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排序方式: 共有557条查询结果,搜索用时 31 毫秒
81.
Asiful H. Seikh Hossam Halfa Muneer Baig Sohail M. A. Khan 《Journal of Materials Engineering and Performance》2017,26(4):1589-1597
In this study, two different grades (M23 and M29) of cobalt-free low nickel maraging steel have been produced through electroslag remelting (ESR) process. The corrosion resistance of these ESR steels was investigated in 1 M H2SO4 solution using linear potentiodynamic polarization (LPP) and electrochemical impedance spectroscopy (EIS) techniques. The experiments were performed for different immersion time and solution temperature. To evaluate the corrosion resistance of the ESR steels, some significant characterization parameters from LPP and EIS curves were analyzed and compared with that of conventional C250 maraging steel. Irrespective of measurement techniques used, the results show that the corrosion resistance of the ESR steels was higher than the C250 steel. The microstructure of ESR steels was composed of uniform and well-distributed martensite accompanied with little amount of retained austenite in comparison with C250 steel. 相似文献
82.
Shahid-ul-Islam Luqman Jameel Rather Mohd Shabbir Mohd Nadeem Bukhari Mohd Shahid Mohd Ali Khan 《Journal of Natural Fibers》2017,14(4):586-596
This study was undertaken to propose alternative use for teak leaves, a timber industry byproduct, as potential dyeing source for wool fibers. The coloring potential of anthraquinone colorants from teak leaves were studied on wool with pre-mordanting method using double and triple mix metal salt combinations (ferrous sulphate, stannous chloride and potassium aluminum sulphate) as mordants. Thirty-six sober and elegant shades were developed on wool by varying the type of metal involved in combination as well as concentration of the dye. The hue of color developed ranged from light orange—brown to dark brown. The color strength (K/S) has been found to be very good in dyed woolen yarn samples and particularly was highest for iron + alum combination. Color fastness with respect to light exposure washing, rubbing for the developed shades ranged between good to very good, which confirmed the possibility of using waste leaves of Tectona grandis as a source of effective brown natural dye. 相似文献
83.
An 80:20 polyester/viscose blended woven fabric was subjected to different softening and sanforising treatments. The effect of different softeners and sanforising treatments on the pilling propensity of the fabric was investigated. It was found that, while some types of softeners had no effect on pilling, the others may result in extreme deterioration of the pilling performance of polyester/viscose blended fabrics. It was further found that, in all cases, sanforising after softening adversely affects the fabric pilling performance. 相似文献
84.
Viera Crosignani Sohail Jahid Alexander S. Dvornikov Enrico Gratton 《Microscopy research and technique》2014,77(5):368-373
We describe a novel two‐photon fluorescence microscopy system capable of producing high‐quality second harmonic generation (SHG) images in thick turbid media by using an innovative detection system. This novel detection system is capable of detecting photons from a very large surface area. This system has proven effective in providing images of thick turbid samples, both biological and artificial. Due to its transmission detection geometry, the system is particularly suitable for detecting SHG signals, which are generally forward directed. In this article, we present comparative data acquired simultaneously on the same sample with the forward and epidetection schemes. Microsc. Res. Tech. 77:368–373, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
85.
Single‐cell protein production through microbial conversion of lignocellulosic residue (wheat bran) for animal feed 下载免费PDF全文
Fakhar‐un‐Nisa Yunus Muhammad Nadeem Farzana Rashid 《Journal of the Institute of Brewing》2015,121(4):553-557
Agricultural residue (wheat bran) rich in carbohydrates was utilized in the fermentation process to produce microbial biomass. Single‐cell biomass consists of the dried cells of microorganisms, which are used as protein supplements in human food and in animal feed. In the present study, two different microorganisms (Candida utilis and Rhizopus oligosporus) were studied for biomass production. To enhance the nutritional contents of wheat bran, a number of different fermentation parameters (effect of inoculum size, age of inoculum, incubation period, moisture to substrate ratio and incubation temperature) were optimized. Maximum yield was obtained at an inoculum size of 10% (v/w), with the age of the inoculum being a 48 h old culture. A fermentation period of 48 h was found to give the maximum protein yield and viable counts of yeast cells and mould hyphae. The microorganisms showed good growth at 30 °C. After complete optimization of the fermentation parameters, a batch of wheat bran was fermented with C. utilis and R. oligosporus under the optimized conditions, resulting in a maximum crude protein yield of 41.02% compared with the 4.21% crude protein of the non‐fermented wheat bran. Copyright © 2015 The Institute of Brewing & Distilling 相似文献
86.
