The CCD instrument background of the SMILE SXI

The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.The shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen Belts.Therefore,two radiation environments can be approximated based on the shutter door position:open and closed.The instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two environments.Due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.The results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.This is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

Study of Secondary Cosmic Rays and Astronomical X-Ray Sources using Small Stratospheric Balloons

The X-ray sources of the universe are extraterrestrial in nature which emit X-ray photons.The closest strong X-ray source is the Sun,which is followed by various compact sources such as neutron stars,black holes,the Crab pulsar,etc.In this paper,we analyze the data received from several low-cost lightweight meteorological balloon-borne missions launched by the Indian Centre for Space Physics.Our main interest is to study the variation of the vertical intensity of secondary cosmic rays,the detection of strong X-ray sources,and their spectra in the energy band of^(1)0–80 keV during the complete flights.Due to the lack of an onboard pointing system,low exposure time,achieving a maximum altitude of only~42 km,and freely rotating the payload about its axis,we modeled the background radiation flux for the X-ray detector using physical assumptions.We also present the source detection method,observation of the pulsation of the Crab(^(3)3 Hz),and spectra of some sources such as the quiet Sun and the Crab pulsar.

Evaluation on residual stresses of silicon-doped CVD diamond films using X-ray diffraction and Raman spectroscopy

The effect of silicon doping on the residual stress of CVD diamond films is examined using both X-ray diffraction (XRD) analysis and Raman spectroscopy measurements. The examined Si-doped diamond films are deposited on WC-Co substrates in a home-made bias-enhanced HFCVD apparatus. Ethyl silicate (Si(OC2H5)4) is dissolved in acetone to obtain various Si/C mole ratio ranging from 0.1% to 1.4% in the reaction gas. Characterizations with SEM and XRD indicate increasing silicon concentration may result in grain size decreasing and diamond [110] texture becoming dominant. The residual stress values of as-deposited Si-doped diamond films are evaluated by both sin2ψ method, which measures the (220) diamond Bragg diffraction peaks using XRD, with ψ-values ranging from 0° to 45°, and Raman spectroscopy, which detects the diamond Raman peak shift from the natural diamond line at 1332 cm-1. The residual stress evolution on the silicon doping level estimated from the above two methods presents rather good agreements, exhibiting that all deposited Si-doped diamond films present compressive stress and the sample with Si/C mole ratio of 0.1% possesses the largest residual stress of ~1.75 GPa (Raman) or ~2.3 GPa (XRD). As the silicon doping level is up further, the residual stress reduces to a relative stable value around 1.3 GPa.

Residual stress measurement and analysis of siliceous slate-containing quartz veins

Engineering geological disasters such as rockburst have always been a critical factor affecting the safety of coal mine production.Thus,residual stress is considered a feasible method to explain these geomechanical phenomena.In this study,electron backscatter diffraction(EBSD)and optical microscopy were used to characterize the rock microcosm.A measuring area that met the requirements of X-ray diffraction(XRD)residual stress measurement was determined to account for the mechanism of rock residual stress.Then,the residual stress of a siliceous slate-containing quartz vein was measured and calculated using the sin^(2) ϕ method equipped with an X-ray diffractometer.Analysis of microscopic test results showed homogeneous areas with small particles within the millimeter range,meeting the requirements of XRD stress measurement statistics.Quartz was determined as the calibration mineral for slate samples containing quartz veins.The diffraction patterns of the(324)crystal plane were obtained under different ϕ and φ.The deviation direction of the diffraction peaks was consistent,indicating that the sample tested had residual stress.In addition,the principal residual stress within the quartz vein measured by XRD was compressive,ranging from 10 to 33 MPa.The maximum principal stress was parallel to the vein trend,whereas the minimum principal stress was perpendicular to the vein trend.Furthermore,the content of the low-angle boundary and twin boundary in the quartz veins was relatively high,which enhances the resistance of the rock mass to deformation and promotes the easy formation of strain concentrations,thereby resulting in residual stress.The proposed method for measuring residual stress can serve as a reference for subsequent observation and related research on residual stress in different types of rocks.

Evaluation of multiaxial stress in textured cubic films by x-ray diffraction

X-ray diffraction is used extensively to determine the residual stress in bulk or thin film materials on the as- sumptions that the material is composed of fine crystals with random orientation and the stress state is biaxial and homogeneous through the x-ray penetrating region. The stress is calculated from the gradient of ε ～ sin^2 φ linear relation. But the method cannot be used in textured films due to nonlinear relation. In this paper, a novel method is proposed for measuring the multiaxial stresses in cubic films with any [hkl] fibre texture. As an example, a detailed analysis is given for measuring three-dimensional stresses in FCC films with [111] fibre texture.

