Based on the two-pass differential temperature rolling bonding method,the effects of prefabricated steel/aluminum composite panel temperature on interface characteristics and microstructure properties were investigate...Based on the two-pass differential temperature rolling bonding method,the effects of prefabricated steel/aluminum composite panel temperature on interface characteristics and microstructure properties were investigated through experimental analysis and finite element simulations.When the temperature exceeds 400℃,the effective preparation of the steel-aluminum transition joint can be achieved,and with the increase in temperature,the interface shear and pull-off strength of the steel-aluminum transition joint exhibits an initial decrease followed by an increase.Both the interface shear and pull-off fractures are in 1060 aluminum matrix.As the temperature increases,the size of the average grain in 1060 aluminum matrix increases and then decreases.When the temperature reaches 550℃,the comprehensive performance of the prepared steel-aluminum transition joint is the best,with the interface shear strength of 77 MPa and the interface pull-off strength of 153 MPa,exceeding the bonding strength of the explosive compounding method.There are no pinholes,wrinkles,or cracks in the lateral bending matrix and the interface.展开更多
Pancreatic cancer continues to be a leading cause of cancer-related death worldwide and there is an urgent need to develop novel diagnostic and therapeutic strategies to reduce the mortality of patients with this dise...Pancreatic cancer continues to be a leading cause of cancer-related death worldwide and there is an urgent need to develop novel diagnostic and therapeutic strategies to reduce the mortality of patients with this disease. In pancreatic cancer, some tight junction proteins, including claudins, are abnormally regulated and therefore are promising molecular targets for diagnosis, prognosis and therapy. Claudin-4 and-18 are overexpressed in human pancreatic cancer and its precursor lesions. Claudin-4 is a high affinity receptor of Clostridium perfringens enterotoxin(CPE). The cytotoxic effects of CPE and monoclonal antibodies against claudin-4 are useful as novel therapeutic tools for pancreatic cancer. Claudin-18 could be a putative marker and therapeutic target with prognostic implications for patients with pancreatic cancer. Claudin-1,-7, tricellulin and marvelD3 are involved in epithelial to mesenchymal transition(EMT) of pancreatic cancer cells and thus might be useful as biomarkers during disease. Protein kinase C is closely related to EMT of pancreatic cancer and regulates tight junctions of normal human pancreatic duct epithelial cells and the cancer cells. This review focuses on the regulation of tight junctions via protein kinase C during EMT in human pancreatic cancer for the purpose of developing new diagnostic and therapeutic modalities for pancreatic cancer.展开更多
The ancient emission formulas of Langmuir and Richardson entered the calculations of subtle effects in semiconductor devices as basic ones.But,in the physics of semiconductor devices,these models have long played a pu...The ancient emission formulas of Langmuir and Richardson entered the calculations of subtle effects in semiconductor devices as basic ones.But,in the physics of semiconductor devices,these models have long played a purely decorative role,since they can describe in the most rough approximation only individual sections of the I-V characteristic.But it is precisely the fact that these formulas are basic when describing the barrier current-voltage characteristics(CVC)and prevented the consideration and use of thermoelectric effects in materials on a nano-scale.Thus,as these basic emission models actually imposed a ban on the MEASURABILITY of local thermoelectric effects,the existence of which has already been proven both phenomenologically and experimentally.The quantum transition technique is based on classical models.But it can also be used to correct these classic formulas.The calculation of the spatial transition of electrons over the potential barrier,taking into account the polarity of the kinetic energy,gives currents that are significantly higher than the currents of Langmuir and Richardson,including in the initial section of the I-V characteristic.Moreover,ballistic currents are concentrated at energy levels close to the threshold.This effect of condensation of electrons flowing down the barrier transforms the"anomalous"Seebeck coefficients into normal MEASURABLE Local Thermal EMF,including in p-n junctions.展开更多
