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101.
Stearoyl chloride was reacted with 3‐(acryloyloxy)‐2‐hydroxypropyl methacrylate (AHM). Then the resulting product (SAHM) was reacted with 3‐amino propyl ethoxysilane (APTES) by Michael addition on the acrylate. The product (SAHMA) is a specialized coupling agent containing an oleophilic 18 carbon alkyl chain, a radically polymerizable methacrylate and an alkoxysilane group capable of coupling to inorganic surfaces, analyzed by FT‐IR, NMR, and UV techniques. Photopolymerization and free radical homo and copolymerization of SAHMA with styrene were examined. SAHMA was coupled to powdered titanium dioxide (P25‐Degussa) and polymerized. TiO2 filled materials were analyzed by SEM, UV and TGA techniques. Glass transiton temperatures (Tg) of the polymers were determined by differential scanning calorimeter (DSC). Interfacial compatibility between SAHMA and TiO2 was demonstrated by FT‐IR spectroscopy. The photocatalytic degradation of the TiO2‐SAHMA polymer films was also investigated under medium pressure mercury lamp illumination in air. SAHMA based film containing 2 wt % TiO2 showed the highest degradation and the highest loss in weight. The weight of the polymer was reduced by 25% of its initial value after irradiation for 40 h. To examine the surface morphology of the irradiated polymer films, SEM analysis was carried out and cavities were detected around TiO2 particles. The photocatalytic and thermomechanical properties of SAHMA and styrene (STY) based copolymers were also investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
102.
N. Seddiki Tarik Ouahrani B. Lasri T. Benouaz A.H. Reshak B. Bouhafs 《Materials Science in Semiconductor Processing》2013,16(6):1454-1465
First principles calculations within the density functional theory framework were carried out to calculate electronic structures and dielectric constant predictions of InGaP2 and InAlP2 compounds. We use three arrangements of these compounds: CuAu-I, CuPt and chalcopyrite ones. Different approximations have been dealt with in order to predict valuable bands gaps energy using DFT calculations. Electronics structure results are promising, due to the good agreement with a number of observable physical-chemistry properties. On the other hand, electron localization function and atom in molecule formalisms have been done to give more insight on the bonding properties. Capabilities that exhibit the InAlP2 in its CuAu-I structure, such as the anisotropy and second harmonic generation, make it promising for an intensive optoelectronic application. 相似文献
103.
Tarik M. Labib S.I. Hawash K.M. El-Khatib Abbas M. Sharaky G.I. El Diwani E. Abdel Kader 《Egyptian Journal of Petroleum》2013,22(1):9-16
Fatty acid methyl ester (biodiesel) has been identified as biodiesel alternative fuel obtained from renewable sources. Efforts in Egypt are directed toward the development of new non-edible sources. At the forefront of these non-edible sources comes Jatropha curcas oil (JCO) because it has been grown successfully in Egypt using primary treated municipal wastewater for irrigation. Based on previous research findings for the production of biodiesel from (JCO) using heterogeneous catalyst, some kinetic data on the transesterification reaction were provided. This was achieved by conducting the reaction at various temperatures, reaction time, and dose of catalyst and reactant molar ratios. The transesterification reaction was observed with regard to the percent biodiesel yield versus time and the reaction order was found to be a first order reaction rate equation. Techno-economic indicators revealed that the price of biodiesel produced by heterogeneous base catalyzed method was $0.665/L with a gross profit per year of $37,403,643. 相似文献
104.
Tarek Y.M.A. El-Hariri Ahmed S. Mousa Tarik F. Moustafa Sherif Farouk 《Egyptian Journal of Petroleum》2012,21(1):71-79
The biostratigraphy, microfacies association, mineralogical interferences, depositional environments and geochemical properties of the Abu Qada Formation, which exposed at Gabal El-Gunna Southeastern Sinai, Egypt were delineated. It belongs to the planktonic foraminiferal Whiteinella archaeocretacea Zone of the Late Cenomanian-Early Turonian and consists of calcareous shale and limestone. The calcareous shale facies is characterized by chlorite, smectite and illite with high concentration of P2O5, Zn, Ni, V, and Cr. The carbonate rocks are characterized by foraminiferal wakestone and bioclastic grainstone. These microfacies associations are characterized by barite with high content of Sr. The facies types with faunal contents, geochemical and mineralogical studies suggest a restricted to shelf lagoon open circulation environment. 相似文献
105.
Maurine Malak Nicolas Pavy Fr��d��ric Marty Elodie Richalot Ai-Qun Liu Tarik Bourouina 《Microsystem Technologies》2011,17(4):543-552
In this paper, we introduce a novel design for high performance silicon-based Fabry?CPérot cavities and their corresponding design model. According to the design model, the new design shows higher stability, lower insertion loss and higher quality factor Q. Our methodology was based, on one hand, on taking advantage of light reflection and refraction over curved surfaces with curvatures along 2 orthogonal directions, in order to confine the Gaussian beam inside the cavity, thus reducing loss due to beam divergence. Such design enables approaching new limits, where Q-factor is mainly governed by the mirrors reflectance. On the other hand, the use of Bragg reflectors, obtained by DRIE etching enables reaching reflectances above 99%, thus enabling very high Q-factors. 相似文献
106.
