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Strengthening the Disciplinary Construction of History of Medicine: A Call for Action by Chinese Academy of Medical Sciences & Peking Union Medical College
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作者 Jian-Hong Yao Da-Qing Zhang +7 位作者 Xin-Zhong Yu Shu-Jian Zhang Yong-An Zhang Xiang-Yin Yang Zhong He Huan Liu Yong Wang Yue-Ying Jin 《Chinese Medical Sciences Journal》 CAS CSCD 2023年第2期94-96,共3页
Recent years have witnessed a dynamic develop of Peking Union Medical College(PUMC),which was founded in 1921,and Chinese Academy of Medical Sciences(CAMS),which was founded in 1956.In the new era of building a"H... Recent years have witnessed a dynamic develop of Peking Union Medical College(PUMC),which was founded in 1921,and Chinese Academy of Medical Sciences(CAMS),which was founded in 1956.In the new era of building a"Healthy China",General Secretary Xi Jinping has emphasized the importance of a profound understanding of the Chinese civilization to let the world better know and understand China,and urged efforts to combine theories and practices to expound how to better uphold the Chinese path,promote the Chinese spirit,and pool together the Chinese strength[1].As an active response,PUMC organized the first Conference of History of Medicine on May 20-21,2023[2],Based on the rich history of PUMC and with an attempt to explore history,inherit the traditional Chinese culture,and promote the spirit of modern medicine,we issued the following call at the conference。 展开更多
关键词 HISTORY COMBINE PEKING
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Review on the Impact of Climate Change on Great Lakes Region’s Agriculture and Water Resources
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作者 Zeyu Shen 《Journal of Geoscience and Environment Protection》 2024年第7期165-176,共12页
This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technol... This study investigates the multifaceted impacts of climate change on the Midwest region of the United States, particularly the rising temperatures and precipitation brought about by hot weather activities and technological advances since the 19th century. From 1900 to 2010, temperatures in the Midwest rose by an average of 1.5 degrees Fahrenheit, which would also lead to an increase in greenhouse gas emissions. Precipitation is also expected to increase due to increased storm activity and changes in regional weather patterns. This paper explores the impact of these changes on urban and agricultural areas. In urban areas such as the city of Chicago, runoff from the increasing impervious surface areas poses challenges to the drainage system, and agriculture areas are challenged by soil erosion, nutrient loss, and fewer planting days due to excessive rainfall. Sustainable solutions such as no-till agriculture and the creation of grassland zones are discussed. Using historical data, recent climate studies and projections, the paper Outlines ways to enhance the Midwest’s ecology and resilience to climate change. 展开更多
关键词 Climate Change Midwest USA Agricultural Impacts Urban Runoff Sustainable Practices Precipitation Patterns Temperature Increase Greenhouse Gas Emissions Soil Erosion Water Management
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Effect of acetyl-L-carnitine on hypersensitivity in acute recurrent caerulein-induced pancreatitis and microglial activation along the brain’s pain circuitry 被引量:4
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作者 Sabrina L McIlwrath Marlene E Starr +2 位作者 Abigail E High Hiroshi Saito Karin N Westlund 《World Journal of Gastroenterology》 SCIE CAS 2021年第9期794-814,共21页
BACKGROUND Acute pancreatitis(AP)and recurring AP are serious health care problems causing excruciating pain and potentially lethal outcomes due to sepsis.The validated caerulein-(CAE)induced mouse model of acute/recu... BACKGROUND Acute pancreatitis(AP)and recurring AP are serious health care problems causing excruciating pain and potentially lethal outcomes due to sepsis.The validated caerulein-(CAE)induced mouse model of acute/recurring AP produces secondary persistent hypersensitivity and anxiety-like behavioral changes for study.AIM To determine efficacy of acetyl-L-carnitine(ALC)to reduce pain-related behaviors and brain microglial activation along the pain circuitry in CAE-pancreatitis.METHODS Pancreatitis was induced with 6 hly intraperitoneal(i.p.)injections of CAE(50μg/kg),3 d a week for 6 wk in male C57BL/6J mice.Starting in week 4,mice received either vehicle or ALC until experiment’s end.Mechanical hypersensitivity was assessed with von Frey filaments.Heat hypersensitivity was determined with the hotplate test.Anxiety-like behavior was tested in week 6 using elevated plus maze and open field tests.Microglial activation in brain was quantified histologically by immunostaining for ionized calcium-binding adaptor molecule 1(Iba1).RESULTS Mice with CAE-induced pancreatitis had significantly reduced mechanical withdrawal thresholds and heat response latencies,indicating ongoing pain.Treatment