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351.
Yuanyuan Zhang Li Wang Soumyadeep Dey Mawadda Alnaeeli Sukanya Suresh Heather Rogers Ruifeng Teng Constance Tom Noguchi 《International journal of molecular sciences》2014,15(6):10296-10333
Erythropoietin (EPO) regulation of red blood cell production and its induction at reduced oxygen tension provides for the important erythropoietic response to ischemic stress. The cloning and production of recombinant human EPO has led to its clinical use in patients with anemia for two and half decades and has facilitated studies of EPO action. Reports of animal and cell models of ischemic stress in vitro and injury suggest potential EPO benefit beyond red blood cell production including vascular endothelial response to increase nitric oxide production, which facilitates oxygen delivery to brain, heart and other non-hematopoietic tissues. This review discusses these and other reports of EPO action beyond red blood cell production, including EPO response affecting metabolism and obesity in animal models. Observations of EPO activity in cell and animal model systems, including mice with tissue specific deletion of EPO receptor (EpoR), suggest the potential for EPO response in metabolism and disease. 相似文献
352.
Petr Ptáček Tomáš Opravil František Šoukal Jaromír Wasserbauer Jiří Másilko Jan Baráček 《Journal of the European Ceramic Society》2013,33(13-14):2793-2799
The structural order of kaolinite is an important factor that shows a substantial effect on the processes which take place during the thermal treatment of kaolin. The influence of structural order on the dehydroxylation process was investigated by simultaneous thermogravimetry and differential thermal analysis (TG-DTA). The thermal analysis was performed on the samples with gradually decreasing structural order prepared by milling procedure. The apparent activation energy of dehydroxylation process decreases with decreasing structural order according to the exponential function. The extrapolation of experimental data leads to the estimation of apparent activation energy of 76.6 kJ mol?1 and of frequency factor of 0.12 × 104 s?1 related to completely disordered form of kaolinite, while the ordered form shows the apparent activation energy of 216.17 kJ mol?1 and the frequency factor of 9.26 × 104 s?1. The relationships between features such as the infrared pattern of treated material, the degree of structural order and the apparent activation energy were established. 相似文献
353.
天然裂缝性储层的特征 总被引:2,自引:0,他引:2
Tom Bratton Dao Viet Canh Nguyen Van Que Nguyen V.Duc Paul Gillespie David Hunt BingjianLi Richard Marcinew Satyaki Ray Bernard Montaron Ron Nelson David Schoderbek Lars Sonneland 《国外测井技术》2008,23(1):47-66
天然裂缝性储层给开采带来了一个矛盾难题。这类储层包括低油气采收率储层,这些储层最初可能表现出高产,但产能下降得非常快。此外,这类储层还经常出现早期见气或见水等问题。而另一方面,一些天然裂缝性储层也是全球最大、产量最高的储层。这类储层的这种矛盾特性激发业界尽力去深入了解其特征,以便更有把握地对其进行模拟分析。 相似文献
354.
Micro heat engines have attracted considerable interest in recent years for their potential exploitation as micro power sources in microsystems and portable devices. Thermodynamic modeling can predict the theoretical performance that can be potentially achieved by micro heat engine designs. An appropriate model can not only provide key information at the design stage but also indicate the potential room for improvement in existing micro heat engines. However, there are few models reported to date which are suitable for evaluating the power performance of micro heat engines. This paper presents a new thermodynamic model for determining the theoretical limit of power performance of micro heat engines with consideration to finite heat input and heat leakage. By matching the model components to those of a representative heat engine layout, the theoretical power, power density, and thermal efficiency achievable for a micro heat engine can be obtained for a given set of design parameters. The effects of key design parameters such as length and thermal conductivity of the engine material on these theoretical outputs are also investigated. Possible trade-offs among these performance objectives are discussed. Performance results derived from the developed model are compared with those of a working micro heat engine (P3) as an example. 相似文献
355.
