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91.
There has been growing emphasis on the development of coupled treatment systems (e.g., advanced oxidation–biological) for treating poorly biodegradable wastewater. An attempt has been made in the present study to couple photocatalytic (TiO2/UV) pretreatment with conventional activated sludge process to achieve improvement in the biodegradation of H-acid. The combination of titanium dioxide and UV light has been known to generate strong oxidants that degrade several organic pollutants into carbon dioxide via the formation of some intermediates. The intermediates formed may undergo biodegradation readily. Accordingly, photodegradation experiments were carried out initially at an optimized TiO2 dose and the minimum pretreatment time required for transforming H-acid was identified. For this purpose, UV–vis spectrophotometry and high-performance liquid chromatography (HPLC) were extensively used. Subsequently, it was attempted to biodegrade untreated and pretreated H-acid using activated sludge from the textile industry acclimatized to H-acid. It was found that photocatalytic pretreatment of H-acid for 30 min, during which period approximately 8–10% chemical oxygen demand (COD) removal occurred, can be coupled to second-stage biological treatment for achieving enhanced biodegradation of H-acid. 相似文献
92.
Experimental data of Ogata1 has been curve-fitted to obtain the forward and reverse rate constants for nylon-66 polymerization. Its molecular weight distribution (MWD) has been simulated in homogeneous continuous-flow stirred tank reactors (HCSTR) for 11 h of residence time when the reaction mass is very close to equilibrium. The set of algebraic equations have been solved using Brown's algorithm,2 which was found to be more efficient compared to the Gauss-Jordon techniques of solution. The MWD thus obtained is compared with our earlier simulation of the molecular weight distribution from batch reactors3 and was found to differ significantly. In HCSTR, the weight fraction distribution does not undergo a maximum and the polydispersity index ρ of the polymer formed is much higher than that obtained from batch reactors. The number and weight average of the polymer formed in HCSTR is found to be significantly lower. 相似文献
93.
Paul P. Lynn Santosh K. Arya 《International journal for numerical methods in engineering》1973,6(1):75-88
This paper presents a new method of formulating the finite element relationships based on the least squares criterion. To overcome the high degree of inter-element continuity, a method of reducing the original governing differential equation to a set of equivalent system of first-order differential equations is proposed. The validity of the method is demonstrated by means of several numerical examples. In particular, application of the method to problems with unknown variational functionals is considered. 相似文献
94.
A multivariate regression analysis of viscosity-molecular weight-concentration data is presented which is superior to the methods currently used. Four sets of data from the literature are analysed to show the efficacy of the method. 相似文献
95.
The current work considers the multi-scale nature of surface roughness in a new model that predicts the real area of contact and surface separation as functions of load. This work is based upon a previous rough surface multi-scale contact model which used stacked elastic–plastic spheres to model the multiple scales of roughness. Instead, this work uses stacked 3D sinusoids to represent the asperities in contact at each scale of the surface. By summing the distance between the two surfaces at all scales, a model of surface separation as a function of dimensionless load is obtained. Since the model makes predictions for the real area of contact, it is also able to make predictions for thermal and electrical contact resistance. In accordance with concerns in previous works that the iterative calculation of the real contact area in multi-scale methods does not converge, this work not only tests but also gives conditions required for convergence in these techniques. The results are also compared to other existing rough surface contact models. 相似文献
96.
Chris Lee Kapil Gupta Tomas Ruis Osborne Santosh Thorat Purva Jamdade Suril Patel Dharmesh Thakker Niti Gourisaria Vrinda Seksaria Udayan Mazumdar Fram Petit 宋刚 《城市环境设计》2009,(8):66-67
Serie建筑师事务所是一个国际化事务所,涉及的领域包括建筑、城市的设计。事务所关注于当代城市中建筑类型的进化和变异以及这些智慧形式在空间解决方案上的应用。类型学式的研究,或者用他们的名词,“连续”(SERIES)的思考和探索(利用建筑类型的累积智慧)是Serie作品的关键。 相似文献
97.
In this letter, we propose an extension to the ordered subcarrier selection algorithm (OSSA) for orthogonal frequency division multiplexing (OFDM) systems. The result is a simple algorithm for minimizing the bit error rate of the OFDM system at a fixed throughput. The proposed algorithm employs multiple modulations (non-uniform bit loading) within an OFDM symbol. However, unlike existing bit loading algorithms that have a very high computational complexity, the proposed algorithm is based only on the ordered statistics of the subcarrier gains and is consequently very simple. After ordering the subcarriers based on their gains, progressively higher order modulations are used with increasing gains. The key aspect here that greatly simplifies the algorithm is that the modulation used on a subcarrier depends only on the position of its gain in the ordered set and not on the actual values of the gains. We show an analytical approach for determining the parameters of the algorithm. 相似文献
98.
