检索结果-南通市图书馆

Surface treatments of CdGeAs2 single crystals

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2019年第7期38卷 683-688页

作者： Wei Huang Bei-Jun Zhao Shi-Fu Zhu zhi-yu he Bao-Jun Chen Zhen Zhen yun-Xiao Pu College of Materials Science and Engineering Sichuan University

The performances of second harmonic gen eration (SHG) and optical parametric oscillator (OPO) in CdGeAs2 crystal are strongly influenced by surface quality. In this paper, the surfaces of samples were treated by mechanical polishing (MP), chemical polishing (CP), chemical-mechanical polishing (CMP) and CP following CMP closely (CMP + CP). Then, the surface state was characterized by optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM measurements show that an ultra-smooth surface is achieved after CMP + CP treatment and the roughness value is 0.98 nm. Meanwhile, the roughness of the surfaces treated by MP, CP and CMP are 4.53, 2.83 and 1.38 nm, respectively. By XRD rocking curves, the diffraction peak which belongs to the wafer treated by CMP + CP is the highest in intensity and best symmetrical in shape. XPS analysis indicates that Ge4+ proportions of GeO2 in total Ge content of CdGeAs2 wafers' surface after MP, CP, CMP and CMP + CP treatment are 27.6%, 42.8%, 6.1% and 30.3%, respectively.

关键词： CdGeAs2 single crystal Surface treatments Surface roughness

Annealing and optical homogeneity of large ZnGeP_(2) single crystal

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第9期41卷 3214-3219页

作者： Li-Qiang Cao Bei-Jun Zhao Shi-Fu Zhu Bao-Jun Chen zhi-yu he Deng-Hui Yang Hui Liu Hu Xie College of Materials Science and Engineering Sichuan UniversityChengdu610064China

A high-quality ZnGeP_(2)(ZGP)single crystal with large size ofΦ30 mm×80 mm was grown by a modified vertical Bridgman *** wafers were annealed with ZGP polycrystalline powder for 300 h at 550,600 and 650℃,*** as-grown and annealed crystals were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FTIR),IR microscope and energy-dispersive spectroscopy(EDS).Results show that the quality of all wafers is improved evidently after annealing and the optimum annealing temperature obtained is 600℃.The IR transmittance of the wafer measured by FTIR is up to 56.78%at wavelength of 2.0μm nearby and exceeds 59.00%in the wavelength range of 3.0-8.0μ*** deviations from stoichiometry decrease,and the homogeneity of the crystal is also improved after *** this paper,scanning infrared map was proposed as a new nondestructive method to evaluate optical quality and homogeneity of crystal through comparing the IR transmittance with the three-dimensional IR spectral contour map.

关键词： ZnGeP_(2)crystals Annealing Infrared transmittance Scanning infrared map Optical homogeneity

The effect of Ti and Zr content on the structure,mechanics and energy-release characteristics of Ti—Zr—Ta alloys

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 343-350页

作者： Jia-yu Meng Jing-zhi he Bin Zhang Jin Chen Shun Li Dun Niu yu Tang Xi’an Modern Chemistry Research Institute Xi'an710065China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China

Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage *** this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were *** microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of *** the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of *** evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta *** synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation *** as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually *** higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content.

关键词： Energetic structural materials Ti-Zr-Ta Multi-element alloy Energy release characteristics

Growth and characterizations of CdGeAs2single crystal by descending crucible with rotation method

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2014年第2期33卷 210-214页

作者： Wei Huang Bei-Jun Zhao Shi-Fu Zhu zhi-yu he Bao-Jun Chen Jing-Jing Tang Wei-Jia Liu Department of Materials Science Sichuan University

By the method of descending crucible with rotation, crack-free CdGeAs2single crystals of U15 mm 950 mm were grown in a furnace with three independen heating zones after optimizing the temperature field, and the descending and rotational speed to meet the need of CdGeAs2crystal growth. The properties of as-grown crysta were characterized by a variety of techniques. The results of X-ray diffraction（XRD） show that there are two cleavage faces, which are（110） and（101）. The peaks are in high intensity and good symmetry, which demonstrates that the crystal is integral in structure and well crystallized. The energy-dispersive spectrometry results indicate that the wafer of the CdGeAs2crystal is closer to the stoichiometry The IR transmittance of the wafer is ＊48.6 % at 5.5 lm, and the maximum value is up to 51.6 % in the range of2.3–18.0 lm. Etch pits of（001） face are observed and the density of the etch pits is evaluated to be 1 9 105cm-2.