with ALC attenuated inflammation-induced hypersensitivity,but hypersensitivity due to abdominal wall injury caused by repeated intraperitoneal injections persisted.Animals with pancreatitis displayed spontaneous anxiety-like behavior in the elevated plus maze compared to controls.Treatment with ALC resulted in increased numbers of rearing activity events,but time spent in“safety”was not changed.After all the abdominal injections,pancreata were translucent if excised at experiment’s end and opaque if excised on the subsequent day,indicative of spontaneous healing.Post mortem histopathological analysis performed on pancreas sections stained with Sirius Red and Fast Green identified wide-spread fibrosis and acinar cell atrophy in sections from mice with CAE-induced pancreatitis that was not rescued by treatment with ALC.Microglial Iba1 immunostaining was significantly increased in hippocampus,thalamus(intralaminar nuclei),hypothalamus,and amygdala of mice with CAE-induced pancreatitis compared to naïve controls but unchanged in the primary somatosensory cortex compared to naïves.CONCLUSION CAE-induced pancreatitis caused increased pain-related behaviors,pancreatic fibrosis,and brain microglial changes.ALC alleviated CAE-induced mechanical and heat hypersensitivity but not abdominal wall injury-induced hypersensitivity caused by the repeated injections. 展开更多
关键词 Acute recurrent pancreatitis Neuropathic pain Mechanical hypersensitivity Heat hypersensitivity Anxiety-like behavior Ionized calcium-binding adaptor molecule 1
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Biaxial mechanical behavior of closed-cell aluminum foam under combined shear-compression loading 被引量:3
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作者 Zhi-bin LI Xue-yan LI Yu-xuan ZHENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第1期41-50,共10页
Combined shear-compression tests and simulations were performed on a closed-cell aluminum foam over a wide range of loading angles in order to probe their yield behaviors under biaxial loading conditions.Combined shea... Combined shear-compression tests and simulations were performed on a closed-cell aluminum foam over a wide range of loading angles in order to probe their yield behaviors under biaxial loading conditions.Combined shear-compression tests were carried out by using a pair of cylindrical bars with beveled ends.The yield surfaces were experimentally measured and compared with various theoretical yield surface models.The cellular structures of closed-cell aluminum foams were modeled as tetrakaidecahedrons and their biaxial crushing behaviors were simulated by the finite element method.The results show that,yield initiates from the stress-concentrated corners in the specimens under combined shear-compression loading and the stress distribution is no longer uniform at the specimen/bar interfaces.In the range of cell sizes studied,the larger the foam cell size is,the higher the yield stress is.Aluminum foam density is found to be the dominant factor on its mechanical properties compared with the cell size and is much more significant in engineering practice. 展开更多
关键词 combined shear-compression closed-cell aluminum foam yield surface biaxial loading yield behavior
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Optimal maneuvering strategy of spacecraft evasion based on angles-only measurement and observability analysis 被引量:3
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作者 ZHANG Yijie WANG Jiongqi +2 位作者 HOU Bowen WANG Dayi CHEN Yuyun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第1期172-184,共13页
Spacecraft orbit evasion is an effective method to ensure space safety. In the spacecraft’s orbital plane, the space non-cooperate target with autonomous approaching to the spacecraft may have a dangerous rendezvous.... Spacecraft orbit evasion is an effective method to ensure space safety. In the spacecraft’s orbital plane, the space non-cooperate target with autonomous approaching to the spacecraft may have a dangerous rendezvous. To deal with this problem, an optimal maneuvering strategy based on the relative navigation observability degree is proposed with angles-only measurements. A maneuver evasion relative navigation model in the spacecraft’s orbital plane is constructed and the observability measurement criteria with process noise and measurement noise are defined based on the posterior Cramer-Rao lower bound. Further, the optimal maneuver evasion strategy in spacecraft’s orbital plane based on the observability is proposed. The strategy provides a new idea for spacecraft to evade safety threats autonomously. Compared with the spacecraft evasion problem based on the absolute navigation, more accurate evasion results can be obtained. The simulation indicates that this optimal strategy can weaken the system’s observability and reduce the state estimation accuracy of the non-cooperative target, making it impossible for the non-cooperative target to accurately approach the spacecraft. 展开更多
关键词 rendezvous evasion orbit maneuver angles-only measurement observability degree posterior Cramer-Rao lower bound