Sara Sadiq Muhammad Imran Muhammad Nadeem Hassan Mazhar Iqbal Yusuf Zafar Fauzia Yusuf Hafeez 《LWT》2014
Antimicrobial behavior of lactic acid bacteria (LAB) has been explored since many years to assess their ability to produce bacteriocin, a natural preservative, to increase the shelf life of food. This study aims to characterize bacteriocin producing strains of lactic acid bacteria isolated from acidic to slightly acidic raw vegetables including tomato, bell pepper and green chili and to investigate their potential to inhibit food related bacteria. Among twenty nine LAB screened for antimicrobial activity, three exhibited antagonism against closely related bacterial isolates which was influenced by varying temperature and pH. They were identified up to strain level as Lactococcus lactis subsp. lactis TI-4, L. lactis subsp. lactis CE-2 and L. lactis subsp. lactis PI-2 based on 16S rRNA gene sequence. Their spectrum of inhibition was observed against food associated strains of Bacillus subtilis and Staphylococcus aureus. Moreover, L. lactis subsp. lactis PI-2 selected on the basis of higher antimicrobial activity was further evaluated for bacteriocin production which was detected as nisin A and nisin Z. These findings suggest the possible use of L. lactis strains of vegetable origin as protective cultures in slightly acidic as well as slightly alkaline food by the bio-preservative action of bacteriocins. 相似文献
87.
Yousef A. Al-Salloum Tarek H. Almusallam Saleh H. Alsayed Nadeem A. Siddiqui 《Canadian Metallurgical Quarterly》2011,15(4):522-534
In this paper, the efficiency and effectiveness of carbon-fiber-reinforced polymer (CFRP) sheets for upgrading the shear strength and ductility of a seismically deficient exterior beam-column joint were studied and compared with an American Concrete Institute (ACI)-based design joint specimen. One as-built joint specimen, representing the preseismic code design and construction practice for joints and one ACI-based design joint specimen, satisfying the seismic design requirements of the current code of practice were cast. The as-built specimen was used as baseline (control) specimen. These two specimens (i.e., the as-built control and the ACI-based specimens) were subjected to cyclic lateral load histories to induce damage equivalent to damage expected from a severe earthquake. The damaged control specimen was then repaired by filling its cracks with epoxy and externally bonding CFRP sheets to the joint, the beam, and part of the column regions. This specimen was identified as the repaired specimen. The repaired specimen was subjected to a similar cyclic lateral load history, and its response history was recorded. The response histories of the as-built control, the repaired, and the ACI-based design specimen were then compared. The test results demonstrated that externally bonded CFRP sheets can effectively improve both the shear strength and the deformation capacity of seismically deficient and damaged beam-column joints to a state comparable to the ACI-based design joint. 相似文献
88.
