以离心压缩机变工况性能换算、特性曲线变转速二次拟合、基于BWRS方程的气体物性计算为理论基础,以NetBeans IDE 6.7为开发平台,结合Excel,采用Java语言开发了离心压缩机性能评价软件。软件能够准确计算与压缩机工作过程相关的气体物性...以离心压缩机变工况性能换算、特性曲线变转速二次拟合、基于BWRS方程的气体物性计算为理论基础,以NetBeans IDE 6.7为开发平台,结合Excel,采用Java语言开发了离心压缩机性能评价软件。软件能够准确计算与压缩机工作过程相关的气体物性参数,实现电子图像版压缩机特性曲线的数字化,可对不同入口条件下的特性曲线进行换算及变转速拟合,确定压缩机的流量控制界限。以某天然气长输管道首站的历史运行数据为依据,验证了软件计算结果的准确性。该软件可用于优化压气站运行方案。展开更多
Noble metal-based high-entropy alloy nanoparticles(NM-HEA NPs) have exhibited brilliant catalytic performance toward electrocatalytic energy conversion and attracted increasing attention. The near-equimolar mixed elem...Noble metal-based high-entropy alloy nanoparticles(NM-HEA NPs) have exhibited brilliant catalytic performance toward electrocatalytic energy conversion and attracted increasing attention. The near-equimolar mixed elements of NM-HEA NPs may result in the unique properties including cocktail effect, high entropy effect and lattice distortion effect, which are beneficial for improving the catalytic performance and reducing the amount of noble metal. Herein, several advanced NM-HEA NPs as electrocatalysts for energy conversion are systematically summarized. The preparation methods of NM-HEA NPs are evaluated as well as the catalytic properties and mechanism are discussed classified by electrocatalytic reactions. Finally,the challenges and prospects in this field are carefully discussed. This review provides an overview on recent advances of NM-HEA electrocatalysts for energy conversion and draws more attention in this infant research field.展开更多
以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,...以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,在标准配方条件下,延长聚合反应时间,转化率可以达到70%。转化率为70%时所得SBR与转化率为62%时所得SBR相比,前者的生胶凝胶含量和胶乳黏度均增大了1倍,数均相对分子质量、重均相对分子质量和Z均相对分子质量均高于后者,相对分子质量分布变宽,且前者的生胶结合苯乙烯含量能够达到产品标准,而生胶门尼黏度和在50 m in时的300%定伸应力偏高于产品优级品要求。展开更多
The utilization of urea in camels has beneficial and negative effects. The aims of this study were to investigate the effects of different levels of urea supplementation on nutrients intake, digestibility,growth perfo...The utilization of urea in camels has beneficial and negative effects. The aims of this study were to investigate the effects of different levels of urea supplementation on nutrients intake, digestibility,growth performance, feed efficiency and economics in growing camels fed roughage based complete pellet diets. In the present study, eighteen growing camels with an average live body weight of306.17 ± 2.05 kg were randomly assigned in three treatments: T1 = roughage complete pellet diet without urea,T2 = T1 plus 1% urea,and T3 = T1 plus 2% urea. The results showed that the urea supplementation significantly affected average daily feed and nutrient intake of dry matter(DM), organic matter(OM), crude protein(CP), neutral detergent fiber(NDF), and acid detergent fiber(ADF)(P < 0.05).On the contrary, the average daily intake of nitrogen free extract(NFE) and water were not influenced by increasing urea supplementation(P > 0.05). Similarly, digestion coefficient of DM, CP, ether extract(EE),crude fiber(CF) and ADF was influenced by increasing urea level(P < 0.05), while the digestion coefficient of OM, NFE and NDF was not affected by increasing urea level(P > 0.05). The intake of digestive nutrients was similar among all treatment groups. Total body live weight gain and average daily gain were significantly higher in urea supplemented groups(P < 0.05) than in the control group. The supplementation of urea at 1% in low quality roughage complete pellet diets significantly improved(P < 0.05) the feed efficiency. In conclusion,these results indicated that the incorporation of urea at 1% in roughage based complete pellet diets could positively improve nutrients intake, digestibility, growth performance and feed conversion efficiency of growing camels.展开更多
Climate change caused by the increasing emission of CO_(2)to the atmosphere has become a global concern.To ameliorate this issue,converting CO_(2)into valuable chemicals is highly desirable,enabling a sustainable low-...Climate change caused by the increasing emission of CO_(2)to the atmosphere has become a global concern.To ameliorate this issue,converting CO_(2)into valuable chemicals is highly desirable,enabling a sustainable low-carbon future.To this end,developing efficient catalytic systems for CO_(2)conversion has sparked intense interests from both academia and industry.Taking advantage of their highly porous structures and unique properties,metal−organic frameworks(MOFs)have shown great potential as heterogeneous catalysts for CO_(2)conversion.Various transformations involving CO_(2)have been accomplished over MOFs-based materials.Here we provide a comprehensive and up-to-date review on recent advances of heterogeneous CO_(2)thermocatalysis using MOFs,highlighting relationships between structures and properties.Special attention is given to the design strategies for improving the catalytic performance of MOFs.Avenues available to enrich the catalytic active sites in MOF structures are stressed and their respective impacts on CO_(2)conversion efficiency are presented.The synergistic effects between each active site within the structure of MOFs and derivatives are discussed.In the end,future perspectives and challenges in CO_(2)conversion by heterogeneous catalysis with MOFs are described.展开更多