In this paper, the positive influence of a uni-traveling-carrier （UTC） structure to ease the contract between the respon- sivity and working speed of the InP-based double hetero-junction phototransistor （DHPT） is ...In this paper, the positive influence of a uni-traveling-carrier （UTC） structure to ease the contract between the respon- sivity and working speed of the InP-based double hetero-junction phototransistor （DHPT） is illustrated in detail. Different results under electrical bias, optical bias or combined electrical and optical bias are analyzed for an excellent UTC-DHPT performance. The results show that when the UTC-DHPT operates at three-terminal （3T） working mode with combined electrical bias and optical bias in base, it keeps a high optical responsivity of 34.72 A/W and the highest optical transition frequency of 120 GHz. The current gain of the 3T UTC-DHPT under 1.55-μm light illuminations reaches 62 dB. This indicates that the combined base electrical bias and optical bias of 3T UTC-DHPT can make sure that the UTC-DHPT provides high optical current gain and high optical transition frequency simultaneously.展开更多
In this paper we study the traffic states and jams in vehicular traffic merging and bifurcating at a junction on a two-lane highway. The two-lane traffic model for the vehicular motion at the junction is presented whe...In this paper we study the traffic states and jams in vehicular traffic merging and bifurcating at a junction on a two-lane highway. The two-lane traffic model for the vehicular motion at the junction is presented where a jam occurs frequently due to merging, lane changing, and bifurcating. The traffic flow is called the weaving. At the weaving section, vehicles slow down and then move aside on the other lane for changing their direction. We derive the fundamental diagrams (flow-density diagrams) for the weaving traffic flow. The traffic states vary with the density, slowdown speed, and the fraction of vehicles changing the lane. The dynamical phase transitions occur. It is shown that the fundamental diagrams depend highly on the traffic states.展开更多
The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with...The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with identical junctions and the series SQUIDs with different junctions were successfully fabricated. The Nb/Al-AlOx/Nb trilayer and input Nb coils were prepared by asputtering equipment. The SQUID devices were prepared by a sputtering and the lift-off method.Investigations by AFM, OM and SEM revealed the morphology and roughness of the Nb films and Nb/Al-AlOx/Nb trilayer.In addition, the current–voltage characteristics of the SQUID devices with identical junction and different junction areas were measured at 2.5 K in the He^3 refrigerator. The results show that the SQUID modulation depth is obviously affected by the junction area. The modulation depth obviously increases with the increase of the junction area in a certain range. It is found that the series SQUID with identical junction area has a transimpedance gain of 58 Ω approximately.展开更多
Mixed epithelial and stromal tumour(MEST)is an uncommon renal tumour with a tendency to protrude into the collecting system.We present a 50-year-old woman with a renal tumour extending up to the vesicoureteric junctio...Mixed epithelial and stromal tumour(MEST)is an uncommon renal tumour with a tendency to protrude into the collecting system.We present a 50-year-old woman with a renal tumour extending up to the vesicoureteric junction(VUJ)who was suspected to have an upper tract transitional cell carcinoma for which a nephroureterectomy was performed.Histopathologic examination revealed a MEST arising from the kidney and extending up to the VUJ.To the best of our knowledge,this is the first report of a renal MEST with extension to the VUJ.展开更多
可编程约瑟夫森电压基准(programmable Josephson voltage standard,PJVS)通过生成阶梯波构建交流量子电压,其产生量子电压台阶过程中,会伴生过渡过程,导致电压台阶两端数据的准确性较低。常见的数据处理方法是将过渡过程的数据剔除,仅...可编程约瑟夫森电压基准(programmable Josephson voltage standard,PJVS)通过生成阶梯波构建交流量子电压,其产生量子电压台阶过程中,会伴生过渡过程,导致电压台阶两端数据的准确性较低。常见的数据处理方法是将过渡过程的数据剔除,仅利用量子电压台阶上平稳区的数据,实现交流量子电压量值的复现。针对常用的3σ(σ为数据标准差)准则、片段采样方法等数据筛选准则,该文提出一种由量子电压台阶中心双向延拓并最小化A类测量不确定度的平稳区与过渡区判据,通过自动识别量子电压台阶的平稳区与过渡区,提升PJVS电压阶梯波复现交流电压量值的准确性。实验结果表明:该文提出的数据平稳区与过渡区的判据具有较高的鲁棒性和交流电压复现准确性,在2.5 kHz范围内,可使量子电压阶梯波信号复现交流电压幅值的偏差和A类测量不确定度均优于2.5×10-6。研究成果可有效提升量子电压阶梯波信号的测算准确性。展开更多
