Middle and near ultraviolet spectrograph of the Scientific Experimental system in Near SpacE(SENSE)

The Scientific Experimental system in Near SpacE(SENSE)consists of different types of instruments that will be installed on a balloon-based platform to characterize near-space environmental parameters.As one of the main scientific payloads,the middle and near ultraviolet spectrograph(MN-UVS)will provide full spectra coverage from middle ultraviolet(MUV,200−300 nm)to near ultraviolet(NUV,300−400 nm)with a spectral resolution of 2 nm.Its primary mission is to acquire data regarding the UV radiation background of the upper atmosphere.The MN-UVS is made up of six primary components:a fore-optical module,an imaging grating module,a UV intensified focal plane module,a titanium alloy frame,a spectrometer control module,and a data processing module.This paper presents in detail the engineering design of each functional unit of the MN-UVS,as well as the instrument’s radiometric calibration,wavelength calibration,impact test,and low-pressure discharge test.Furthermore,we are able to report ground test and flight test results of high quality,showing that the MN-UVS has a promising future in upcoming near-space applications.

An Exposure Meter of Lijiang Fiber-fed High-Resolution Spectrograph

In 2016,an exposure meter was installed on the Lijiang Fiber-fed High-Resolution Spectrograph to monitor the coupling of starlight to the science fiber during observations.Based on it,we investigated a method to estimate the exposure flux of the CCD in real time by using the counts of the photomultiplier tubes(PMT)of the exposure meter,and developed a piece of software to optimize the control of the exposure time.First,by using flat-field lamp observations,we determined that there is a linear and proportional relationship between the total counts of the PMT and the exposure flux of the CCD.Second,using historical observations of different spectral types,the corresponding relational conversion factors were determined and obtained separately.Third,the method was validated using actual observation data,which showed that all values of the coefficient of determination were greater than 0.92.Finally,software was developed to display the counts of the PMT and the estimated exposure flux of the CCD in real-time during the observation,providing a visual reference for optimizing the exposure time control.

An Active Flexure Compensation Method for LAMOST spectrograph based on BP-Neural Network

The Large sky Area Multi-Object fiber Spectroscopic Telescope(LAMOST)is a Chinese national scientific research facility operated by National Astronomical Observatories,Chinese Academy of Sciences(NAOC).The LAMOST survey for the Milky Way Galaxy and extra-galactic objects has been carried out for several years.The accuracies in measuring radial velocity are expected to be 5 km s-1 for the low resolution spectroscopic survey(R=1800),and 1 km s-1 for the medium resolution mode.The stability of spectrograph is the main factor affecting the accuracies in measuring radial velocity,so an Active Flexure Compensation Method(AFCM)based on Back Propagation Neural Network(BPNN)is proposed in this paper.It utilizes a deep BP(4-layer,5-layer etc.)model of thermal-induced flexure to periodically predict and apply flexure corrections by commanding the corresponding tilt and tip motions to the camera.The spectrograph camera system is adjusted so that the positions of these spots match those in a reference image.The simulated calibration of this compensation method analytically illustrates its performance on LAMOST spectrograph.

A solar radio dynamic spectrograph with flexible temporal-spectral resolution

Observation and research on solar radio emission have unique scientific values in solar and space physics and related space weather forecasting applications, since the observed spectral structures may carry important information about energetic electrons and underlying physical mechanisms. In this study, we present the design of a novel dynamic spectrograph that has been installed at the Chashan Solar Radio Observatory operated by the Laboratory for Radio Technologies, Institute of Space Sciences at Shandong University. The spectrograph is characterized by real-time storage of digitized radio intensity data in the time domain and its capability to perform off-line spectral analysis of the radio spectra. The analog signals received via antennas and amplified with a low-noise amplifier are converted into digital data at a speed reaching up to 32 k data points per millisecond. The digital data are then saved into a high- speed electronic disk for further off-line spectral analysis. Using different word lengths （1-32k） and time cadences （5 ms-10 s） for off-line fast Fourier transform analysis, we can obtain the dynamic spectrum of a radio burst with different （user-defined） temporal （5 ms-10 s） and spectral （3 kHz-320kHz） resolutions. This enables great flexibility and convenience in data analysis of solar radio bursts, especially when some specific fine spectral structures are under study.

Broadband Frequency Comb for Calibration of Astronomical Spectrographs

We present our state-of-the-art version of a frequency comb for calibration of astronomical spectrographs. The mode spacing of the frequency comb can be designed to match the resolution of a spectrograph. Combined with its excellent accuracy and stability, the spectral coverage of more than 70% of the whole visible spectrum range makes the frequency comb an ideal calibration source. In addition, the new version introduces the automatic start-up function that brings convenience to the astronomers.

Direct Electron－transfer Reaction of Cytochrome C at a Bare Spectrographic Graphite Electrode

he electrochemistry of cytochrome C was investigated at a spectrographicgraphite electrode. In phosphate buffer solution (pH= 7. 0) , cytochrome C showedstable and quasi-reversible response. The formal potential E￣(o') was 0. 015 V (at25℃ , vs. SCE) and the heterogeneous electron transfer rate constant k_s obtainedvaried form 1. 10×10￣(-3) cm · s￣(-1) to 1. 80k×10￣(-3) cm · s￣(-1). The thermodynamic pa-rameters of the electron transfer reaction of cvtochrome C was also estimated. Fur-thermore, the effect of the various electrode surface states on the electrochemistryof cytochrome C was discussed.