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Integrated Design and Accuracy Analysis of Star Sensor and Gyro on the Same Benchmark for Satellite Attitude Determination System 被引量:2
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作者 Bowen Hou Zhangming He +1 位作者 Haiyin Zhou Jiongqi Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第4期1074-1080,共7页
As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude deter... As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude determination.The error influence of different benchmarks and the disintegration mode between the star sensor and the gyro is analyzed in theory.The integrated design of the star sensor and the gyro on the same benchmark can effectively avoid the error influence and improves the spacecraft attitude determination accuracy.Simulation results indicate that when the stars sensor optical axis vectors overlap the reference coordinate axis of the gyro in the same benchmark,the attitude determination accuracy improves. 展开更多
关键词 ACCURACY analysis ATTITUDE determination GYRO integrated design SAME BENCHMARK STAR sensor
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Impact of atmospheric ionization by delayed radiation from highaltitude nuclear explosions on radio communication 被引量:2
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作者 Heng Xu Jian-Ming Ouyang +2 位作者 Shang-Wu Wang Yun Liu Xu Sun 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第12期58-64,共7页
In this study,we investigated the motion,shape,and delayed radiation intensity of a radioactive cloud by establishing a volume-source model of delayed radiation after high-altitude nuclear explosions.Then,the spatial ... In this study,we investigated the motion,shape,and delayed radiation intensity of a radioactive cloud by establishing a volume-source model of delayed radiation after high-altitude nuclear explosions.Then,the spatial distribution of electron number density at different moments on the north side of the explosion point generated by delayed γ-rays and delayed β-rays from the radioactive cloud under the influence of the geomagnetic field was calculated by solving chemical reaction kinetics equations.The impact of radio communication in the different frequency bands on the process of atmospheric ionization was also studied.The numerical results of the high-altitude nuclear explosion (120 km high and with a 1 megaton equivalent at 40°N latitude) indicated that the peak of electron number density ionized delayed γ-rays is located at a height of approximately 100 km and that of electron number density ionized delayed β-rays is about 90 km high.After 1 min of explosion,the radio communication in the medium frequency (MF) and high-frequency (HF)bands was completely interrupted,and the energy attenuation of the radio wave in the very high-frequency (VHF)band was extremely high.Five minutes later,the VHF radio communication was basically restored,but the energy attenuation in the HF band was still high.After 30 min,theVHF radio communication returned to normal,but its influence on the HF and MF radio communication continued. 展开更多
关键词 HIGH-ALTITUDE NUCLEAR explosions DELAYED RADIATION IONIZATION effect Radio communication
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The Practice of Physical Medicine and Rehabilitation in subSaharan Africa and Antarctica:A White Paper or a Black Mark? 被引量:3
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作者 Andrew J. Haig MD Jonathan Im +2 位作者 Ayodeji Adewole, MD Virgina S. Nelson, MD, M.P.H Brian Krabak, MD, M.B.A. 《中国康复医学杂志》 CAS CSCD 北大核心 2009年第5期385-389,共5页
Objective:To explore the practice of PM&R in subSaharan Africa and Antarctica.Method:Medline searches,membership data searches,fax survey of medical schools,Internet searches,and interviews with experts.Result:The... Objective:To explore the practice of PM&R in subSaharan Africa and Antarctica.Method:Medline searches,membership data searches,fax survey of medical schools,Internet searches,and interviews with experts.Result:The continents are dissimilar in terms of climate and government.However both Antarctica and subSaharan Africa have no PM&R training programs,no professional organizations,no specialty board requirements,and no practicing physicians in the field.Since there is no known disabled child on Antarctica and adults are airlifted to world-class health care,the consequences of this deficit are minimal there.However the 788,000,000 permanent residents of subSaharan Africa including approximately 78 million persons with disability are left unserved.Conclusion:Antarctica is doing fine.Africa is in a crisis.Local medical schools,hospitals doctors,and persons with disability;along with foreign volunteers,aid groups,and policymakers can impact the crisis.However government-specifically national ministries of health-is ultimately responsible for the health and wellbeing of citizens. 展开更多
关键词 体格检查 医学 文献资料 因特网