A METHOD FOR CORRECTING INTENSITY IN CONTINU-OUS SCANNING X-RAY STRESS MEASUREMENT

A set of absorption curves was priorly prepared on transparent films to fit the background and peak intensities in continuous scanning X-ray stress measurement.It may be better to correct both background and absorption of pure diffraction intensity.Experimental results revealed this to be a reliable correction method.

X-Ray Measurement of Residual Stress in Plastic Bonded Explosives

The X-ray diffractive technology was adopted for tentative study of plastic bonded explosive.The datum of some new diffractive peaks in standard PDF cards were added.The effects of strain to interplanar distance and crystal size of the explosive were studied.The results show that grain size of plastic bonded explosive is decreasing with the increasing of the pressure,and the residual stress of the explosive is draw stress.

Residual stress measurement of coarse-grain aluminum alloy using X-ray diffraction method

When measuring residual stress of coarse-grain aluminum alloy using X-ray diffraction method, the diffraction profile shows two peaks and position of measured 20 will be changed, which lead to an inaccurate measurement result. Hence, in this paper, some methods were employed to improve the measurement accuracy. During the measuring process, different parameters （diameter of irradiated area, Ψ-oscillation range and exposure time） were selected and profile peak shift method was utilized. Moreover, when the 20 of profiles was determined, different calculation methods were used to calculate the residual stress. The results show that diameter of irradiated area and Ψ-oscillation range have significant influence on the measuring result. For stress value calculated directly from the test equipment, cross correlation method is more accurate than the absolute peak. Furthermore, another two calculation methods of slope with 2θ- sin^2Ψ and ε- sin^2Ψwere used to calculate the stress based on parameters （2θ, ε） obtained from cross correlation method. It is concluded that 2θ - sin^2Ψ method can further improve the measurement accuracy.

X-ray diffraction study of effect of deposition conditions on α-β phase transition and stress evolution in sputter-deposited W coatings

Pure W and W-Cu-W trilayer coatings were deposited on an Fe substrate by d.c. magnetron sputtering. The α-β phase evolution, intragranular stress evolution in sputter-deposited W layer were investigated by x-ray diffraction. They are directly related to the film microstructure, density and adhesion. Therefore, control of the film stress and phase component transition is essential for its applications. The phase component transition from β-W to α-W and intragranular stress evolution from tensile to compressive strongly depend on the deposition parameters and can be induced by lowering Ar pressure and rising target power. The compressively stressed films with α-W phase have a dense microstructure and high adhesion to Fe substrate.

Prospects of the Hard X-Ray Instrument POLAR to Measure Polarization of Solar Flares

In-depth studies of solar flares emissions and energy releases include analyses of polarization data. Polarization gives clear information about mechanisms and processes leading to electron acceleration and photon production. Despite of many past attempts, the key energy range of hard X-rays was only rarely explored and results were inconclusive. To large extend it was due to greater instrumental complications. Currently several novel polarimeters are either to be employed or under constructions for both balloon and satellite based observations. The novel hard X-ray polarimeter POLAR is an instrument developed by a collaboration between Switzerland, China and Poland. It is primarily designed for high accuracy polarization measurements from the prompt photon emissions of the gamma-ray bursts. The satellite orientation and instrument pointing direction make it also capable for precise measurements of polarization in solar flares. The instrument should fly in near future onboard of the Chinese Space Station TG2.

Simulation of X-ray Diffraction Line Broadening Caused by Stress Gradients and Determination of Stress Distribution by Fourier Analysis

Different physical, mechanical and chemical processes, such as： ion implantation, oxidation, nitridation and others create on the surface of materials residual stress state, characterized by high level and strong gradient. X-ray diffraction method widely used for stress measurements has some difficulties in interpretation of experimental data, when the depth of X-ray penetration is compared with thickness of surface layer where inhomogeneous stress distribution is localized. Early it has been shown by authors that diffraction line broadening occurs when analyzed surface is characterized by strong gradient. The interest to study the diffraction line broadening is connected to the possibility of obtaining information about parameters of surface stress distribution. In the present paper the convolution and deconvolution concepts of Fourier analysis were applied to study X ray diffraction line broadening caused by surface stress gradients. Developed methodology allows determining of stress distribution in superficial layers of materials.

Determination of Residuals Stresses Induced by the Autofrettage Treatment by the X-Rays Diffraction Method

Some meaningful advances have been made these last years to value precise and reliable way the residual stresses experimentally created by the autofrettage. The autofrettage process is used widely to introduce residual stresses into thick walled tubes;traditionally residual stresses have been measured using the Sachs method destructive or non-destructive methods. In this paper we describe the application of the X-rays diffraction;this technique permits to justify the presence of the compressive tangential residual stresses, and to value their distribution after two different autofrettage internal pressures loading. The results show that there is a large difference in the residual stresses find in the different autofrettege pressure. One can see the influence of the autofrettage’s pressure quantity on residual stresses created in the thickness of the test tubes.

