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91.
链霉菌TD-1代谢产物对饲料中污染霉菌的抑制作用及稳定性 总被引:2,自引:0,他引:2
采用对峙培养法,检测分离于土壤中的链霉菌TD-1代谢产物对饲料中污染霉菌构巢曲霉(Aspergillus nidulans)、纯绿青霉(Penicillium verrucosum)、赭曲霉(Aspergillus ochraceus)、黄曲霉(Aspergillus flavus)、黑曲霉(Aspergillus niger)、米曲霉(Aspergillus oryzae)、茄腐镰刀菌(Fusarium solani)、桔青霉(Penicillum citrinum)、串珠镰刀菌(Fusarium moniliforme)的抑菌活性,结果表明:TD-1菌株代谢产物对以上霉菌具有较强的抑制作用,抑菌带宽度为10 mm左右.通过TD-1菌株的代谢过程曲线发现,该菌株发酵至第6 d抑菌率达90%左右.稳定性试验结果显示:该菌株所产生的活性物质具有较好的耐热性、耐酸碱性、抗紫外辐射能力. 相似文献
92.
通过荧光光谱法和碳酸钙沉积法研究了荧光标记复配水处理剂的性能并进行了评价。试验表明,该荧光标记复配水处理剂的荧光强度与其质量浓度呈良好的线性关系,且荧光示踪剂对复配水处理剂的阻垢性能基本没有影响。同时考察了温度、时间、pH等因素对荧光标记复配水处理剂荧光强度的影响。结果表明,荧光标记复配水处理剂的稳定性良好,受上述情况的影响较小。因此通过对荧光标记复配水处理剂的荧光强度分析可以确定水处理系统内复配水处理剂的含量。将荧光发射值与此复配水处理剂的浓度关联起来,从而定量地控制循环冷却水中复配水处理剂的有效浓度。 相似文献
93.
研究了复合型缓蚀剂SM2001对45#碳钢在模拟工艺水中的缓蚀性能,原子吸收法测定冷却水中溶出Fe^2 量及极化曲线测试结果表明,SM2001对45#碳钢具有良好的腐蚀性能,在金属表面形成性能良好的缓蚀膜。 相似文献
94.
The interaction of bacteria and metal surfaces 总被引:2,自引:0,他引:2
Florian Mansfeld 《Electrochimica acta》2007,52(27):7670-7680
This review discusses different examples for the interaction of bacteria and metal surfaces based on work reported previously by various authors and work performed by the author with colleagues at other institutions and with his graduate students at CEEL. Traditionally it has been assumed that the interaction of bacteria with metal surfaces always causes increased corrosion rates (“microbiologically influenced corrosion” (MIC)). However, more recently it has been observed that many bacteria can reduce corrosion rates of different metals and alloys in many corrosive environments. For example, it has been found that certain strains of Shewanella can prevent pitting of Al 2024 in artificial seawater, tarnishing of brass and rusting of mild steel. It has been observed that corrosion started again when the biofilm was killed by adding antibiotics. The mechanism of corrosion protection seems to be different for different bacteria since it has been found that the corrosion potential Ecorr became more negative in the presence of Shewanella ana and algae, but more positive in the presence of Bacillus subtilis. These findings have been used in an initial study of the bacterial battery in which Shewanella oneidensis MR-1 was added to a cell containing Al 2024 and Cu in a growth medium. It was found that the power output of this cell continuously increased with time. In the microbial fuel cell (MFC) bacteria oxidize the fuel and transfer electrons directly to the anode. In initial studies EIS has been used to characterize the anode, cathode and membrane properties for different operating conditions of a MFC that contained Shewanella oneidensis MR-1. Cell voltage (V)—current density (i) curves were obtained using potentiodynamic sweeps. The current output of a MFC has been monitored for different experimental conditions. 相似文献
95.
以三氯硫磷为原料,与正丁胺进行亲核取代反应合成中间体正丁基硫代磷酰二氯,再将正丁基硫代磷酰二氯与液氨通过氨解反应合成正丁基硫代磷酰三胺,商品名为Nitrogeny.反应中产生的HCl用三乙胺来吸收.探讨了各种反应因素如反应物的配比,三乙胺的用量,反应时间,温度等因素对抑制剂活性的影响,通过正交实验确定了正丁基硫代磷酰三胺的最佳工艺合成反应条件:n(RNH2):n(PSCl3)=1:1.2;三乙胺17.5 mL,液氨80 g;反应温度θ1=10 ℃,θ2=0 ℃;反应时间t1=3.5 h,t2=60 min.此时抑制活性达到最大值92.50%. 相似文献
96.
