Developing cost-effective and high-performance catalyst systems for dry reforming of methane(DRM)is crucial for producing hydrogen(H_(2))sustainably.Herein,we investigate using iron(Fe)as a promoter and major alumina ...Developing cost-effective and high-performance catalyst systems for dry reforming of methane(DRM)is crucial for producing hydrogen(H_(2))sustainably.Herein,we investigate using iron(Fe)as a promoter and major alumina support in Ni-based catalysts to improve their DRM performance.The addition of iron as a promotor was found to add reducible iron species along with reducible NiO species,enhance the basicity and induce the deposition of oxidizable carbon.By incorporating 1 wt.%Fe into a 5Ni/10ZrAl catalyst,a higher CO_(2) interaction and formation of reducible"NiO-species having strong interaction with support"was observed,which led to an∼80%H_(2) yield in 420 min of Time on Stream(TOS).Further increasing the Fe content to 2 wt.%led to the formation of additional reducible iron oxide species and a noticeable rise in H_(2) yield up to 84%.Despite the severe weight loss on Fe-promoted catalysts,high H_(2) yield was maintained due to the proper balance between the rate of CH_(4) decomposition and the rate of carbon deposit diffusion.Finally,incorporating 3 wt.%Fe into the 5Ni/10ZrAl catalyst resulted in the highest CO_(2) interaction,wide presence of reducible NiO-species,minimumgraphitic deposit and an 87%H_(2) yield.Our findings suggest that ironpromoted zirconia-alumina-supported Ni catalysts can be a cheap and excellent catalytic system for H_(2) production via DRM.展开更多
Storage of hydrogen in solid-state materials offers a safer and compacter way compared to compressed and liquid hydrogen.Vanadium(V)-based alloys attract wide attention,owing to the total hydrogen storage capacity of ...Storage of hydrogen in solid-state materials offers a safer and compacter way compared to compressed and liquid hydrogen.Vanadium(V)-based alloys attract wide attention,owing to the total hydrogen storage capacity of 3.8 wt% and reversible capacity above 2.0 wt%at ambient conditions,surpassing the AB_(5)-,AB_(2)-and ABtype hydrogen storage alloys.However,several challenges,such as insufficient capacity,cyclic stability and high raw material costs,hinder the practical applications of V-based alloys.This review provides an overview of the recent advances in hydrogen storage properties of V-based alloys.The mechanism and optimization strategies of hydrogen storage properties and cyclic stability are discussed in detail,and furthermore,the approaches to reduce manufacturing costs are compared comprehensively.展开更多
The external use of drugs is a simple,ef-fective,sate and cheap means of treatmentof T.C.M..The following is an introductionto the method.1.Conduction through channels andcollaterals (经络传导):Channels andcollaterals...The external use of drugs is a simple,ef-fective,sate and cheap means of treatmentof T.C.M..The following is an introductionto the method.1.Conduction through channels andcollaterals (经络传导):Channels andcollaterals are important parts of the humanbody.This special system is connected to theskin,muscles and tendons superficially展开更多
Londoners are great readers. They buy vast numbers of newspapers and magazines and even of books--especially paper-backs, whick are still comparatively cheap in spite of ever-increasing rises in the costs of printing....Londoners are great readers. They buy vast numbers of newspapers and magazines and even of books--especially paper-backs, whick are still comparatively cheap in spite of ever-increasing rises in the costs of printing. They still continue to buy’proper’books, too. printed on good paper and bound between hardcovers. There are many streets in London containing shops which展开更多
朋友对我讲了这么一件事:一次,在同外商谈生意时,翻译把'我们的产品物美价廉。'译成'Our products are of good quality and cheap.'当时外商就迷惑不解:good quality 的产品,怎么又 cheap 了呢?随之而来的便是一番解释...朋友对我讲了这么一件事:一次,在同外商谈生意时,翻译把'我们的产品物美价廉。'译成'Our products are of good quality and cheap.'当时外商就迷惑不解:good quality 的产品,怎么又 cheap 了呢?随之而来的便是一番解释,直到外商看见了产品,又得到了报价,这才放下心来。问题出在哪里?原来,cheap 不光指价格低廉,它还有其它的意思。先请看例句:Her socks looked cheap and nasty.她的袜子价廉质劣。展开更多
The circular economy is an advocate of harmony with the Earth＇ s natural resources and environment, mutual interdependence of social and economic development model, it requires economic production systems within and ...The circular economy is an advocate of harmony with the Earth＇ s natural resources and environment, mutual interdependence of social and economic development model, it requires economic production systems within and between different production departments and interconnected way matter and energy exchange and transfer, to achieve maximum utilization of material and energy into the system, resulting in ＂two low and one high＂ approach to development in harmony with the natural environment. And it has become a mainstream trend since the 1990s and social development of the countries in the world One.展开更多