Automation of choice of instrumental equipment and study of thermo-stressed conditions of metal-cutting instrument

This article about possibility of automations of choice of instrumental equipment. In it described problems of choice of equipment, which are decided by means of mathematical model, developed on the base of finite element method.

水平孔多参数综合测试仪器研发与应用

为研究引大济岷工程隧洞岩体特征、岩溶发育特征、地应力特征和地下水特征等,在泸定取水中线方案的引水线路中布置水平钻孔8个,共计2300 m。为满足对水平孔综合测试的需求,研制了一套适用于水平钻孔的存储式综合测井仪器。本文分析了水平孔多参数综合测试仪器各参数测量的基本工作原理;详细阐述了各功能单元的电路构成选型,主要采用DSP微处理器和大规模集成电路,结合传感器技术实现多种参数的综合测量,包括:水平钻孔的压力、温度、自然伽马、声波波速、孔内电视图像。综合测试仪器集成了模拟传感器、模拟调理电路、数据采集、数据处理、信息存储、数据通讯、信息交换、测控软硬件、电脑显示等功能,是水平孔综合测试不可缺少的技术。在引大济岷工程的水平定向孔中成功应用,一趟起下钻解决了水平钻孔的井斜、方位角、压力、温度、自然伽马、孔内电视测试的难题,尽最大可能保证了钻孔的安全及降低了劳动强度。

基于FPGA和LabVIEW的磁声发射应力检测系统设计

磁声发射(Magnetoacoustic emission,MAE)是一种应力检测的有效方法,针对传统检测仪器设计参数固定,灵活性较差的问题,结合FPGA(现场可编辑逻辑门阵列)和LabVIEW设计了参数可调的磁声发射应力检测系统。其中,FPGA负责激励信号产生波形,并将接收到的AD转换数据发送至上位机进行处理。设计的LabVIEW上位机程序负责信号接收、数据处理和存储。试验结果表明,所设计的检测系统简单可靠,集成度高,能够灵活调整激励信号,满足应力检测的需求。

盆底康复治疗仪联合盆底肌锻炼对产后压力性尿失禁患者的应用效果

目的探究盆底康复治疗仪与盆底肌锻炼联合治疗产后压力性尿失禁(PSUI)患者的临床效果及对盆底肌力等级分布、盆底肌肌电值、血清相关指标的影响。方法收集2020年5月至2022年4月南阳市宛城区第一人民医院108例PSUI患者的临床资料,依据治疗方法分为两组,将行盆底肌锻炼治疗的51例设为对照组,行盆底康复治疗仪联合盆底肌锻炼治疗的57例设为观察组。比较两组临床疗效、治疗前与治疗2个月后盆底肌力等级分布、盆底肌肌电值、血清相关指标[基质金属蛋白酶-1(MMP-1)、结缔组织生长因子(CTGF)、骨桥蛋白(OPN)]及预后情况。结果观察组总有效率较对照组高(P<0.05);观察组治疗2个月后盆底肌力等级分布优于对照组,盆底耐力收缩值、紧张收缩值、快速收缩最大值均高于对照组(P<0.05);观察组治疗2个月后血清MMP-1、CTGF、OPN水平低于对照组(P<0.05);治疗2个月后,观察组漏尿量低于对照组,尿失禁生活质量评定量表(I-QOL)评分高于对照组(P<0.05)。结论盆底康复治疗仪联合盆底肌锻炼治疗PSUI,能抑制病情因子表达,促进盆底肌收缩能力恢复,进而增强疗效,改善患者预后。

Development and applications of the quasi‐dynamic triaxial apparatus for deep rocks

The mechanical behaviors of deep rocks have always posed a challenge for the implementation and safe operation of major underground engineering projects.To this end,this study modified the existing mainstream rock mechanics instruments equipped with a dynamic disturbance loading system and developed a second‐generation TFD‐2000/D triaxial instrument.The first‐generation device is equipped with an independent disturbance system and an advanced EDC‐580 all‐digital servo controller,which can apply disturbing load independently,implement the function of cyclic disturbance,and combine dynamic and static disturbances.The instrument was found to be reliable for use in analyzing the damage process of rocks in the disturbance test of marbles.The second‐generation instrument tackles three limitations of the first‐generation instrument:(i)it upgrades the strain measurement system and uses extensometers with linear variable differential transformers to accurately measure deformation;(ii)it uses the self‐balanced chamber to replace the Hoek–Franklin triaxial cell and auto‐balancing triaxial pressure chamber;and(iii)the loading rod is independently equipped with an EDC‐580 all‐digital servo controller,which measures precise loads.The experimental findings confirmed that the second‐generation instrument can be used for rock mechanics testing under cyclic disturbance loading,the disturbance–stress relaxation cycle,and the creep–fatigue cycle.In this sense,the second‐generation instrument can be a useful addition to deep rock mechanical instruments and provide a valuable reference.

