由于传统的插入式系统结构繁杂且频繁插拔容易发生电火花等危险,因此无线电能传输(wireless power transfer,WPT)系统凭借其固有的优势得到了广泛的研究,逐渐融入各种工业应用中.为了确保电池的性能及使用寿命,有效地为电池提供所需的...由于传统的插入式系统结构繁杂且频繁插拔容易发生电火花等危险,因此无线电能传输(wireless power transfer,WPT)系统凭借其固有的优势得到了广泛的研究,逐渐融入各种工业应用中.为了确保电池的性能及使用寿命,有效地为电池提供所需的恒定充电电流和恒定充电电压是非常必要的.然而在充电过程中,电池的等效电阻会发生显著变化从而导致系统很难在近似零相位角(zero phase angle,ZPA)运行下同时实现与负载无关的恒流输出和恒压输出.鉴于此,提出1种基于S/LCL补偿的WPT系统,该系统可以在2个固定频率下实现具有ZPA运行的恒流和恒压输出.最后,搭建了1台恒流充电为3 A和恒压充电为80 V的验证性实验样机,验证了所设计的WPT系统的正确性和可行性.展开更多
Vertebrate digits are essential structures for movement, feeding and communication. Specialized regions of the developing limb bud including the zone of polarizing activity （ZPA）, the apical ectodermal ridge （AER）...Vertebrate digits are essential structures for movement, feeding and communication. Specialized regions of the developing limb bud including the zone of polarizing activity （ZPA）, the apical ectodermal ridge （AER）, and the non-ridge ectoderm regulate the patterning of digits. Although a series of signaling molecules have been characterized as patterning signals from the organizing centers, the delicate cellular and molecular mechanisms that interpret how these patterning signals control the detailed digit anatomy remain unclear, Recent studies from model organisms and human hand malformations provide new insights into the mechanisms regulating this process. Here, we review the current understanding of the genetic networks governing digit morphogenesis展开更多
感应耦合能量传输(inductively coupled power transfer,ICPT)系统中补偿网络能够改善系统特性,目前针对谐振补偿网络的输出电流和电压特性没有一种简单易行的分析模型。首先分析了LC电路、??型电路和T型电路实现与负载无关的恒流或恒...感应耦合能量传输(inductively coupled power transfer,ICPT)系统中补偿网络能够改善系统特性,目前针对谐振补偿网络的输出电流和电压特性没有一种简单易行的分析模型。首先分析了LC电路、??型电路和T型电路实现与负载无关的恒流或恒压输出的谐振条件,并针对高阶无源谐振网络提出一种建模方法,通过将谐振网络等效成2阶LC网络和多级3阶???型电路或多级3阶T型电路的串联,研究其恒流或恒压输出的物理机理。ICPT系统中双边LCC谐振腔实质上是一个9阶谐振网络,基于所提建模方法,分析双边LCC谐振腔输出电流和电压特性。此外,提出仅切换一次系统工作频率便可以实现系统先恒流再恒压输出的方法,且恒流和恒压模式下系统工作频率均满足SAEJ2954标准要求,分别能实现谐振腔输入电压、电流之间的零相角和原边逆变器MOSFETs的零电压开通。搭建3.3kW电动汽车感应耦合能量传输系统的Matlab仿真平台和实验样机,验证理论分析的正确性和可行性。恒流和恒压模式下实验样机谐振腔的效率分别为92.1%和89.7%。展开更多
无线电能传输(Wireless Power Transfer,WPT)是电力电子领域当下的热点研究方向之一。在许多应用场合,需要无线电能传输系统具备不受松耦合变压器线圈自感所限制,且与负载无关的恒定电流输出能力。文章提出一种基于S-LCL补偿的磁场感应...无线电能传输(Wireless Power Transfer,WPT)是电力电子领域当下的热点研究方向之一。在许多应用场合,需要无线电能传输系统具备不受松耦合变压器线圈自感所限制,且与负载无关的恒定电流输出能力。文章提出一种基于S-LCL补偿的磁场感应式无线充电系统及其补偿参数的整定方法。通过对系统补偿参数的合理设置,系统能够在近似零相位角(Zero Phase Angle,ZPA)运行下实现电流的恒定输出。通过调整补偿参数的大小,功率MOSFET能够实现零电压开关(Zero-Voltage Switching,ZVS)。为验证理论分析的正确性,文章搭建了实验样机,其输入直流电压为50 V,输出直流电流为4 A,电能最大传输效率达92.8%。展开更多
Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment.Herein,we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the“prec...Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment.Herein,we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the“precise strike”of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid(HA)and hypoxia-dependent factor carbonic anhydrase IX(CA IX)-inhibitor acetazolamide(AZ).The core of nanobullets is the special zinc(II)phthalocyanine aggregates(ZPA)which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy(PTT),along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy(TDT).The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional(reactive oxygen species(ROS)-mediated)cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.展开更多
Understanding limb development not only gives insights into the outgrowth and differentiation of the limb,but also has clinical relevance.Limb development begins with two paired limb buds(forelimb and hindlimb buds),w...Understanding limb development not only gives insights into the outgrowth and differentiation of the limb,but also has clinical relevance.Limb development begins with two paired limb buds(forelimb and hindlimb buds),which are initially undifferentiated mesenchymal cells tipped with a thickening of the ectoderm,termed the apical ectodermal ridge(AER).As a transitional embryonic structure,the AER undergoes four stages and contributes to multiple axes of limb development through the coordination of signalling centres,feedback loops,and other cell ac-tivities by secretory signalling and the activation of gene expression.Within the scope of proximodistal pattering,it is understood that while fibroblast growth factors(FGFs)function sequentially over time as primary components of the AER signalling process,there is still no consensus on models that would explain proximodistal patterning itself.In anteroposterior pattermning,the AER has a dual-direction regulation by which it promotes the sonic hedgehog(Shh)gene expression in the zone of polarizing activity(ZPA)for proliferation,and inhibits Shh expression in the anterior mesenchyme.In dorsoventral patterming,the AER activates Engrailed-1(En1)expression,and thus represses Wnt family member 7a(Wnt7a)expression in the ventral ectoderm by the expression of Fgfs,Sp6/8,and bone morpho-genetic protein(Bmp)genes.The AER also plays a vital role in shaping the individual digits,since levels of Fgf4/8 and Bmps expressed in the AER affect digit patterning by controlling apoptosis.In summary,the knowledge of crosstalk within AER among the three main axes is essential to understand limb growth and pattern fomation,as the development of its areas proceeds simultaneously.展开更多
基金the National Basic Research Program of China (973 Program) (No. 2007CB947301).
