For a many-atom battery coupled with a common thermal bath, the useful energy is maximized at an optimal number of the atoms for a fixed harmonic driving field, i.e., the so-called optimal building block [see Chang et...For a many-atom battery coupled with a common thermal bath, the useful energy is maximized at an optimal number of the atoms for a fixed harmonic driving field, i.e., the so-called optimal building block [see Chang et al. New J. Phys.23 103026(2021)]. Here we consider the useful energy defined by the ergotropy and a continuous-wave driving field. For the single-atom case, we present analytical results of the increased energy and the ergotropy in the long-time limit(i.e.,the steady-state ergotropy). It is found that there exists an optimal value of the driving-field strength. Such an observation holds for many-atom cases. Numerically, we show that the optimal strength increases linearly with the number N of the atoms. Using the optimal strength for each N, both the increased energy and the ergotropy increase monotonically with N.展开更多
Obesity is a major risk factor for cancers including hepatocellular carcinoma(HCC)that develops from a background of non-alcoholic fatty liver disease(NAFLD).Hypercholesterolemia is a common comorbidity of obesity.Alt...Obesity is a major risk factor for cancers including hepatocellular carcinoma(HCC)that develops from a background of non-alcoholic fatty liver disease(NAFLD).Hypercholesterolemia is a common comorbidity of obesity.Although cholesterol biosynthesis mainly occurs in the liver,its role in HCC development of obese people remains obscure.Using high-fat high-carbohydrate diet-associated orthotopic and spontaneous NAFLD-HCC mouse models,we found that hepatic cholesterol accumulation in obesity selectively suppressed natural killer T(NKT)cell-mediated antitumor immunosurveillance.Transcriptome analysis of human liver revealed aberrant cholesterol metabolism and NKT cell dysfunction in NAFLD patients.Notably,cholesterol-lowering rosuvastatin restored NKT expansion and cytotoxicity to prevent obesogenic diet-promoted HCC development.Moreover,suppression of hepatic cholesterol biosynthesis by a mammalian target of rapamycin(mTOR)inhibitor vistusertib preceded tumor regression,which was abolished by NKT inactivation but not CD8^(+)T cell depletion.Mechanistically,sterol regulatory element-binding protein 2(SREBP2)-driven excessive cholesterol production from hepatocytes induced lipid peroxide accumulation and deficient cytotoxicity in NKT cells,which were supported by findings in people with obesity,NAFLD and NAFLD-HCC.This study highlights mTORC1/SREBP2/cholesterol-mediated NKT dysfunction in the tumor-promoting NAFLD liver microenvironment,providing intervention strategies that invigorating NKT cells to control HCC in the obesity epidemic.展开更多
An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM ...An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive Couple Plasma-Mass Spectrometry(ICP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, Cd, Sb, I, Se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while Sc, Al, Fe, Mn, Sm, La, Sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn */V * and Bi/Al indicate that both TSP and PM 10 of La/Sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis(APCA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.展开更多
The deformation characteristic of bland in deep drawing is discussed. It is pointed out that the friction and lubrication conditions in for drawing are different from that in mechanical motion or machine work or other...The deformation characteristic of bland in deep drawing is discussed. It is pointed out that the friction and lubrication conditions in for drawing are different from that in mechanical motion or machine work or other plastic process. The common test methods in laboratories are analyzed. It shows that though all those test methods can test the friction coefficient, the probe test method is most suitable for the research of friction and lubrication and the process in deep drawing, for this method is identical with the actual work condition either from the test principle or deformation status of the blank. Last the successful application in the deep drawing simulator newly developed the the probe method are intro- duced in detail.展开更多
针对在氩弧焊型高压电缆铝护套焊接过程中易出现表面漏焊、埋藏未焊透和焊穿等缺陷的问题,提出了焊缝缺陷的交流电磁场检测(alternating current field measurement, ACFM)方法。首先,利用COMSOL多物理场仿真软件建立高压电缆铝护套焊...针对在氩弧焊型高压电缆铝护套焊接过程中易出现表面漏焊、埋藏未焊透和焊穿等缺陷的问题,提出了焊缝缺陷的交流电磁场检测(alternating current field measurement, ACFM)方法。首先,利用COMSOL多物理场仿真软件建立高压电缆铝护套焊缝缺陷ACFM模型,研究U形磁芯上的励磁线圈在不同类型铝护套焊缝缺陷区域产生的感应电流的密度分布特点和和磁场信号特征;其次,设计了可获取缺陷长度和深度信息的正交式接收线圈,制作了带有缺陷的电缆铝护套焊缝试件及ACFM实验平台;最后,进行了不同类型铝护套焊缝缺陷的检测及结果分析。实验结果表明,ACFM方法能够有效用于3 mm厚的高压电缆铝护套焊缝表面漏焊和焊穿缺陷的检测,并且能够有效识别埋深为2 mm,长、宽、深分别为10,0.3,1 mm的埋藏未焊透缺陷。研究结果为高压电缆铝护套焊缝缺陷的识别和焊缝质量的评价提供了重要参考。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12075209, 11905185, and 11935012)partially supported by the Science Foundation of Zhejiang Sci-Tech University (Grant No. 18062145-Y)。
文摘For a many-atom battery coupled with a common thermal bath, the useful energy is maximized at an optimal number of the atoms for a fixed harmonic driving field, i.e., the so-called optimal building block [see Chang et al. New J. Phys.23 103026(2021)]. Here we consider the useful energy defined by the ergotropy and a continuous-wave driving field. For the single-atom case, we present analytical results of the increased energy and the ergotropy in the long-time limit(i.e.,the steady-state ergotropy). It is found that there exists an optimal value of the driving-field strength. Such an observation holds for many-atom cases. Numerically, we show that the optimal strength increases linearly with the number N of the atoms. Using the optimal strength for each N, both the increased energy and the ergotropy increase monotonically with N.
