Long-term stability test of Mo/HZSM-5-N catalysts（HZSM-5-N stands for nano-sized HZSM-5） in methane dehydroaromatization（MDA）reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 100...Long-term stability test of Mo/HZSM-5-N catalysts（HZSM-5-N stands for nano-sized HZSM-5） in methane dehydroaromatization（MDA）reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 1000 h.During this test,methane conversion ranges from 13% to 16%,and mean yield to aromatics（i.e.benzene and naphthalene） exceeds 10%.N2-physisorption,XRD,NMR and TPO measurements were performed for the used Mo/HZSM-5 catalysts and coke deposition,and the results revealed that the periodic hydrogenation can effectively suppress coke deposition by removing the inert aromatic-type coke,thus ensuring Mo/HZSM-5 partly maintained its activity even in the presence of large amount of coke deposition.The effect of zeolite particle size on the catalytic activity was also explored,and the results showed that the nano-sized zeolite with low diffusion resistance performed better.It is recognized that the size effect was enhanced by reaction time,and it became more remarkable in a long-term MDA reaction even at a low space velocity.展开更多
目的探讨卵巢-附件影像报告和数据系统(Ovarian-Adnexal Reporting and Data System,O-RADS)分类联合超声造影及血清糖类抗原125(carbohydrate antigen 125,CA125)和人附睾分泌蛋白4(human epididymis protein 4,HE4)在诊断绝经后卵巢...目的探讨卵巢-附件影像报告和数据系统(Ovarian-Adnexal Reporting and Data System,O-RADS)分类联合超声造影及血清糖类抗原125(carbohydrate antigen 125,CA125)和人附睾分泌蛋白4(human epididymis protein 4,HE4)在诊断绝经后卵巢肿物中的应用价值。方法回顾性分析2021年1月至2022年3月在本院收治并经病理证实的76例绝经后妇女卵巢肿物患者。患者术前均行常规超声、超声造影及血清CA125和HE4检查,以病理诊断为金标准,采用受试者工作特征(receiver operating characteristic,ROC)曲线分析常规超声O-RADS分类联合超声造影及血清CA125和HE4指标对绝经后卵巢肿物的诊断价值。结果76例绝经后卵巢肿物病理诊断良性55例,恶性21例。超声O-RADS分类诊断敏感度、特异度和准确度分别为71.4%、76.4%和75.0%。超声造影显示,卵巢恶性肿物始增时间和达峰时间均低于良性肿物,峰值强度高于良性肿物(均P<0.05)。超声O-RADS分类、超声造影联合血清CA125和HE4检测诊断卵巢良恶性肿物的敏感度、特异度、准确度和曲线下面积(area the under curve,AUC)分别为85.7%、92.7%、90.8%和0.892,高于单一检测技术(均P<0.05)。结论超声O-RADS分类、超声造影联合血清CA125和HE4检测可提高绝经后卵巢肿物的诊断效能。展开更多
Using scientific metrological method,this paper analyzed all literature published by top 4 marketing periodicals( JCR,JM,JMR,and MS) in 2009- 2013. It is intended to find out hot issues and frontier topics of current ...Using scientific metrological method,this paper analyzed all literature published by top 4 marketing periodicals( JCR,JM,JMR,and MS) in 2009- 2013. It is intended to find out hot issues and frontier topics of current marketing research through cluster analysis of key words,get to know cooperation and exchange of organizations through analysis of organization cooperative network,explore new topics of marketing researches with the aid of analysis of abrupt change words,and explore evolution path and development rules of marketing researches through co-citation network analysis.展开更多
The present paper deals with the existence of periodic orbits in the Circular Restricted Four-Body Problem (CR4BP) in two-dimensional co-ordinate system when the second primary is a triaxial rigid body and the third p...The present paper deals with the existence of periodic orbits in the Circular Restricted Four-Body Problem (CR4BP) in two-dimensional co-ordinate system when the second primary is a triaxial rigid body and the third primary of inferior mass (in comparison of the other primaries) is placed at triangular libration point L4 of the Circular Restricted Three-Body Problem (CR3BP). With the help of generating solutions, we formed a basis for the existence of periodic orbits, then an analytical approach given by Hassan et al. [1], was applied to our model of equilateral triangular configuration. It is found that in general solution also;the character of periodic orbits is conserved. For verification of the existence of periodic orbits, we have applied the criterion of Duboshin [2] and found satisfied.展开更多
Mr. Chairman, Distinguished Members of the Committee, First of all, I would like to extend, on behalf of the Chinese delegation, our greetings and respects to all the distinguished members of the Committee. The Commit...Mr. Chairman, Distinguished Members of the Committee, First of all, I would like to extend, on behalf of the Chinese delegation, our greetings and respects to all the distinguished members of the Committee. The Committee has made enormous efforts and played an important role in promoting the purposes and principles of the Convention and reinforcing the global efforts to ban and prevent torture. The Chinese Government appreciates your endeavor and will continue to support the work of the Committee.展开更多
This qualitative research study attempts to discover the real thinking process of learners who are native Chinese speakers in Academic English Writing(AEW)through interviews.Introspecting an EFL learner’s thinking pr...This qualitative research study attempts to discover the real thinking process of learners who are native Chinese speakers in Academic English Writing(AEW)through interviews.Introspecting an EFL learner’s thinking process in English writing is based on two theories:critical period hypothesis and translanguaging.The results of the study indicate that translanguaging has a positive impact on the English CET-4 writing of learners who lack proficiency in English.For those learners who lack proficiency in the second language,translanguaging is an effective auxiliary tool for them to complete AEW.展开更多
