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121.
Andrey S. Yasinskiy Petr V. Polyakov Yan V. Voyshel Tatiana R. Gilmanshina Sai Krishna Padamata 《Journal of Dispersion Science and Technology》2018,39(10):1492-1501
The paper describes the sedimentation behavior of concentrated high-temperature oxide-fluoride slurries with alumina particles volume fraction range 0.24?≤?φ?≤?0.32 at ~700 °C. The behavior is of interest due to perspectives of the non-Newtonian fluids usage in the future aluminium reduction technology. To characterize sedimentation behavior several techniques were used: density analysis, X-Ray diffraction, microphotography and electron scanning microscopy. Sample with ?63?µm dispersed phase as well as smelter-grade alumina which contains particles in a range of 10–150?µm has been examined. It has been found that particle settling occurs with the initial velocity 0.97·10?5 m·s?1 at φ?=?0.24 and gradually reduces reaching zero at φ close to 0.32 which was considered as a maximum packing fraction. MS?1 sedimentation mode has been identified, the type of sedimentation was found to be changed from type 1 to type 3 in the sample with φ?=?0.24. The alumina partial density distribution in suspension as a function of time was determined. Alumina average motion velocity during sedimentation was calculated to be 154·10?3?kg·m?2·s?1 at φ?=?0.24 in the top layer of the sample within the first 150?s of sedimentation. It had been reducing drastically before it reached zero after 300?s. An alumina flow was higher in the top layers. Some of the rheological properties (such as relaxation time, which increased from 7.2·10?3 to 17.7·10?3?s after the increase of φ from 0.24 to 0.28) has been determined. 相似文献
122.
Y. K. Leong Prof. David V. Boger G. B. Christie D. E. Mainwaring 《Rheologica Acta》1993,32(3):277-285
The paper describes how the theology of low concentration brown coal suspensions can be exploited to produce high concentration, low viscosity suspensions which are attractive as a potential coal-water fuel. Brown coal suspensions with solid concentrations approaching those of bituminous black coal have been prepared. The high inherent water content ( 60 wt %) and macroporosity of the brown coal have been reduced by thermal and chemical means. The hydrophobicity of the coal surface has been increased sufficiently to reduce the tendency for swelling and water uptake. This, together with densification, has allowed the solids content to be progressively improved from 30 wt % solids with raw coal to 65 wt% solids with modified coals while maintaining the viscosity of the suspension at a low level. The high solid concentration was achieved without additives. 相似文献
123.
Hiroshi Suzuki Tetsu Itotagawa Yuli Setyo Indartono Hiromoto Usui Norihide Wada 《Rheologica Acta》2006,46(2):287-295
Rheological characteristics of trimethylolethane (TME) clathrate–hydrate slurry treated with drag-reducing surfactants were investigated. Friction coefficients and apparent viscosities were measured when the concentration of TME and its hydrate fraction treated with and without drag-reducing surfactants were changed in several steps. From the results, it is found that the surfactant addition causes effective drag reduction in a pipe flow when the hydrate fraction becomes high, while effective drag reduction disappears in the cases of low hydrate fraction. The results of viscosity measurements indicate that the TME molecules disturb the formation of shear-induced structures (SIS) causing drag reduction phenomena. To investigate this interaction between TME and surfactant micelles, the effect of TME concentration on viscosity and relaxation time of solutions was discussed. From this, it was found out that there exists a critical concentration of TME on the formation of SIS and that it becomes larger as shear rate increases. Thus, we conclude that this interaction between TME and micellar structures causes less drag reduction for the cases of low hydrate fraction, while the drag reduction appears in cases of high hydrate fraction because TME concentration in liquid phase becomes small. 相似文献
124.
前置液是影响固井质量的重要因素之一,对于海水钻井液体系,如何选用前置液是一个新的
课题. 提出了一种适宜于海水钻井液体系的新型前置液,对其在固井过程中的各种性能
进行了室内实验研究,结果表明:新型前置液与海水钻井液、固井水泥浆及盐水等环境流体
有良好的相容性,对井壁具有稳定作用,其中的固体颗粒及表面活性剂有利于冲刷海水钻井
液形成的泥饼. 在此基础上,将新型前置液应用于胜利油田的固井作业,进行现场试验,发
现:应用新型前置液后,环空水泥浆界面清晰,混浆段长度缩短,第2界面的胶结质量有明
显提高. 相似文献
125.
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128.
Mingsong Zhou Silong Wu Zhangjian Sun Dongjie Yang 《Journal of Dispersion Science and Technology》2013,34(12):1646-1655
Five interfacial agents with different hydrophilic groups (DBS, SDS, SO, TX, CTAB) are used as model additives to prepare coal-water slurry (CWS). The effects of different interfacial agents on the rheological properties of CWS are systemically investigated, the microscopic aggregation behavior of coal particles in the suspensions and the zeta potentials in coal-water interface are also studied. Based on the interpretation of the results, the rheological behavior of CWS is greatly influenced by the adsorption pattern of the interfacial agents in coal-water interface. The adsorption patterns of anionic interfacial agents on coal surface are mainly influenced by the combining force between the anionic hydrophilic groups with Ca2+, the stronger combining force with Ca2+ leads to the apparent viscosity increase and heavier pseudo-plastic property of CWS. The adsorption pattern of nonionic interfacial agent on coal surface is seldom influenced by the hydrophilic polyoxyethylene chain, and the addition of nonionic interfacial agent reduces the apparent viscosity of CWS. The adsorption pattern of cationic interfacial agent on coal surface is determined by its cationic head, and the addition of cationic interfacial agent increases the apparent viscosity of CWS. The concluded adsorption models of the interfacial agents with different hydrophilic groups can be guidance for the molecular design of high-performance additives of CWS. 相似文献
129.
Pascal Peu Fabrice Béline José Martinez 《International journal of environmental analytical chemistry》2013,93(13):1017-1022
A simple and sensitive liquid chromatography method designed to determine the volatile fatty acids (VFA) content in pig slurry sample is proposed. The acids are isolated with a cation exchange column for carbohydrates using an isocratic phosphate eluant coupled with an ultraviolet detector in series. Centrifuged and filtered samples can be injected directly into the liquid chromatographic system. The accuracy of this new liquid-chromatographic chain using spiked solutions ranging between 20 and 5000?mg/L of VFA standard solution varied from 87 to 124%. The precision of the new procedure, expressed as variability, was between 9.2 and 0.6% for a spike solution concentration of 20 and 5000?mg/L, respectively. 相似文献
130.
Powder River Basin(PRB)coal,which accounts for over 40%of the coal consumed for power generation in the United States,was investigated for preparation of coal water slurry(CWS).The static stability and rheology of the CWS were characterized as a function of loading.The coal loading was varied from 30%to 50%and both ionic(sodium polystyrene sulphonate(PSS))and nonionic(Triton X-100)surfactants were employed as additives.The addition of PSS to PRB slurries was found to yield poor static stability.On the other hand,Triton X-100 was found to be an effective surfactant,reducing the sedimentation by more than 50%compared to the one without surfactant in 45%CWS.Adding Triton X-100 reduces the viscosity of the CWS for coal loadings of30%and 40%.Although the viscosities for coal loading of 42.5%and 45%are higher when Triton X-100 is added,the static stability is significantly better than for samples without surfactant.The highest coal loading for PRB slurry with acceptable viscosity for pumping is 42.5%. 相似文献