关键词： CdGeAs2 crystal Crystal growth X-ray diffraction IR transmittance

Managing immune checkpoint inhibitor-associated gastritis: Insights and strategies

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第24期30卷 3120-3122页

作者： Li-Li yu zhi-Lin he Xin-Lai Qian Department of Pathology The Third Affiliated Hospital of Xinxiang Medical UniversityXinxiang Medical UniversityXinxiang 453003Henan ProvinceChina Department of Basic Medical Sciences Xinxiang Medical UniversityXinxiang 453003Henan ProvinceChina

Immune checkpoint inhibitors(ICIs)are widely used due to their effectiveness in treating various ***-related adverse events(irAEs)are defined as adverse effects resulting from ICI *** irAEs are a common type of irAEs characterized by intestinal side effects,such as diarrhea and colitis,which may lead to the discontinuation of ICIs.

关键词： Immunotherapy Immune checkpoint inhibitor Immune checkpoint inhibitor-related gastritis Immune-related adverse events Autoimmune responses

AMicroseismic Signal Denoising Algorithm Combining VMD and Wavelet Threshold Denoising Optimized by BWOA

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第10期141卷 187-217页

作者： Dijun Rao Min Huang Xiuzhi Shi zhi yu Zhengxiang he Zijin Mining Group Co. Ltd.Xiamen361016China Zijin(Changsha)Engineering Technology Co. Ltd.Changsha410006China State Key Laboratory of Comprehensive Utilization of Low-Grade Refractory Gold Ores Shanghang364204China School of Resources and Safety Engineering Central South UniversityChangsha410083China School of Resources&Environment Engineering Jiangxi University of Science and TechnologyGanzhou341000China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350116China State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and TechnologyXuzhou221116China

The denoising of microseismic signals is a prerequisite for subsequent analysis and *** this research,a new microseismic signal denoising algorithm called the Black Widow Optimization Algorithm(BWOA)optimized VariationalMode Decomposition(VMD)jointWavelet Threshold Denoising(WTD)algorithm(BVW)is *** BVW algorithm integrates VMD and WTD,both of which are optimized by ***,this algorithm utilizes VMD to decompose the microseismic signal to be denoised into several Band-Limited IntrinsicMode Functions(BLIMFs).Subsequently,these BLIMFs whose correlation coefficients with the microseismic signal to be denoised are higher than a threshold are selected as the effective mode functions,and the effective mode functions are denoised using WTD to filter out the residual low-and intermediate-frequency ***,the denoised microseismic signal is obtained through *** ideal values of VMD parameters and WTD parameters are acquired by searching with BWOA to achieve the best VMD decomposition performance and solve the problem of relying on experience and requiring a large workload in the application of the WTD *** outcomes of simulated experiments indicate that this algorithm is capable of achieving good denoising performance under noise of different intensities,and the denoising performance is significantly better than the commonly used VMD and Empirical Mode Decomposition(EMD)*** BVW algorithm is more efficient in filtering noise,the waveform after denoising is smoother,the amplitude of the waveform is the closest to the original signal,and the signal-to-noise ratio(SNR)and the root mean square error after denoising are more *** case based on Fankou Lead-Zinc Mine shows that for microseismic signals with different intensities of noise monitored on-site,compared with VMD and EMD,the BVW algorithm ismore efficient in filtering noise,and the SNR after denoising is higher.