The world is at a critical state of limited resources,growing population,and increasing hazard potential.In the near future,geoscientists will be sought to solve these worldwide woes or face the consequences of a dema...The world is at a critical state of limited resources,growing population,and increasing hazard potential.In the near future,geoscientists will be sought to solve these worldwide woes or face the consequences of a demanding public.Cheap,innovative technology and collaboration among several disciplines are needed to proceed forward and solve the difficult questions that humanity as a whole faces.Years of advances and dilemmas in earthquake prediction highlight a theme that stretches through all of geoscience and society:the need for quick solutions to pressing global concerns.展开更多
INSPIRED by the Belt and Road Initiative,China＇s four-year-old blueprint for multinational trade and economic development, the China Trade Week （CTW）, is making its mark in Africa. Besides dispelling the misconcept...INSPIRED by the Belt and Road Initiative,China＇s four-year-old blueprint for multinational trade and economic development, the China Trade Week （CTW）, is making its mark in Africa. Besides dispelling the misconception that Chinese manufacturers produce only cheap and low-quality items, the event is also a platform to introduce companies from different provinces in China.展开更多
The development of catalytic carbonylation reactions has increased considerably.Although many reviews/chapters/books on carbonylation reactions have been published,summaries on cheap metal-catalyzed catalytic carbonyl...The development of catalytic carbonylation reactions has increased considerably.Although many reviews/chapters/books on carbonylation reactions have been published,summaries on cheap metal-catalyzed catalytic carbonylation reactions of aryl halides and other chemical bonds with high dissociation energy C–Y(Y=O,N,H)are still very rare.Focusing on green and sustainable chemistry,this review summarizes and discusses the achievements on carbonylative transformations of aryl halides(C(sp^(2))–X)and strong bonds C–Y(Y=O,N,H)based on non-expensive metal catalysts(Co,Mn,Mo,Ni,Fe,Cu),photochemical and electrochemical systems developed in recent decades.展开更多
In Refs.[1] and [2], the superior magnetic properties have been reported for theexpensive synthetic ultra-microcrystalline Fe<sub>73.5</sub>Cu<sub>1</sub>Nb<sub>13</sub>Si<sub>...In Refs.[1] and [2], the superior magnetic properties have been reported for theexpensive synthetic ultra-microcrystalline Fe<sub>73.5</sub>Cu<sub>1</sub>Nb<sub>13</sub>Si<sub>13.5</sub>B<sub>9</sub> and Fe<sub>73.1</sub>Cu<sub>12</sub>Nb<sub>3.2</sub>Si<sub>12.5</sub>B<sub>10</sub>alloys. Partly replacing the expensive Nb by cheap Mo, we developed a new material,which was made into ribbons with the thickness of 28 μm and width of 3.0cm.展开更多
The n-acetoacetyl aromatic amide of complexes of copper (Ⅱ)and their ice nucleation has not yet been published. The reactants of the title complexes are cheap and the synthetic method is simple. A mixture of methanol...The n-acetoacetyl aromatic amide of complexes of copper (Ⅱ)and their ice nucleation has not yet been published. The reactants of the title complexes are cheap and the synthetic method is simple. A mixture of methanol so-展开更多
We consider a finite horizon,zero-sum linear quadratic differential game.The feature of this game is that a weight matrix of the minimiser’s control cost in the cost functional is singular.Due to this singularity,the...We consider a finite horizon,zero-sum linear quadratic differential game.The feature of this game is that a weight matrix of the minimiser’s control cost in the cost functional is singular.Due to this singularity,the game can be solved neither by applying the Isaacs MinMax principle nor using the Bellman–Isaacs equation approach,i.e.this game is singular.Aprevious paper of one of the authors analysed such a game in the case where the cost functional does not contain the minimiser’s control cost at all,i.e.the weight matrix of this cost equals zero.In this case,all coordinates of the minimiser’s control are singular.In the present paper,we study the general case where the weight matrix of the minimiser’s control cost,being singular,is not,in general,zero.This means that only a part of the coordinates of the minimiser’s control is singular,while others are regular.The considered game is treated by a regularisation,i.e.by its approximate conversion to an auxiliary regular game.The latter has the same equation of dynamics and a similar cost functional augmented by an integral of the squares of the singular control coordinates with a small positive weight.Thus,the auxiliary game is a partial cheap control differential game.Based on a singular perturbation’s asymptotic analysis of this auxiliary game,the existence of the value of the original(singular)game is established,and its expression is obtained.The maximiser’s optimal state feedback strategy and the minimising control sequence in the original game are designed.It is shown that the coordinates of the minimising control sequence,corresponding to the regular coordinates of the minimiser’s control,are point-wise convergent in the class of regular functions.The optimal trajectory sequence and the optimal trajectory in the considered singular game also are obtained.An illustrative example is presented.展开更多
