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排序方式: 共有940条查询结果,搜索用时 546 毫秒
91.
Papadatou-Pastou Marietta; Martin Maryanne; Munafò Marcus R.; Jones Gregory V. 《Canadian Metallurgical Quarterly》2008,134(5):677
Human handedness, a marker for language lateralization in the brain, continues to attract great research interest. A widely reported but not universal finding is a greater male tendency toward left-handedness. Here the authors present a meta-analysis of k = 144 studies, totaling N = 1,787,629 participants, the results of which demonstrate that the sex difference is both significant and robust. The overall best estimate for the male to female odds ratio was 1.23 (95% confidence interval = 1.19, 1.27). The widespread observation of this sex difference is consistent with it being related to innate characteristics of sexual differentiation, and its observed magnitude places an important constraint on current theories of handedness. In addition, the size of the sex difference was significantly moderated by the way in which handedness was assessed (by writing hand or by other means), the location of testing, and the year of publication of the study, implicating additional influences on its development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
92.
N. Sridhar R. Massabò B.N. Cox I.J. Beyerlein 《International Journal of Fracture》2002,118(2):119-144
Bridged crack models using beam theory formulations have proved to be effective in modeling quasi-static delamination crack growth under large scale bridging conditions in through-thickness reinforced structures. In this paper, beam theory is used to study dynamic mode I crack propagation in through-thickness reinforced laminar structures. In particular, steady state dynamic crack growth for a Double Cantilever Beam (DCB) loaded with a flying wedge is examined. The steady state crack propagation characteristics are mapped out in terms of controllable loading and material parameters including the crack velocity and the properties of the through-thickness reinforcement. For small crack velocities, the through-thickness reinforcement considerably enhances the delamination resistance of the structure. At higher velocities, the kinetic energy term dominates the overall energetics and the relative effect of the reinforcement on the delamination resistance is insignificant. The model suggests a simple fracture test for estimating the properties of the through-thickness reinforcement under dynamic loading conditions. 相似文献
93.
94.
Giovanni Libralato Annamaria Volpi Ghirardini Francesco Avezzù 《Water research》2010,44(15):4437-4450
As a consequence of the Water Framework Directive and Marine Strategy Framework Directive, there is now more focus on discharges from wastewater treatment plants both to transitional and marine-coastal waters. The constraint to encourage sustainable water policy to prevent water deterioration and reduce or stop discharges has entailed new requirements for existing wastewater treatment plants in the form of advanced wastewater treatment technologies as further suggested by the Integrated Pollution and Prevention Control Bureau. A whole toolbox of physico-chemical and ecotoxicological parameters to investigate commercial and mixed domestic and industrial discharges was considered to check the efficiency of an Activated-Sludge Sequencing Batch Reactor (AS-SBR) and two Ultra-Filtration Membrane Biological Reactors (UF-MBRs) on a small scale decentralised basis. All discharges were conveyed into Venice lagoon (Italy), one of the widest impacted Mediterranean transitional environment. The UF-MBRs were able to provide good quality effluents potentially suitable for non-potable reuse, as well as reducing specific inorganic micro-pollutants concentration (e.g. metals). Conversely, the AS-SBR showed unpredictable and discontinuous removal abilities. 相似文献
95.
Annamaria Duszová Radoslav Halgaš Marek Bľanda Pavol Hvizdoš František Lofaj Ján Dusza Jerzy Morgiel 《Journal of the European Ceramic Society》2013,33(12):2227-2232
WC–Co cemented carbide has been investigated using instrumented indentation with maximum applied loads from 0.1 to 10 mN. The hardness and indentation modulus of individual phases and the influence of crystallographic orientation of WC on the hardness and indentation modulus have been studied. The hardness of the Co binder was approximately 10 GPa and that of WC grains up to 50 GPa with relatively large scatter under the indentation load of 1 mN. Investigation of the role of crystallographic orientation of WC grains on hardness at 10 mN load revealed average values of HITbasal = 40.4 GPa (EITbasal = 674 GPa) and HITprismatic = 32.8 GPa (EItprismatic = 542 GPa), respectively. The scatter in the measured values at low indentation loads is caused by the effects of surface and sub-surface characteristics (residual stress, damaged region) and at higher loads by “mix-phase” volume below the indenter. 相似文献
96.