In list-method directed forgetting, participants are cued to intentionally forget a previously studied list while remembering a subsequently presented 2nd list. Results from prior research are inconclusive on whether older adults show deficits in this type of task. In 3 experiments, the authors reexamined the issue and compared younger and older adults' responsiveness to the forget cue. Across the experiments, the forget cue was varied within and between participants, the 2 lists were unrelated and related to each other, and recall of the lists was required simultaneously and successively. In none of the 3 experiments did any age-related difference in directed forgetting performance emerge. List-method directed forgetting is assumed to reflect retrieval inhibition. The present results thus challenge the proposal of a general inhibitory deficit in older adults' memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
Rat strain differences in the acoustic startle response (ASR) and prepulse inhibition (PPI) of that response are of increasing interest, especially as the genetics of PPI may provide an approach to studying the genetics of certain mental illnesses. However, strain differences in PPI are confounded by differences in ASR. To clarify this issue, the authors investigated the ASR and PPI across a range of startling stimulus intensities (70 dB-120 dB) in Wistar and Sprague-Dawley rats (N=96). Sprague-Dawleys showed more PPI of ASR capacity (response limit) than Wistars. In contrast, Wistars exhibited greater PPI than Sprague-Dawleys, as measured by an increase in response threshold. This dissociation suggests that PPI is more complex than that assessed by single startling stimulus intensity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
Inhibition of return (IOR) refers to slower responding to a stimulus that is presented at the same, rather than a different location as a preceding, spatially nonpredictive, stimulus. Repetition priming refers to speeded responding to a stimulus that duplicates the visual characteristics of a stimulus that precedes it. IOR and repetition priming effects interact in nonspatial discrimination tasks but not in localization tasks; three experiments examined whether this is due to processing differences or due to response differences between tasks. Two stimuli, S1 and S2, occurred on each trial. In Experiment 1, S1 and S2 were both peripheral arrows; in Experiment 2, S1 was a central arrow and S2 was a peripheral nondirectional rectangle; in Experiment 3, S1 was a peripheral nondirectional rectangle and S2 was a peripheral arrow. S1 never required a response; S2 required a localization or a discrimination response. Despite evidence that form information was likely extracted from the arrow stimuli, the localization task revealed no repetition priming: IOR occurred regardless of shared visual identity of the S1 and S2 arrows. The discrimination task revealed IOR only when the visual identity changed from S1 to S2; otherwise, facilitation occurred. These results suggest that IOR is masked by repetition priming only when the response depends on the explicit processing of form information; repetition priming does not occur when such information is extracted automatically but is task (and response) irrelevant. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
Kunzmann Ute; Kupperbusch Cenita S.; Levenson Robert W. 《Canadian Metallurgical Quarterly》2005,20(1):144
This study investigated age differences in the ability to suppress and amplify expressive behavior during emotional arousal. Young and old participants viewed 3 film clips about medical procedures while their behavioral, autonomic, and subjective responses were recorded. Half of the participants viewed all 3 films without additional instructions; the other half was asked to suppress and amplify their behavioral expression during the 2nd and 3rd films. Except for heart rate, suppression and amplification produced similar patterns of autonomic activation. Neither suppression nor amplification had effects on self-reported emotion. There were no age differences in the ability to suppress or amplify emotional expression or in their physiological or subjective consequences. Considering that older people's unregulated reactivity was lower than that of young adults, suppression may have been easier and amplification more difficult for older adults. Voluntary emotion regulation might be one domain of human performance that is spared from age-related losses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Visual search has been studied extensively, yet little is known about how its constituent processes affect subsequent emotional evaluation of searched-for and searched-through items. In 3 experiments, the authors asked observers to locate a colored pattern or tinted face in an array of other patterns or faces. Shortly thereafter, either the target or a distractor was rated on an emotional scale (patterns, cheerfulness; faces, trustworthiness). In general, distractors were rated more negatively than targets. Moreover, distractors presented near the target during search were rated significantly more negatively than those presented far from the target. Target-distractor proximity affected distractor ratings following both simple-feature and difficult-conjunction search, even when items appeared at different locations during evaluation than during search and when faces previously tinted during search were presented in grayscale at evaluation. An attentional inhibition account is offered to explain these effects of attention on emotional evaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献