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A Universal Formula for the Secondary Electron Yield of Metals at an incident Angle of θ

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Chinese Physics Letters 2011年第9期28卷 253-256页

作者： XIE Ai-Gen ZHANG Jian WANG Tie-Bang College of Math and Physics Nanjing University of Information Science and TechnologyNanjing 210044

Based on the main physical processes,we deduce the relationships among the incident energy Wp0 of the primary electron,the number of released secondary electrons(i.e.δ_(PEθ))per primary electron entering the metal at incident angleθand the angleθ*** addition,the relationship ofδPEθatθ=0°,i.e.δ_(PE0),with Wp0 is *** the experimental results,the relationship of the ratio atθ=0°,i.e.β_(0) which is the ratio of the average number of released secondary electrons generated by a single primary electron backscattered at the metal surface to that generated by a single primary electron entering the metal,with Wp0 is ***,the relationships among the ratioβθ,Wp0 andθare *** on the relationships among the secondary electron yield atθ(i.e.δθ),the yield atθ=0°(i.e.δ_(0)),the backscattering coefficient atθ(i.e.η_(θ)),the coefficient atθ=0°(i.e.η0),δ_(PEθ)andδ_(PE0),we deduce the universal formula forδ_(θ),δ_(0),η_(θ),η_(0),and W_(p0) for the primary electrons at an incident energy of 2–10 *** secondary electron yields calculated from the universal formula and the experimental yields of some metals are compared,and the results suggest that the proposed formula is universal for estimation of secondary electron yields atθ=0°−80°.

关键词： incident deduce coefficient

A short P-wave duration is associated with incident heart failure in the elderly: a 15 years follow-up cohort study

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Journal of Geriatric Cardiology 2022年第9期19卷 643-650页

作者： Bozena Ostrowska Lars Lind Elena Sciaraffia Carina Blomström-Lundqvist Department of Medical Sciences Uppsala UniversityUppsalaSweden School of Medical Science Faculty of Medi-cine and HealthÖrebro UniversityÖrebroSweden

BACKGROUND Early identification of patients at risk of congestive heart failure(HF)may alter their poor *** aim was therefore to test whether simple electrocardiographic variables,the P-wave and PR-interval,could predict incident *** The PIVUS(Prospective Investigation of the Vasculature in Uppsala Seniors)study(1016 individuals all aged 70 years,50%women)was used to identify predictors of *** with prevalent HF,QRS duration≥130 ms,atrial tachyar-rhythmias,implanted pacemaker/defibrillator,second-and third-degree atrioventricular block or delta waves at baseline were *** proportional hazard analysis was used to relate the PR interval,P-wave duration(Pdur)and amplitude(Pamp),measured in lead V1,to incident *** was performed for gender,RR-interval,beta-blocking agents,systolic blood pressure,body mass index and *** Out of 836 subjects at risk,107 subjects were diagnosed with HF during a follow-up of 15 *** the multivariate analysis,there was a strong U-shaped correlation between Pdur in lead V1 and incident HF(P=0.0001)which was significant for a Pdurincident HF and the PR-interval or the Pamp.A Pdur<60 ms improved discrimination by 3.7%when added to the tradi-tional risk factors including sex,RR-interval,beta-blocking agents,systolic blood pressure,BMI and smoking(P=0.048).CONCLUSIONS A short Pdur,an easily measured parameter on the ECG,may potentially be a useful marker of future HF,enabling its early detection and prevention,thus improving outcomes.

关键词： prevention incident wave

White matter hyperintensity progression is associated with incident probable dementia or mild cognitive impairment

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Stroke & Vascular Neurology 2022年第4期7卷 364-366页

作者： Adam de Havenon Kevin N Sheth Sharon D Yeatts Tanya N Turan Shyam Prabhakaran Neurology Yale UniversityNew HavenConnecticutUSA Public Health Sciences MUSCCharlestonSouth CarolinaUSA Neurology MUSCCharlestonSouth CarolinaUSA Neurology University of Chicago Pritzker School of MedicineChicagoIllinoisUSA

Background White matter hyperintensity(WMH)on brain MRI is associated with developing dementia or mild cognitive impairment(MCI),but WMH progression over time has not been fully investigated as an independent risk *** We performed a post hoc analysis of the Systolic Blood Pressure Intervention Trial-Memory and Cognition in Decreased Hypertension(SPRINT MIND)*** primary outcome was incident probable dementia or MCI(dementia/MCI)before the follow-up MRI at 48 months from *** primary predictor was WMH progression,defined as the Z score difference between the follow-up and baseline WMH *** secondary predictor was a binary WMH progression threshold(≥1.4 mL vs<1.4 mL).Results Among the 433 included patients,33(7.6%)developed dementia/*** were 156(36.0%)patients who met the WMH progression threshold of≥1.4 mL,in whom the rate of dementia/MCI was 12.8%(20/156)vs 4.7%(13/277)of patients with<1.4 mL WMH progression(p=0.002).In multivariable logistic regression,the Z score of WMH progression was associated with dementia/MCI(OR 1.51,95%CI 1.12 to 2.04,p=0.007)as was the WMH progression threshold of≥1.4 mL(OR 2.89,95%CI 1.23 to 6.81,p=0.015).Conclusions In this post hoc analysis of SPRINT MIND,WMH progression over 48 months was associated with the development of probable dementia or MCI.