基金The authors would like to extend their sincere appreciation to Researchers Supporting Project number (RSP2023R368)King Saud University,Riyadh,Saudi Arabia.RK,NP,VKS acknowledge Indus University,Ahmedabad,for supporting research.Dr.Ahmed I.Osman and Prof.David W.Rooney wish to acknowledge the support of The Bryden Centre project (Project ID VA5048)。
文摘Developing cost-effective and high-performance catalyst systems for dry reforming of methane(DRM)is crucial for producing hydrogen(H_(2))sustainably.Herein,we investigate using iron(Fe)as a promoter and major alumina support in Ni-based catalysts to improve their DRM performance.The addition of iron as a promotor was found to add reducible iron species along with reducible NiO species,enhance the basicity and induce the deposition of oxidizable carbon.By incorporating 1 wt.%Fe into a 5Ni/10ZrAl catalyst,a higher CO_(2) interaction and formation of reducible"NiO-species having strong interaction with support"was observed,which led to an∼80%H_(2) yield in 420 min of Time on Stream(TOS).Further increasing the Fe content to 2 wt.%led to the formation of additional reducible iron oxide species and a noticeable rise in H_(2) yield up to 84%.Despite the severe weight loss on Fe-promoted catalysts,high H_(2) yield was maintained due to the proper balance between the rate of CH_(4) decomposition and the rate of carbon deposit diffusion.Finally,incorporating 3 wt.%Fe into the 5Ni/10ZrAl catalyst resulted in the highest CO_(2) interaction,wide presence of reducible NiO-species,minimumgraphitic deposit and an 87%H_(2) yield.Our findings suggest that ironpromoted zirconia-alumina-supported Ni catalysts can be a cheap and excellent catalytic system for H_(2) production via DRM.
基金financially supported by the National Key Research and Development Program of China (No.2022YFB 3 803700)the National Natural Science Foundation of China and the China Academy of Engineering Physics (NSAF)(Nos.U2130208 and 52171205)+1 种基金Sichuan Science and Technology Program(No.PG-PGFT-JFKF23-000009-0)Sichuan Science and Technology Program (No.2021JDJQ0020)。
文摘Storage of hydrogen in solid-state materials offers a safer and compacter way compared to compressed and liquid hydrogen.Vanadium(V)-based alloys attract wide attention,owing to the total hydrogen storage capacity of 3.8 wt% and reversible capacity above 2.0 wt%at ambient conditions,surpassing the AB_(5)-,AB_(2)-and ABtype hydrogen storage alloys.However,several challenges,such as insufficient capacity,cyclic stability and high raw material costs,hinder the practical applications of V-based alloys.This review provides an overview of the recent advances in hydrogen storage properties of V-based alloys.The mechanism and optimization strategies of hydrogen storage properties and cyclic stability are discussed in detail,and furthermore,the approaches to reduce manufacturing costs are compared comprehensively.
文摘The external use of drugs is a simple,ef-fective,sate and cheap means of treatmentof T.C.M..The following is an introductionto the method.1.Conduction through channels andcollaterals (经络传导):Channels andcollaterals are important parts of the humanbody.This special system is connected to theskin,muscles and tendons superficially
文摘Londoners are great readers. They buy vast numbers of newspapers and magazines and even of books--especially paper-backs, whick are still comparatively cheap in spite of ever-increasing rises in the costs of printing. They still continue to buy’proper’books, too. printed on good paper and bound between hardcovers. There are many streets in London containing shops which
文摘朋友对我讲了这么一件事:一次,在同外商谈生意时,翻译把'我们的产品物美价廉。'译成'Our products are of good quality and cheap.'当时外商就迷惑不解:good quality 的产品,怎么又 cheap 了呢?随之而来的便是一番解释,直到外商看见了产品,又得到了报价,这才放下心来。问题出在哪里?原来,cheap 不光指价格低廉,它还有其它的意思。先请看例句:Her socks looked cheap and nasty.她的袜子价廉质劣。
文摘The circular economy is an advocate of harmony with the Earth＇ s natural resources and environment, mutual interdependence of social and economic development model, it requires economic production systems within and between different production departments and interconnected way matter and energy exchange and transfer, to achieve maximum utilization of material and energy into the system, resulting in ＂two low and one high＂ approach to development in harmony with the natural environment. And it has become a mainstream trend since the 1990s and social development of the countries in the world One.
