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991.
Three studies are presented on attention paid to feedback provided by a computer-based assessment for learning on information literacy. Results show that the attention paid to feedback varies greatly. In general the attention focuses on feedback of incorrectly answered questions. In each study approximately fifty percent of the respondents paid attention to feedback of incorrect answers only. Approximately another twenty-five percent did not pay attention to feedback at all. Results suggest that differences in attention paid to feedback are influenced by task difficulty and test length. Supervision, however, does not seem to influence the average attention paid to feedback. On the other hand, results show that indirect and direct supervision lead to a greater impact of feedback provided by a computer-based assessment for learning as the number increases of students taking the test and, as a consequence, paying attention to feedback. 相似文献
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994.
Burhans Lauren B.; Smith-Bell Carrie; Schreurs Bernard G. 《Canadian Metallurgical Quarterly》2008,122(6):1191
Interest in classical conditioning is usually focused on anticipatory responses to a stimulus associated with a significant event, and it is assumed that responses to the event itself are reflexive, involuntary, and relatively invariant. However, there is compelling evidence that both the rabbit nictitating membrane response (NMR) and heart rate response (HR), well-known reflexive reactions to aversive events, can change quite dramatically as a function of learning when measured in the absence of the conditioned stimulus. In the case of NMR conditioning, a simple blink is transformed into a larger and more complex response. For HR conditioning, reflexive heart rate acceleration can actually change to heart rate deceleration. In both cases, the reflex comes to resemble the conditioned response and follows some of the same behavioral laws. This change in response to the aversive event itself or weaker forms of that event is called conditioning-specific reflex modification (CRM). CRM may force us to reevaluate the behavioral and neural consequences of classical conditioning and may have important consequences for the treatment of conditions such as posttraumatic stress disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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PAYA Bernard GAGNOUD Annie MAUSSION Pascal ROEHR Philippe BREVILLE Thierry NEMER Maroun GOUPIL Christophe 《钢铁研究学报(英文版)》2012,(Z2):646-652
The Energy Climate Package is the EU response to the Global Warming Challenge.Induction heating processes can contribute to the energy saving goal:20%saving within 2020.European induction manufacturer already propose many efficient solutions at industrial scale.To improve induction devices for an always better energy efficiency,EDF R&D set up a French cooperative project called ISIS with a financial support of the French National Research Agency.Its objective is to promote induction heating as Best Available Technology(BAT)and to develop innovative solutions to increase its efficiency.The ISIS innovations concern the electroheat conversion of induction devices(auto-adaptive multi-coil power supply,low losses coils)and the recovering of fatally lost energy.This paper shows the mid-term results of this project.Firsts control algorithms were successfully tested on a 100 kW 3-coil power supply.A homogenization technique is proposed to model a multi-strand coil.A heat recovery test bench is build and equipped with a PFC control loop to fit with the production fluctuations. 相似文献
997.
This paper presents an attempt to use differential thermal analysis to study anisothermal precipitation of both the stable delta and the metastable gamma-second phases during cooling of alloy Inconel 718. Observation of the samples by scanning and transmission electron microscopy was carried out to identify the thermal arrests observed upon cooling. When the upper temperature of the cycle is above the solvus of the delta phase, a clear peak is observed that could be related to precipitation of gamma-second for all the cooling rates used in the present work. When this temperature is below the delta solvus, no thermal arrest can be observed, while when it is close to it two faint peaks were noted and associated with stable and metastable precipitation. The most striking result was that dissolution of the metastable gamma-second phase during the heating stage was found to proceed heterogeneously in the material, and this affected reprecipitation of the phases upon subsequent cooling. 相似文献
998.
P Saas J Boucraut AL Quiquerez V Schnuriger G Perrin S Desplat-Jego D Bernard PR Walker PY Dietrich 《Canadian Metallurgical Quarterly》1999,162(4):2326-2333
Astrocytes are a major cellular component of the brain that are capable of intense proliferation and metabolic activity during diverse inflammatory brain diseases (such as multiple sclerosis, Alzheimer's dementia, tumor, HIV encephalitis, or prion disease). In this biological process, called reactive gliosis, astrocyte apoptosis is frequently observed and could be an important mechanism of regulation. However, the factors responsible for apoptosis in human astrocytes are poorly defined. Here, we report that short term cultured astrocytes derived from different brain regions express significant levels of CD95 at their surface. Only late passage astrocytes are sensitive to CD95 ligation using either CD95 mAb or recombinant CD95 ligand. Blocking experiments using caspase inhibitors with different specificities (DEVD-CHO, z-VAD-fmk, and YVAD-cmk), an enzymatic activity assay, and immunoblotting show that CPP32/caspase-3 play a prominent role in CD95-induced astrocyte death. In contrast, early passage astrocytes are totally resistant to death, but a significant increase in astrocytic IL-8 secretion (p < 0.001, by Wilcoxon's test for paired samples) is observed after CD95 triggering. Production of IL-8 contributes to the resistance of astrocytes to CD95 ligation. Furthermore, in the presence of IFN-gamma, resistant astrocytes became sensitive to CD95-mediated death. These data suggest that microenvironmental factors can influence the consequences of CD95 ligation on astrocytes. Therefore, we propose that CD95 expressed by human astrocytes plays a pivotal role in the regulation of astrocyte life and death and may be a key factor in inflammatory processes in the brain, such as reactive gliosis. 相似文献
999.
Rain sensors (RSs) appear to be a useful tool for water conservation at a relatively low cost. However, little evidence related to RS performance and/or reliability exists. The objectives of this experiment were to: (1) evaluate two RS types with respect to the following: Accuracy of their set point, number of irrigation cycles bypassed, and duration in bypass mode; (2) quantify the amount of water that RSs could save; and (3) estimate their payback period. Mini-click (MC) and wireless rain-click (WL) rain sensor models were monitored. For the WL treatment, the dry-out ventilation windows were set half open, and for the MC treatments, rainfall set points of 3, 13, and 25?mm were established. On average, all treatments responded close to their set points with the WL, 3?mm MC, 13?mm MC, and 25?mm MC treatments averaging 1.4, 3.4, 10.0, and 24.5?mm, respectively. However, some replicates showed variable behavior. The number of times that these sensors shut off irrigation (81, 43, 30, and 8 times, respectively) was inversely proportional to the magnitude of their set point, with potential water savings following a similar trend. Where water costs exceed $0.53 per cubic meter ($2.00 per thousand gallons), the payback period is less than a year for WL and MCs set at 13?mm or less. 相似文献
1000.
The void microstructure of a simulated packing of polydisperse spheres has been investigated by means of a radical Delaunay
tessellation. We have focused on creating sphere packings by mimicking processes involved in the construction of embankment
dams: the polydisperse spheres are collectively released under gravity and denser states are mainly obtained by means of shearing
cycles. This study has been performed on a narrowly graded material for four porosities ranging from 0.42 to 0.36. The void
structure is quantified in terms of probability density functions of pore and constriction sizes, cumulative distributions
and connectivity functions. We emphasize the implications of the sample construction technique on the geometric packing arrangements,
among them a well disordered medium where tetrahedra remain the most represented unit void structure. We point out that when
porosity decreases, void distributions become narrower but the initial structure is never destroyed. Nevertheless, the densification
modifies significantly the computed mean void quantities. In this study, usual geometric arrangements obtained for very dense
materials are not encountered. 相似文献