We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the lo...We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the local strong solutions in terms of the gradient of the velocity only, which coincides with the famous Beale-Kato-Majda criterion for ideal incompressible flows.展开更多
The south segment of the China North-South Seismic Belt is located in the southeast margin of the Qinghai Tibet Plateau.This region is characterized by the frequent seismic activity in Chinese mainland.In this paper,t...The south segment of the China North-South Seismic Belt is located in the southeast margin of the Qinghai Tibet Plateau.This region is characterized by the frequent seismic activity in Chinese mainland.In this paper,the geomagnetic field model NGDC-720 and the data of terrestrial heat flow are used to investigate the distribution of crustal magnetic anomalies,the depth of Curie surface,and the characteristics of the crustal thermal structure in the south segment of the North-South Seismic Belt.The distribution characteristics of the vertical component AZ and the magnetic declination AD in the area with earthquakes over a magnitude of 6 and their aftershocks since 1970 are focused on.The results show that the earthquakes are mainly observed in the area of negative magnetic anomaly or the strong and weak transition zone.It especially shows in the AD.The Curie surface in the study area varies significantly,ranging from 20.8 to 31 km.The uplift area of the Curie surface is consistent with the high-value area of terrestrial heat flow.The high geothermal area corresponds to the strong earthquake activity area.The focal depth of most strong earthquakes is shallower than the depth of the Curie surface.The strong earthquakes mainly occur in the deep-shallow transition zones of the Curie surface.The results can be used as a reference for strong earthquake prediction in this area.展开更多
Near-field thermophotovoltaic(NTPV)devices comprising a SiC-hBN-graphene emitter and a graphene-InSb cell with gratings are designed to enhance the performance of the NTPV systems.Fluctuational electrodynamics and rig...Near-field thermophotovoltaic(NTPV)devices comprising a SiC-hBN-graphene emitter and a graphene-InSb cell with gratings are designed to enhance the performance of the NTPV systems.Fluctuational electrodynamics and rigorous coupled-wave analysis are employed to calculate radiative heat transfer fluxes.It is found that the NTPV systems with two graphene ribbons perform better due to the graphene strong coupling effects.The effects of graphene chemical potential are discussed.It is demonstrated that near-field radiative heat transfer of thermophotovoltaic devices is enhanced by the coupling of surface plasmon polaritons,surface phonon polaritons,hyperbolic phonon polaritons,and magnetic polaritons caused by the graphene strong coupling effects.Rabi splitting frequency of different polaritons is calculated to quantify the mutual interaction of graphene strong coupling effects.Finally,the effects of cell grating filling ratio are investigated.The excitation of magnetic polaritons is affected by the graphene ribbon and the cell filling ratio.This investigation provides a new explanation of the enhancement mechanism of graphene-assisted thermophotovoltaic systems and a novel approach for improving the output power of the near-field thermophotovoltaic system.展开更多
Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary partic...Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.展开更多
我国煤矿锚杆强度偏低,对冲击吸收功没有指标要求。通过对煤矿井下锚杆破断情况调查及分析,发现锚杆破断强度低、夹杂物含量高、冲击韧性不足、抗冲击能力不够是造成杆体脆断的重要原因,冲击韧性值低是发生脆断的材质内在因素。介绍了...我国煤矿锚杆强度偏低,对冲击吸收功没有指标要求。通过对煤矿井下锚杆破断情况调查及分析,发现锚杆破断强度低、夹杂物含量高、冲击韧性不足、抗冲击能力不够是造成杆体脆断的重要原因,冲击韧性值低是发生脆断的材质内在因素。介绍了超高强热处理锚杆的主要工艺,对超高强热处理锚杆材料进行了拉伸、拉扭弯及力学性能实验室试验,数据显示这种材料在受拉、扭、弯的情况下可以承受较高的载荷,特别是冲击吸收功指标,是热轧强力锚杆的数倍。在潞安集团漳村煤矿动压巷道进行了井下现场试验,对超高强热处理锚杆受力情况进行了监测,锚杆施加预紧扭矩后初始预紧力为52~98 k N,受力稳定后最大受力为223 k N,小于其破断极限,矿压监测数据表明,支护系统有效地控制了围岩的变形,支护效果良好。展开更多
钙依赖性蛋白激酶(calcium-dependent protein kinases,CDPKs or CPKs)作为一类钙感知蛋白在植物的生长发育和胁迫应答中起着重要的作用。LeCPK2(GenBank accession No.:GQ205414)是我们从番茄中分离的第3个CDPK基因,前期研究表明LeCPK...钙依赖性蛋白激酶(calcium-dependent protein kinases,CDPKs or CPKs)作为一类钙感知蛋白在植物的生长发育和胁迫应答中起着重要的作用。LeCPK2(GenBank accession No.:GQ205414)是我们从番茄中分离的第3个CDPK基因,前期研究表明LeCPK2可能在植物热胁迫应答中发挥作用。为了进一步研究其在热胁迫中的功能,我们通过电子克隆的方法分离了LeCPK2的启动子序列,并通过LeCPK2过表达烟草分析其在高温胁迫中的潜在的功能。生物信息学分析显示,LeCPK2启动子中包含5个热响应元件,和前期试验结果一致。野生型植株在受到热胁迫后,对光更为敏感,强光照下植株叶片发生萎蔫,而强光本身不会对未受热胁迫的健康植株造成伤害。LeCPK2转基因植株热、光胁迫后不会出现受害表型。以上研究表明,LeCPK2在植物的热胁迫应答中发挥重要作用,能够有效保护植株免受高温胁迫的损害,是一个优秀的耐热(光)基因。本研究将为揭示番茄LeCPK2遗传功能及对其开发利用奠定基础。展开更多
基金supported by the China Postdoctoral Science Foundation (20090450333)supported by the National Basic Research Program (2005CB321700)NSFC (40890154)
文摘We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the local strong solutions in terms of the gradient of the velocity only, which coincides with the famous Beale-Kato-Majda criterion for ideal incompressible flows.