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The process of life adjustment in patients at onset of glioma who are receiving continuous oral anticancer drug: A qualitative descriptive study 被引量:2
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作者 Koji Amano Kumi Suzuki 《International Journal of Nursing Sciences》 CSCD 2019年第2期134-140,共7页
Objective: Patients with malignant gliomas have to adjust their daily lives because of the threat of impending death and declining abilities.Thus,clarifying the process of life adjustment in such patients would help t... Objective: Patients with malignant gliomas have to adjust their daily lives because of the threat of impending death and declining abilities.Thus,clarifying the process of life adjustment in such patients would help them lead a normal life.To clarify the process of life adjustment in patients at the onset of glioma,who continuously receive oral anticancer drug.Methods: The study institution consisted of two designated cancer centers.Semi-structured interviews were conducted with 10 patients,and the data were analyzed using the Modified Grounded Theory Approach of Kinoshita (M-GTA).Results: As a core category representing the process of life adjustment in patients at the onset of glioma,"trials and errors for self-fulfillment even in a limited lifespan" was extracted.Patients began "seeking information about the unfamiliar life-threatening disease," and "imaging their uncertain lives after the disease and the resulting disability" while "conducting repeated trials and errors to establish coping methods according to their abilities." When facing difficulties in such trials and errors,they reported "losing self-confidence due to unexpected limitations." However,they regulated their feelings by "resigning themselves to their unchangeable reality." Contrarily,as "functional improvement enhanced their motivation to recover," they attempted to promote functional recovery and organized their daily lives in "fulfilling their desires in their limited lifespan." Conclusion: The process of life adjustment in patients with malignant gliomas involved identifying a way of living despite limited lifespan.To ensure appropriate nursing care for patients at the onset of glioma,it is important to help them establish coping methods in accordance with their abilities. 展开更多
关键词 Adjustment LIFE Malignant glioma PATIENTS Qualitative study
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TOA positioning algorithm of LBL system for underwater target based on PSO 被引量:2
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作者 XING Yao WANG Jiongqi +3 位作者 HE Zhangming ZHOU Xuanying CHEN Yuyun PAN Xiaogang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第5期1319-1332,共14页
For the underwater long baseline(LBL)positioning systems,the traditional distance intersection algorithm simplifies the sound speed to a constant,and calculates the underwa-ter target position parameters with a nonlin... For the underwater long baseline(LBL)positioning systems,the traditional distance intersection algorithm simplifies the sound speed to a constant,and calculates the underwa-ter target position parameters with a nonlinear iteration.However,due to the complex underwater environment,the sound speed changes with time and space,and then the acoustic propagation path is actually a curve,which inevitably causes some errors to the traditional distance intersection positioning algorithm.To reduce the position error caused by the uncertain underwater sound speed,a new time of arrival(TOA)intersection underwater positioning algorithm of LBL system is proposed.Firstly,combined with the vertical layered model of the underwater sound speed,an implicit positioning model of TOA intersection is constructed through the constant gradient acoustic ray tracing.And then an optimization function based on the overall TOA residual square sum is advanced to solve the position parameters for the underwater target.Moreover,the particle swarm optimization(PSO)algorithm is replaced with the tra-ditional nonlinear least square method to optimize the implicit positioning model of TOA intersection.Compared with the traditional distance intersection positioning model,the TOA intersec-tion positioning model is more suitable for the engineering practice and the optimization algorithm is more effective.Simulation results show that the proposed methods in this paper can effectively improve the positioning accuracy for the underwater target. 展开更多
关键词 long baseline(LBL)positioning system sound speed profile constant gradient acoustic ray tracing time of arrival(TOA)intersection model particle swarm optimization(PSO)
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The triple stigma of HIV and chemsex among gays,bisexuals,and other men who have sex with men(GBMSM)in the Philippines 被引量:2
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作者 Rowalt C.Alibudbud 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2022年第11期477-478,共2页
