The action mechanism of the work done by the electric field force on moving charges to stimulate the emergence of carrier generation/recombination in a PN junction

It is discovered that the product of the current and the electric field in a PN junction should be regarded as the rate of work(power)done by the electric field force on moving charges(hole current and electron current),which was previously misinterpreted as solely a Joule heating effect.We clarify that it is exactly the work done by the electric field force on the moving charges to stimulate the emergence of non-equilibrium carriers,which triggers the novel physical phenomena.As regards to Joule heat,we point out that it should be calculated from Ohm’s law,rather than simply from the product of the current and the electric field.Based on this understanding,we conduct thorough discussion on the role of the electric field force in the process of carrier recombination and carrier generation.The thermal effects of carrier recombination and carrier generation followed are incorporated into the thermal equation of energy.The present study shows that the exothermic effect of carrier recombination leads to a temperature rise at the PN interface,while the endothermic effect of carrier generation causes a temperature reduction at the interface.These two opposite effects cause opposite heat flow directions in the PN junction under forward and backward bias voltages,highlighting the significance of managing device heating phenomena in design considerations.Therefore,this study possesses referential significance for the design and tuning on the performance of piezotronic devices.

Development of a new field-deployable RT-qPCR workflow for COVID-19 detection

Background:Outbreaks of coronavirus disease 2019(COVID-19)have been recorded in different countries across the globe.The virus is highly contagious,hence early detection,isolation,and quarantine of infected patients will play an important role in containing the viral spread.Diagnosis in a mobile lab can aid to find infected patients in time.Methods:Here,we develop a field-deployable diagnostic workflow that can reliably detect COVID-19.Instruments used in this workflow can easily fit in a mobile cabin hospital and also be installed in the community.Different steps from sample inactivation to detection were optimized to find the fastest steps and portable instruments in the detection of COVID-19.Each step was compared to that of the normal laboratory diagnosis setup.Results:From the results,our proposed workflow(80 min)was two times faster compared to that of the normal laboratory workflow(183 min)and a maximum of 32 samples could be detected at each run.Additionally,we showed that using 1%Rewocid WK-30 could inactivate the novel coronavirus directly without affecting the overall detection results.Comparison of our workflow using an in-house assay to that of a commercially acquired assay produced highly reliable results.From the 250 hospital samples tested,there was a high concordance 247/250(98.8%)between the two assays.The in-house assay sensitivity and specificity were 116/116(100%)and 131/134(97.8%)compared to that of the commercial assay.Conclusion:Based on these results,we believe that our workflow is fast,reliable,adaptable and most importantly,field-deployable.

Variable Thermal Comfort Index for Indoor Work Space in Office Buildings: A Study in Germany

International standards state the thermal comfort requirements that office spaces must comply with. These are based on a model developed by Prof. Paul Ole Fanger of the Centre for Indoor Environment and Energy, Denmark. Today, forty-year research shows an evolution in these experiences. The work presented here is to develop a tool to evaluate the thermal comfort of working environments of office buildings. A methodology is devised on the basis of on-site measurements and questionnaire responses. For measurements, a mobile unit equipped with sensors is used, whereas the questionnaire obtains user responses on thermal quality of the work space. The thermal conditions of thirty office buildings presenting different acclimatization systems have been surveyed. The correlation between objective and subjective data allows developing a formula that shows the thermal comfort level for a given environment as a function of local aspects. For the surveyed buildings, the resulting comfortable temperature was 23.3℃, and the minimum percentage of user individuals experiencing discomfort with such temperature was 7%.

