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Determination of gamma ray spectrometry efficiency for the attenuation coefficients of some bismuth borate glasses by MCNP and(ISOCS)techniques

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Radiation Detection Technology and Methods 2018年第2期2卷 67-74页

作者： Ahmed Y.El-Haseib Z.Ahmed Yasser b.Saddeek Radiation Safety Department Egyptian Nuclear and Radiological Regulatory Authority(ENRRA)Nasr CityCairoEgypt Nuclear Safeguards and Physical Protection Department Egyptian Nuclear and Radiological Regulatory Authority(ENRRA)Nasr CityCairoEgypt Physics Department Faculty of ScienceAl-Azhar UniversityAssiut 71524Egypt

background Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called *** efficiency is one of the main parameters in detection system besides many other different parameters of the *** detector in experimental physics is an instrument that converts radiation energy into an electrical signal,and this is achieved basically by either ionization or *** choice for any type of a detector(gas-filled,scintillation or semiconductor)for any application depends upon the X-ray of gamma energy range of interest.A working model is therefore developed which is capable of describing the overall NaI(Tl)detection efficiency as a function of several known *** The attenuation coefficients for the bismuth borate glasses with different concentrations were measured using gamma spectroscopy *** numerical absolute efficiency calibration of a detector can be determined by In-Situ Object Calibration Software(ISOCS)and Monte Carlo Neutral Particle version 5(MCNP5)techniques which does not require any calibration standards or reference *** by using the ISOCS and MCNP5 methodologies,the full energy peak efficiency of a scintillator detector(3“X3”NaI(Tl))exposed to Co-60 and Cs-137 gamma ray sources with average accuracy range 0.126–1.224%for the used samples can be *** used materials are ternary and are located between the detector and the source to determine the attenuation coefficients for these samples by using the calculated full energy peak efficiencies of a *** The average accuracy ranged from−1.808 to 1.960%for linear attenuation coefficient(μ),while it ranged from−1.999 to 1.888%and from−1.924 to 1.960%for half value layer(HVL)and mass linear attenuation coefficient(μm),*** The calculated values of the absolute full energy peak efficiency have been used to determi

关键词： Detection efficiency Sodium iodine(NaI) Linear attenuation coefficient(μ) Mass linear attenuation coefficient(μm) Half-value layer(HVL)

Microstructures and mechanical properties of Ti3Al/Ni-based superalloy joints brazed with AuNi filler metal

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Journal of Materials Science & Technology 2019年第9期35卷 2070-2078页

作者： H.S. Ren H.P.Xiong W.M. Long b. Chen Y.X. Shen J. Pang Welding and Plastic Forming Division Beijing Institutes of Aeronautical MatericalBeijing 100095China State Key Laboratory of Advanced brazing Filler Metals and Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001 China Department of Material Science and Engineering Beihang UniversityBeijing 100191China

For the purpose of high-temperature service and the weight reduction in aviation engineering applications, the dissimilar joining of Ti3Al-based alloy to Ni-based superalloy (GH536) was conducted using Au-17.5Ni (wt%) brazing filler metal. The microstructure and chemical composition at the interfaces were investigated by scanning electron microscope, X-ray diffraction and transmission electron microscope. The diffusion behaviors of elements were analyzed as well. The results indicated that the Ti3Al/GH536 joint microstructure was characterized by multiple layer structures. Element Ni from Au-Ni filler metal reacted with Ti3Al base metal, leading to the formation of AlNi2Ti and NiTi compounds. Element Ni from Ti3Al base metal reacted with Ni and thus Ni3Nb phase was detected in the joint central area. Due to the dissolution of Ni-based superalloy,(Ni,Au) solid solution ((Ni,Au)ss) and Ni-rich phase were visible adjacent to the superalloy side. The average tensile strength of all the joints brazed at 1253 K for 5-20 min was above 356 MPa at room-temperature. In particular, the joints brazed at 1253 K/15 min presented the maximum tensile strength of434 MPa at room-temperature, and the strength of 314 MPa was maintained at 923 K. AlNi2Ti compound resulted in the highest hardness area and the fracture of the samples subjected to the tensile test mainly occurred in this zone.

关键词： Ti3Al-based alloy Ni-based superalloy brazing Microstructure Tensile strength

一个新型的毫米波无线信号光纤传输系统及本振信号远程传送结构(英文)

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光子学报 2006年第11期35卷 1725-1729页

作者：周明拓 Sharma A b 张建国 Fujise M 日本国家信息与通信技术研究院无线通信研究所亚洲理工大学工程技术学院中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室西安710068 日本国家信息与通信技术研究院无线通信研究所新

提出一个新型的毫米波光纤传输系统及本振信号远程传送的结构.此技术能为将来使用皮蜂窝网络提供宽带无线接入服务给出一个简单的基站接入点解决方案.计算和仿真结果表明,在激光器输出功率为-6.5 dbm,光放大增益为6 db,激光线宽为1 MHz,... 详细信息

提出一个新型的毫米波光纤传输系统及本振信号远程传送的结构.此技术能为将来使用皮蜂窝网络提供宽带无线接入服务给出一个简单的基站接入点解决方案.计算和仿真结果表明,在激光器输出功率为-6.5 dbm,光放大增益为6 db,激光线宽为1 MHz,75 MHz或150 MHz,误码率不超过10-9的情形下,622 Mbit/s的下行相移键控信号能够在传统单模光纤上传输超过30 km的距离.在具有相对大的激光器线宽150 MHz和光纤距离为30 km时,由激光器相位噪音和光纤色散所引起的(通过远程传送的)毫米波本振信号的额外相位误差的方差仅为1.74°.