The Philippines has an HIV crisis that mostly affects gays,bisexuals,and other men who have sex with men(GBMSM)[1,2].Between 2010 and 2017,the number of people newly diagnosed with HIV increased from 16000 to 68000[1]... The Philippines has an HIV crisis that mostly affects gays,bisexuals,and other men who have sex with men(GBMSM)[1,2].Between 2010 and 2017,the number of people newly diagnosed with HIV increased from 16000 to 68000[1].During the COVID-19 pandemic,the crisis worsened with HIV testing and antiretroviral treatment decreasing by 61%and 28%,respectively[2].Among others,pervasive societal stigma contributes to the HIV crisis in the country[1-3]. 展开更多
关键词 GBM mostly WHO
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Study of neutron production and moderation for sulfur neutron capture therapy 被引量:1
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作者 Meng Peng Guo-Zhu He +3 位作者 Qi-Wei Zhang Bin Shi Hong-Qing Tang Zu-Ying Zhou 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第1期59-66,共8页
Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy ... Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy is whether the neutron beam flux and the resonance capture cross section of ^(33)S(n;α)^(30) Si reaction at 13.5 keV can achieve the requirements of radiotherapy. In this research,the authors investigated the production of 13.5 keV neutron production and moderation based on an accelerator neutron source. A lithium glass detector was used to measure the neutron flux produced via near threshold^7 Li(p,n)~7 Be reaction using the time-of-flight method. Furthermore, the moderation effects of different kinds of materials were investigated using Monte Carlo simulation. 展开更多
关键词 SULFUR NEUTRON CAPTURE THERAPY BORON NEUTRON CAPTURE THERAPY 33S(n α)3 Si resonance reaction 7Li(p n)^7 Be NEUTRON source
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Numerical studies on the radiation uniformity of Z-pinch dynamic hohlraum 被引量:2
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作者 Fuyuan Wu Yanyun Chu +13 位作者 Rafael Ramis Zhenghong Li Yanyun Ma Jianlun Yang Zhen Wang Fan Ye Zhanchang Huang Jianmin Qi Lin Zhou Chuan Liang Shijia Chen Zheyi Ge Xiaohu Yang Shangwu Wang 《Matter and Radiation at Extremes》 SCIE EI CAS 2018年第5期248-255,共8页
Radiation uniformity is important for Z-pinch dynamic hohlraum driven fusion. In order to understand the radiation uniformity of Z-pinchdynamic hohlraum, the code MULTI-2D with a new developed magnetic field package i... Radiation uniformity is important for Z-pinch dynamic hohlraum driven fusion. In order to understand the radiation uniformity of Z-pinchdynamic hohlraum, the code MULTI-2D with a new developed magnetic field package is employed to investigate the related physical processeson Julong-I facility with drive current about 7e8 MA. Numerical simulations suggest that Z-pinch dynamic hohlraum with radiation temperaturemore than 100 eV can be created on Julong-I facility. Although some X-rays can escape out of the hohlraum from Z-pinch plasma and electrodes, the radiation field near the foam center is quite uniform after a transition time. For the load parameters used in this paper, the transitiontime for the thermal wave transports from r = 1 mm to r = 0 mm is about 2.0 ns. Implosion of a testing pellet driven by cylindrical dynamichohlraum shows that symmetrical implosion is hard to achieve due to the relatively slow propagation speed of thermal wave and the compressionof cylindrical shock in the foam. With the help of quasi-spherical implosion, the hohlraum radiation uniformity and corresponding pelletimplosion symmetry can be significantly improved thanks to the shape modulation of thermal wave front and shock wave front. 展开更多
关键词 Z-PINCH Dynamic hohlraum Radiation uniformity Shock wave Thermal wave
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Role of Bloch oscillation in high-order harmonic generation from periodic structure 被引量:1
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作者 Lu Liu Jing Zhao +1 位作者 Jian-Min Yuan Zeng-Xiu Zhao 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第11期60-66,共7页
The high-order harmonic generation from a model solid structure driven by an intense laser pulse is investigated using the semiconductor Bloch equations(SBEs). The main features of harmonic spectrum from SBEs agree we... The high-order harmonic generation from a model solid structure driven by an intense laser pulse is investigated using the semiconductor Bloch equations(SBEs). The main features of harmonic spectrum from SBEs agree well with the result of the time-dependent Schro¨dinger equation(TDSE), and the cut-off energy can be precisely estimated by the recollision model. With increasing the field strength, the harmonic spectrum shows an extra plateau. Based on the temporal population of electron and the time–frequency analysis, the harmonics in the extra plateau are generated by the Bloch oscillation. Due to the ultrafast time response of the Bloch electron, the generated harmonics provide a potential source of shorter isolated attosecond pulse. 展开更多
关键词 high-order harmonic generation attosecond pulse semiconductor Bloch equations time-dependent Schrodinger equation
