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81.
中国氨纶的现状与未来 总被引:3,自引:0,他引:3
简单比较了熔纺及干纺氨纶的优缺点,对国外氨纶的市场情况及国内氨纶的现状及发展情况进行了详细的介绍,并对运作中国氨纶市场提出了建议。 相似文献
82.
K. G. Shkadinskii N. I. Ozerkovskaya S. V. Kostin 《Combustion, Explosion, and Shock Waves》2004,40(3):285-294
The specific features of dynamics of the thermal explosion in systems porous reagent–active gas–solid product under conditions where the heattransfer and masstransfer regions are separated from the ambient medium are considered. In addition to the competition of heat release and heat removal, the process of initiation of exothermal chemical interaction in these systems under normal pressures depends significantly on conditions of filtration transport of the gaseous reagent. The induction and postinduction periods of the thermal explosion are studied. The theoretical analysis of thermalexplosion issues is supplemented by an experimental study of the process for the porous titanium–nitrogen–titanium nitride system. 相似文献
83.
Johannes C. Jansen Marialuigia Macchione Raniero Mendichi Enrico Drioli 《Polymer》2005,46(25):11366-11379
Asymmetric gas separation membranes were prepared by the dry-casting technique from PEEKWC, a modified amorphous glassy poly(ether ether ketone). The phase inversion process and membrane performance were correlated to the properties of the polymer and the casting solution (molar mass, polymer concentration, solution rheology and thermodynamics). It was found that a broad molar mass distribution of the polymer in the casting solution is most favourable for the formation of a highly selective membrane with a dense skin and a porous sub-layer. Thus, membranes with an effective skin thickness of less than 1 μm were obtained, exhibiting a maximum O2/N2 selectivity of 7.2 and a CO2/CH4 selectivity of 39, both significantly higher than in a corresponding thick dense PEEKWC membrane and also comparable to or higher than that of the most commonly used polymers for gas separation membranes. The CO2 and O2 permeance were up to 9.5×10−3 and 1.8×10−3 m3/(m2 h bar) (3.5 and 0.67 GPU), respectively. 相似文献
84.
Gijs Calliauw Véronique Gibon Wim De Greyt Laurence Plees Imogen Foubert Koen Dewettinck 《Journal of the American Oil Chemists' Society》2007,84(9):885-891
Refined palm olein was dry fractionated via three different cooling programs on laboratory-scale fractionation equipment.
The enrichment and depletion of the main triacylglycerols in the liquid and solid phase was plotted as a function of the crystallization
degree of the oil. It was shown that for the given conditions and palm olein composition, the initial crystals mainly consisted
of PPP, diacylglycerols, POP and PLP. At higher crystallization degrees, a sharp viscosity increase in the crystal suspension
was primarily related to an obvious decrease of POP but also of POS in the recovered superolein, while the general crystallization
rate of the system remained unchanged. Rather than a change in crystallization rate of POP, a change in the ratio between
the crystallizing monounsaturated triacylglycerols is linked with the high viscosity of the crystal slurry. For a comparable
degree of crystallization, the superolein of the more viscous crystal slurry, obtained through a membrane press filtration
up to 15 bar, was more unsaturated than the superolein filtered from the less viscous slurry. Consequently, the high unsaturation
in the corresponding soft palm mid fraction is only the result of an incomplete phase separation, and not due to an increased
intersolubility of unsaturated triacylglycerols in the crystals. 相似文献
85.
