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81.
东太湖水源水臭氧氧化过程中溴酸盐控制技术 总被引:1,自引:0,他引:1
针对东太湖水中溴离子含量较高,采用臭氧-活性炭工艺很可能会导致出厂水中溴酸盐超标的问题,研究了加氨和高锰酸钾预氧化对东太湖水源水在臭氧氧化中溴酸盐生成的控制作用。结果表明,加氨可以有效抑制溴酸盐的生成,在加氨量低于0.04 mmol/L时,随着加氨量的增加,其抑制效果逐渐增强;当加氨量超过0.04 mmol/L时,加氨对溴酸盐抑制率不再继续增加。当水中溴离子质量浓度为120~260μg/L,p H值为6.8~8.7,水温为8~40℃时,加氨可以有效抑制水中溴酸盐的生成,且对原水水质影响较小。当高锰酸钾投加量低于6μmol/L时,其对溴酸盐的生成具有一定的抑制作用;高猛酸钾投加量高于6μmol/L时,反而会提高溴酸盐的生成量;同时较高的p H值和水温均不利于高锰酸钾对溴酸盐的控制,反而会增加其生成量。通过比较可知,对于东太湖水源水,加氨控制溴酸盐生成的效果比高锰酸钾更稳定和有效,实际生产中可以选用加氨控制臭氧-活性炭工艺中溴酸盐的生成。 相似文献
82.
本文讨论了NSS与DSS和GDSS间的区别,描述了NSS 的一般特征和设计NSS时所应注意的几个关键问题,并对这些问题逐一进行了分析,指出了应采取的措施。 相似文献
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84.
机械活化木薯淀粉氧化产物软化硬水能力的研究 总被引:2,自引:0,他引:2
采用搅拌球磨机对木薯淀粉进行机械活化,以不同活化时间的木薯淀粉为原料,CuSO4为催化剂,H2O2为氧化剂干法制备氧化淀粉,并以钙离子配位能力为评价指标,分别考察羧基含量、pH值、温度、钙离子浓度、配合时间等因素对木薯氧化淀粉软化硬水能力的影响。实验结果表明,机械活化对木薯氧化淀粉软化硬水的能力有显著的影响。由活化60 min的木薯淀粉制得的氧化淀粉当羧基含量为0.49%及0.84%时,在体系pH 10、温度30°C、钙离子浓度4 mmol/L、配合时间20 min的条件下钙离子的配合量分别为106.7 mg/g及136.70 mg/g,而在相同条件下,由原木薯淀粉制得的氧化淀粉当羧基含量为0.49%时,钙离子的配合量仅为48.0 mg/g。 相似文献
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86.
《International Journal of Hydrogen Energy》2019,44(33):18532-18544
This research presents the test results carried out in a diesel engine converted to spark ignition (SI) using gaseous fuels, applying a geometry change of the pistons combustion chamber (GCPCC) to increase the turbulence intensity during the combustion process; with similar compression ratio (CR) of the original diesel engine; the increase in turbulence intensity was planned to rise turbulent flame speed of biogas, to compensate its low laminar flame speed. The research present the test to evaluate the effect of increase turbulence intensity on knocking tendency; using fuel blends of biogas with natural gas, propane and hydrogen; for each fuel blend the maximum output power was measured just into the knocking threshold before and after GCPCC; spark timing (ST) was adjusted for optimum generating efficiency at the knocking threshold. Turbulence intensity with GCPCC was estimated using Fluent 13, with 3D Combustion Fluid Dynamics (CFD) numerical simulations; 12 combustion chamber geometries were simulated in motoring conditions; the selected geometry had the greatest simulated turbulent kinetic energy (TKE) and Reynolds number (Re) during combustion. The increased turbulence intensity was measured indirectly through the periods of combustion duration to mass fraction burn 0–5%, 0–50% and 0–90%; for almost all the fuel blends the increased turbulence intensity of the engine, increased the knocking tendency requiring to reduce the maximum output power to keep engine operation just into the knocking threshold. Biogas was the only fuel without power derating by the conditions of higher pressure and higher turbulence during combustion by GCPCC and improve its generating efficiency. Peak pressure, heat release rate, mean effective pressure and exhaust temperature were lower after GCPCC. Tests results indicated that knocking tendency was increased because of the higher turbulent flame speed; fuel blends with high laminar flame speed and low methane number (MN) had higher knocking tendency and lower output power. 相似文献
87.
《Inorganic chemistry communications》2003,6(6):643-645
The existence of a new compound – gaseous FeF4 – was assumed based on the results of Knudsen effusion mass spectrometry and FTIR spectroscopy. Hyperfluorination was achieved by applying excessive amount of CeF4(s) fluorinating agent in reaction with FeF3(s) at high temperatures (T=930–1050 K). The 758.5 cm−1 vibrational frequency was attributed to the Fe–F stretching mode of argon isolated FeF4 molecules. 相似文献
88.
《Inorganic chemistry communications》2002,5(3):226-229
Four new optically active complexes of the composition LnL3Cl3 (where, L=(S,S)-(+)-2,3-dimethoxyl-N,N′-dimethyl-1,4-diaminobutane, Ln=La3+, Sm3+, Pr3+ and Nd3+) were prepared and characterized on the basis of their chemical analyses, molar conductance, magnetic properties, CD, XPS, visible and IR spectra. It is found that the complexes behave as non-electrolytes in DMSO and in methanol solution and possess the stoichiometric ratio of Ln:C:N:O:Cl =1.1:24.0:6.1:6.0:3.1 which is consistent with the analyses data. The magnetic moments of the complexes show little deviation from the Van Vleck values, indicating that 4f electrons do not participate in bond formation in these chelates. The thermal analysis revealed that all the complexes are anhydrous. Their dominant conformers were determined from CD spectra. A nine-coordinated model was proposed for these complexes. 相似文献
89.
《Inorganic chemistry communications》2002,5(9):671-673
Semiconductor single-crystal ZnS nanowires with diameters 40–80 nm and lengths up to tens of micron, which can bend and wind, have been synthesis by the reaction of Zn2+ with S2− in reverse micelle for the inducing template. The formation mechanism of ZnS nanowires has been studied. The results indicated that the formation of ZnS nanowires probably was via the process of the directional aggregation and orientated growth of the ZnS nanoparticles. 相似文献
90.