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1.
2.
本文论述了负硬水只用氯化铵再生时离子交换器的运行过程及离子交换软化除碱的方法,并阐述了控制出水中残留碱的简便方法。经研究证明,此方法可达到除碱度、除硬度、除盐、延长锅炉使用寿命、减少腐蚀、减少排污量、节约燃煤等效果。经济效益十分显著。 相似文献
3.
Characteristics of nitrogen and phosphorus removal in SBR and SBBR with different ammonium loading rates 总被引:2,自引:0,他引:2
Dong-Seog Kim No-Sung Jung Young-Seek Park 《Korean Journal of Chemical Engineering》2008,25(4):793-800
Laboratory scale experiments were conducted to study the deterioration of enhanced biological phosphorus removal (EBPR) due
to influent ammonium concentration, and to compare the performance of two types of sequencing batch reactor (SBR) systems,
a conventional SBR and sequencing batch biofilm reactor (SBBR). Both in SBR and SBBR, the total nitrogen removal efficiency
decreased from 100% to 53% and from 87.5% to 54.4%, respectively, with the increase of influent ammonium concentration from
20 mg/l to 80 mg/l. When the influent ammonium concentration was as low as 20 mg/l (C: N: P=200: 20: 15), denitrifying glycogen-accumulating organisms (DGAOs) were successfully grown and activated by using
glucose as a sole carbon source in a lab-scale anaerobic-oxic-anoxic (A2O) SBR. In the SBR, due to the effect of incomplete denitrification and pH drop, the nitrogen and phosphorus removal efficiency
decreased from 77% to 33.3% when the influent ammonium concentration increased from 20 mg/l to 80 mg/l. However, in the SBBR, simultaneous nitrification/denitrification (SND) occurred, and the nitrification rate in the aerobic
phase did not change remarkably in spite of the increase in influent ammonium concentration. Phosphorus removal was not affected
by the increase of influent ammonium concentration. 相似文献
4.
Large amounts of water containing-ammonium nitrogen(NH4+-N)have attracted increasing attention.Catalytic ozonation technology,involving the generation of hydroxyl radical(OH)with strong oxidation ability,was originally utilized to degrade organic-containing wastewater.In this paper,Ce/MnOx composite metal oxide catalysts prepared with different preparation conditions were used to degrade wastewater containing inorganic pollutant(NH4+-N).The as-prepared catalyst features were characterized using X-ray diffraction(XRD),Brunauer-Emmett-Teller method(BET),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and H2-temperature programmed reduction(H2-TPR)techniques.The results show that the catalyst,prepared by conditions with precipitant Na2CO3 and Ce/Mn molar ratio 1:2 calcined at 400℃for 3 h in pH 11.0,displays the optimal performance,with the removal rate of NH4+-N and selectivity to gaseous nitrogen,88.14 wt%and 53.67 wt%,respectively.The effects of several operating factors including solution pH,initial NH4+-N concentrations and scavengers were evaluated.In addition,XRD patterns of catalyst with the best performance and the comparative study on decontamination of NH4+-N by various processes(O3,catalyst and catalyst/O3)show that the primary metal oxides are CeO2 and MnO2 in Ce/MnOx composite metal oxide catalysts,which have a synergistic effect on the catalytic ozonation of NH4+-N,and the new phase MnO2 plays a great role.After 5 consecutive use cycles,the degradation efficiency is declined slightly,and can still achieve better than 70 wt%over 1 h reaction.Additionally,the application of catalytic ozonation for actual wastewater on the removal rate of NH4+-N was investigated.Possible mechanism and degradation pathway of NH4+-N were also proposed.In a word,the application of CeO2-MnO2 composite metal oxide catalysts in catalytic ozonation can be regarded as an effective,feasible and promising method for the treatment of NH4+-N. 相似文献
5.
Gamal A. M. Hussein 《Powder Technology》1994,80(3):265-270
The thermal decomposition up to 400 °C of ammonium ferric citrate hydrate, of unknown structure and formula weight, was studied by thermogravimetry, differential thermal analysis, infrared (IR) spectroscopy and X-ray diffractometry. The possible identities of the formula weight and the intermediate products of calcination are discussed. The results revealed that the parent material is amorphous and contains two moles of water and two moles of ammonia. Decomposition takes place via six weight-loss processes, three endothermic (90–230 °C) and three exothermic (240–298 °C), leading eventually to the formation of Fe2O3. The intermediate solid products are mainly unstable amorphous oxycarbonates, as indicated by X-ray and IR spectroscopies. The gas-phase decomposition products identified by IR spectroscopy are NH3, CO2, CO, CH3COCH3, CH4 and NH4OH. Surface area measurement and scanning electron microscopy showed that Fe2O3, the final product at 400 °C, hada surface area of 40 m2/g and good crystalline and porous character. 相似文献
6.
探讨了该厂化肥生产中碳铵发青的原因,通过硫化氢含量的测定,分析了系统内外影响因素,提出了解决措施,达到了不停车稳定产品质量的目的。 相似文献
7.
8.
改性硝酸铵的工业制备方法及其性能 总被引:2,自引:0,他引:2
硝酸铵饱和溶液中加入表面活性剂辛基三甲基溴化铵,采用真空膨胀结晶技术工业制备一种新型改性硝酸铵,并介绍其性能特点。 相似文献
9.
还原硅钼酸盐分光光度法测定偏钒酸铵中硅的含量 总被引:1,自引:0,他引:1
李静 《化学工业与工程技术》2002,23(5):47-49
介绍了还原硅钼酸盐分光光度法测定偏钒酸铵中的硅含量 ,讨论了吸收波长、还原剂、酸度及掩蔽剂加入量等因素对测定结果的影响。结果表明 ,还原硅钼酸盐分光光度法测定偏钒酸铵中的硅含量 ,数据准确 相似文献
10.
Comparison of single and coastal superphosphate for subterranean clover on phosphorus leaching soils
Coastal superphosphate, a partially acidulated rock phosphate (PARP), is being considered as an alternative fertilizer to single superphosphate for pastures in high rainfall (> 800 mm annual average) areas of south-western Australia. The effectiveness of single and coastal superphosphate, as P fertilizers, was measured in two field experiments using dry herbage yield of subterranean clover (Trifolium subterraneum). The experiments were started in April 1990 and were terminated at the end of 1993. In the years after P applications, soil samples were collected each January to measure Colwell soil-test P, which was related to plant yields measured later on that year, to provide soil P test calibrations.Relative to freshly-applied single superphosphate, the effectiveness of freshly-applied coastal superphosphate and the residues of previously-applied single and coastal superphosphate were less effective in some years (from 3% as effective to equally effective), and up to 100% more effective in other years. This large range in effectiveness values in different years is attributed to different climatic conditions. Soil P test calibrations were different for soils treated with single or coastal superphosphate. The calibrations were also different for different yield assessments (harvests) in the same year, and in different years. Consequently soil P testing can only provide a very crude estimate of the current P status of the soils. 相似文献