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排序方式: 共有73条查询结果,搜索用时 171 毫秒
1.
分析了典型二次含砷物料化学成分特点,概括了当前有色冶炼工业中产生的二次含砷物料碱法脱砷工艺及原理,主要包括湿法脱砷工艺和火法—湿法联合脱砷工艺。其中,碱法脱砷工艺常用NaOH单碱浸出、NaOH-Na_2S混合碱浸出和NaOH+Na_2S混合碱两段浸出三种体系,并采用双氧水、加压、曝气、微波、球磨等氧化手段强化砷的浸出;火法—湿法联合脱砷工艺主要有低温碱性熔炼—水浸、焙烧预氧化—碱性浸出以及低温碱性焙烧—热水浸出工艺,低温碱性焙烧—热水浸出工艺选择性脱砷效果好,物料普适性广。最后,结合现有研究指出了碱法脱砷工艺存在的问题及二次含砷物料无害化、资源化研究方向。  相似文献   
2.
以碘吸附值为评价指标,活化时间、活化温度和浸渍比为影响因素,采用响应面法试验设计对磷酸活化法制备咖啡渣活性炭的工艺条件进行优化,并通过静态吸附试验研究了不同吸附时间、溶液pH值和吸附温度条件下,活性炭对水溶液中Cr(Ⅵ)吸附性能的影响,最后利用Langmuir、Freundlich吸附等温方程、准一级动力学方程、准二级动力学方程和颗粒内部扩散方程进行拟合。试验结果表明,制备咖啡渣活性炭的最佳工艺条件为活化时间1 h、活化温度498℃、浸渍比1.72;在此条件下活性炭得率为30.4%,碘吸附值为(799±16)mg/g,比表面积为1 006 m2/g,孔容为0.779 cm3/g、微孔孔容为0.051 cm3/g、平均孔径为3.088 nm。较低pH值和较高温度能够促进活性炭对Cr(Ⅵ)的吸附;Langmuir等温方程能够更好地描述活性炭对Cr(Ⅵ)的吸附效果;活性炭对Cr(Ⅵ)的吸附分3个阶段:快速吸附阶段、慢速吸附阶段和吸附平衡阶段,10 min内可完成吸附总量的79%,360 min内达到吸附平衡,该吸附过程符合准二级吸附动力学方程。分析表明咖啡渣活性炭对Cr(Ⅵ)的吸附主要为单分子层的化学吸附。  相似文献   
3.
根据自动化生产线分拣站的工艺流程和自动化控制的要求,提出基于工业机器人、PLC以及传送带的货物码垛自动化解决方案。构建以三菱FX3U型PLC、传送带和工业机器人等组成的全自动分拣码垛系统。分析了PLC的动作过程,提供了PLC的程序流程图;分析了工业机器人码垛的工作过程,提供了工业机器人码垛的程序流程图。工业机器人引入到自动化生产系统后,能够进一步提高工厂自动化水平、提高生产效率,减小劳动强度,降低人工成本。  相似文献   
4.
This study was carried out to develop a carbamide-based dithiocarbamate (CDTC) chelator for the removal of heavy metal ions from wastewater. Its structural properties were characterized by FT-IR, 1H NMR and 13C NMR. Results confirmed the functional groups of HNC(S)S existed. The adsorption isotherms showed CDTC had a high adsorption capability for Zn (119.8 mg/g) and Cu (63.1 mg/g). It exhibited a distinctive selectivity for the removal of metal ions (Cu2+ > Zn2+ > Cr3+ > Pb2+ > Cd2+) as they coexisted. The influence of initial pH of wastewater for the removal efficiency of metal ions was also investigated and a pH > 7 was preferred.  相似文献   
5.
Two-dimensional molybdenum carbide (2D-Mo2C) is thought to be promising for catalytic hydrogenation of CO2 to CH4, but little is known about its catalytic reaction mechanism. In this work, we investigate the hydrogenation of CO2 to CH4 on 2D-Mo2C using density functional theory. Our calculations show that Mo on the surface can efficiently decompose CO2 to CO and O, and also H2 to H. The hydrogenation of CO produces CHO that is readily deoxygenated to CH, and CH is selectively hydrogenated to produce CH4. Interestingly, the embedded Ir1 on 2D-Mo2C can act as a single-atom promoter to improve the performance of CO2 methanation, while on the other hand maintaining its high selectivity for CH4. This work provides insight into the mechanism of 2D-Mo2C-catalyzed CO2 methanation reactions and suggests a strategy to improve the performance of such catalysts through single-atom promoters.  相似文献   
6.