MY WORK IN THE FIELD OF NUCLEAR PHYSICS

After graduating from the physics department of Qinghua University in 1952, I started working in the development of nuclear detectors (including cloud chambers and scintillometers) under the instruction of Profs. Yang Chengzhong and Dai Chuanzeng at the CAS Institute of Modern Physics.From 1956 to 1958,I studied at Lebedev’s Institute of Physics under the Soviet Academy

MY R&.D WORK IN THE FIELD OF HF RADAR SYSTEMS

Since 1958. I bave been doing research and teaching work at Harbin Polytechnic on the theories of radar,navigational guidance,and signal processing & information treatment by developing new radar systems. In 1979, I went to England in the status of an honorary research fellow and stayed there for two years.probing into HF radar systems under the guidance of the world-famous British marine telemetrist Professor Shearman at Birmingham University.Here.I briefly

MY WORK IN THE FIELD OF FLUID MECHANICS

I graduated from the National Peiyang University (now called Tianjin University) in 1950, majoring in hydraulic engineering. Starting from 1952, my teaching work was basically in mechanics.My first academic probe was in cybernetics, resulting in the publication of the first Chinese paper concerning optimal control. After 1963, I worked on the theory of hydrodynamic stability. My explorative thrust is at the eigenvalues of the Orr Sommerfeld Equation,a non-self adjoint problem in

作为历史空间的海域世界——近代以来日本的海洋史研究

一迈向作为自主历史空间的海域世界之路在与兵库县接壤的冈山县日生町,有一通田渊屋甚九郎的碑。至今还流传着第一代田渊屋甚九郎(?~1734)在享保年间置办千石船,经由五岛列岛,前往朝鲜、吕宋岛等地的传说。备前国冈山藩似乎也有这一故事,在冈山市还有与田渊屋颇有渊源的甚九郎稻荷神社、甚九郎桥。

Rapid excavation with a newly developed retaining system: Spiral assembly steel structure

The spiral assembly steel structure, a newly developed retaining wall for the rapid excavation of small-sized foundation pits in unsaturated soil, is presented. This new type of retaining structure is prefabricated in the factory and is assembled on site in the excavation of a pit. This retaining structure is composed of several prefabricated steel structural units, in which the adjacent steel structural units are joined with connectors. Each steel structural unit has one steel pipe in the radial direction and is welded to a single piece of steel plate. After full installation in situ, the retaining structure becomes a cylindrical steel structure. With the protection afforded by this new type of retaining structure, excavation work can be completed within 24 h to a depth up to 5 m. In order to verify the reliability and effectiveness of this new retaining structure, field construction tests were conducted in Beijing, China. The test construction was monitored. The monitoring program included measuring stress in the structure, lateral earth pressure, and lateral deformation of the surrounding soil. The monitoring data from the field test were compared with the theoretical results. The results show that the proposed new structure is reliable and effective.

双屿港16世纪遗存考古调查报告

16世纪上半叶,葡萄牙人在发现绕经好望角的东西方航线之后,沿马六甲海峡北上,试图在明朝东南沿海寻找贸易立足点,建立包括中、日、朝鲜半岛的东方贸易体系。在广东沿海的尝试挫败后,受福建海商引诱,北上浙江双屿港,即今舟山群岛新区的六横岛,与中、日等国海商进行国际贸易。这与明朝厉行海禁政策相违背,嘉靖二十七年(1548)明军剿灭了双屿港的葡萄牙人,并以木石将港区填塞。

The Road Traffic Analysis Based on an Urban Traffic Model of the Circular Working Field

Under a relatively realistic model, this paper theoretically analyzes the road traffic status inside an urban working field, including its radial roads and circular ones. Concretely, the radial and the circular average traveling distances of a car commuter in a tiny ring with wide dx are first derived, and then the necessary road area, road area rate distributions, the proportion between the radial and the circular roads to be needed are also calculated. The results presented here and the properties shown through the numerical analysis are considered to be significant at the very beginning stage of designing an urban city.

Thermal Crown Model and Shifting Effect Analysis of Work Roll in Hot Strip Mills

Considering the effect of work roll shifting on roll temperature field,a finite difference method of PR format for roll temperature field was presented,which can meet the requirements of accuracy and speed of online calculation.The step-by-step accumulation method was used to simulate the roll temperature field and thermal crown,and the evolution of roll thermal crown in a rolling campaign was studied.And then,the effects of strip width,rolling rhythm and work roll shifting on roll thermal crown were analyzed.It is found that work roll shifting can disperse the thermal expansion of the roll body especially the edge to make roll thermal contour uniform.The effect of work roll shifting on roll thermal crown is mainly concentrated in regions around twice of roll shifting stroke,and the change range of roll thermal crown is±30μm or so in the same roll body location.