On the basis of energy and continuity equations a simple one-dimensionalformulation was proposed to predict the transitional flow at an open-channel junction. An empilicalrelation between the junction losses, the junc...On the basis of energy and continuity equations a simple one-dimensionalformulation was proposed to predict the transitional flow at an open-channel junction. An empilicalrelation between the junction losses, the junction angle, and the discharge ratio was suggestedwhich agrees well with the experimental results. The results calculated by the present formulationfor the depth ratio were compared with the results of earlier one-dimensional formulations andexperiments. It is found that the present results coincide better with experiments than those ofothers.展开更多
The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson ef...The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson effect can be generated in the spin superconductor/normal metal/spin superconductor junctions.Here we study the spin supercurrent in the Josephson junctions consisting of two spin superconductors with noncollinear spin polarizations.For the Josephson junctions with out-of-plane spin polarizations,the possibleπ-state spin supercurrent appears due to the Fermi momentum-splitting Andreev-like reflections at the normal metal/spin superconductor interfaces.For the Josephson junctions with in-plane spin polarizations,the anomalous spin supercurrent appears and is driven by the misorientation angle of the in-plane polarizations.The symmetry analysis shows that the appearance of the anomalous spin Josephson current is possible when the combined symmetry of the spin rotation and the time reversal is broken.展开更多
We investigate dynamical phase transitions that are induced by interspecies interaction in a two-species bosonic Josephson junctions （B J J）, based on semi-classical theory. In zero-phase mode, similar to the case o...We investigate dynamical phase transitions that are induced by interspecies interaction in a two-species bosonic Josephson junctions （B J J）, based on semi-classical theory. In zero-phase mode, similar to the case of a single-species B J J, we observe the well-known dynamical phase transition from Josephson oscillation to self-trapping, which can be induced by both enhanced repulsive and attractive interspecies interactions. In π phase mode, dynamical phase transitions are even more interesting and counter- intuitive. We characterize a dynamical phase transition with the merging of two separate phase space domains into one, which is induced by increasing repulsive interspecies interaction. On the other hand, we find that by increasing attractive interspecies interaction, a phase separation of two formally overlapped phase space domains will occur. At last, we reveal that these intriguing dynamical phase transitions are caused by different kinds of bifurcations.展开更多
对一种应用于三相电压型脉宽调制(pulse width modulation,PWM)变流器的零电流开关(zero current transition,ZCT)软开关技术进行深入理论分析,通过数学推导和实验验证指出,由于功率器件二极管反向恢复和结电容的影响,理想的软开关过程...对一种应用于三相电压型脉宽调制(pulse width modulation,PWM)变流器的零电流开关(zero current transition,ZCT)软开关技术进行深入理论分析,通过数学推导和实验验证指出,由于功率器件二极管反向恢复和结电容的影响,理想的软开关过程很难实现,特别是在大功率应用场合。研究表明,虽然采用此ZCT软开关技术可减小主开关管的部分开关损耗,但却引入了多个二极管的反向恢复,总体效率能否提高与功率器件二极管反向恢复电荷和结电容大小有关。展开更多
基金supported by the National Natural Science Foundation of China(52005361)the Central Science and Technology Research Fund(YDZJSX2022A022)+3 种基金the Postdoctoral Science Foundation of China(2021M692373)the State Key Laboratory of Material Processing and Mold Technology of Huazhong University of Science and Technology(P2022-004)the China Postdoctoral Science Foundation Project(2023T160474)Open Research Fund from the Hai'an&Taiyuan University of Technology Advanced Manufacturing and Intelligent Equipment Industrial Research Institute(2023HA-TYUTKFYF019).
文摘Based on the two-pass differential temperature rolling bonding method,the effects of prefabricated steel/aluminum composite panel temperature on interface characteristics and microstructure properties were investigated through experimental analysis and finite element simulations.When the temperature exceeds 400℃,the effective preparation of the steel-aluminum transition joint can be achieved,and with the increase in temperature,the interface shear and pull-off strength of the steel-aluminum transition joint exhibits an initial decrease followed by an increase.Both the interface shear and pull-off fractures are in 1060 aluminum matrix.As the temperature increases,the size of the average grain in 1060 aluminum matrix increases and then decreases.When the temperature reaches 550℃,the comprehensive performance of the prepared steel-aluminum transition joint is the best,with the interface shear strength of 77 MPa and the interface pull-off strength of 153 MPa,exceeding the bonding strength of the explosive compounding method.There are no pinholes,wrinkles,or cracks in the lateral bending matrix and the interface.