基金This project is supported by the University Grants Committee through the Collaborative Research Fund(C4045-18W)AstraZeneca Research Program(2017),General Research Fund(14105419,14104820)the Li Ka Shing Foundation,and the Terry Fox Foundation.
文摘Obesity is a major risk factor for cancers including hepatocellular carcinoma(HCC)that develops from a background of non-alcoholic fatty liver disease(NAFLD).Hypercholesterolemia is a common comorbidity of obesity.Although cholesterol biosynthesis mainly occurs in the liver,its role in HCC development of obese people remains obscure.Using high-fat high-carbohydrate diet-associated orthotopic and spontaneous NAFLD-HCC mouse models,we found that hepatic cholesterol accumulation in obesity selectively suppressed natural killer T(NKT)cell-mediated antitumor immunosurveillance.Transcriptome analysis of human liver revealed aberrant cholesterol metabolism and NKT cell dysfunction in NAFLD patients.Notably,cholesterol-lowering rosuvastatin restored NKT expansion and cytotoxicity to prevent obesogenic diet-promoted HCC development.Moreover,suppression of hepatic cholesterol biosynthesis by a mammalian target of rapamycin(mTOR)inhibitor vistusertib preceded tumor regression,which was abolished by NKT inactivation but not CD8^(+)T cell depletion.Mechanistically,sterol regulatory element-binding protein 2(SREBP2)-driven excessive cholesterol production from hepatocytes induced lipid peroxide accumulation and deficient cytotoxicity in NKT cells,which were supported by findings in people with obesity,NAFLD and NAFLD-HCC.This study highlights mTORC1/SREBP2/cholesterol-mediated NKT dysfunction in the tumor-promoting NAFLD liver microenvironment,providing intervention strategies that invigorating NKT cells to control HCC in the obesity epidemic.
文摘An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive Couple Plasma-Mass Spectrometry(ICP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, Cd, Sb, I, Se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while Sc, Al, Fe, Mn, Sm, La, Sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn */V * and Bi/Al indicate that both TSP and PM 10 of La/Sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis(APCA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.
文摘The deformation characteristic of bland in deep drawing is discussed. It is pointed out that the friction and lubrication conditions in for drawing are different from that in mechanical motion or machine work or other plastic process. The common test methods in laboratories are analyzed. It shows that though all those test methods can test the friction coefficient, the probe test method is most suitable for the research of friction and lubrication and the process in deep drawing, for this method is identical with the actual work condition either from the test principle or deformation status of the blank. Last the successful application in the deep drawing simulator newly developed the the probe method are intro- duced in detail.
文摘针对在氩弧焊型高压电缆铝护套焊接过程中易出现表面漏焊、埋藏未焊透和焊穿等缺陷的问题,提出了焊缝缺陷的交流电磁场检测(alternating current field measurement, ACFM)方法。首先,利用COMSOL多物理场仿真软件建立高压电缆铝护套焊缝缺陷ACFM模型,研究U形磁芯上的励磁线圈在不同类型铝护套焊缝缺陷区域产生的感应电流的密度分布特点和和磁场信号特征;其次,设计了可获取缺陷长度和深度信息的正交式接收线圈,制作了带有缺陷的电缆铝护套焊缝试件及ACFM实验平台;最后,进行了不同类型铝护套焊缝缺陷的检测及结果分析。实验结果表明,ACFM方法能够有效用于3 mm厚的高压电缆铝护套焊缝表面漏焊和焊穿缺陷的检测,并且能够有效识别埋深为2 mm,长、宽、深分别为10,0.3,1 mm的埋藏未焊透缺陷。研究结果为高压电缆铝护套焊缝缺陷的识别和焊缝质量的评价提供了重要参考。