Flame retardants are a growing area of research interest. Nonhalogenated, durable, and nonleachable flame retardants are one of the main strategies used in the research of flame retardant polymers. In this regard, the covalent attachment of phosphorus-containing flame retardants onto cotton fabric has been developed. Two types of reactive phosphorus-containing flame retardants (MKT-1 and MKT-2) have been synthesized and used as a surface coating for cotton fabric. MKT-1 possesses anhydride and acid functionalities that can react with the OH functionalities in cellulose. In addition, MKT-2 has both acid and organosilicon groups that can also react with the hydroxy group present in cellulose. The structures of the reactive flame retardants (MKT-1 and MKT-2) were characterized using 13C and 31P nuclear magnetic resonance spectroscopy. Thermal properties of the coated and uncoated cotton fabrics were investigated using thermogravimetric analysis. Surface characterization was carried out using scanning electron microscopy and X-ray photoelectron spectroscopy. A standard test method used to evaluate the flammability of blankets (BS 5852) was also applied to characterize the fire retardant properties of the coated and uncoated cotton fabrics studied. Different loadings of MKT-1 and MKT-2 on the fabric (10, 20, and 30% by weight in dimethylformamide solution) were applied in the dip coating process. The cotton fabric coated with 30% MKT-2 does not burn after being subjected to a propane burner for 20 s and also produced the highest char yield (36%) at 500 °C. Inductively coupled plasma–optical emission spectrometry showed that MKT-1 contains 8.23 ± 0.33 P% whereas MKT-2 contains 3.88 ± 0.15 P%. Although MKT-1 possess a higher P content than MKT-2, the additive effect caused by the organosilicon and nitrogen groups present in MK-2 enhance its flame retardant properties. Furthermore, the covalently attached flame retardant materials are durable and do not hydrolyze during washing. The mechanical properties of coated fabrics were characterized by a tensile test and significant change in elongation at break was observed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47935. 相似文献
107.
Tarik Benabdelouahab Riad Balaghi Rachid Hadria Hayat Lionboui Julien Minet Bernard Tychon 《International journal of remote sensing》2013,34(15):4018-4036
Irrigated agriculture is an important strategic sector in arid and semi-arid regions. Given the large spatial coverage of irrigated areas, operational tools based on satellite remote sensing can contribute to their optimal management. The aim of this study was to evaluate the potential of two spectral indices, calculated from SPOT-5 high-resolution visible (HRV) data, to retrieve the surface water content values (from bare soil to completely covered soil) over wheat fields and detect irrigation supplies in an irrigated area. These indices are the normalized difference water index (NDWI) and the moisture stress index (MSI), covering the main growth stages of wheat. These indices were compared to corresponding in situ measurements of soil moisture and vegetation water content in 30 wheat fields in an irrigated area of Morocco, during the 2012–2013 and 2013–2014 cropping seasons. NDWI and MSI were highly correlated with in situ measurements at both the beginning of the growing season (sowing) and at full vegetation cover (grain filling). From sowing to grain filling, the best correlation (R2 = 0.86; p < 0.01) was found for the relationship between NDWI values and observed soil moisture values. These results were validated using a k-fold cross-validation methodology; they indicated that NDWI can be used to estimate and map surface water content changes at the main crop growth stages (from sowing to grain filling). NDWI is an operative index for monitoring irrigation, such as detecting irrigation supplies and mitigating wheat water stress at field and regional levels in semi-arid areas. 相似文献
108.
Safak Dogan Nihan Akin Ceren Baskose Tarik Asar Tofig Memmedli Suleyman Ozcelik 《材料科学与工程:中英文B版...》2013,(8):518-523
Porous silicon layers manufactured by using (100), 1-5 ohm-cm p-type (boron doped) wafer by electrochemical etching in HF etanol solution. Photoluminescence (PL) spectra of anodically etched silicon obtained for different conditions studied and surface characteristics are investigated by AFM. This study gives a simple way to determine specific surface are of porous silicon which plays a major role with porosity for explaining the blue shift in photoluminescence peak. Properties such as specific surface area, pore size, and pore size distribution, the main surface properties of layer are investigated from AFM data which are important material characteristics in many processing applications. The "specific surface area" (Sspecific) generally defined as the area of solid surface per unit mass of material, solid volume or cross section area. From 3-D reconstructions of AFM data, the surface area and the volume of the porous layer can be estimated directly and volume-surface specific area is calculated. For porous silicon this feature can be defined as the total surface area per volume and given by the unit m2/cm3. The method is simple not need to construct a special set up for measurement and non destructive. 相似文献
109.
110.