not yet a definitive answer regarding color vision in horses (Equus caballus). In this study, a pseudoisochromatic plate test--which is highly effective in testing color vision both in small children and in adult humans--was used for the first time on a nonhuman animal. Stimuli consisted of different colored dotted circles set against backgrounds of varying dots. The coloration of the circles corresponded to the visual capabilities of different types of color deficiencies (anomalous trichromacy and dichromacy). Four horses were tested on a 2-choice discrimination task. All horses successfully reached criterion for gray circles and demonstration circles. None of the horses were able to discriminate the protan-deutan plate or the individual protan or deutan plates. However, all were able to discriminate the tritan plate. The results suggest that horses are dichromats with color vision capabilities similar to those of humans with red-green color deficiencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
Chlorisondamine is a charged molecule that acts as long-acting nicotinic antagonist in many species, including pigeon. Evidence indicates that, despite the charged nature of chlorisondamine, it blocks some central effects of nicotine. The present study examined the time course of chlorisondamine's blockade of nicotine-induced c-fos expression in the pigeon brain. Chlorisondamine's central blockade was examined from 1 hr to 28 days prior to nicotine administration. Nicotine stimulated increases in c-fos mRNA in the hippocampus, hyperstriatum accessorium, hyperstriatum ventrale, nucleus accumbens, bulbus olfactorius, paleostriatum augmentatum, and stratum griseum et fibrosum superficiale. Nicotinic receptors labeled by [(125)I]-epibatidine were not always found in the same regions as nicotine-induced increases in c-fos expression. Acute chlorisondamine increased the level of c-fos mRNA in the cerebellum, hippocampus, hyperstriatum accessorium, locus parolfactorius, nucleus accumbens, tectum opticum, paleostriatum augmentatum, and stratum griseum et fibrosum superficiale but had no effect on its own 24 hr after administration. Chlorisondamine blocked nicotine-induced increases in c-fos RNA for 4 days in the nucleus accumbens, a week in the bulbus olfactorius, and 2 weeks in the stratum griseum et fibrosum superficiale. The time course of chlorisondamine's blockade of nicotine-induced c-fos expression is consistent with the time course of the ability of chlorisondamine to block behavioral and physiological responses to nicotine. 相似文献
14.
Deffenbacher Jerry L.; Thwaites Gregory A.; Wallace Traci L.; Oetting Eugene R. 《Canadian Metallurgical Quarterly》1994,41(3):386
Inductive social skills training (ISST), skill assembly social skills training (SASST), and cognitive relaxation coping skills (CRCS) training were compared with a no-treatment control condition for general anger reduction. At 4-wk follow-up, compared with the control group, all treatment groups showed equivalent reductions of the amount of anger experienced in a wide range of situations. ISST and CRCS Ss reported less anger in their worst ongoing provocation than did control Ss, whereas SASST Ss did not differ from Ss of other groups. Treatment groups enhanced anger control equally relative to the control group, but only the CRCS group significantly lowered outward, negative expression of anger, and only the ISST group reduced anger suppression, although active treatment groups did not differ from one another on these measures. The ISST group lowered day-to-day anger more than other groups. No treatment effects were found for nontargeted trait anxiety and assertiveness. Results are discussed in terms of prior findings and the efficacy and flexibility of ISST. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
15.
Jennings Jerry L.; Williams Charles; Thompson-Owens Margie 《Canadian Metallurgical Quarterly》1994,31(4):700
Presents a model for conceptualizing 4 basic types of suicidality among substance abusers (avoidance of painful consequences, the depressive experience of "crashing," the threat of personal loss, and environmental strain) and offers practical tips for treating the problem. Four general forms of intervention are discussed: pacing the crisis encounter; desensitizing the patient's sense of desperation; talking frankly about the suicidality; and attending to one's own needs as a counselor. These crisis-intervention tips are intended to aid counselors in handling suicidality as it is manifested in substance-abusing populations. Tips and guidelines for suicidal risk assessment with drug and alcohol abusers are given. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
16.
