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341.
Hoda Shahiri Tabarestani Mohsen Jahanshahi Ali Motamedzadegan Mohebbat Mohebbi 《International Journal of Food Properties》2016,19(12):2788-2804
Physicochemical and rheological properties of white-cheek shark (Carcharhinus dussumieri) skin gelatin were determined as a function of either an alkaline-acid or an acid pretreatment. With alkaline-acid pretreatment, the purity of white-cheek shark skin gelatin was increased, with a significantly lower extraction yield, a higher retention of high molecular weight components, and greater preservation of the triple helical structure. Moreover, gelatin from alkaline-acid treated skins showed denser spherical structure, significantly (p < 0.05) different textural properties, better thermostability (Tg = 21°C, Tm = 27.5°C), higher values of both G′ and G″, higher gel strength (330 g), more imino acids (20.3%), and lighter colored gels compared with acid treated white-cheek shark skin gelatin. 相似文献
342.
Hassan Rayat AZIMI Mahmood GHORANNEVISS Seyed Mohammad ELAHI Mohammad Reza MAHMOUDIAN Farid JAMALI-SHEINI Ramin YOUSEFI 《材料科学前沿(英文版)》2016,10(4):385-393
ZnS/graphene nanocomposites with different graphene concentrations (5, 10 and 15 wt.%) were synthesized using L-cysteine as surfactant and graphene oxide (GO) powders as graphene source. Excellent performance for nanocomposites to remove methylene blue (MB) dye and hexavalent chromium (Cr(VI)) under visible-light illumination was revealed. TEM images showed that ZnS NPs were decorated on GO sheets and the GO caused a significant decrease in the ZnS diameter size. XRD patterns, XPS and FTIR spectroscopy results indicated that GO sheets changed into reduced graphene oxide (rGO) during the synthesis process. Photocurrent measurements under a visiblelight source indicated a good chemical reaction between ZnS NPs and rGO sheets. 相似文献
343.
Assessment of manufacturing systems reconfiguration smoothness 总被引:1,自引:0,他引:1
Ayman M. A. Youssef Hoda A. ElMaraghy 《The International Journal of Advanced Manufacturing Technology》2006,30(1-2):174-193
The effect of the configuration selection on the smoothness and easiness of manufacturing systems reconfiguration process cannot be neglected, especially when dealing with reconfigurable manufacturing systems (RMS). The term “reconfiguration smoothness” is introduced in this paper to address this issue. In order to evaluate the level of reconfiguration smoothness (RS), a metric was developed to provide a relative measure of the expected cost, time, and effort required to convert from one configuration to another. This metric is composed of three components representing different levels of reconfiguration, namely; market-level reconfiguration smoothness (TRS), system-level reconfiguration smoothness (SRS), and machine-level reconfiguration smoothness (MRS). Rules are introduced to guide the development of execution plans for system-level reconfiguration, which we call “reconfiguration planning”. These plans help reduce the physical effort of reconfiguring the system. A case study is presented to demonstrate the use of the developed metric followed by sensitivity analysis to show the effect of changing different metric parameters. The results show how the developed metric provides a powerful relative assessment tool for the transitional smoothness between a current configuration and a number of candidate feasible configurations for the next period. This can affect the configuration selection decisions at the beginning of each configuration period. 相似文献
344.
Khaled M. Ghanem Samy A. El-Aassar Hoda H. Yusef 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1992,54(2):115-121
Reichstein's compound S was transformed into prednisolone in a single-step fermentation using immobilized mixed cultures, entrapped in different gels or adsorbed on clay particles. Calcium alginate at a gel concentration of 2% gave the highest transformation activities and prednisolone yields. The entrapped mixed cultures could be repeatedly used in batch-wise transformation for at least six times when suspended in diluted nutrient medium and for three times when suspended in distilled water; in the latter case the entrapped cultures required to be reactivated in nutrient medium for further reuse. Mixed cultures adsorbed on clay particles were successfully reused 18 times, with reactivation after the 9th and 15th uses. Continuous transformation of substance S into prednisolone by mixed cultures adsorbed on clay particles was more efficient than batch-wise reused adsorbed cultures and was dependent on the daily working medium volume. 相似文献
345.
An investigation is made of the error due to truncated impulse response for the block mode or sectioning technique. The upper bound on the error in terms of the sectioning parameters is obtained and shown to be independent of block size; this results in a simpler approach to obtaining an optimal sectioning procedure. 相似文献
346.