关键词： Variational mode decomposition microseismic signal denoising wavelet threshold denoising black widow optimization algorithm

Study of primordial deuterium abundance in Big Bang nucleosynthesis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第3期35卷 208-215页

作者： zhi-Lin Shen Jian-Jun he Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)he,^(4)he,and^(7) Li produced in the early *** these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent *** date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational *** this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium *** found that the reaction rate uncertainties of the four reactions d(d,n)^(3)he,d(d,p)t,d(p,γ)^(3)he,and p(n,γ)d had the largest influence on the calculated D/H ***,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) he *** the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2625-2637页

作者： zhi-Qiang he he-Ping Xie Ling Chen Jian-Ping Yang Bo yu Zi-Jie Wei Ming-Zhong Gao State Key Laboratory of Intelligent Construction and healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and Hydropower Sichuan University Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green Energy College of Civil and Transportation Engineering Shenzhen University School of Mechanical Engineering Sichuan University College of Polymer Science and Engineering Sichuan University

Deep oil and gas reservoirs are under high-temperature conditions, but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability, resulting in distorted resource assessments. The development of in situ temperaturepreserved coring(ITP-Coring) technology for deep reservoir rock is urgent, and thermal insulation materials are key. Therefore, hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials) were proposed as thermal insulation materials. The materials properties under coupled hightemperature and high-pressure(HTHP) conditions were tested. The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased; additionally,increasing temperature accelerated the process. High temperatures directly caused the thermal conductivity of the materials to increase; additionally, the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity. High temperatures weakened the matrix, and high pressures destroyed the HGM, which resulted in a decrease in the tensile mechanical properties of the materials. The materials entered the high elastic state at 150.C, and the mechanical properties were weakened more obviously, while the pressure led to a significant effect when the water absorption was above 10%. Meanwhile, the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86% at 100.C and 100 MPa, respectively, which meet the application requirements of the self-designed coring device. Finally, K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100.C and 100 MPa. To further improve the materials properties, the interface layer and EP matrix should be optimized. The results can provide references for the optimization and engineering application of materials and thus technical su

关键词： Deep oil and gas reservoir rock In situ temperature-preserved coring (ITP-Coring) Hollow glass microsphere/epoxy resin thermal insulation materials (HGM/EP materials) High-temperature and high-pressure (HTHP) Physical and mechanical properties

Shock temperature and reflectivity of precompressed H2O up to 350 GPa:Approaching the interior of planets

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第12期27卷 405-412页

作者： zhi-yu he Hua Shu Xiu-Guang Huang Qi-Li Zhang Guo Jia Fan Zhang yu-Chun Tu Jun-yue Wang Jun-Jian Ye zhi-Yong Xie zhi-heng Fang Wen-Bing Pei Si-Zu Fu Shanghai Institute of Laser Plasma CAER P.O.Box 800-229Shanghai201800China IFSA Collaborative Innovation Center Shanghai Jiaotong UniversityShanghai 200240China Institute of Applied Physics and Computational Mathematics Beijing 100088China Center for High Pressure Science and Technology Advance Research Beijing 100094China

Using a combination of static precompression and laser-driven shock compression, shock temperature and reflectivity of H2O have been measured up to 350 GPa and 2.1×10~4 K. here, two calibration standards were applied to enhance temperature measurement reliability. Additionally, in temperature calculations, the discrepancy in reflectivity between active probe beam wavelength and self-emission wavelength has been taken into account to improve the data’s *** water’s temperature–pressure data are in very good agreement with our quantum molecular dynamics model,suggesting a superionic conductor of H2O in the icy planets’ deep interior. A sluggish slope gradually approaching Dulong–Petit limit at high temperature was found at a specific heat capacity. Also, high reflectivity and conductivity were observed at the same state. By analyzing the temperature–pressure diagram, reflectivity, conductivity and specific heat comprehensively at conditions simulating the interior of planets in this work, we found that as the pressure rises, a change in ionization appears; it is supposedly attributed to energetics of bond-breaking in the H2O as it transforms from a bonded molecular fluid to an ionic state. Such molecular dissociation in H2O is associated with the conducting transition because the dissociated hydrogen atoms contribute to electrical properties.

关键词： high temperature measurement equation of state of water laser-driven shock diamond anvil cell