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
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(Y¼O,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(sp2)–X)and strong bonds C–Y(Y¼O,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
A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-M...A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-MS）. When this method was adopted, samples were pretreated by modified QuEChERS（quick, easy, cheap, effective, rugged and safe） method. An environmentally friendly extractant（ethanol aqueous solution） replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin（BSA） with phthalates show that there was a high-affinity interaction between phthalate and protein, de- creasing the extraction efficiency of phthalates from fish samples. However, in the 80%（volume fraction, ~） ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in ^（ethanol） 80% aqueous solution than in either ~p（ethanol） 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the puri- fication steps were greatly simplified. Overall recoveries were 81.77%--90.5% with limits of detection between 2.53 and 9.61 ~tg/L, and relative standard deviation values at 1.15%---4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.展开更多
Molecular fluorescence spectrometry, resonance Rayleigh scattering and gas chromatography-mass spectroscopy（GC-MS） were used to study the effect of pure fish serum albumin（FSA） as the model protein on the extracti...Molecular fluorescence spectrometry, resonance Rayleigh scattering and gas chromatography-mass spectroscopy（GC-MS） were used to study the effect of pure fish serum albumin（FSA） as the model protein on the extraction of three chlorobenzenes（CBs： 1,3-DCB, 1,2-DCB and 1,2,4-TCB; DCB=dichlorobenzene; TCB=trichlorobenzene） in fish samples. The results show that there was a strong binding effect between CB and FSA. In an aqueous solution of 90%（volume fraction） acetone, a slow but full protein denaturation might take place, which would cause the unfolding of protein and the releasing of CBs. Based on these results, a QuEChERS（quick, easy, cheap, effective, rugged and safe） method was modified by replacing the traditional acetonitrile with acetone aqueous solution in the present work. This modified QuEChERS method was applied in the determination of CBs in fish samples. The spiked recoveries and the limits of detection were 80.4%--118.3% and 2.4--7.3 ng/g, respectively. This paper proposes a new strategy by slowing down the protein denaturation and releasing bound organic compounds to enhance the extraction efficiency of CBs in fish samples.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
A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugge...A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)method.Cereals samples were mixed with a certain amount of quartz,Ci8 and the primary second amine(PSA),and extracted successively with the acetonitrile-water solution(80%,VIV)under microwave irradiation.The obtained eluate was directly introduced into a collection tube containing NaCl and MgSO4.Finally,the supemate was evaporated and reconstructed,and determined by gas chromatographic spectrometry.Some factors affecting the experimental results were studied and optimized.The extraction and purification processes were carried out coinstantaneously and 12 samples could be treated in one step in 4 min.Low limits of tection(0.43—1.31 p.g/kg)for OPPs were obtained in cereals.The relative standard deviations(RSDs)were 2.1%—9.3%.The recoveries of OPPs ranged from 76.1%to 100.2%.By combining the advantages of DMAE with QuEChERS,the sample pretreatment process was simple to operate,with little amount of organic solvent.The whole extraction process was completed in a closed environment,therefore it was very appropriate for daily analysis of OPPs in cereals.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
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(Y¼O,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(sp2)–X)and strong bonds C–Y(Y¼O,N,H)based on non-expensive metal catalysts(Co,Mn,Mo,Ni,Fe,Cu),photochemical and electrochemical systems developed in recent decades.
基金Supported by the National Natural Science Foundation of China（No.20973149） and the Natural Science Foundation of Shandong Province, China（No.ZR2011BM009）.
文摘A simple, environmentally friendly and high efficient extraction method was proposed for the determina- tion of five phthalates in aquatic products by gas chromatography combined with mass spectrometry detector （GC-MS）. When this method was adopted, samples were pretreated by modified QuEChERS（quick, easy, cheap, effective, rugged and safe） method. An environmentally friendly extractant（ethanol aqueous solution） replaced toxic acetonitrile for extracting phthalates in the protein-matrix samples. Fluorescence quenching spectra of bovine serum albumin（BSA） with phthalates show that there was a high-affinity interaction between phthalate and protein, de- creasing the extraction efficiency of phthalates from fish samples. However, in the 80%（volume fraction, ~） ethanol aqueous solution, a slow but full protein denaturation takes place, which would cause the unfolding of protein and the release of phthalates. Meanwhile, the fat-soluble impurities are extracted less in ^（ethanol） 80% aqueous solution than in either ~p（ethanol） 100% or hydrophobic solvents in the liquid-liquid extraction procedure. Therefore the puri- fication steps were greatly simplified. Overall recoveries were 81.77%--90.5% with limits of detection between 2.53 and 9.61 ~tg/L, and relative standard deviation values at 1.15%---4.85%. The proposed approach was satisfactorily applied to the determination of phthalates in real aquatic products, such as fish, shrimp and oyster.
基金Natural Science Foundation of Shandong Province,China
文摘Molecular fluorescence spectrometry, resonance Rayleigh scattering and gas chromatography-mass spectroscopy（GC-MS） were used to study the effect of pure fish serum albumin（FSA） as the model protein on the extraction of three chlorobenzenes（CBs： 1,3-DCB, 1,2-DCB and 1,2,4-TCB; DCB=dichlorobenzene; TCB=trichlorobenzene） in fish samples. The results show that there was a strong binding effect between CB and FSA. In an aqueous solution of 90%（volume fraction） acetone, a slow but full protein denaturation might take place, which would cause the unfolding of protein and the releasing of CBs. Based on these results, a QuEChERS（quick, easy, cheap, effective, rugged and safe） method was modified by replacing the traditional acetonitrile with acetone aqueous solution in the present work. This modified QuEChERS method was applied in the determination of CBs in fish samples. The spiked recoveries and the limits of detection were 80.4%--118.3% and 2.4--7.3 ng/g, respectively. This paper proposes a new strategy by slowing down the protein denaturation and releasing bound organic compounds to enhance the extraction efficiency of CBs in fish samples.
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-
基金Supported by the National Key R&D Program of China(No.2018 YFD040013).
文摘A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)method.Cereals samples were mixed with a certain amount of quartz,Ci8 and the primary second amine(PSA),and extracted successively with the acetonitrile-water solution(80%,VIV)under microwave irradiation.The obtained eluate was directly introduced into a collection tube containing NaCl and MgSO4.Finally,the supemate was evaporated and reconstructed,and determined by gas chromatographic spectrometry.Some factors affecting the experimental results were studied and optimized.The extraction and purification processes were carried out coinstantaneously and 12 samples could be treated in one step in 4 min.Low limits of tection(0.43—1.31 p.g/kg)for OPPs were obtained in cereals.The relative standard deviations(RSDs)were 2.1%—9.3%.The recoveries of OPPs ranged from 76.1%to 100.2%.By combining the advantages of DMAE with QuEChERS,the sample pretreatment process was simple to operate,with little amount of organic solvent.The whole extraction process was completed in a closed environment,therefore it was very appropriate for daily analysis of OPPs in cereals.
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.