A Novel Method for the Production of Biodiesel from the Whole Stillage-Extracted Corn Oil 总被引:1,自引:0,他引:1
Hossein Noureddini Santosh R. P. Bandlamudi Emily A. Guthrie 《Journal of the American Oil Chemists' Society》2009,86(1):83-91
The extraction of corn oil from whole stillage and condensed distillers’ solubles (CDS) with hexane and its conversion to
biodiesel were investigated. The analysis of the extracted oil showed 6–8 wt.% free fatty acid (FFA) in this oil. Acid, base,
acid–base, and acid–base catalyzed transesterifications with intermediate neutralization with anion exchange resin were investigated.
Experiments were performed with model corn oil substrates which contained 1.0–6.0 wt.% FFA. The effect of catalyst at 0.50–1.25 wt.%
was studied at a 1:8 oil/methanol molar ratio. At 6.0 wt.% FFA concentration, the acid-catalyzed scheme was slow and resulted
in less than 20% yield after 4 h, while the base-catalyzed was mostly consumed by the FFA and very little conversion was achieved.
The acid–base catalyzed scheme succeeded in reducing the FFA content of the oil through the acid-catalyzed stage, and yields
in excess of 85% were achieved after the second stage of the reaction with a base catalyst. However, formation of water and
soap prevented the separation of product phases. An alternative acid–base catalyzed scheme was examined which made use of
a strong anion exchange resin to neutralize the substrate after the initial acid-catalyzed stage. This scheme resulted in
the effective removal of the acid catalyst as well as the residual FFA prior to the base-catalyzed stage. The subsequent base-catalyzed
stage resulted in yields in excess of 98% for a 7.0 wt.% FFA corn oil and for the corn oil extracted from CDS. 相似文献
99.
Magdalena Markowicz-Piasecka Johanna Huttunen Ahmed Montaser Santosh Kumar Adla Seppo Auriola Marko Lehtonen Kristiina M. Huttunen 《International journal of molecular sciences》2021,22(14)
Efflux transporters, namely ATP-binding cassette (ABC), are one of the primary reasons for cancer chemoresistance and the clinical failure of chemotherapy. Ganciclovir (GCV) is an antiviral agent used in herpes simplex virus thymidine kinase (HSV-TK) gene therapy. In this therapy, HSV-TK gene is delivered together with GCV into cancer cells to activate the phosphorylation process of GCV to active GCV-triphosphate, a DNA polymerase inhibitor. However, GCV interacts with efflux transporters that are responsible for the resistance of HSV-TK/GCV therapy. In the present study, it was explored whether GCV and its more lipophilic derivative (1) could inhibit effluxing of another chemotherapeutic, methotrexate (MTX), out of the human breast cancer cells. Firstly, it was found that the combination of GCV and MTX was more hemocompatible than the corresponding combination with compound 1. Secondly, both GCV and compound 1 enhanced the cellular accumulation of MTX in MCF-7 cells, the MTX exposure being 13–21 times greater compared to the MTX uptake alone. Subsequently, this also reduced the number of viable cells (41–56%) and increased the number of late apoptotic cells (46–55%). Moreover, both GCV and compound 1 were found to interact with breast cancer resistant protein (BCRP) more effectively than multidrug-resistant proteins (MRPs) in these cells. Since the expression of BCRP was higher in MCF-7 cells than in MDA-MB-231 cells, and the cellular uptake of GCV and compound 1 was smaller but increased in the presence of BCRP-selective inhibitor (Fumitremorgin C) in MCF-7 cells, we concluded that the improved apoptotic effects of higher MTX exposure were raised mainly from the inhibition of BCRP-mediated efflux of MTX. However, the effects of GCV and its derivatives on MTX metabolism and the quantitative expression of MTX metabolizing enzymes in various cancer cells need to be studied more thoroughly in the future. 相似文献
100.
Saad Ahmed Muhammad Ali Yangben Cai Yunhua Lu Zaheer Ahmad Santosh Khannal Shiai Xu 《应用聚合物科学杂志》2019,136(22):47603
In the present study, multi-walled carbon nanotubes (MWCNTs) were sulfonated by 1,3-propane sultone and distillation–precipitation polymerization, respectively, and then incorporated into chitosan (CS) to prepare CS/MWCNTs composite membranes for fuel cell applications. CS/MWCNTs membranes show better thermal and mechanical stability than pure CS membrane due to the strong electrostatic interaction between the SO3H groups of MWCNTs and the NH2 groups of CS, which can restrict the mobility of CS chain. The sulfonated MWCNTs provide efficient proton hopping sites ( SO3H, SO3− …. 3+HN ), thereby resulting in the formation of continuous proton conducting channels. The composite membranes with 5 wt % of MWCNTs modified by two different ways show a proton conductivity of 0.026 and 0.025 S·cm−1, respectively. In conclusion, CS/MWCNTs membrane is a promising proton exchange membrane for fuel-cell applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47603. 相似文献