In this study of the transfer function of copies of the Vienna-type differential mobility analyser (DMA) it was found that three, supposedly identical, DMAs exhibited distinct differences with respect to the width of the transfer function. This means that the transfer function of a DMA needs to be determined on an individual basis in order to obtain accurate results from DMA measurements. The size dependence of the transfer function width and the penetration of three DMAs were investigated experimentally in a broad range of Peclet numbers (400–400 000). Two of the three DMAs exhibited transfer function widths in excess of the broadening induced by diffusion. The size dependence of the width of all three DMAs could be explained within a few percents by assuming an instrument-specific, size-independent broadening in addition to diffusion broadening. The penetration was evaluated by relating to deposition in a circular tube. Excellent agreement between the experimental data and the simple model was obtained. The penetration study was extended to include literature data, showing that the simple model could be applied and that there are distinct differences between different DMA types. The results of this study indicate that the size dependence of the width of the transfer function and the penetration can be estimated by measuring the transfer function for a single particle size, thus greatly reducing the amount of work required by DMA users to characterise their instruments.  相似文献   
7.
利用双水相系统同时分离火龙果皮中的天然红色素和果胶,提高火龙果皮资源的利用。以火龙果皮为原料,采用PEG/硫酸铵双水相体系分离火龙果皮中的色素和果胶。分析PEG相对分子质量、PEG质量分数、体系pH、硫酸盐质量分数4个因素对色素与果胶分离的影响。结果表明,随着双水相PEG和盐的质量分数增加,火龙果皮中的色素和果胶得率随之增加;当相比接近0.5时,上相中色素和下相中果胶获得较佳的分离。最佳的双水相分离条件为:利用质量分数16%的PEG6000,质量分数19%硫酸铵双水相体系,pH4.0,在此条件下,富集在上相的红色素和下相的果胶得率分别为1.82%±0.04%、3.68%±0.13%。因而,采用双水相萃取技术不仅可以同时分离火龙果皮中色素和果胶,还具有萃取条件温和、工艺简单、得率高的优点,本研究为火龙果皮的综合利用和开发提供了实验依据。  相似文献   
8.
《Ceramics International》2017,43(3):2956-2961
Ternary metal oxides have great potential for chemical storage devices because of their outstanding synergistic effects as well as rich redox reactions. However, there are limited reports of 3D structure BiCoO3 materials and relevant electrochemical properties. Meanwhile, the study of BiCoO3 is reasonably important for underlying metal oxides researches. In this work, we have successfully developed a 3D urchin-like BiCoO3 material without using any template and surfactant. For the supercapacitor application, the BiCoO3 material showed a specific capacitance of 152 F g−1 at the current density of 1 A g −1, and this value exhibited a rate capability of 82.3% at a high current density of 10 A g −1. Furthermore, the sample showed the ideal cycling stability (92.7% retention after 5000 times cycles at the current density of 1 A g −1 and nearly invariable specific capacitance during different current density cycles). These results suggest that the obtained urchin-like BiCoO3 sample has superb electrochemical performances which suggest its promising applications as renewable and clean energy storage devices electrode materials in the future.  相似文献   
9.
《Ceramics International》2016,42(10):11757-11765
The effects of NiO powder morphology and sintering temperature on the microstructure and the electrochemical performance of Nickel-scandia-stabilized zirconia (Ni-ScSZ) cermet anodes for solid oxide fuel cells (SOFCs) were investigated. The particle size and agglomeration of the starting powders were found to affect both the microstructure and electrochemical performance of the Ni-ScSZ cermet anodes. The lowest polarization resistance, 0.690 Ω cm2 at 700 °C, was measured for the Ni-ScSZ anode prepared with fine NiO powder (~0.5 µm grain size). This was attributed to the increase in the number of reaction sites afforded by the small grains and well-dispersed Ni and ScSZ phases. The effect of the anode sintering temperature was also found to affect the anode microstructure, adhesion with the electrolyte, and consequently anode polarization resistance. The lowest polarization resistance was observed for the anode sintered at 1400 °C and this was 3–5 times lower than the corresponding values for anodes sintered at lower temperatures.  相似文献   
10.
5G定制专网建设是5G网络发展的关键、是5G业务增长的核心,5G定制专网在各类园区(工厂、办公园区、港口、校园、医院)的部署应用,可提供可靠网络、数据安全、云网协同等服务,满足智慧工厂、智慧园区、智慧交通和智慧校园等的定制化网络服务需求。分析各类园区不同行业的5G定制专网部署需求、部署模式,分析并提出所面临的挑战,望为5G定制专网的应用提供参考。  相似文献   
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