运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可...运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可靠性满意度最大和配置成本最低为目标的模型,将可靠性指标配置到具体的工程技术特征上。并以数控车床电主轴为例,对模型的有效性进行了验证。展开更多
OBJECTIVE:To evaluate the effects of electric acupoint stimulation on gastrointestinal hormones and motility among geriatric postoperative patients with gastrointestinal tumors,and to explore an efficient and noninvas...OBJECTIVE:To evaluate the effects of electric acupoint stimulation on gastrointestinal hormones and motility among geriatric postoperative patients with gastrointestinal tumors,and to explore an efficient and noninvasive method for postoperative recovery of bowel functions.METHODS:Forty patients were randomly and evenly assigned into a regular nursing care group(RNC) and an acupoint electric stimulation group(AES).Patients in the RNC group received regular nursing care and patients in the AES group received regular nursing care plus electric stimulation of acupoints.The serum levels of gastrin(GAS),motilin(MOT),and cholecystokinin(CCK),and an electrogastrogram(EGG) of all the patients were evaluated on the first,third,and fifth day after surgery.The time to first flatus after surgery and the number of patients with side effects such as abdominal pain,abdominal distention,and diarrhea were recorded.RESULTS:There were significant differences between the two groups in GAS,MOT,EGG,time to first flatus,abdominal pain,abdominal distention,and diarrhea(P < 0.05).CONCLUSION:Electric stimulation on acupoints could increase levels of GAS and MOT,promote the recovery of gastrointestinal functions,and decrease complications among postoperative senile patients with gastrointestinal tumors.展开更多
Journal of Materials Sciences & Technology is a monthly journal for the rapid dissemination of new, important results in material and related fields. Submission Electronic files of MS Word and PDF are acceptable. ...Journal of Materials Sciences & Technology is a monthly journal for the rapid dissemination of new, important results in material and related fields. Submission Electronic files of MS Word and PDF are acceptable. Please visit http://www.jmst.org and submit online. Submission of a manuscript must be the original work of the author(s) and has not been published elsewhere or under consideration for another publication, or a substantially similar form in any language.展开更多
Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel...Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel cell(PEMFC),already commercialized by automobile giants.For mass popularization,however,three major criteria must be balanced:performance,durability and cost.The electrocatalysts used in both the anode and cathode are the kernel of PEMFCs,being essential for efficient operation.First in the firing‐line is the oxygen reduction reaction(ORR)at the cathode,which is normally very sluggish:over six orders of magnitude slower than the anode hydrogen oxidation reaction(HOR)[1].Thus,considerable efforts have been made to improve the cathode ORR.Identifying the main active sites is key to the design of optimum materials for enhanced ORR.Considering the complex balance of preparation,performance and cost,the active sites of metal‐nitrogen‐carbon(M‐N‐C)catalysts are particularly promising.Coupled with the single metal atom(SMA)catalysts[2–5],two excellent M‐N‐C catalysts were recently reported[6,7].New insights were thereby gained into the delicate architecture of carbon‐based SMA catalysts for ORR.展开更多
Hydrogen energy is an important energy carrier,which is an ideal choice to meet energy demand and reduce harmful gas emissions.The green recycling of hydrogen energy depends on water electrolysis and hydrogen fuel cel...Hydrogen energy is an important energy carrier,which is an ideal choice to meet energy demand and reduce harmful gas emissions.The green recycling of hydrogen energy depends on water electrolysis and hydrogen fuel cells,which involves hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER).The activity of HER/HOR in alkaline electrolyte,however,exhibits a significantly lower magnitude(2–3 orders)compared to that observed in an acidic medium,which hinders the development of alkaline water electrolysis and alkaline membrane fuel cells.Therefore,comprehending the characteristics of HOR/HER activity in alkaline electrolytes and elucidating its underlyingmechanismis a prerequisite for the designof advanced electrocatalysts.Based on this background,this reviewwill briefly summarize the explanations and controversies about the basic HOR mechanism,including bifunctional mechanismand hydrogen binding energy theory.Moreover,the crucial affecting factors of theHOR kinetics,such as dband center theory,interfacial water recombination,alkali metal cations and electronic effects,are discussed.Thus,based on the above theories,the design principle,catalytic performance,and latest progress ofHOR electrocatalysts are summarized.An outlook and future research perspectives of advanced catalysts for hydrogen energy recycling are addressed.This reviewis helpful to understand the latest development ofHORmechanismand design cost-effective and high-performance HOR electrocatalysts towards the production of clean renewable energies.展开更多
With the first rays of dawn peeking through the rainforest at Shiti Village,Dehong Dai and Jingpo Autonomous Prefecture,Yunnan Province,Xu Xiaolong,a bird-watching guide from the Jingpo ethnic group,led a German bird-...With the first rays of dawn peeking through the rainforest at Shiti Village,Dehong Dai and Jingpo Autonomous Prefecture,Yunnan Province,Xu Xiaolong,a bird-watching guide from the Jingpo ethnic group,led a German bird-watching group into the jungle.His great-grandfather made a living by hunting“weird-looking birds”in the mountains.Today,the birds(Great Hornbill)are attracting tourist dollars from other parts of the world without dodging bullets.In Shiti Village,bird-watchers can enjoy the chirping of Great Hornbills and feel the rumbling in the air as the birds fly past.The village on the Chinese border with Myanmar was formerly poverty-stricken,with an average annual income of barely 2,000 yuan(US$305)per household 10 years ago.Today,the average annual income has grown to 150,000 yuan(US$23,075).It is a shining example of the successful practice of the notion that“lucid waters and lush mountains are invaluable assets.”展开更多
文摘运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可靠性满意度最大和配置成本最低为目标的模型,将可靠性指标配置到具体的工程技术特征上。并以数控车床电主轴为例,对模型的有效性进行了验证。
基金Supported by the National Natural Science Foundation Project of China(Transcutaneous Electrical Acupoint Stimulation Prevents the Deep Vein Thrombosis:the Role of Endothelium Modulation,No.81202750)
文摘OBJECTIVE:To evaluate the effects of electric acupoint stimulation on gastrointestinal hormones and motility among geriatric postoperative patients with gastrointestinal tumors,and to explore an efficient and noninvasive method for postoperative recovery of bowel functions.METHODS:Forty patients were randomly and evenly assigned into a regular nursing care group(RNC) and an acupoint electric stimulation group(AES).Patients in the RNC group received regular nursing care and patients in the AES group received regular nursing care plus electric stimulation of acupoints.The serum levels of gastrin(GAS),motilin(MOT),and cholecystokinin(CCK),and an electrogastrogram(EGG) of all the patients were evaluated on the first,third,and fifth day after surgery.The time to first flatus after surgery and the number of patients with side effects such as abdominal pain,abdominal distention,and diarrhea were recorded.RESULTS:There were significant differences between the two groups in GAS,MOT,EGG,time to first flatus,abdominal pain,abdominal distention,and diarrhea(P < 0.05).CONCLUSION:Electric stimulation on acupoints could increase levels of GAS and MOT,promote the recovery of gastrointestinal functions,and decrease complications among postoperative senile patients with gastrointestinal tumors.