Tom Bajcar Leon Gosar Brane Širok Franci Steinman Gašper Rak 《Chemical Engineering and Processing: Process Intensification》2010
The paper presents an experimental study of suspension flow patterns and velocity field inside a circular settling tank with continuous operation. Research was focused on the impact of a specific flow pattern on the sedimentation efficiency of the prototype settling tank. The latter differed from a common circular settling tank in that it was peripherally fed and had the central draw-off. Experiment was carried out on a settling tank section made of plexiglass and represented a radial slice of a prototype settling tank. The flow field and local suspension concentration was determined by computer-aided visualization. Sedimentation efficiency was assessed relatively by comparison of the amount of settled particles (sludge height measurements) between different types of flow in a certain time period of the settling tank operation. Results showed that there were two types of flow in the settling tank that were initiated by a horizontal or vertical inflow from the distribution ring. The type of inflow (horizontal or vertical) was a function of the suspension height in the settling tank. Significant differences in sedimentation efficiency were observed between both types of flow, particularly at lower inlet suspension concentrations. Horizontal inflow proved to be less efficient in terms of settling. 相似文献
356.
Abigail Durrant David S. Kirk Steve Benford Tom Rodden 《Computer Supported Cooperative Work (CSCW)》2012,21(1):43-79
In this paper, we present the theme park as a novel commercial setting and distinct cultural ecology for CSCW research, presenting
challenges to technology designers interested in supporting cultural visiting activities. We report findings from an empirical
field study of theme park visiting by groups. Our account focuses on how visitors encountered the theme park, and how they
worked with or “geared in” to what the park provided in order to pursue leisure activities to their own ends. We further demonstrate
that, whilst theme park visiting features thrilling and fun activities, it also features the prosaic concerns of planning,
parenting and money that connect it to ordinary social life. As such, we present the theme park as a setting in which work
and leisure are intertwined as concerns of both visitors and the park, for producing and consuming theme park experience.
We have focussed on the work of visiting groups to pursue leisure, and their combined use of park-provided and personal technologies
in various “trajectories of interaction” within the park. Our findings point to considerations for the design of services
that connect with park-provided and personal technologies to support group visiting, in theme parks and related settings. 相似文献
357.
Clayton A. Pullins Tom E. Diller 《International Journal of Heat and Mass Transfer》2011,54(15-16):3369-3380
The need for in situ heat flux measurements in hot structures, used in hypersonic vehicle thermal protection system development, combustion and propulsion research, and fire testing requires that heat flux sensors are characterized over their entire operating temperature range. The in-cavity heat flux sensor calibration technique has been adapted to accommodate elevated sensor temperatures, in an effort to develop a primary calibration scheme for high temperature heat flux sensors using an existing blackbody calibration system. The new scheme has been demonstrated through the calibration of a high temperature, thermopile-type heat flux sensor. The output temperature dependence of the high temperature heat flux sensor (HTHFS) has been successfully characterized over the range of 175–960 °C with acceptable uncertainty limits. The calibrated HTHFS sensitivity agrees well with a theoretical sensitivity model, suggesting that the extended in-cavity calibration technique is a viable choice for primary calibration of heat flux sensors at elevated sensor temperatures. 相似文献
358.
359.
The advantages of mathematical simulations of the process of cured hide desalination are presented. Full three‐dimensional model is presented and then its one‐dimensional and a two‐dimensional special cases are considered and compared. In the case of one‐dimensional approximation, the solution can be obtained in an analytic form, while for the two‐dimensional case only numerical solution is available. A possible occurrence of a concentration shock is modelled, and a method of its prevention is proposed to reduce losses in the hide substance. The predictions of the mathematical model are then compared with experimental data and found to be in good agreement. 相似文献
360.
Proteases occupy the most relevant position among industrial enzymes. Plant proteases have been used in medicine, detergent
manufacturing, and food science for many years, but their production is diminishing in favor of those of microbial origin
because lower production costs. Papain, bromelain, and ficin are the most frequently employed plant proteases, although new
proteases with new and more appealing physicochemical properties for industry are still emerging. DNA technology and genetic
engineering shall play, without a doubt, an important role for the production of these proteases at the industrial level.
The present review focuses on the applications of traditional plant proteases as well as new proteases discovered during the
last 20 years, some of which have already been genetically engineered either to increase production or to strengthen some
of their physicochemical properties. The review also refers to the protease classification, action pattern, and main characteristics. 相似文献