关键词：光纤通信无线信号的光纤传输毫米波通信马赫-曾德调制器远程本振信号传送

Interface Structure of Ag/SnO_2 Nanocomposite Fabricated by Reactive Synthesis

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Journal of Materials Science & Technology 2010年第1期26卷 49-55页

作者： Jingchao Chen Jing Feng b. Xiao K.H. Zhang Y.P. Du Z.J. Hong R. Zhou Key Laboratory of Advanced Materials of Precious-Nonferrous Metals Education Ministry of China and Key Lab of Advanced Materials of Yunnan Province Kunming University of Science and Technology Kunming 650093 China State Key Laboratory of Mechanical behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Xi'an 710049 China

The electric contact material of Ag/SnO2 composite was achieved by reactive synthesis method. The compositions and microstructure of Ag/SnO2 composite were analyzed and characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and high-resolution electron microscopy （HRTEM）. The struc- tural feature was typical of the particle reinforced composites. The HRTEM images revealed that the observed Ag/SnO2 interface was absence of the precipitated phase and the lattice contrast across the interface was clear and sharp. The average particle size of SnO2 in composite was near 50 nm and it was well dispersed in spherical shape. The thermodynamic mechanism of reactive synthesis method was also discussed. The electronic density distribution analysis of the interface showed the charges of Ag atoms transmitted to 0 atoms and the conductivity of the material was also affected. No extra compounds expected such as AgxOy formed at interface. The distribution of electrons was of inequality near the interface which explained why the mechanical property of the metal/ceramic materials was improved but the machining property declined.

关键词： Metal-matrix composites Electric contact material Interface In situ

Dyeing of Polyester and Nylon with Semi-synthetic Azo Dye by Chemical Modification of Natural Source Areca Nut

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Natural Products and bioprospecting 2018年第1期8卷 23-29页

作者： Ashitosh b.Pawar Sandeep P.More R.V.Adivarekar Department of Fibers and Textile Processing Technology Institute of Chemical TechnologyMumbaiIndia

Various azo compounds(Modified dyes)have been synthesised by chemical modification of areca nut extract(epicate-chin),a plant-based Polyphenolic compound to get semi-synthetic *** different primary amines namely p-nitro aniline,p-anisidine and aniline,were diazotized to form their corresponding diazonium salts which were further coupled with an areca nut *** characterization of the areca nut extract and the resultant azo compounds(Modified dyes)was carried out in terms of melting point,solubility tests,thin layer chromatography,UV-Visible and FTIR *** modified dyes were further applied on polyester and nylon fabrics and%dye exhaustion was *** fabrics were further tested for their fastness properties such as wash fastness,rubbing fastness,light fastness and sublimation *** results of the fastness tests indicate that,all the three modified dyes have good dyeability for polyester and nylon *** dyed fabrics were also tested for ultraviolet protection factor which showed very good ultraviolet protection.

关键词： Semi-synthetic azo dye Chemical modification Modified dyes Areca nut Ultraviolet protection factor

Takotsubo cardiomyopathy:A comprehensive review

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World Journal of Cardiology 2022年第6期14卷 355-362页

作者： Walker barmore Himax Patel Sean Harrell Daniel Garcia Joe b Calkins Jr Department of Internal Medicine Augusta University Medical CenterAugustaGA 30912United States Department of Cardiovascular Medicine Augusta University Medical CenterAugustaGA 30912United States

Takotsubo cardiomyopathy(TCM),also known as stress cardiomyopathy,occurs in the setting of catecholamine surge from an acute *** cardiomyopathy mimics acute myocardial infarction in the absence of coronary *** classic feature of TCM is regional wall motion abnormalities with characteristic ballooning of the left *** etiology of the stressor is often physical or emotional stress,however iatrogenic causes of TCM have been reported in the *** our review,we discuss medications,primarily the exogenous administration of catecholamines,and a wide array of procedures with subsequent development of iatrogenic *** is unique in that it is transient and has favorable outcomes in most ***,beta-blockers and ACE-inhibitors have been prescribed in individuals with cardiomyopathy;however,unique to TCM,no specific treatment is required other than temporary supportive measures as this process is ***,no improvement in mortality or recurrence have been reported in patients on these *** aim of this review is to elucidate on the iatrogenic causes of TCM,allowing for prompt recognition and management by clinicians.