Baschnagel Joseph S.; Hawk Larry W. Jr.; Colder Craig R.; Richards Jerry B. 《Canadian Metallurgical Quarterly》2007,121(6):1372
In humans, prepulse inhibition (PPI) of startle is greater during attended prestimuli than it is during ignored prestimuli, whereas in rats, most work has focused on passive PPI, which does not require attention. In the work described in this article, researchers developed a paradigm to assess attentional modification of PPI in rats using motivationally salient prepulses. Water-deprived rats were either conditioned to attend to a conditioned stimulus (CS; 1-s, 7-dB increase in white noise) paired with water (CS+ group), or they received uncorrelated presentations of white noise and water (CSo group). After 10 conditioning sessions, startle probes (50 ms, 115 dB) were introduced, with the CS serving as a continuous prepulse. Three experiments examined PPI across a range of prepulse intensities (4-10 dB) and stimulus onset asynchronies (SOAs; 30-960 ms). PPI was consistently reduced in the CS+ group, particularly with a 10-dB prepulse and a 60-ms SOA. Thus, PPI in rats differed between attended and ignored prestimuli, but the effect was reversed in the results of research with humans. A fourth study eliminated the group difference by reversing the CS-water contingency. Methodological and motivational hypotheses regarding the current findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
17.
Deffenbacher Jerry L.; Lynch Rebekah S.; Oetting Eugene R.; Kemper Calvin C. 《Canadian Metallurgical Quarterly》1996,43(2):149
High-anger 6–8th graders received cognitive-relaxation coping skills (CRCS), social skills training (SST), or no treatment. Compared to the control, CRCS and SST were equally effective in reducing trait, general, and personal–situational anger and outward negative anger expression, as well as increasing controlled anger expression. On other variables, however, CRCS showed some superiority. Although both interventions led to equivalent reductions on one measure of anxiety, CRCS lowered depression, shyness, general deviance, and another measure of anxiety, whereas SST did not and was not significantly different from other groups. CRCS lowered school deviance more than SST. No between-group differences were found on self-esteem, alcohol consumption, or intoxication. Possible explanations of these findings were discussed, along with methodological issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
The Journal of Supercomputing - Travelling salesman problem (TSP) is a graph problem that has been widely used in many applications, especially for transportation and logistics. Because TSP is a NP... 相似文献
19.
Nouioua Mourad Fournier-Viger Philippe Wu Cheng-Wei Lin Jerry Chun-Wei Gan Wensheng 《Applied Intelligence》2021,51(10):6785-6809
Applied Intelligence - High utility itemset mining is a popular pattern mining task, which aims at revealing all sets of items that yield a high profit in a transaction database. Although this task... 相似文献
20.
Pauline V. Marck Marco T. Pessoa Yunhui Xu Laura C. Kutz Dominic M. Collins Yanling Yan Cierra King Xiaoliang Wang Qiming Duan Liquan Cai Jeffrey X. Xie Jerry B. Lingrel Zijian Xie Jiang Tian Sandrine V. Pierre 《International journal of molecular sciences》2021,22(7)
The Na/K-ATPase is the specific receptor for cardiotonic steroids (CTS) such as ouabain and digoxin. At pharmacological concentrations used in the treatment of cardiac conditions, CTS inhibit the ion-pumping function of Na/K-ATPase. At much lower concentrations, in the range of those reported for endogenous CTS in the blood, they stimulate hypertrophic growth of cultured cardiac myocytes through initiation of a Na/K-ATPase-mediated and reactive oxygen species (ROS)-dependent signaling. To examine a possible effect of endogenous concentrations of CTS on cardiac structure and function in vivo, we compared mice expressing the naturally resistant Na/K-ATPase α1 and age-matched mice genetically engineered to express a mutated Na/K-ATPase α1 with high affinity for CTS. In this model, total cardiac Na/K-ATPase activity, α1, α2, and β1 protein content remained unchanged, and the cardiac Na/K-ATPase dose–response curve to ouabain shifted to the left as expected. In males aged 3–6 months, increased α1 sensitivity to CTS resulted in a significant increase in cardiac carbonylated protein content, suggesting that ROS production was elevated. A moderate but significant increase of about 15% of the heart-weight-to-tibia-length ratio accompanied by an increase in the myocyte cross-sectional area was detected. Echocardiographic analyses did not reveal any change in cardiac function, and there was no fibrosis or re-expression of the fetal gene program. RNA sequencing analysis indicated that pathways related to energy metabolism were upregulated, while those related to extracellular matrix organization were downregulated. Consistent with a functional role of the latter, an angiotensin-II challenge that triggered fibrosis in the α1r/rα2s/s mouse failed to do so in the α1s/sα2s/s. Taken together, these results are indicative of a link between circulating CTS, Na/K-ATPase α1, ROS, and physiological cardiac hypertrophy in mice under baseline laboratory conditions. 相似文献