文摘The world is at a critical state of limited resources,growing population,and increasing hazard potential.In the near future,geoscientists will be sought to solve these worldwide woes or face the consequences of a demanding public.Cheap,innovative technology and collaboration among several disciplines are needed to proceed forward and solve the difficult questions that humanity as a whole faces.Years of advances and dilemmas in earthquake prediction highlight a theme that stretches through all of geoscience and society:the need for quick solutions to pressing global concerns.
文摘INSPIRED by the Belt and Road Initiative,China＇s four-year-old blueprint for multinational trade and economic development, the China Trade Week （CTW）, is making its mark in Africa. Besides dispelling the misconception that Chinese manufacturers produce only cheap and low-quality items, the event is also a platform to introduce companies from different provinces in China.
基金financial support from the National Key R&D Program of China(No.2023YFA1507500)We also appreciate the general support provided by Prof.Armin Borner at Leibniz-Institute for Catalysis.
文摘The development of catalytic carbonylation reactions has increased considerably.Although many reviews/chapters/books on carbonylation reactions have been published,summaries on cheap metal-catalyzed catalytic carbonylation reactions of aryl halides and other chemical bonds with high dissociation energy C–Y(Y=O,N,H)are still very rare.Focusing on green and sustainable chemistry,this review summarizes and discusses the achievements on carbonylative transformations of aryl halides(C(sp^(2))–X)and strong bonds C–Y(Y=O,N,H)based on non-expensive metal catalysts(Co,Mn,Mo,Ni,Fe,Cu),photochemical and electrochemical systems developed in recent decades.
文摘In Refs.[1] and [2], the superior magnetic properties have been reported for theexpensive synthetic ultra-microcrystalline Fe<sub>73.5</sub>Cu<sub>1</sub>Nb<sub>13</sub>Si<sub>13.5</sub>B<sub>9</sub> and Fe<sub>73.1</sub>Cu<sub>12</sub>Nb<sub>3.2</sub>Si<sub>12.5</sub>B<sub>10</sub>alloys. Partly replacing the expensive Nb by cheap Mo, we developed a new material,which was made into ribbons with the thickness of 28 μm and width of 3.0cm.
文摘The n-acetoacetyl aromatic amide of complexes of copper (Ⅱ)and their ice nucleation has not yet been published. The reactants of the title complexes are cheap and the synthetic method is simple. A mixture of methanol so-
文摘We consider a finite horizon,zero-sum linear quadratic differential game.The feature of this game is that a weight matrix of the minimiser’s control cost in the cost functional is singular.Due to this singularity,the game can be solved neither by applying the Isaacs MinMax principle nor using the Bellman–Isaacs equation approach,i.e.this game is singular.Aprevious paper of one of the authors analysed such a game in the case where the cost functional does not contain the minimiser’s control cost at all,i.e.the weight matrix of this cost equals zero.In this case,all coordinates of the minimiser’s control are singular.In the present paper,we study the general case where the weight matrix of the minimiser’s control cost,being singular,is not,in general,zero.This means that only a part of the coordinates of the minimiser’s control is singular,while others are regular.The considered game is treated by a regularisation,i.e.by its approximate conversion to an auxiliary regular game.The latter has the same equation of dynamics and a similar cost functional augmented by an integral of the squares of the singular control coordinates with a small positive weight.Thus,the auxiliary game is a partial cheap control differential game.Based on a singular perturbation’s asymptotic analysis of this auxiliary game,the existence of the value of the original(singular)game is established,and its expression is obtained.The maximiser’s optimal state feedback strategy and the minimising control sequence in the original game are designed.It is shown that the coordinates of the minimising control sequence,corresponding to the regular coordinates of the minimiser’s control,are point-wise convergent in the class of regular functions.The optimal trajectory sequence and the optimal trajectory in the considered singular game also are obtained.An illustrative example is presented.