关键词： Takotsubo Cardiomyopathy Iatrogenic Heart Failure Myocardial Infarction

The effect of wilderness and medical training on injury and altitude preparedness among backcountry hikers in Rocky Mountain National Park

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World Journal of Emergency Medicine 2018年第3期9卷 172-177页

作者： Michael D.T.Yue David W.Spivey Daniel b.Gingold Douglas G.Sward University of Maryland School of Medicine BaltimoreMarylandUSA Department of Emergency Medicine University of Maryland School of MedicineBaltimoreMarylandUSA Division of Hyperbaric Medicine Program in TraumaUniversity of Maryland Medical CenterBaltimoreMarylandUSA

bACKGROUND:The purpose of this study was to document the correlation between medical and wilderness training with levels of preparedness for acute mountain sickness(AMS),illness,and injury among backcountry ***:We conducted a cross-sectional,convenience survey in Rocky Mountain National Park in July and August *** study group consisted of 380 hikers who completed a written survey that collected information about demographics,wilderness experience,altitude experience,hiking equipment,communications devices,and trip ***:Factors such as wilderness training(wilderness first aid[WFA],wilderness first responder[WFR],or wilderness emergency medical technician[WEMT]),wilderness experience,and altitude experience all affected hikers’emergency *** with medical training were more prepared to avoid or respond to AMS(62.3%vs.34.3%[Pbe prepared to avoid or respond to AMS(52.3%vs.36.8%[P=0.025])but not significantly more likely to be prepared to manage illness/injury(31.8%vs.22.0%[Pbe prepared to avoid or manage AMS,medical emergencies,and injuries than their non-medically trained *** training increased hikers’preparedness for AMS but did not significantly alter preparedness for illness/injury.

关键词： Hiking wilderness Acute mountain illness Injury Training

Assessing decontamination practices at a medical microbiology research laboratory

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Journal of biosafety and biosecurity 2022年第2期4卷 124-129页

作者： Merna M.Alfy Sherine b.El Sayed Mona El-Shokry Medical Microbiology and Immunology Department Faculty of MedicineAin Shams UniversityCairoEgypt

To our knowledge,this is the first study to conduct an objective assessment of the routine decontamination practices at a medical microbiology research laboratory(MRL)a year after a biosafety training was provided to all laboratory *** March 28th and June 28th,2021,unobtrusive observations were carried out to identify-three high-touch surfaces at the MRL during different working *** was used to evaluate the effectiveness of the disinfectant used in the *** three high-touch surfaces were sampled before and after decontamination with 200 ppm of 5%sodium hypochlorite(household bleach)to quantify the microbial load and identify the types of organisms residing on the laboratory surfaces.A higher concentration(500 ppm)of 5%sodium hypochlorite was employed after refresher training was provided to housekeeping staff,and resampling of the three surfaces was carried out during a 4-week follow-up period using the same *** three high-touch surfaces identified were the two sides of the workbench(22%–24%)and the front surface of one incubator(14%).Anthracoid bacilli and Staphylococcus aureus were the most commonly found organisms on laboratory surfaces preintervention(100%and 89%,respectively)and post-intervention(56%and 44%,respectively).Other microorganisms detected included Salmonella spp.(27.7%),Proteus spp.(5.6%),Escherichia coli(5.6%),and Klebsiella spp.(33.3%).Employing a higher concentration(500 ppm)of sodium hypochlorite significantly(pbic colony count from an average of 15–250 cfu/cm2 to 10–60 cfu/cm^(2).This study demonstrated suboptimal decontamination practices at the MRL and the need to apply a higher concentration(500 ppm)of sodium hypochlorite to reduce the overall microbial *** also demonstrated the importance of quantitative assessment to monitor decontamination practices and ensure staff *** studies are needed to identify bacterial communities within the laboratory,which will

关键词： biosafety Laboratory-acquired infection Sodium hypochlorite Environmental decontamination bacterial contamination Egypt

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“理论词典学”概念的范围与内容

辞书研究 1990年第4期 33-38,18页

作者： b.b.莫尔科夫金郑云苏联

译者曾撰写《Lexicography的两种不同定义》一文,介绍苏联与西方学者对这一概念的不同理解,并初步探讨了产生这种分歧的原因(详见《辞书研究》1988年第4期)。苏联莫斯科普希金语言学院词典部主任b.b.莫尔科夫金的文章更深入地阐述了苏... 详细信息

译者曾撰写《Lexicography的两种不同定义》一文,介绍苏联与西方学者对这一概念的不同理解,并初步探讨了产生这种分歧的原因(详见《辞书研究》1988年第4期)。苏联莫斯科普希金语言学院词典部主任b.b.莫尔科夫金的文章更深入地阐述了苏联学者对这一问题的新认识,特此译出,以飨读者。因篇幅所限,略有删节。原文载(《语言学问题》)1987年第6期。

关键词：新认识原始材料词典编纂者理论词典学要素研究词典类型语言学词典学理论研究对象概念