基金Supported by Ministry of Education,Culture,Sports Science,and Technology,and the Ministry of Health,Labour and Welfare of Japan
文摘Pancreatic cancer continues to be a leading cause of cancer-related death worldwide and there is an urgent need to develop novel diagnostic and therapeutic strategies to reduce the mortality of patients with this disease. In pancreatic cancer, some tight junction proteins, including claudins, are abnormally regulated and therefore are promising molecular targets for diagnosis, prognosis and therapy. Claudin-4 and-18 are overexpressed in human pancreatic cancer and its precursor lesions. Claudin-4 is a high affinity receptor of Clostridium perfringens enterotoxin(CPE). The cytotoxic effects of CPE and monoclonal antibodies against claudin-4 are useful as novel therapeutic tools for pancreatic cancer. Claudin-18 could be a putative marker and therapeutic target with prognostic implications for patients with pancreatic cancer. Claudin-1,-7, tricellulin and marvelD3 are involved in epithelial to mesenchymal transition(EMT) of pancreatic cancer cells and thus might be useful as biomarkers during disease. Protein kinase C is closely related to EMT of pancreatic cancer and regulates tight junctions of normal human pancreatic duct epithelial cells and the cancer cells. This review focuses on the regulation of tight junctions via protein kinase C during EMT in human pancreatic cancer for the purpose of developing new diagnostic and therapeutic modalities for pancreatic cancer.
文摘The ancient emission formulas of Langmuir and Richardson entered the calculations of subtle effects in semiconductor devices as basic ones.But,in the physics of semiconductor devices,these models have long played a purely decorative role,since they can describe in the most rough approximation only individual sections of the I-V characteristic.But it is precisely the fact that these formulas are basic when describing the barrier current-voltage characteristics(CVC)and prevented the consideration and use of thermoelectric effects in materials on a nano-scale.Thus,as these basic emission models actually imposed a ban on the MEASURABILITY of local thermoelectric effects,the existence of which has already been proven both phenomenologically and experimentally.The quantum transition technique is based on classical models.But it can also be used to correct these classic formulas.The calculation of the spatial transition of electrons over the potential barrier,taking into account the polarity of the kinetic energy,gives currents that are significantly higher than the currents of Langmuir and Richardson,including in the initial section of the I-V characteristic.Moreover,ballistic currents are concentrated at energy levels close to the threshold.This effect of condensation of electrons flowing down the barrier transforms the"anomalous"Seebeck coefficients into normal MEASURABLE Local Thermal EMF,including in p-n junctions.
基金Project supported by the National Natural Science Foundation of China(Grant No.61006044)the Natural Science Foundation of Beijing,China(Grant Nos.4122014 and 4142007)the Fund from the Beijing Municipal Education Committee,China(Grant No.KM200910005001)
文摘In this paper, the positive influence of a uni-traveling-carrier （UTC） structure to ease the contract between the respon- sivity and working speed of the InP-based double hetero-junction phototransistor （DHPT） is illustrated in detail. Different results under electrical bias, optical bias or combined electrical and optical bias are analyzed for an excellent UTC-DHPT performance. The results show that when the UTC-DHPT operates at three-terminal （3T） working mode with combined electrical bias and optical bias in base, it keeps a high optical responsivity of 34.72 A/W and the highest optical transition frequency of 120 GHz. The current gain of the 3T UTC-DHPT under 1.55-μm light illuminations reaches 62 dB. This indicates that the combined base electrical bias and optical bias of 3T UTC-DHPT can make sure that the UTC-DHPT provides high optical current gain and high optical transition frequency simultaneously.
文摘In this paper we study the traffic states and jams in vehicular traffic merging and bifurcating at a junction on a two-lane highway. The two-lane traffic model for the vehicular motion at the junction is presented where a jam occurs frequently due to merging, lane changing, and bifurcating. The traffic flow is called the weaving. At the weaving section, vehicles slow down and then move aside on the other lane for changing their direction. We derive the fundamental diagrams (flow-density diagrams) for the weaving traffic flow. The traffic states vary with the density, slowdown speed, and the fraction of vehicles changing the lane. The dynamical phase transitions occur. It is shown that the fundamental diagrams depend highly on the traffic states.
基金Project supported by the National Natural Science Foundation of China(Grant No.11653001)the National Basic Research Program of China(Grant No.2011CBA00304)Tsinghua University Initiative Scientific Research Program,China(Grant No.20131089314)
文摘The superconducting quantum interference device（SQUID） amplifier is widely used in the field of weak signal detection for its low input impedance, low noise, and low power consumption. In this paper, the SQUIDs with identical junctions and the series SQUIDs with different junctions were successfully fabricated. The Nb/Al-AlOx/Nb trilayer and input Nb coils were prepared by asputtering equipment. The SQUID devices were prepared by a sputtering and the lift-off method.Investigations by AFM, OM and SEM revealed the morphology and roughness of the Nb films and Nb/Al-AlOx/Nb trilayer.In addition, the current–voltage characteristics of the SQUID devices with identical junction and different junction areas were measured at 2.5 K in the He^3 refrigerator. The results show that the SQUID modulation depth is obviously affected by the junction area. The modulation depth obviously increases with the increase of the junction area in a certain range. It is found that the series SQUID with identical junction area has a transimpedance gain of 58 Ω approximately.