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Utilizing bimetallic catalysts to mitigate coke formation in dry reforming of methane 被引量:1
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作者 Jaylin Sasson Bitters Tina He +3 位作者 Elizabeth Nestler Sanjaya D.Senanayake Jingguang G.Chen Cheng Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第5期124-142,共19页
Dry reforming of methane(DRM) involves the conversion of carbon dioxide(CO_(2)) and methane(CH_(4)) into syngas(a mixture of hydrogen, H_(2), and carbon monoxide, CO), which can then be used to produce a wide range of... Dry reforming of methane(DRM) involves the conversion of carbon dioxide(CO_(2)) and methane(CH_(4)) into syngas(a mixture of hydrogen, H_(2), and carbon monoxide, CO), which can then be used to produce a wide range of products by means of Fischer–Tropsch synthesis. DRM has gained much attention as a means of mitigating damage from anthropogenic greenhouse gas(GHGs) emissions to the environment and instead utilizing these gases as precursors for value-added chemicals or to synthesize sustainable fuels and chemicals. Carbon deposition or coke formation, a primary cause of catalyst deactivation, has proven to be a major challenge in the development of DRM catalysts. The use of nickel-and cobalt-based catalysts has been extensively explored for DRM for their high activity and low cost but suffer from poor stability due to coke formation that has hindered their commercialization. Numerous articles have reviewed the various aspects of catalyst deactivation and strategies for mitigation, but few has focused on the benefit of bimetallic catalysts for mitigating coke formation. Bimetallic catalysts, often improve the catalytic stability over their monometallic counterparts due to synergistic effects resulting from two metal-tometal interactions. This review will cover DRM literature for various bimetallic catalyst systems, including the effect of supports and promoters, on the mitigation of carbonaceous deactivation. 展开更多
关键词 Dry reforming of methane Carbon dioxide Bimetallic catalysts Coke formation Catalyst stability
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Addressing the needs and rights of sex workers for HIV healthcare services in the Philippines 被引量:1
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作者 ROWALT C ALIBUDBUD 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第8期335-336,共2页
The right to health for all people means that healthcare services and programs are available,accessible,and acceptable for everyone in need.However,certain groups in the society may be marginalized from their needed h... The right to health for all people means that healthcare services and programs are available,accessible,and acceptable for everyone in need.However,certain groups in the society may be marginalized from their needed healthcare services.In this regard,this paper discusses the challenges in providing HIV-related services to sex workers,a group that remains marginalized in Philippine society. 展开更多
关键词 SERVICES workers EVERYONE
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Polarity Reversal of Terahertz Electric Field from Heavily p-Doped Silicon Surfaces 被引量:1
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作者 Hai-Zhong Wu Quan Guo +7 位作者 Yan-Yun Tu Zhi-Hui Lyu Xiao-Wei Wang Yong-Qiang Li Zhao-Yan Zhou Dong-Wen Zhang Zeng-Xiu Zhao Jian-Min Yuan 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第7期34-39,共6页
Above-band-gap optical excitation of electron-hole pairs screens the doping-induced surface electric field and generates terahertz(THz)pulses via free-carrier transport.THz emission from a heavily doped silicon surfac... Above-band-gap optical excitation of electron-hole pairs screens the doping-induced surface electric field and generates terahertz(THz)pulses via free-carrier transport.THz emission from a heavily doped silicon surface is much weaker than that of lightly doped samples.A polarity reversal of the THz electric field is observed in heavily doped p-type silicon,indicating that the doping related and carrier induced surface electric fields oppose each other.By comparing the penetration depth of the excitation laser with the thickness of the depletion layer for the doped silicon,it is shown that competition between diffusion and drift current causes the polarity reversal. 展开更多
关键词 EXCITATION DOPING polarity
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General analytical method of designing shielded coils for arbitrary axial magnetic field
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作者 Yi Zhang Yu-Jiao Li +3 位作者 Qi-Yuan Jiang Zhi-Guo Wang Tao Xia and Hui Luo 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第11期134-139,共6页