文摘以离心压缩机变工况性能换算、特性曲线变转速二次拟合、基于BWRS方程的气体物性计算为理论基础,以NetBeans IDE 6.7为开发平台,结合Excel,采用Java语言开发了离心压缩机性能评价软件。软件能够准确计算与压缩机工作过程相关的气体物性参数,实现电子图像版压缩机特性曲线的数字化,可对不同入口条件下的特性曲线进行换算及变转速拟合,确定压缩机的流量控制界限。以某天然气长输管道首站的历史运行数据为依据,验证了软件计算结果的准确性。该软件可用于优化压气站运行方案。
基金financially supported by the National Natural Science Foundation of China(Nos.21706074 and 21972038)the Natural Science Foundation of Henan Province(No.2023000410209)+1 种基金the Key Research and Promotion Project of Henan Province(Nos.202102210261 and 202102310267)the Top-notch Personnel Fund of Henan Agricultural University(No.30500682)。
文摘Noble metal-based high-entropy alloy nanoparticles(NM-HEA NPs) have exhibited brilliant catalytic performance toward electrocatalytic energy conversion and attracted increasing attention. The near-equimolar mixed elements of NM-HEA NPs may result in the unique properties including cocktail effect, high entropy effect and lattice distortion effect, which are beneficial for improving the catalytic performance and reducing the amount of noble metal. Herein, several advanced NM-HEA NPs as electrocatalysts for energy conversion are systematically summarized. The preparation methods of NM-HEA NPs are evaluated as well as the catalytic properties and mechanism are discussed classified by electrocatalytic reactions. Finally,the challenges and prospects in this field are carefully discussed. This review provides an overview on recent advances of NM-HEA electrocatalysts for energy conversion and draws more attention in this infant research field.
文摘以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,在标准配方条件下,延长聚合反应时间,转化率可以达到70%。转化率为70%时所得SBR与转化率为62%时所得SBR相比,前者的生胶凝胶含量和胶乳黏度均增大了1倍,数均相对分子质量、重均相对分子质量和Z均相对分子质量均高于后者,相对分子质量分布变宽,且前者的生胶结合苯乙烯含量能够达到产品标准,而生胶门尼黏度和在50 m in时的300%定伸应力偏高于产品优级品要求。
基金funded by NSFC(3150196431501965+1 种基金31402088)research program of State Key Laboratory of Food Science and Technology,Nanchang University(Project No.SKLF-ZZB-201509)
文摘The utilization of urea in camels has beneficial and negative effects. The aims of this study were to investigate the effects of different levels of urea supplementation on nutrients intake, digestibility,growth performance, feed efficiency and economics in growing camels fed roughage based complete pellet diets. In the present study, eighteen growing camels with an average live body weight of306.17 ± 2.05 kg were randomly assigned in three treatments: T1 = roughage complete pellet diet without urea,T2 = T1 plus 1% urea,and T3 = T1 plus 2% urea. The results showed that the urea supplementation significantly affected average daily feed and nutrient intake of dry matter(DM), organic matter(OM), crude protein(CP), neutral detergent fiber(NDF), and acid detergent fiber(ADF)(P < 0.05).On the contrary, the average daily intake of nitrogen free extract(NFE) and water were not influenced by increasing urea supplementation(P > 0.05). Similarly, digestion coefficient of DM, CP, ether extract(EE),crude fiber(CF) and ADF was influenced by increasing urea level(P < 0.05), while the digestion coefficient of OM, NFE and NDF was not affected by increasing urea level(P > 0.05). The intake of digestive nutrients was similar among all treatment groups. Total body live weight gain and average daily gain were significantly higher in urea supplemented groups(P < 0.05) than in the control group. The supplementation of urea at 1% in low quality roughage complete pellet diets significantly improved(P < 0.05) the feed efficiency. In conclusion,these results indicated that the incorporation of urea at 1% in roughage based complete pellet diets could positively improve nutrients intake, digestibility, growth performance and feed conversion efficiency of growing camels.
文摘Climate change caused by the increasing emission of CO_(2)to the atmosphere has become a global concern.To ameliorate this issue,converting CO_(2)into valuable chemicals is highly desirable,enabling a sustainable low-carbon future.To this end,developing efficient catalytic systems for CO_(2)conversion has sparked intense interests from both academia and industry.Taking advantage of their highly porous structures and unique properties,metal−organic frameworks(MOFs)have shown great potential as heterogeneous catalysts for CO_(2)conversion.Various transformations involving CO_(2)have been accomplished over MOFs-based materials.Here we provide a comprehensive and up-to-date review on recent advances of heterogeneous CO_(2)thermocatalysis using MOFs,highlighting relationships between structures and properties.Special attention is given to the design strategies for improving the catalytic performance of MOFs.Avenues available to enrich the catalytic active sites in MOF structures are stressed and their respective impacts on CO_(2)conversion efficiency are presented.The synergistic effects between each active site within the structure of MOFs and derivatives are discussed.In the end,future perspectives and challenges in CO_(2)conversion by heterogeneous catalysis with MOFs are described.