The possibility of replacement of the high cost sinter manganese ore by manganese rich slag for the production of high carbon ferromanganese was experimentally demonstrated. The experimental heats were designed and carried out to optimize this replacement through the adjustment of different production parameters. The results of pilot plant experimental heats showed that replacement of 50% of the sinter in the blend (or 25% of the blend) by slag containing 32% Mn and operation under slag basicity 0.9 and low (MgO)/(CaO) ratio of about 0.2-0.3 are the optimum conditions to attain the highest manganese content in the produced ferromanganese, the highest manganese recovery and the highest metallic yield. The industrial application of reusing manganese slag clarified the economic efficiency of charging manganese slag up to 20-25% of the blend in reducing the production cost due to reducing the cost of manganese ores. Charging of 20-25% manganese slag reduces the cost of manganese ores and the total production cost by about 13 and 6% respectively, comparing with the conventional technology (without using manganese slag in the blend). 相似文献
347.
Current interactive services for digital TV are limited. They basically display a Web page alongside the TV program, which enhances the viewer's experience by providing extra information about the TV program. We define new interactive services for digital TV, which provide DVD-like interactivity to TV viewers. These services enable viewers to control the content and final presentation of a TV program. Some of the attractive applications of our services include parental management, multilingual audio, multiangle video, video in video, etc. The challenge in implementing these services is in transmitting an extra audio or video stream (called incidental) along with the main streams of the TV program. In the first part of this paper, we present a framework for adding the incidental streams to the original transmission stream without increasing the required bandwidth, degrading the picture quality of the main streams, or violating the compatibility of the transmitted stream with standard TV receivers. In the second part of this paper, we explore the two basic mechanisms of the presented framework: traffic characterization and admission control. We present methods for implementing these mechanisms. Using our methods, one can determine whether a TV transmission network has the capability of sending an incidental stream or not. Simulations were conducted to test the validity of our method. The results verify that our method successfully transmits the incidental streams without any discrepancy and without affecting the quality of the main streams. 相似文献
348.
Hoda S. Ahmed Seham A. Shaban Mohamed F. Menoufy Fathy Y. El Kady 《Egyptian Journal of Petroleum》2013,22(3):367-372
Accelerated deactivation tests of the pre-sulfided Mo–W/SiO2–Al2O3 commercial catalyst were performed using heavy vacuum petroleum feedstock. High reaction temperature employed in the accelerated catalyst aging resulted in large amounts of carbonaceous deposition with high aromaticity, which was found to be the principal deactivation cause. The effect of catalyst deactivation on hydrocracking of vacuum residue was studied. Experiments were carried out in a batch reactor at 60 bar, feed to catalyst ratio 10:1 and temperature 425 °C. The duration time for a cycle-run was 4 h. On increasing the interval duration times from 4 to 20 h (i.e. five cycles), the quality of the hydrocracked products was decreased. In each cycle-run, a fresh feedstock was used with the same sulfide catalyst. The quality of distillate products, such as hydrodesulfurization (HDS) was decreased from 61.50% to 39.52%, while asphaltene contents of the total liquid product were increased from 2.7% to 5.2% and their boiling ranges were increased during these duration times due to the successive catalyst deactivation during the 5 cycle-runs, caused by successive adsorption of coke formation. 相似文献
349.
350.
The paper presents a detailed simulation of a V-shaped micro heat pipe. The effect of the substrate temperature on the model has been considered. A new method for calculating dry-out length has been proposed. The sensitivity of the model to variations in thermophysical properties and design parameters has been studied. The variations in the contact angle for the substrate-coolant liquid system, surface tension and viscosity of the coolant liquid, inclination, groove angle, length of adiabatic section and radius of ungrooved substrate have been considered. The effect of design and operating parameters on the performance of the heat pipe has been studied. The variations in contact angle have been found to significantly affect the performance of a micro heat pipe. The performance of a micro heat pipe is susceptible to ungrooved area of a V-shaped micro heat pipe. If the groove is not sharp enough i.e., the radius of ungrooved substrate is more; the micro heat pipe may cease to work even before it reaches its other operating limits. The various sensitivity studies made in this work gives better understanding of variations in thermophysical properties and design parameters of a micro heat pipe. 相似文献