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41.
Tiwari S.P. Namdas E.B. Ramgopal Rao V. Fichou D. Mhaisalkar S.G. 《Electron Device Letters, IEEE》2007,28(10):880-883
Solution-processed n-type organic field-effect transistors (OFETs) based on the fullerene derivative {6}-1-(3-(2- thienylethoxycarbonyl)-propyl)-{5}-l-phenyl-[5,6]-C61 (TEPP) and phenyl-C61-butyric acid methyl ester (PCBM) in a multiring source/drain structure are reported. Devices with TEPP show high electron mobility up to 7.8 x 10-2 cm2/Vs in the saturation regime for bottom-contact OFETs with Au S/D electrodes with a solution-processed fullerene derivative. The ON/OFF ratios reported in this letter, which are in the range of 105 -106, are among the highest values reported for such devices. This mobility is always higher compared to PCBM devices prepared in identical conditions. The mobility of TEPP and PCBM increased with increasing temperatures in the range of 100-300 K with activation energy of 78 and 113 meV, respectively, which suggests that the thermally activated hopping of electrons is dominant in TEPP. 相似文献
42.
Masood Parang Rao V. Arimilli Satish P. Ketkar 《International Communications in Heat and Mass Transfer》1985,12(2):179-189
A special boundary integral method developed for two-dimensional regions containing circular holes is used to calculate temperature and heat transfer on the boundaries of several selected regions. The geometrical configuration of the region is arbitrary and convective boundary conditions are assumed. An important feature of the method is analytic representation of temperature and its normal derivative on the interior circular holes in the form of a harmonic series. This makes the application of the boundary integral method convenient and free from conditioning problems associated with small interior boundaries. Heat transfer from circular isothermal interior holes are calculated for several illustrative examples using three terms of the harmonic series representation for heat transfer at each of the circular boundaries. The results are presented and discussed. 相似文献
43.
S B Watson M Charlton Y R Rao T Howell J Ridal B Brownlee C Marvin S Millard 《Water science and technology》2007,55(5):1-8
The Laurentian Great Lakes of North America are a drinking water source for millions of Canadian and US consumers. These waterbodies have undergone extensive change over the past century as a result of widespread degradation and remediation. Many of the Lakes are prone to taste and odour (T&O), and although these outbreaks have been poorly monitored, evidence suggests that they are increasing in frequency. Tracing and controlling T&O in such large systems presents a challenging task, due to their physical size and complexity. This paper presents an overview of recent investigative and management approaches to T&O in Lake Ontario and its outflow, the St. Lawrence River. We have identified three distinct patterns of T&O in these source-waters, caused by geosmin and 2-methylisoborneol and differing in their planktonic and benthic sources, and temporal and spatial dynamics. Each pattern has required a different approach by scientists and management, in partnership with the water industry. We have shown these T&O outbreaks are caused and moderated by physical, chemical and biological mechanisms over a spectrum of spatial and temporal scales. Canadian municipalities affected by these outbreaks have been key to the investigation of the links between T&O and ecosystem processes with the aim to develop more proactive water treatment and long-term management. 相似文献
44.
D. Srinivasa Rao H. Suresh Hebbar M. Komaraiah 《Materials and Manufacturing Processes》2007,22(7):825-829
Burnishing is used increasingly as a finishing operation which gives additional advantages such as increased hardness, fatigue strength, and wear resistance. Experimental work based on 34 factorial design was carried out to establish the effects of ball burnishing parameters on the surface hardness of high-strength low alloy steels (HSLA) dual-phase (DP) steel specimens. Statistical analysis of the results shows that the speed, feed, lubricant and ball diameter have significant effect on surface hardness. 相似文献
45.
In air-compression systems, instabilities occur during operation close to their peak pressure-rise capability. However, the
peak efficiency of a compression system lies close to this region of instability. A surge is a violent mode of instability
where there is total breakdown of flow in the system and pressure-rise capability is lost drastically. Generally, all compression
systems operate with a margin defined as the ‘surge margin’, and, consequently, system operational efficiency is lower. It
is of interest to study compression-system surge to understand its dynamics in order to operate compression systems close
to the instability for achieving high efficiency safely without encountering surge. Unsteady pressure data from a compression
system, captured during surge oscillations, reveal many aspects of flow physics and are analysed to understand the surge dynamics
of the system. A set of controlled experiments was conducted with a simple desktop experimental test set-up and essential
aspects of surge dynamics have been characterised. 相似文献
46.
催化技术在降低汽油机排放方面的应用 总被引:3,自引:2,他引:1
本文介绍了当前催化技术在改善和降低汽油机排放方面的应用情况,指出:催化技术是改善汽油机排放的一种有效措施和重要手段。 相似文献
47.
48.
Rao R. Srivastava A. Blaauw D. Sylvester D. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2004,12(2):131-139
We develop a method to estimate the variation of leakage current due to both intra-die and inter-die gate length process variability. We derive an analytical expression to estimate the probability density function (PDF) of the leakage current for stacked devices found in CMOS gates. These distributions of individual gate leakage currents are then combined to obtain the mean and variance of the leakage current for an entire circuit. We also present an approach to account for both the inter- and intra-die gate length variations to ensure that the circuit leakage PDF correctly models both types of variation. The proposed methods were implemented and tested on a number of benchmark circuits. Comparison to Monte Carlo simulation validates the accuracy of the proposed method and demonstrates the efficiency of the proposed analysis method. Comparison with traditional deterministic leakage current analysis demonstrates the need for statistical methods for leakage current analysis. 相似文献
49.
The General Packet Radio Service (GPRS) provides a packet switched data service for mobile users. However, the existing GPRS specification does not provide the push mechanism and it is difficult to support GPRS services such as call termination (incoming call) for wireless voice over IP (VoIP). Based on the short message service, this paper proposes a push mechanism for GPRS supporting private IP addresses. Our approach does not need to modify the existing GPRS structure. 相似文献
50.
Nonlinear dynamical method of projecting the transmission of an epidemic is accurate if the input parameters and initial value
variables are reliable. Here, such a model is proposed for predicting an epidemic. A method to supplement two variables and
two parameters for this proposed model is demonstrated through a robust statistical approach. The method described here worked
well in case of three continuous distributions. Model predictions could be lower estimates due to under-reporting of disease
cases. Anad hoc procedure with a technical note is provided in the appendix
An earlier version of this paper was presented at the annual conference of the Indian Society for Mathematical Modelling &
Computer Simulation, Bangalore, November 14–15, 2002 相似文献