基金supported by National Natural Science Foundation of China(No.41864003 and 41964004)as well as Yunnan Fundamental Research Projects(202101AT070181).
文摘The south segment of the China North-South Seismic Belt is located in the southeast margin of the Qinghai Tibet Plateau.This region is characterized by the frequent seismic activity in Chinese mainland.In this paper,the geomagnetic field model NGDC-720 and the data of terrestrial heat flow are used to investigate the distribution of crustal magnetic anomalies,the depth of Curie surface,and the characteristics of the crustal thermal structure in the south segment of the North-South Seismic Belt.The distribution characteristics of the vertical component AZ and the magnetic declination AD in the area with earthquakes over a magnitude of 6 and their aftershocks since 1970 are focused on.The results show that the earthquakes are mainly observed in the area of negative magnetic anomaly or the strong and weak transition zone.It especially shows in the AD.The Curie surface in the study area varies significantly,ranging from 20.8 to 31 km.The uplift area of the Curie surface is consistent with the high-value area of terrestrial heat flow.The high geothermal area corresponds to the strong earthquake activity area.The focal depth of most strong earthquakes is shallower than the depth of the Curie surface.The strong earthquakes mainly occur in the deep-shallow transition zones of the Curie surface.The results can be used as a reference for strong earthquake prediction in this area.
基金supported by the National Natural Science Foundation of China(Grant No.52276075)sponsored by the Natural Science Foundation of Shanghai(Grant No.21ZR1433500)。
文摘Near-field thermophotovoltaic(NTPV)devices comprising a SiC-hBN-graphene emitter and a graphene-InSb cell with gratings are designed to enhance the performance of the NTPV systems.Fluctuational electrodynamics and rigorous coupled-wave analysis are employed to calculate radiative heat transfer fluxes.It is found that the NTPV systems with two graphene ribbons perform better due to the graphene strong coupling effects.The effects of graphene chemical potential are discussed.It is demonstrated that near-field radiative heat transfer of thermophotovoltaic devices is enhanced by the coupling of surface plasmon polaritons,surface phonon polaritons,hyperbolic phonon polaritons,and magnetic polaritons caused by the graphene strong coupling effects.Rabi splitting frequency of different polaritons is calculated to quantify the mutual interaction of graphene strong coupling effects.Finally,the effects of cell grating filling ratio are investigated.The excitation of magnetic polaritons is affected by the graphene ribbon and the cell filling ratio.This investigation provides a new explanation of the enhancement mechanism of graphene-assisted thermophotovoltaic systems and a novel approach for improving the output power of the near-field thermophotovoltaic system.
文摘Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.
文摘我国煤矿锚杆强度偏低,对冲击吸收功没有指标要求。通过对煤矿井下锚杆破断情况调查及分析,发现锚杆破断强度低、夹杂物含量高、冲击韧性不足、抗冲击能力不够是造成杆体脆断的重要原因,冲击韧性值低是发生脆断的材质内在因素。介绍了超高强热处理锚杆的主要工艺,对超高强热处理锚杆材料进行了拉伸、拉扭弯及力学性能实验室试验,数据显示这种材料在受拉、扭、弯的情况下可以承受较高的载荷,特别是冲击吸收功指标,是热轧强力锚杆的数倍。在潞安集团漳村煤矿动压巷道进行了井下现场试验,对超高强热处理锚杆受力情况进行了监测,锚杆施加预紧扭矩后初始预紧力为52~98 k N,受力稳定后最大受力为223 k N,小于其破断极限,矿压监测数据表明,支护系统有效地控制了围岩的变形,支护效果良好。
文摘钙依赖性蛋白激酶(calcium-dependent protein kinases,CDPKs or CPKs)作为一类钙感知蛋白在植物的生长发育和胁迫应答中起着重要的作用。LeCPK2(GenBank accession No.:GQ205414)是我们从番茄中分离的第3个CDPK基因,前期研究表明LeCPK2可能在植物热胁迫应答中发挥作用。为了进一步研究其在热胁迫中的功能,我们通过电子克隆的方法分离了LeCPK2的启动子序列,并通过LeCPK2过表达烟草分析其在高温胁迫中的潜在的功能。生物信息学分析显示,LeCPK2启动子中包含5个热响应元件,和前期试验结果一致。野生型植株在受到热胁迫后,对光更为敏感,强光照下植株叶片发生萎蔫,而强光本身不会对未受热胁迫的健康植株造成伤害。LeCPK2转基因植株热、光胁迫后不会出现受害表型。以上研究表明,LeCPK2在植物的热胁迫应答中发挥重要作用,能够有效保护植株免受高温胁迫的损害,是一个优秀的耐热(光)基因。本研究将为揭示番茄LeCPK2遗传功能及对其开发利用奠定基础。