基金financially supported by the"Strategic Priority Research Program"of Chinese Academy of Sciences(No.XDA09030101)the National Natural Science Foundation of China(No.21103181 and 21473185)+1 种基金DICP Fundamental Research Program for Clean Energy(DICP M201301)Shaanxi Yanchang Petroleum Group Co.Ltd
文摘Long-term stability test of Mo/HZSM-5-N catalysts（HZSM-5-N stands for nano-sized HZSM-5） in methane dehydroaromatization（MDA）reaction has been performed with periodic CH4-H2 switch at 1033-1073 K for more than 1000 h.During this test,methane conversion ranges from 13% to 16%,and mean yield to aromatics（i.e.benzene and naphthalene） exceeds 10%.N2-physisorption,XRD,NMR and TPO measurements were performed for the used Mo/HZSM-5 catalysts and coke deposition,and the results revealed that the periodic hydrogenation can effectively suppress coke deposition by removing the inert aromatic-type coke,thus ensuring Mo/HZSM-5 partly maintained its activity even in the presence of large amount of coke deposition.The effect of zeolite particle size on the catalytic activity was also explored,and the results showed that the nano-sized zeolite with low diffusion resistance performed better.It is recognized that the size effect was enhanced by reaction time,and it became more remarkable in a long-term MDA reaction even at a low space velocity.
文摘目的探讨卵巢-附件影像报告和数据系统(Ovarian-Adnexal Reporting and Data System,O-RADS)分类联合超声造影及血清糖类抗原125(carbohydrate antigen 125,CA125)和人附睾分泌蛋白4(human epididymis protein 4,HE4)在诊断绝经后卵巢肿物中的应用价值。方法回顾性分析2021年1月至2022年3月在本院收治并经病理证实的76例绝经后妇女卵巢肿物患者。患者术前均行常规超声、超声造影及血清CA125和HE4检查,以病理诊断为金标准,采用受试者工作特征(receiver operating characteristic,ROC)曲线分析常规超声O-RADS分类联合超声造影及血清CA125和HE4指标对绝经后卵巢肿物的诊断价值。结果76例绝经后卵巢肿物病理诊断良性55例,恶性21例。超声O-RADS分类诊断敏感度、特异度和准确度分别为71.4%、76.4%和75.0%。超声造影显示,卵巢恶性肿物始增时间和达峰时间均低于良性肿物,峰值强度高于良性肿物(均P<0.05)。超声O-RADS分类、超声造影联合血清CA125和HE4检测诊断卵巢良恶性肿物的敏感度、特异度、准确度和曲线下面积(area the under curve,AUC)分别为85.7%、92.7%、90.8%和0.892,高于单一检测技术(均P<0.05)。结论超声O-RADS分类、超声造影联合血清CA125和HE4检测可提高绝经后卵巢肿物的诊断效能。
基金Supported by Project of National Natural Science Foundation(71273102)Fundamental Research Funds for the Central Universities(2012RW004)
文摘Using scientific metrological method,this paper analyzed all literature published by top 4 marketing periodicals( JCR,JM,JMR,and MS) in 2009- 2013. It is intended to find out hot issues and frontier topics of current marketing research through cluster analysis of key words,get to know cooperation and exchange of organizations through analysis of organization cooperative network,explore new topics of marketing researches with the aid of analysis of abrupt change words,and explore evolution path and development rules of marketing researches through co-citation network analysis.
文摘The present paper deals with the existence of periodic orbits in the Circular Restricted Four-Body Problem (CR4BP) in two-dimensional co-ordinate system when the second primary is a triaxial rigid body and the third primary of inferior mass (in comparison of the other primaries) is placed at triangular libration point L4 of the Circular Restricted Three-Body Problem (CR3BP). With the help of generating solutions, we formed a basis for the existence of periodic orbits, then an analytical approach given by Hassan et al. [1], was applied to our model of equilateral triangular configuration. It is found that in general solution also;the character of periodic orbits is conserved. For verification of the existence of periodic orbits, we have applied the criterion of Duboshin [2] and found satisfied.
文摘Mr. Chairman, Distinguished Members of the Committee, First of all, I would like to extend, on behalf of the Chinese delegation, our greetings and respects to all the distinguished members of the Committee. The Committee has made enormous efforts and played an important role in promoting the purposes and principles of the Convention and reinforcing the global efforts to ban and prevent torture. The Chinese Government appreciates your endeavor and will continue to support the work of the Committee.
文摘This qualitative research study attempts to discover the real thinking process of learners who are native Chinese speakers in Academic English Writing(AEW)through interviews.Introspecting an EFL learner’s thinking process in English writing is based on two theories:critical period hypothesis and translanguaging.The results of the study indicate that translanguaging has a positive impact on the English CET-4 writing of learners who lack proficiency in English.For those learners who lack proficiency in the second language,translanguaging is an effective auxiliary tool for them to complete AEW.
