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1.
Sheikh A. Akbar 《Journal of Materials Science》1992,27(12):3125-3132
The path probability method (PPM) of irreversible statistical mechanics has been successfully applied to various diffusion problems. The major advantage of this atomistic treatment over the phenomenological approach of irreversible thermodynamics is that all Onsager matrix coefficients can be derived analytically so that relations among measurable quantities can be clearly understood in terms of microscopic parameters. This review article attempts to present the PPM in the simplest possible form. The importance of the PPM as an atomistic technique is illustrated using a simple example. The applicability and limitations of the technique are also emphasized. 相似文献
2.
Hamidreza Alighourchi Mohsen Barzegar Soleiman Abbasi 《European Food Research and Technology》2008,227(3):881-887
Anthocyanins (ACs) are phenolic compounds that are distributed widely in fruits and vegetables. Apart from imparting color
to plants, ACs also have an array of health-promoting benefits. In this research, the amounts of major ACs of 15 pomegranate
(Punica granatum L.) varieties obtained from Yazd province were determined. The major ACs detected in the studied varieties were as follows:
delphinidin 3-glucoside (2.19–16.29 mg/L), delphinidin 3,5-diglucoside (2.36–63.07 mg/L), pelargonidin 3-glucoside (0.26–1.36 mg/L),
pelargonidin 3,5-diglucoside (0.01–8.11 mg/L), cyanidin 3-glucoside (5.78–30.38 mg/L), and cyanidin 3,5-diglucoside (4.39–166.32 mg/L).
The effect of storage time of unprocessed and pasteurized juices on ACs content of four selected varieties was also studied.
Average degradation percentage of each AC was between 23.0 and 83.0% during 10 days at 4 °C. Moreover, in pasteurized juices
average degradation of ACs was 42.8 ± 0.5% after 10 weeks storage at 4 °C. 相似文献
3.
Akbar Eslami Simin Nasseri Bahram Yadollahi Alireza Mesdaghinia Foroogh Vaezi Ramin Nabizadeh Shahrokh Nazmara 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(11):1447-1453
BACKGROUND: Over the past several decades methyl tert‐butyl ether (MTBE) as additive to gasoline, intended to either boost ratings of fuel or to reduce air pollution, has been accepted worldwide. Since MTBE has high water solubility, the occurrence of fuel spills or leaks from underground storage tanks or transferring pipeline has led to the contamination of natural waters. In this study the degradation of aqueous MTBE at relatively high concentrations was investigated by a UV‐visible/ZnO/H2O2 photocatalytic process. The effects of important operational parameters such as pH, amount of H2O2, catalyst loading and irradiation time were also investigated. Concentration of MTBE and intermediates such as tert‐butyl formate and tert‐butyl alcohol were measured. RESULTS: Time required for complete degradation increased from 20 to 150 min when the initial concentration was increased from 10 to 500 mg L?1. The first‐order rate constants for degradation of MTBE were estimated to be 0.183–0.022 min?1 as the concentration increased from 10 to 500 mg L?1. Study of the overall mineralization monitored by total organic carbon analysis showed that at an initial concentration of 100 mg L?1 MTBE complete mineralization was obtained after 100 min under UV‐visible/ZnO/H2O2 photocatalysis. CONCLUSION: The data presented in this paper clearly indicated that UV‐visible/ZnO/O2 as an advanced oxidation process provides an efficient treatment alternative for the remediation of MTBE‐contaminated waters. Copyright © 2008 Society of Chemical Industry 相似文献
4.
5.
BACKGROUND: The organ donor shortage has led to a reconsideration of the use of non-heart-beating donors (NHBDs). However, graft injury due to warm ischemia in NHBD livers strongly affects posttransplant outcome. The present study was aimed at investigating the role of the cellular cyclic (c)AMP second messenger signal with regard to hepatic viability after cold preservation of NHBD livers. METHODS: Cardiac arrest was induced in Wistar rats by frenotomy of the anesthetized nonheparinized animal. After 30 min, the livers were excised and flushed with 20 ml of heparinized saline solution, rinsed with 10 ml of University of Wisconsin (UW) solution, and stored submerged in UW solution at 4 degrees C for 24 hr. In half of the experiments, UW solution was supplemented with glucagon (0.5 microg/ml) to increase the cAMP signal in the liver. Reperfusion was carried out in vitro after all livers were incubated at 25 degrees C in saline solution to replicate the period of slow rewarming during surgical implantation in vivo. RESULTS: Hepatic levels of cAMP (nmol/g dry weight) declined from 1.21+/-0.05 to 0.53+/-0.03 (P<0.01) at 30 min after cardiac arrest. Subsequent storage in UW solution resulted in a further decline to 0.35+/-0.04 after 24 hr in group A, whereas glucagon treatment enhanced cellular cAMP signal to 0.64+/-0.06 (P<0.01). Upon reperfusion, liver integrity was significantly improved after glucagon administration, with 66% reduction in alanine aminotransferase release and a threefold increase in hepatic bile production as compared with untreated livers. Moreover, liver ATP tissue levels were restored to only 2.19+/-0.51 micromol/g in the untreated group but reached 4.97+/-0.41 micromol/g (P<0.05) after treatment with glucagon. CONCLUSIONS: Posthoc conditioning of predamaged livers by glucagon enhances cAMP tissue levels during ischemic preservation and improves hepatic integrity upon reperfusion. This may represent a promising approach for the use of livers from non-heart-beating donors in clinical transplantation. 相似文献
6.