关键词： impairment Blood incident

Predicting the incident Cases of Emerging Infectious Disease Using a Bayesian Probability Model--China,February 2020

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China CDC weekly 2020年第52期2卷 999-1003页

作者： Yewu Zhang Xiaofeng Wang Yanfei Li Siyu Wu Ming Wan Xuemei Su Shigui Yang Hanjiang Lai Zhongwei Jia Jiaqi Ma Center for Public Health Surveillance and Information Service Chinese Center for Disease Control and PreventionBeijingChina School of Public Health Peking UniversityBeijingChina State Key Laboratory for Diagnosis and Treatment of Infectious Diseases Collaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhouZhejiangChina Sun Yat-sen University GuangzhouGuangdongChina

What is already known about this topic?The exact number of incident cases of emerging infectious diseases on a daily basis is of great importance to the disease control and prevention,but it is not directly available from the current surveillance system in *** is added by this report?In this study,a Bayesian statistical method was proposed to estimate the posterior parameters of the gamma probability distribution of the lag time between the onset date and the reporting time based on the surveillance *** then the posterior parameters and corresponding cumulative gamma probability distribution were used to predict the actual number of new incident cases and the number of unreported cases per *** proposed method was used for predicting COVID-19 incident cases from February 5 to February 26,*** final results show that Bayesian probability model predictions based on data reported by February 28,2020 are very close to those actually reported a month *** are the implications for public health practice?This research provides a Bayesian statistical approach for early estimation of the actual number of cases of incidence based on surveillance data,which is of great value in the prevention and control practice of epidemics.

关键词： prevention Probability incident

Emergency Response for a Laboratory Biosafety incident

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Biomedical and Environmental Sciences 2019年第3期32卷 231-233页

作者： ZHANG En Min WANG Jia Qi GAO Li Dong ZHAN Zhi Fei ZHANG Heng HU Yan Hong WEI Jian Chun LIANG Xu Dong WAN Kang Lin WEI Qiang National Institute for Communicable Disease Control and Prevention Chinese Center for Disease Control and Prevention/State Key Laboratory for Infectious Disease Prevention and Control Chinese Center for Disease Control and Prevention Hunan Provincial Center for Disease Control and Prevention Changsha Center for Disease Control and Prevention Yuelu District Center for Disease Control and Prevention

On December 14, 2017, a faculty member of a university in Hunan Province reported that an anthrax vaccine strain might have recovered virulence during an undergraduate experiment and potential exposure could not be ruled out for the students involved. Upon receiving the case report, the CDC, health bureaus, and local governments at the county, prefectural, and provincial levels promptly organized experts in different fields (including epidemiologists, biosafety experts, and laboratory testing experts) for case investigation, evaluation, and response. As the investigation results showed, no virulence recovery was identified in the involved anthrax vaccine strain;and no contamination of Bacillus anthracis was detected at the involved areas. Thus, the university returned to normal functioning.

关键词： Emergency Response Laboratory Biosafety incident

An incident of chloroform poisoning on a university campus

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World Journal of Emergency Medicine 2022年第2期13卷 155-157页

作者： Si-qi Cui Yi-ming Tao Tian-zi Jian Jie Han Ying-li Ren Zhong-chen Zhang Ce-ce Sun Guang-cai Yu Bao-tian Kan Xiang-dong Jian School of Public Health Cheeloo College of MedicineShandong UniversityJinan 250012China Department of Poisoning and Occupational Diseases Emergency MedicineQilu HospitalShandong UniversityJinan 250012China Department of Digestive Internal Medicine Qilu HospitalCheeloo College of MedicineShandong UniversityJinan 250012China Department of Geriatric Medicine Qilu HospitalCheeloo College of MedicineShandong UniversityJinan 250012China

Dear editor,University laboratory-related events include fire,explosion,chemical gas leakage,poisoning related to the loss of toxic reagents,specific pathogen infection,leakage of radioactive material,etc.[1]Chloroform is an important material used frequently in the laboratory,for organic synthesis or used as an organic glass binder and organic matter extractor.[2]As a widely used anesthetic in clinics in the 1950s and the 1960s,[3]chloroform was abandoned because of hepatorenal *** report a case of a 24-year-old suicidal female student with chloroform poisoning.