Prof. Dr. Annamaria Passantino 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2011,16(2):215-221
Studies on the welfare of donkey (Equus asinus) have developed slowly, because considered very rustic animals, reared prevalently under extensive production systems and
widespread mainly in marginal areas. The diffusion of extensive breeding of this species has led to the belief that donkey
did not need any welfare assessment. More recently, the scenario has changed, due to a gradual diffusion of intensive and
semi-intensive production systems, especially in highly productive dairy breeds, to the growing concern of consumers about
the life conditions of farmed animals, and to the issuing of a number of national and European rules / laws on the safety
of animal products and well-being of farmed livestock. Relating with the importance of this species on food farming industry,
the Author underlines the missing of specific recommendations concerning the welfare of farmed donkey. In absence of common
criteria and guidelines, it is possible to make reference to the well-known “five freedoms”. This paper will review the main
welfare issues of donkeys and the following aspects will be considered: nutrition, housing and management, clinical problems,
behaviour problems. 相似文献
97.
98.
The paper presents the results of an experimental study on ventilated walls with an external clay cladding in a temperate Mediterranean climate.The aim of this work is to assess the actual thermal performance of the ventilated façade with a complete thermo-fluid dynamic analysis.The paper describes the experimental work carried out on walls with different exposure and various heights of the ventilation channel (6 m and 12 m) with controlled internal air temperature. The air velocities, temperatures and heat fluxes in the ventilated facade were monitored and correlations between the thermo-physical parameters were identified.The study showed that, on sunny days, the external surface temperatures, temperatures in the air cavity and air velocity in the gap are considerably higher for the 12 m wall, while during the nighttime lower temperatures are found for the various layers of the wall.The data obtained allowed us to calculate the Reynolds number and to identify the airflow rate in the channel. Correlations were found between the air velocity in the gap, the airflow rate, the Reynolds number and the sun–air temperature. These correlations are useful for modelling ventilated walls, which are generally very complex, with simplified equivalent walls. Finally it was possible to identify the peak temperatures with respect to exposure and thermal lag. The thermo-graphic analysis showed that the behaviour of the walls is almost uniform without thermal bridges. 相似文献
99.
100.
MP Reilly D Praticò N Delanty G DiMinno E Tremoli D Rader S Kapoor J Rokach J Lawson GA FitzGerald 《Canadian Metallurgical Quarterly》1998,98(25):2822-2828
BACKGROUND: F2 isoprostanes are stable, free radical-catalyzed products of arachidonic acid that reflect lipid peroxidation in vivo. METHODS AND RESULTS: Specific assays were developed by use of mass spectrometry for the F2 isoprostanes iPF2alpha-III and iPF2alpha-VI and arachidonic acid (AA). Urinary excretion of the 2 F2 isoprostanes was significantly increased in hypercholesterolemic patients, whereas substrate AA in urine did not differ between the groups. iPF2alpha-III (pmol/mmol creatinine) was elevated (P<0.0005) in homozygous familial hypercholesterolemic (HFH) patients (85+/-5. 5; n=38) compared with age- and sex-matched normocholesterolemic control subjects (58+/-4.2; n=38), as were levels of iPF2alpha-VI (281+/-22 versus 175+/-13; P<0.0005). Serum cholesterol correlated with urinary iPF2alpha-III (r=0.41; P<0.02) and iPF2alpha-VI (r=0. 39; P<0.03) in HFH patients. Urinary excretion of iPF2alpha-III (81+/-10 versus 59+/-4; P<0.05) and iPF2alpha-VI (195+/-18 versus 149+/-20; P<0.05) was also increased in moderately hypercholesterolemic subjects (n=24) compared with their controls. Urinary excretion of iPF2alpha-III and iPF2alpha-VI was correlated (r=0.57; P<0.0001; n=106). LDL iPF2alpha-III levels (ng/mg arachidonate) were elevated (P<0.01) in HFH patients (0.32+/-0.08) compared with controls (0.09+/-0.02). The concentrations of iPF2-III in LDL and urine were significantly correlated (r=0.42; P<0.05) in HFH patients. CONCLUSIONS: Asymptomatic patients with moderate and severe hypercholesterolemia have evidence of oxidant stress in vivo. 相似文献