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71.
U. Sridevi Narayan C. Pradhan B.K.B. Rao C.V. Satyanarayana B.S. Rao 《Catalysis Letters》2002,79(1-4):69-73
The alkylation of benzene with isopropyl alcohol was studied in an integral pressure reactor over silicon substituted aluminophosphate molecular sieves, SAPO-5. The influence of various process parameters such as temperature, pressure, time on stream, weight hourly space velocity, and mole ratio of reactants on cumene yield and selectivity were investigated. The activity of SAPO-5 was compared with that of Hbeta for this reaction under similar conditions and in the same reactor. At pressures higher than atmospheric, almost the theoretical maximum yields of cumene were achieved on this SAPO-5. Among the diisopropyl benzenes formed by the alkylation of cumene, the meta-isomer was found to form in a significant amount followed by the para-isomer. The ortho-isomer with relatively high strain energy of 4.26 kcal/mol was almost negligible. The cumene yield goes through a maximum in the temperature range 498-543 K studied. Cumene selectivity was found to decrease at higher temperatures, higher pressures and lower benzene to isopropanol mole ratios. 相似文献
72.
醇溶剂中TS-1催化丙烯环氧化的本征动力学与反应机理研究 总被引:1,自引:0,他引:1
研究了在三种不同醇溶剂(甲醇、异丙醇和仲丁醇)水溶液中TS—l催化丙烯过氧化氢环氧化反应的本征动力学,反应条件为温度30~60℃,丙烯压力0.4-0.6MPa。根据实验现象和各组分在TS-1上的吸附特点建立了该反应的Eley-Rideal机理模型,环氧化反应在吸附态的H2O2分子与游离态的丙烯分子之间进行,表面反应为速度控制步骤。通过实验数据对机理模型进行了参数估值,检验结果表明拟合效果较好,平均偏差在10%以内。最后对过程进行了进一步讨论,为该过程的工业化提供了依据。 相似文献
73.
The quantitative aspects of the role of interfacial mass-transfer and reaction kinetics in ethoxylation of lauryl alcohol were examined in a batch recirculation reactor. The liquid droplets falling through a gas column were obtained by utilizing a recirculation loop and a set of spray nozzles. The CO2/NaOH reaction was employed to characterize the interfacial area. The alkoxylation reaction was studied at temperatures between 124°C and 171°C, at catalyst levels between 0.09 and 0.50 weight percent and at ethylene oxide partial pressures between 68 kPa and 204 kPa. A model was developed which permits the prediction of reactor performance at various operating conditions. The mass-transfer during free fall dominates the interfacial mass-transfer and the contributions during the drop formation and coalescence stages are small. The rate of ethylene oxide (EO) addition to lauryl alcohol was constant during the batch run, indicating similar activity for the unreacted lauryl alcohol and the lauryl alcohol ethoxylated to varying extents. The rate of ethoxylation is first-order in both catalyst and ethylene oxide concentrations. The liquid-phase reaction kinetics and interfacial mass-transfer occur in series, with kinetics dominating the overall ethoxylation rate. As expected, an increasing role of mass transfer is observed at higher temperatures, and/or higher catalyst concentrations where the kinetic rate becomes significantly high. The intrinsic activation energy for the ethoxylation of lauryl alcohol is 55.2 kJ/mole. 相似文献
74.
脂肪醇聚氧乙烯醚的厌氧与好氧生物降解性 总被引:9,自引:0,他引:9
以脂肪醇聚氧乙烯醚(AEO)为目标污染物,在等同条件下做厌氧消化污泥和好氧活性污泥对其生物降解性能的对比实验,得出了同一系列AEO分子中聚氧乙烯基与整个分子的降解难易程度的关系。表明:①污泥会对AEO分子产生吸附一脱附作用而出现假降解率,克服假降解率的干扰是准确测定AEO生物降解性的关键因素;②厌氧和好氧条件下,AEO均可降解,但厌氧降解要稍优于好氧降解;③AEO中聚氧乙烯基的单元数(n)是影响其生物降解的重要因素,相同碳链的直链烷基,生物降解率随n的增加而明显降低。 相似文献
75.