2024年新疆乌什M_(S)7.1地震数据产品及其分析

2024年1月23日,地处印度洋板块和欧亚板块碰撞前沿地带的新疆乌什地区发生M_(S)7.1地震。地震发生后,中国地震台网中心立即启动应急响应,国家测震台网中心快速产出地震数据产品,为地震发震构造研究、震源区地震危险性评估提供基础数据。基于中国地震台网资料,采用双差定位方法,对新疆乌什地震及主震后38天内3487次余震进行重新定位。定位结果显示,主震震中位置为(41.28°N,78.62°E),震源深度为31 km,余震序列呈NE-SW向线性展布,扩展范围约80 km,震源深度优势分布在30 km以浅范围内,发震断层倾向NW。同时,基于所得地震定位和前人震源机制解结果,采用PSGRN/PSCMP软件包,计算本次地震不同深度上的库仑应力分布,根据结果分析表明,主震发生使得主震周边区域进入应力卸载状态,并分析了主震对余震发生的触发作用。最后,使用国家地震烈度速报与预警工程站网数据计算本次地震仪器烈度,显示最大烈度值为Ⅸ度,烈度区域小,且集中在主震NEE方向。基于上述结果,结合周边地质构造,认为此次新疆乌什M_(S)7.1地震事件为一次兼具走滑性质的逆冲型地震。

2023年甘肃积石山MS 6.2地震数据产品

2023年12月18日,地处青藏高原东北缘的甘肃积石山发生MS6.2地震。地震发生后,中国地震台网中心立即启动应急响应,测震台网快速产出地震数据产品,为地震发震构造研究、震源区地震危险性评估提供基础数据。基于中国地震台网资料,采用gCAP方法获得主震震源机制解,结果显示,此次地震为1次逆冲型为主、兼有左旋分量的事件,矩心深度为11 km。采用双差定位方法对积石山地震及主震后27天内623次余震序列进行重新定位,定位结果显示,主震位置为35.75°N、102.83°E,震源深度为14 km,余震序列展布方向为NNW,长度约18 km,震源深度优势分布在5—17 km,断层面有略向东倾趋势。另外,基于研究所得地震定位和震源机制结果,采用PSGRN/PSCMP软件包,计算此次地震不同深度上的库仑应力分布,结果显示,主震发生使得主震周边区域进入应力卸载状态。最后,使用中国地震预警网数据计算此次地震仪器烈度,显示最大烈度值为Ⅸ度,烈度区域小,且主要集中在主震NNW方向。结合周边地质构造,认为甘肃积石山MS6.2地震事件为一次带有左旋走滑分量的逆冲型地震。

盆底治疗仪联合盆底肌锻炼在剖宫产产后压力性尿失禁患者中的应用效果

目的:观察盆底治疗仪联合盆底肌锻炼在剖宫产产后压力性尿失禁(SUI)患者中的应用效果。方法:选取2020年1月至2022年8月该院收治的106例剖宫产产后SUI患者进行前瞻性研究,按照随机数字表法将其分为研究组和对照组各53例。对照组采用盆底肌锻炼,研究组在对照组基础上采用盆底治疗仪治疗。比较两组临床疗效、治疗前后盆底肌力、尿动力学指标[最大尿流率(Qmax)、最大尿道闭合压(MUCP)、腹部漏尿点压(ALPP)]水平、生命质量[尿失禁生活质量量表(I-QOL)]评分和不良反应发生率。结果:研究组治疗总有效率为92.45%(49/53),高于对照组的77.36%(41/53),差异有统计学意义(P<0.05);治疗后,两组盆底肌肌力分级均优于治疗前,且研究组优于对照组,差异有统计学意义(P<0.05);两组Q_(max)、MUCP、ALPP水平均高于治疗前,且研究组高于对照组,差异有统计学意义(P<0.05);两组逃避和限制性行为、心理社会影响、社会活动受限等I-QOL评分均高于治疗前,且研究组高于对照组,差异有统计学意义(P<0.05);治疗期间,两组均未发生明显不良反应。结论:盆底治疗仪联合盆底肌锻炼应用于剖宫产产后SUI患者可提高治疗总有效率、尿动力学指标水平和生命质量评分,改善盆底肌肌力分级,其效果优于单纯盆底肌锻炼。