Magnetic coils for specific requirements are widely used in modern quantum physics. In this study, a general analytical method of designing the shielded coils for generating an arbitrary axial magnetic field is propos... Magnetic coils for specific requirements are widely used in modern quantum physics. In this study, a general analytical method of designing the shielded coils for generating an arbitrary axial magnetic field is proposed. The theoretical formula for an axial magnetic field generated by a single shielded coil is obtained and used to construct specific coils. The structural parameters of these coils are determined by fitting the theoretical formula with their specific requirements. The feasibility of this method is proved by realizing four concrete kinds of coils: uniform magnetic field generating coils, gradient magnetic field generating coils, asymmetrical uniform magnetic field generating coils, and parabolic magnetic field generating coils. The correctness of these theoretical results is demonstrated by both the finite element simulations and the relevant experimental results. Furthermore, the application of this method is of great significance for developing the quantum physics and quantum devices in future. 展开更多
关键词 MAGNETIC coils ANALYTICAL method SHIELDING QUANTUM DEVICE
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The Failure Mechanisms of Ultra-high Molecular Weight Polyethylene Fibre Composites Under In-plane Compression
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作者 刘国亮 张玉武 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2020年第1期240-247,共8页
The in-plane compressive characteristics of the ultra-high molecular weight polyethylene(UHMWPE)fibre(Dyneema█)reinforced composites,both in 0/90°and±45°fibre orientations with respect to the loading d... The in-plane compressive characteristics of the ultra-high molecular weight polyethylene(UHMWPE)fibre(Dyneema█)reinforced composites,both in 0/90°and±45°fibre orientations with respect to the loading direction,have been investigated.The composite made from unidirectional high modulus fibres(volume fraction 83%)and low strength polyurethane matrix(volume fraction 17%)is layered in an orthogonally alternating manner.The different failure mechanisms for the composites with 0/90°and±45°fibre orientations have been detected with the methods of experimental measurement,SEM observation and theoretical analysis.The composites specimens of 0/90°fibre orientation failed with macro-buckling of the high-modulus UHMWEP fibre layers with the matrix damage,whereas the specimens of±45°fibre orientation failed with the shearing of the soft matrix.Hence,the composite specimens in 0/90°fibre orientation had higher stiffness as well as compressive strength than those in±45°fibre orientation.The failure criteria of the composites under in-plane compression was employed to characterize the failure mechanism.Compared with the traditional thermoset matrix,the soft thermoplastic matrix leads to lower strength and higher failure strain of fibre reinforced composites under in-plane compression.In addition,the composite specimens cut by waterjet machine exhibited higher stress levels than those cut by bandsaw that introduced more initial imperfections with the temperature rising and tensile shocking.The comparison between the methodologies for cutting the tough composites can provide a valuable suggestion to obtain required composite structures without reducing the mechanical properties. 展开更多
关键词 UHMWPE FIBRE composites IN-PLANE compression FAILURE mechanisms FIBRE BUCKLING matrix SHEARING
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EXPONENTIAL STABILITY OF A MULTI-PARTICLE SYSTEM WITH LOCAL INTERACTION AND DISTRIBUTED DELAY
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作者 Yicheng LIU 《Acta Mathematica Scientia》 SCIE CSCD 2022年第5期2165-2187,共23页
For a collective system,the connectedness of the adjacency matrix plays a key role in making the system achieve its emergent feature,such as flocking or multi-clustering.In this paper,we study a nonsymmetric multi-par... For a collective system,the connectedness of the adjacency matrix plays a key role in making the system achieve its emergent feature,such as flocking or multi-clustering.In this paper,we study a nonsymmetric multi-particle system with a constant and local cut-off weight.A distributed communication delay is also introduced into both the velocity adjoint term and the cut-off weight.As a new observation,we show that the desired multi-particle system undergoes both flocking and clustering behaviors when the eigenvalue 1 of the adjacency matrix is semi-simple.In this case,the adjacency matrix may lose the connectedness.In particular,the number of clusters is discussed by using subspace analysis.In terms of results,for both the non-critical and general neighbourhood situations,some criteria of flocking and clustering emergence with an exponential convergent rate are established by the standard matrix analysis for when the delay is free.As a distributed delay is involved,the corresponding criteria are also found,and these small time lags do not change the emergent properties qualitatively,but alter the final value in a nonlinear way.Consequently,some previous works[14]are extended. 展开更多
关键词 semi-simple eigenvalue flocking emergence clustering emergence distributed delay exponential convergence
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