文摘Mixed epithelial and stromal tumour(MEST)is an uncommon renal tumour with a tendency to protrude into the collecting system.We present a 50-year-old woman with a renal tumour extending up to the vesicoureteric junction(VUJ)who was suspected to have an upper tract transitional cell carcinoma for which a nephroureterectomy was performed.Histopathologic examination revealed a MEST arising from the kidney and extending up to the VUJ.To the best of our knowledge,this is the first report of a renal MEST with extension to the VUJ.
文摘可编程约瑟夫森电压基准(programmable Josephson voltage standard,PJVS)通过生成阶梯波构建交流量子电压,其产生量子电压台阶过程中,会伴生过渡过程,导致电压台阶两端数据的准确性较低。常见的数据处理方法是将过渡过程的数据剔除,仅利用量子电压台阶上平稳区的数据,实现交流量子电压量值的复现。针对常用的3σ(σ为数据标准差)准则、片段采样方法等数据筛选准则,该文提出一种由量子电压台阶中心双向延拓并最小化A类测量不确定度的平稳区与过渡区判据,通过自动识别量子电压台阶的平稳区与过渡区,提升PJVS电压阶梯波复现交流电压量值的准确性。实验结果表明:该文提出的数据平稳区与过渡区的判据具有较高的鲁棒性和交流电压复现准确性,在2.5 kHz范围内,可使量子电压阶梯波信号复现交流电压幅值的偏差和A类测量不确定度均优于2.5×10-6。研究成果可有效提升量子电压阶梯波信号的测算准确性。
文摘On the basis of energy and continuity equations a simple one-dimensionalformulation was proposed to predict the transitional flow at an open-channel junction. An empilicalrelation between the junction losses, the junction angle, and the discharge ratio was suggestedwhich agrees well with the experimental results. The results calculated by the present formulationfor the depth ratio were compared with the results of earlier one-dimensional formulations andexperiments. It is found that the present results coincide better with experiments than those ofothers.
基金Project supported by the National Key R&D Program of China(Grant No.2022YFA1403601).
文摘The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson effect can be generated in the spin superconductor/normal metal/spin superconductor junctions.Here we study the spin supercurrent in the Josephson junctions consisting of two spin superconductors with noncollinear spin polarizations.For the Josephson junctions with out-of-plane spin polarizations,the possibleπ-state spin supercurrent appears due to the Fermi momentum-splitting Andreev-like reflections at the normal metal/spin superconductor interfaces.For the Josephson junctions with in-plane spin polarizations,the anomalous spin supercurrent appears and is driven by the misorientation angle of the in-plane polarizations.The symmetry analysis shows that the appearance of the anomalous spin Josephson current is possible when the combined symmetry of the spin rotation and the time reversal is broken.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 11104217 and 11402199）, the Science Plan Foundation office of the Education Department of Shaanxi Province （Grant No. 14JK1676）, and the Natural Science Foundation of Shaanxi Province （Grant No. 14JQ1022）.
文摘We investigate dynamical phase transitions that are induced by interspecies interaction in a two-species bosonic Josephson junctions （B J J）, based on semi-classical theory. In zero-phase mode, similar to the case of a single-species B J J, we observe the well-known dynamical phase transition from Josephson oscillation to self-trapping, which can be induced by both enhanced repulsive and attractive interspecies interactions. In π phase mode, dynamical phase transitions are even more interesting and counter- intuitive. We characterize a dynamical phase transition with the merging of two separate phase space domains into one, which is induced by increasing repulsive interspecies interaction. On the other hand, we find that by increasing attractive interspecies interaction, a phase separation of two formally overlapped phase space domains will occur. At last, we reveal that these intriguing dynamical phase transitions are caused by different kinds of bifurcations.
文摘对一种应用于三相电压型脉宽调制(pulse width modulation,PWM)变流器的零电流开关(zero current transition,ZCT)软开关技术进行深入理论分析,通过数学推导和实验验证指出,由于功率器件二极管反向恢复和结电容的影响,理想的软开关过程很难实现,特别是在大功率应用场合。研究表明,虽然采用此ZCT软开关技术可减小主开关管的部分开关损耗,但却引入了多个二极管的反向恢复,总体效率能否提高与功率器件二极管反向恢复电荷和结电容大小有关。