文摘Journal of Materials Sciences & Technology is a monthly journal for the rapid dissemination of new, important results in material and related fields. Submission Electronic files of MS Word and PDF are acceptable. Please visit http://www.jmst.org and submit online. Submission of a manuscript must be the original work of the author(s) and has not been published elsewhere or under consideration for another publication, or a substantially similar form in any language.
基金Support by the Jilin Province/Jilin University co-Construction Project-Funds for New Materials (SXGJSF2017-3, Branch-2/440050316A36)the National Key R&D Program of China (2016YFA0200400)+3 种基金the NSFC (51372095)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT)"Double-First Class" Discipline for Materials Science & Engineeringthe Special Funding for Academic Leaders~~
文摘Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel cell(PEMFC),already commercialized by automobile giants.For mass popularization,however,three major criteria must be balanced:performance,durability and cost.The electrocatalysts used in both the anode and cathode are the kernel of PEMFCs,being essential for efficient operation.First in the firing‐line is the oxygen reduction reaction(ORR)at the cathode,which is normally very sluggish:over six orders of magnitude slower than the anode hydrogen oxidation reaction(HOR)[1].Thus,considerable efforts have been made to improve the cathode ORR.Identifying the main active sites is key to the design of optimum materials for enhanced ORR.Considering the complex balance of preparation,performance and cost,the active sites of metal‐nitrogen‐carbon(M‐N‐C)catalysts are particularly promising.Coupled with the single metal atom(SMA)catalysts[2–5],two excellent M‐N‐C catalysts were recently reported[6,7].New insights were thereby gained into the delicate architecture of carbon‐based SMA catalysts for ORR.
基金supported by the National Natural Science Foundation of China(22234005 and 21974070)the Natural Science Foundation of Jiangsu Province(BK20222015)Young Academic Leaders of the Qing Lan Project of Jiangsu Province(SUJIAOSHIHAN[2022]No.29).
文摘Hydrogen energy is an important energy carrier,which is an ideal choice to meet energy demand and reduce harmful gas emissions.The green recycling of hydrogen energy depends on water electrolysis and hydrogen fuel cells,which involves hydrogen oxidation reaction(HOR)and hydrogen evolution reaction(HER).The activity of HER/HOR in alkaline electrolyte,however,exhibits a significantly lower magnitude(2–3 orders)compared to that observed in an acidic medium,which hinders the development of alkaline water electrolysis and alkaline membrane fuel cells.Therefore,comprehending the characteristics of HOR/HER activity in alkaline electrolytes and elucidating its underlyingmechanismis a prerequisite for the designof advanced electrocatalysts.Based on this background,this reviewwill briefly summarize the explanations and controversies about the basic HOR mechanism,including bifunctional mechanismand hydrogen binding energy theory.Moreover,the crucial affecting factors of theHOR kinetics,such as dband center theory,interfacial water recombination,alkali metal cations and electronic effects,are discussed.Thus,based on the above theories,the design principle,catalytic performance,and latest progress ofHOR electrocatalysts are summarized.An outlook and future research perspectives of advanced catalysts for hydrogen energy recycling are addressed.This reviewis helpful to understand the latest development ofHORmechanismand design cost-effective and high-performance HOR electrocatalysts towards the production of clean renewable energies.
文摘With the first rays of dawn peeking through the rainforest at Shiti Village,Dehong Dai and Jingpo Autonomous Prefecture,Yunnan Province,Xu Xiaolong,a bird-watching guide from the Jingpo ethnic group,led a German bird-watching group into the jungle.His great-grandfather made a living by hunting“weird-looking birds”in the mountains.Today,the birds(Great Hornbill)are attracting tourist dollars from other parts of the world without dodging bullets.In Shiti Village,bird-watchers can enjoy the chirping of Great Hornbills and feel the rumbling in the air as the birds fly past.The village on the Chinese border with Myanmar was formerly poverty-stricken,with an average annual income of barely 2,000 yuan(US$305)per household 10 years ago.Today,the average annual income has grown to 150,000 yuan(US$23,075).It is a shining example of the successful practice of the notion that“lucid waters and lush mountains are invaluable assets.”