关键词： chloroform incident synthesis

Integrable high-efficiency generation of three-photon entangled states by a single incident photon

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Photonics Research 2022年第2期10卷 389-400页

作者： Yunning Lu Zeyang Liao Fu-Li Li Xue-Hua Wang State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices School of PhysicsXi'an Jiaotong UniversityXi’an 710049China

Generation of multi-photon entangled states with high efficiency in integrated photonic quantum systems is still a big challenge. The usual three-photon generation efficiency based on the third-order nonlinear effect is extremely low. Here, we propose a scheme to generate three-photon correlated states, which are entangled states in frequency space and bound states in real space, with high efficiency. This method relies on two crucial *** one hand, by employing a Sagnac interferometer, an incident photon can be transformed into a symmetric superposition of the clockwise and counterclockwise modes of the Sagnac loop, which can then be perfectly absorbed by the emitter. On the other hand, the coupling strengths of the two transition paths of the emitter to the Sagnac loop are set to be equal, under which the absorbed photon can be emitted completely from the cascaded transition path due to quantum interference. By adjusting the coupling strengths among the three transition paths of the emitter and the waveguide modes, we can control the spectral entanglement and spatial separation among the three photons. Our proposal can be used to generate three-photon entangled states on demand, and the efficiency can be higher than 90% with some practical parameters, which can find important applications in integrated quantum information processing.

关键词： incident quantum transformed

Terahertz bound states in the continuum with incident angle robustness induced by a dual period metagrating

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Photonics Research 2022年第3期10卷 810-819页

作者： Wenqiao Shi Jianqiang Gu Xingyuan Zhang Quan Xu Jiaguang Han Quanlong Yang Longqing Cong Weili Zhang Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering Tianjin Universityand Key Laboratory of Optoelectronics Information and TechnologyMinistry of EducationTianjin 300072China Nonlinear Physics Centre Australian National UniversityCanberraACT 2601Australia Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhen 518055China School of Electrical and Computer Engineering Oklahoma State UniversityStillwaterOklahoma 74078USA

Metasurface-empowered bound state in the continuum(BIC)provides a unique route for fascinating functional devices with infinitely high quality *** method is particularly attractive to the terahertz community because it may essentially solve the deficiencies in terahertz filters,sensors,lasers,and nonlinear ***,most BIC metasurfaces are limited to specified incident angles that seriously dim their application ***,we propose that a dual-period dielectric metagrating can support multiple families of BICs that originate from guided mode resonances in the dielectric grating and exhibit infinite quality factors at arbitrarily tilted *** robustness was analyzed based on the Bloch theory and verified at tilted incident *** also demonstrate that inducing geometric asymmetry is an efficient way to manipulate the leakage and coupling of these BICs,which can mimic the electromagnetically induced transparency(EIT)effect in our dual-period *** this demonstration,a slow-light effect with a measured group delay of 117 ps was *** incidence-insensitive BICs proposed here may greatly extend the application scenarios of the BIC *** high Q factor and outstanding slow-light effect in the metagrating show exciting prospects in realizing high-performance filters,sensors,and modulators for prompting terahertz applications.

关键词： incident dielectric continuum

Acoustic transmissive cloaking with adjustable capacity to the incident direction

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Microsystems & Nanoengineering 2022年第5期8卷 43-51页

作者： Meng Lian Linqiu Duan Junjie Chen Jingyuan Jia Ying Su Tun Cao School of Optoelectronic Engineering and Instrumentation Science Dalian University of Technology116024 DalianChina

Zero-refractive-index(ZRI)phononic crystals(PhCs),in which acoustic waves can be transmitted without phase variations,have considerable potential for engineering wavefronts and thus are applicable to invisibility ***,the creation of the transmissive cloaking achieved by ZRI-PhCs is challenging under an oblique incidence,which substantially hinders their practical ***,we experimentally demonstrate acoustic transmissive cloaking with the adjustable capacity to the incident *** transmissive cloaking of arbitrarily shaped obstacles can be obtained through a hybrid acoustic structure consisting of one outer layer of a programmable phaseengineered metasurface(PPEM)and one inner layer of a double zero-refractive-index(DZRI)-*** DZRI-PhC is functionally the same as an equiphase area and can guide acoustic waves around the obstacle,a process known as acoustic *** PPEM perpendicularly transfers the incident acoustic waves to the DZRI-PhC and allows the emergent waves from the DZRI-PhC to transmit along the original incident *** DZRI-PhC is made of an array of iron squares in the *** reciprocal of the effective bulk modulus and the effective mass density is approximately zero at a frequency of 3015 Hz(0.5187 v0/a)originating from the zeroth-order Fabry–Pérot(FP)resonance that possesses infinite phase *** meta-atom of the outer metasurface consists of a line channel and four shunted Helmholtz resonators,which have effective masses that are engineered by a mechanics *** amplitude and phase of the sound waves propagating through each meta-atom can be controlled continuously and dynamically,enabling the metasurface to obtain versatile wavefront manipulation *** cloaking is visually demonstrated by experimentally scanning the acoustic field over the hybrid structure at a frequency of 3000 Hz(0.5160 v0/a).Our work may provide applications with great potential,including underwater

关键词： incident Acoustic outer