Hasan Abbasi Nozari Hamed Dehghan Banadaki Mohammad Mokhtare Somayeh Hekmati Vahed 《浙江大学学报:C卷英文版》2012,(9):701
This study deals with the neuro-fuzzy (NF) modelling of a real industrial winding process in which the acquired NF model can be exploited to improve control performance and achieve a robust fault-tolerant system. A new simulator model is proposed for a winding process using non-linear identification based on a recurrent local linear neuro-fuzzy (RLLNF) network trained by local linear model tree (LOLIMOT), which is an incremental tree-based learning algorithm. The proposed NF models are compared with other known intelligent identifiers, namely multilayer perceptron (MLP) and radial basis function (RBF). Comparison of our proposed non-linear models and associated models obtained through the least square error (LSE) technique (the optimal modelling method for linear systems) confirms that the winding process is a non-linear system. Experimental results show the effectiveness of our proposed NF modelling approach. 相似文献
7.
Engineering with Computers - A novel Harris hawks optimization algorithm is applied to microchannel heat sinks for the minimization of entropy generation. In the formulation of the heat transfer... 相似文献
8.
Sajjad Zare Akbar Ghaffarpour Rahbar 《Journal of Network and Computer Applications》2012,35(1):459-468
Congestion is one of the most important challenges in optical networks. In a Passive Optical Network (PON), the Optical Line Terminal (OLT) is a bottleneck and congestion prone. In this paper, a framework is proposed with Forward Error Correction (FEC) at the IP layer combined with Weighted Round Robin (WRR) at the scheduling level to overcome packet-loss due to congestion in the OLT in order to achieve efficient video multicasting over PON. In the FEC scheme, Reed-Solomon (RS(n,k)) with erasure coding is used, where (n−k) erroneous symbols per n symbol blocks can be corrected. In our framework, an Internet Protocol TeleVision (IPTV) service provider uses the mentioned RS coding and generates redundant packets from regular IPTV packets in such a way that an Optical Network Unit (ONU) can recover lost packets from received packets, thus resulting in a better video quality. Simulation results show that using the proposed framework, an ONU can recover many lost packets and achieve better video quality under different traffic loads for its users. For instance, the proposed method can reduce packet loss rate by almost 55% and 10% under traffic load 0.9, respectively, compared with the Round Robin (RR) and WRR methods under symmetric traffic load. When High Receivers Queue (HRQ) traffic (i.e., traffic received by many users) is twice Low Receivers Queue (LRQ) traffic (i.e., traffic received by a small number of users), this reduction is almost 86% and 30% under traffic load 0.9. Finally, when LRQ traffic is twice HRQ traffic, the reduction in packet loss rate is almost 70% and 91% at traffic load 0.5. 相似文献
9.
Relating Sediment Yield Estimations to the Wet Front Term Using Rainfall Simulator Field Experiments
Norouzi-Shokrlu Akbar Pajouhesh Mehdi Abdollahi Khodayar 《Water Resources Management》2020,34(13):4181-4196
Water Resources Management - Depth to wet front is generally considered as the amount of water that penetrates into soil and wets the internal soil layer. This is an important variable especially... 相似文献
10.
Arnaud Hubaux Patrick Heymans Pierre-Yves Schobbens Dirk Deridder Ebrahim Khalil Abbasi 《Software and Systems Modeling》2013,12(3):641-663
Feature diagrams have become commonplace in software product line engineering as a means to document variability early in the life cycle. Over the years, their application has also been extended to assist stakeholders in the configuration of software products. However, existing feature-based configuration techniques offer little support for tailoring configuration views to the profiles of the various stakeholders. In this paper, we propose a lightweight, yet formal and flexible, mechanism to leverage multidimensional separation of concerns in feature-based configuration. We propose a technique to specify concerns in feature diagrams and to generate automatically concern-specific configuration views. Three alternative visualisations are proposed. Our contributions are motivated and illustrated through excerpts from a real web-based meeting management application which was also used for a preliminary evaluation. We also report on the progress made in the development of a tool supporting multi-view feature-based configuration. 相似文献