Tsugio Sato Kenji Dosaka Toshiaki Yoshioka Akitsugu Okuwaki Kazuo Torii Yoshiro Onodera 《Journal of the American Ceramic Society》1992,75(3):552-556
Amorphous CeO2 –ZrO2 gels were prepared by coprecipitation in ammonia solutions. The onset of crystallization of the gels, from calcining in air, was 420°C, while 200° to 250°C in the presence of water and organic solvents such as methanol and ethanol. The sintering behaviors of CeO2 –ZrO2 powders were sensitive to the crystallizing conditions, since hard agglomerates formed when the precipitated gels were crystallized by normal calcination in air, whereas soft agglomerates formed when they were crystallized in water or organic solvents. CeO2 –ZrO2 powders crystallized in methanol and water at 250°C were sintered to full theoretical density at 1150° and 1400°C, respectively, whereas that crystallized by calcination in air at 450°C was sintered to only 95.2% of theoretical density, even at 1500°C. 相似文献
76.
Ccile Donze Pavel Korovchenko Pierre Gallezot Michle Besson 《Applied catalysis. B, Environmental》2007,70(1-4):621-629
The synthesis of substituted benzaldehydes, benzoic acids, heterocyclic aromatic aldehydes and acids has been studied via the oxidation of the aromatic alcohols with air under mild pressure (<20 bar) at 100 °C, in the presence of a 1.95 wt.% Pt/C catalyst. The solvent was found to play the most important role in determining the selectivity of the oxidation products. Changing the solvent enabled tuning the reaction either to the aldehyde (pure dioxane), or the carboxylic acid (dioxane/aqueous solution without or with addition of sodium hydroxide). This oxidation method allowed to effectively oxidize many substituted benzylalcohols with various electron-releasing or -attracting groups (NO2, Me, OMe, Cl, Br, OH, phenyl, …) and heterocyclic alcohols including nitrogen and sulphur atoms (2-thiophenemethanol, 2- and 4-pyridine methanol compounds). 相似文献
77.
以两性离子单体二甲氨基丙基丙烯酰胺-1-羧酸(ZM)、木薯淀粉(CSt)和聚乙烯醇(PVA)为主要原料,采用"一锅法",通过冷冻交联制备ZM接枝共聚CSt-PVA互穿网络复合凝胶(ZPG2)。使用FTIR、TGA、POM、SEM-EDS对ZPG2进行了表征,评价了ZPG2对Cu~(2+)的静态吸附效果。结果表明:300℃以下,ZPG2的热稳定性良好;ZM的存在可产生反聚电解质效应和化学配位效应,显著提高凝胶吸附能力;在吸附温度25℃、ZPG20.1 g、Cu~(2+)质量浓度2×10~3 mg/L、溶液体积100 mL时,饱和吸附量为199 mg/g;吸附过程符合Langmuir等温吸附模型和准二级动力学模型。 相似文献
78.
79.
甲磺酸伊马替尼的合成 总被引:3,自引:0,他引:3
以4-甲基-3-硝基苯胺为起始原料,经过缩合、还原、环合等反应制得抗肿瘤药物甲磺酸伊马替尼。并分别讨论了采用无水碳酸钾代替二异丙基乙胺、水合肼和普通催化剂代替铂炭催化剂以及采用异戊醇作为溶剂的优点。最终反应总收率超过50%,用高效液相色谱分析产品纯度在99.5%以上。 相似文献
80.
介绍国内外脂肪醇聚氧乙烯醚(AE)和脂肪醇聚氧乙烯醚硫酸盐(AES)的生产现状及供需情况.2003年全球AE的总产能为391.7万t/a,总产量为155.8万t,总消费量为148.3万t;AES的总产能为377.5万t/a,产量约为300万t,消费量约为90万t.2004年我国AE的产能已超过50万t/a,但产量只有15万t,消费量为30.5万t;AES的总产能为37.95万t/a,产量为14万t,市场需求约10万t.最后补充介绍乙氧基化的技术进展. 相似文献