Mohsin Ahmad Khan Nadia Hassan Nadeem Ahmad Muhammad Islam Khan Ahmad Usman Zafar Faidad Khan Tayyab Husnain 《Yeast (Chichester, England)》2014,31(1):13-28
Human interferon α2b (hIFNα2b) is the most important member of the interferon family. Escherichia coli, yeasts, mammalian cell cultures and baculovirus‐infected insect cells have been used for expressing recombinant human interferon. Recently a Pichia pastoris‐based expression system has emerged as an attractive system for producing functional human recombinant IFNα2b. In this regard, gene dosage is considered an important factor in obtaining the optimum expression of recombinant protein, which may vary from one protein to another. In the present study we have shown the effect of IFNα2b gene dosage on extracellular expression of IFNα2b recombinant protein from P. pastoris. Constructs containing from one to five repeats of IFNα2b‐expressing cassettes were created via an in vitro multimerization approach. P. pastoris host strain X‐33 was transformed using these expression cassettes. Groups of P. pastoris clones transformed with different copies of the IFNα2b expression cassette were screened for intrachromosomal integration. The IFNα2b expression level of stable transformants was checked. The copy number of integrated IFNα2b was determined by performing qPCR of genomic DNA of recombinant P. patoris clones. It was observed that an increase in copy number generally had a positive effect on the expression level of IFNα2b protein. Regarding the performance of multicopy strains, those obtained from transformation of multicopy vectors showed relatively high expression, compared to those generated using transformation vector having only one copy of IFNα2b. It was also observed that an increase in drug resistance of a clone did not guarantee its high expression, as integration of a marker gene did not always correlate with integration of the gene of interest. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
89.
Inayat Ali Khan Amin Badshah Muhammad Amtiaz Nadeem Naghma Haider Muhammad Arif Nadeem 《International Journal of Hydrogen Energy》2014
The article describes the conversion of MOF-199 to Cu–Cu2O–CuO/C 700 (1) and Cu–Cu2O–CuO/C 800 (2) nanostructures by simple pyrolysis at 700 and 800 °C under inert atmosphere. The X-ray photoelectron spectroscopy analysis reveals that the nanostructures Cu–Cu2O–CuO/C consist of graphitic carbon functionalized with carboxylic, carbonyl and hydroxyl functional groups with copper/copper oxide particles on surfaces. The electrochemical properties of 1 and 2 are evaluated as electrode material for supercapacitors using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results for the capacitive performance from cyclic voltammetry and galvanostatic charge/discharge reveal that both the samples have gravimetric capacitance greater than 750 F g−1 at a scan rate of 2 mV s−1 and current density of 2 mA cm−2. The samples retain about 43% of their initial capacitance even at high scan rate of 75 mV s−1. The cycling performance of the nanostructures illustrate that there is 5.5% capacitance loss after 3000 cycles. The sample 1 and 2 are washed with 1 mol L−1 HCl solution to obtain copper oxide free materials Cu/C 700 (3) and Cu/C 800 (4). Samples 3 and 4 are tested as electrocatalysts for glucose sensing and the cyclic voltammetry measurement shows enhanced current densities compared to the literature values. 相似文献
90.
Dr. Rhushikesh A. Kulkarni Dr. Nadeem A. Vellore Matthew R. Bliss Dr. Stephanie M. Stanford Matthew D. Falk Prof. Nunzio Bottini Prof. Riccardo Baron Prof. Amy M. Barrios 《Chembiochem : a European journal of chemical biology》2013,14(13):1640-1647
Assay design is an important variable that influences the outcome of an inhibitor screen. Here, we have investigated the hypothesis that protein tyrosine phosphatase inhibitors with improved biological activity could be identified from a screen by using a biologically relevant peptide substrate, rather than traditional phosphotyrosine mimetic substrates. A 2000‐member library of drugs and drug‐like compounds was screened for inhibitors of lymphoid tyrosine phosphatase (LYP) by using both a peptide substrate (Ac‐ARLIEDNE‐pCAP‐TAREG‐NH2, peptide 1) and a small‐molecule phosphotyrosine mimetic substrate (difluoromethyl umbelliferyl phosphate, DiFMUP). The results demonstrate that compounds that inhibited enzyme activity on the peptide substrate had greater biological activity than compounds that only inhibited enzyme activity on DiFMUP. Finally, epigallocatechin‐3,5‐digallate was identified as the most potent inhibitor of lymphoid tyrosine phosphatase activity to date, with an IC50 of 50 nM and significant activity in T‐cells. Molecular docking simulations provided a first model for binding of this potent inhibitor to LYP; this will constitute the platform for ongoing lead optimization efforts. 相似文献