文摘Vertebrate digits are essential structures for movement, feeding and communication. Specialized regions of the developing limb bud including the zone of polarizing activity （ZPA）, the apical ectodermal ridge （AER）, and the non-ridge ectoderm regulate the patterning of digits. Although a series of signaling molecules have been characterized as patterning signals from the organizing centers, the delicate cellular and molecular mechanisms that interpret how these patterning signals control the detailed digit anatomy remain unclear, Recent studies from model organisms and human hand malformations provide new insights into the mechanisms regulating this process. Here, we review the current understanding of the genetic networks governing digit morphogenesis
文摘感应耦合能量传输(inductively coupled power transfer,ICPT)系统中补偿网络能够改善系统特性,目前针对谐振补偿网络的输出电流和电压特性没有一种简单易行的分析模型。首先分析了LC电路、??型电路和T型电路实现与负载无关的恒流或恒压输出的谐振条件,并针对高阶无源谐振网络提出一种建模方法,通过将谐振网络等效成2阶LC网络和多级3阶???型电路或多级3阶T型电路的串联,研究其恒流或恒压输出的物理机理。ICPT系统中双边LCC谐振腔实质上是一个9阶谐振网络,基于所提建模方法,分析双边LCC谐振腔输出电流和电压特性。此外,提出仅切换一次系统工作频率便可以实现系统先恒流再恒压输出的方法,且恒流和恒压模式下系统工作频率均满足SAEJ2954标准要求,分别能实现谐振腔输入电压、电流之间的零相角和原边逆变器MOSFETs的零电压开通。搭建3.3kW电动汽车感应耦合能量传输系统的Matlab仿真平台和实验样机,验证理论分析的正确性和可行性。恒流和恒压模式下实验样机谐振腔的效率分别为92.1%和89.7%。
基金the National Natural Science Foundation of China(51903203,51703178,81770728)the China Postdoctoral Science Foundation(2019M653661,2019M663742)+3 种基金the Natural Science Foundation of Shaanxi Province(2020JQ-046)Natural Science Foundation of Zhejiang Province(LWY20H180002)the Natural Science Foundation of Guangxi Zhuang Autonomous Region(2017GXNSFBA198028).Y.H.,M.G.,Y.S.Z.,G.H.and X.Z.were not supported by any of these fundsinstead,support by MIT,Harvard,Stanford University and the Brigham Research Institute are acknowledged.
文摘Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment.Herein,we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the“precise strike”of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid(HA)and hypoxia-dependent factor carbonic anhydrase IX(CA IX)-inhibitor acetazolamide(AZ).The core of nanobullets is the special zinc(II)phthalocyanine aggregates(ZPA)which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy(PTT),along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy(TDT).The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional(reactive oxygen species(ROS)-mediated)cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.
基金Key Research and Development Project of Shandong Province(No.2017G006043),China。
文摘Understanding limb development not only gives insights into the outgrowth and differentiation of the limb,but also has clinical relevance.Limb development begins with two paired limb buds(forelimb and hindlimb buds),which are initially undifferentiated mesenchymal cells tipped with a thickening of the ectoderm,termed the apical ectodermal ridge(AER).As a transitional embryonic structure,the AER undergoes four stages and contributes to multiple axes of limb development through the coordination of signalling centres,feedback loops,and other cell ac-tivities by secretory signalling and the activation of gene expression.Within the scope of proximodistal pattering,it is understood that while fibroblast growth factors(FGFs)function sequentially over time as primary components of the AER signalling process,there is still no consensus on models that would explain proximodistal patterning itself.In anteroposterior pattermning,the AER has a dual-direction regulation by which it promotes the sonic hedgehog(Shh)gene expression in the zone of polarizing activity(ZPA)for proliferation,and inhibits Shh expression in the anterior mesenchyme.In dorsoventral patterming,the AER activates Engrailed-1(En1)expression,and thus represses Wnt family member 7a(Wnt7a)expression in the ventral ectoderm by the expression of Fgfs,Sp6/8,and bone morpho-genetic protein(Bmp)genes.The AER also plays a vital role in shaping the individual digits,since levels of Fgf4/8 and Bmps expressed in the AER affect digit patterning by controlling apoptosis.In summary,the knowledge of crosstalk within AER among the three main axes is essential to understand limb growth and pattern fomation,as the development of its areas proceeds simultaneously.