The effect of miscible low molecular weight additives on the mobility of the carbonate group in bisphenol-A polycarbonate (BPAPC) has been studied using n.m.r. and dielectric relaxation experiments in the solid state. Proton-enhanced dipolar-decoupled carbon-13 n.m.r. spectra of BPAPC, isotopically enriched at the carbonate position, are obtained without magic-angle sample spinning. The resolved chemical shift anisotropy allows study of nuclear spin relaxation for the carbonate groups in the polymer that have different orientations relative to the static magnetic field in the laboratory frame. The spin-lattice relaxation time in the rotating frame (T1?) is measured at a motional-probe frequency of 50 kHz for the undiluted polymer and for BPAPC-diluent blends containing either dibutylphthalate or dinitrobiphenyl. The T1? exhibits some dependence on orientation in all systems studied. In the blend containing dibutylphthalate (DBP), T1? is decreased by a factor of two for all orientations of the carbonate group. This implies that DBP substantially increases the spectral density of 50 kHz motions in the carbonate region of the polymer at ambient temperature. In contrast, dinitrobiphenyl does not significantly alter the Fourier component of thermal fluctuations at 50 kHz. Dielectric relaxation measurements at 10 kHz reveal that the primary (Tg) and secondary (β) motional processes in BPAPC are affected by low molecular weight additives. An intermediate relaxation process appears in the temperature interval between the glass transition temperature (Tg) and the sub-Tg β-relaxation (Tβ) in the polymer-diluent blends. The n.m.r. spin-lattice relaxation rate in the rotating frame, T?11?, correlates well with the relative magnitude of the dielectric dissipation factor (tan δε) between Tg and Tβ. 相似文献
86.
雷学联 《硫磷设计与粉体工程》2005,(3):30-33
磷矿中SiO2与氟的组分往往是不匹配的。分析了n(SiO2)/n(F)偏高或偏低时对湿法磷酸生产的影响,着重讨论了对尾气洗涤系统正常生产的影响,通过对卧式错流洗涤器洗涤液配置等的改进,用硅氟摩尔比偏高的磷矿生产湿法磷酸时,取得了较好的效果。 相似文献
87.
A. A. Bukaemskii N. A. Sosedov L. S. Tarasova 《Combustion, Explosion, and Shock Waves》2005,41(1):97-105
A method is proposed to study the sequence of phase transitions in powdered materials under a shock-wave action. It is shown that the aluminum hydroxide-alumina system has the following sequence of phase transformations under a shock-wave action: bayerite boehmite -Al2O3 -Al2O3. It is found that there are no transitional high-temperature modifications of alumina. A method is developed for obtaining a submicron alumina powder, which allows obtaining materials with a controlled phase composition, including a thermodynamically stable -modification of Al2O3. The specific features of the morphological structure and the phase and structural characteristics of powders after a shock-wave action are considered.Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 1, pp. 110–119, January–February, 2005. 相似文献
88.
焦化废水除氟技术及其应用 总被引:1,自引:0,他引:1
阐述了焦化废水中氟离子的降解机理,分析了化学沉淀法和混凝沉降法等除氟工艺及其处理效果,并对宝钢焦化废水的除氟工艺的进行了评价。 相似文献
89.
90.
Guang Su Huang Xiang Ru He Jing Rong Wu Qi Ying Pan Jing Zhen Zhuo Hong 《应用聚合物科学杂志》2006,102(4):3127-3133
In this study, a kind of novel damping materials was prepared based on the blend of chlorinated butyl rubber (CIIR) and polyacrylate (PAc) synthesized by different molar ratio of butyl methacrylate and ethyl acrylate. Research results from experiments and analyses by employing DMA, TEM, and FTIR show that whether at a cocured system or noncocured system, it can be achieved to shift a loss peak of CIIR towards a higher temperature region and to keep the damping value from markedlly decreasing, which broadens the effective damping function area of CIIR to the vicinity of ambient temperature. In the former system, the thermodynamical miscibility of CIIR and PAc, to some extent, is predominated by the molecular design of PAc, while in the latter system, covulcanized networks play a more significant role in improving compatibility and abating the peak split, though the suppression effect of thermal stress on the transition of CIIR Tll transition still can not be neglected. Furthermore, transition state derived from the cocuring CIIR and PAc cannot make the phase separation completely take place, and consequently results in the deformation of phase morphology of the cocured CIIR/PAc blend. It is the influence of thermodynamics miscibility and forced compatibility in different size that makes the suppression effect of foreign PAc on CIIR Tll transition be controllable. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3127–3133, 2006 相似文献