The Coude Echelle Spectrograph for the Lijiang 1.8 m telescope

The Coude Echelle Spectrograph(CES)was originally mounted on Xinglong 2.16 m telescope in 1994.When the High Resolution Fiber-fed Spectrograph(HRS)was commissioned at Xinglong 2.16 m telescope,the red path of CES was moved to Lijiang 1.8 m telescope,following some redesign and reinstallation.The CES of Lijiang 1.8 m telescope has the spectral resolution(R=λ/?λ)ranging from 20000 to 50000 corresponding to different slit widths.With a 2 k×2 k PI CCD,CES has a wavelength coverage between 570 nm to 1030 nm.In particular,the resolution of 37000 at 0.5 mm slit corresponds to 1.3′′on the sky.The limiting magnitude is V=11.5 with the use of the tip-tilt feedback system,and the S/N is about 40 for 1 hour exposure at 600 nm(R=37000).During the installation of CES,the tip-tilt mirror technology had successfully fulfilled high precision guiding and tracking for high resolution spectral observation and significantly improved the observation efficiency.

Spectrographic analysis of laser induced plasma in process of high power laser welding

During high power laser welding, the amount of energy reaching the workpiece, the weld penetration and the geometry of the welds are strongly affected by the laser induced plasma. Light emissions during welding were recorded by a spectrometer. Based on the collected spectroscopic data, the electron density and the temperature of plasma were calculated using the relative intensity method. Several relationships between weld penetrations and electron density are given.

Investigating the efficiency of the Beijing Faint Object Spectrograph and Camera(BFOSC)of the Xinglong 2.16-m reflector

The Beijing Faint Object Spectrograph and Camera （BFOSC） is one of the most important instruments operating in conjunction with the 2.16-m telescope at Xinglong Observatory. Every year there are - 20 SCI-papers published based on observational data acquired with this telescope. In this work, we have systemically measured the total efficiency of the BFOSC that operates as part of the 2.16-m reflector, based on observations of two ESO flux standard stars. We have obtained the total efficiencies of the BFOSC instrument of different grisms with various slit widths in almost all ranges, and analyzed factors which effect the efficiency of this telescope and spectrograph. For astronomical observers, the result will be useful for them to select a suitable slit width, depending on their scientific goals and weather conditions during observations. For technicians, the result will help them to systemically identify the real efficiency of the telescope and spectrograph, and to further improve the total efficiency and observing capacity of the telescope technically.

The Coudé Echelle Spectrograph for the Xinglong 2.16m Telescope

A brief description of the NAO coude echelle spectrograph mounted on the 2.16 m telescope at Xinglong station is given. This echelle spectrograph is located at the coudé focus with a prism cross disperser. The echelle image covers the spectral region from 330 to 1100 nm displayed in 80 spectral orders in one exposure through two light beams. With a slit height of 2mm, spectral orders are separated by 15 to 23 pixels in blue region and by 7 to 19 pixels in red region. Alternatively, two additional resolution modes corresponding to different focal length cameras with resolving power R 16000, 170 000 in the blue beam and R = 13000, 170 000 in the red beam could be provided by this spectrograph. The bias, dark, wavelength calibration, flat field and science exposure are described in details. The limiting magnitude for 1 hour exposure with an S/N ratio of 100 scales to V = 9.5 in the red path and to V = 7.2 in the blue path.

Model of Spectral Fluxes for Solar Spectrograph

Taking use of the solar spectrograph in Yunnan Observatory, we built a model to estimate the spectral fluxes of solar spectrograph with computer and confirmed the result by observations. The spectral fluxes in visible and near infrared bands were calculated for the solar spectrograph of Yunnan Observatory.

Spectrographic Characteristics of Turkish /h/

/h/ is described differently by different researchers. While some argue that /h/ is a glottal fricative, others argue that it is the voiceless counterpart of the following vowel, yet others argue that /h/ is a glide or an approximant. However, de- tailed acoustic studies focusing on /h/ are very limited. This study aims to describe the spectrographic characteristics of /h/ in Turkish. Test words consisted of 48 monosyllabic and disyllabic words containing /h/ which was followed by eight Turkish vowels. Totally 1440 tokens were analyzed. After segmentation, /h/ was classified based on its spectrographic characteristics: 1) segment exhibiting formants, 2) segment exhibiting frication (but no formants) with energy in lower frequencies and 3) segment exhibiting almost no energy. In order to find out if there is a significant difference among these three categories, Chi-square test was applied. The spectrographic characteristics of /h/ in Turkish suggest that it is more like the voiceless version of the surrounding vowels, significantly when it is in syllable initial position and the preceding vowel when in syllable final position.

The Application of Permanent Magnet Synchronous Motor with Small Electrical Time Constant in Fiber Positioner

With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a suitable replacement for Faulhaber Precistep stepper motors.However,the small electrical time constant of such coreless motors poses a challenge,as the problem of severe commutation torque ripple in a fiber positioner running a position loop has been tricky.To overcome this challenge,it is advised to increase the Pulse Width Modulation(PWM)frequency as much as possible to mitigate the effects of the current fluctuation.This must be done while ensuring adequate resolution of the PWM generator.By employing a voltage open-loop field-oriented control based on a modulation frequency of 1 MHz,the drive current only costs 25 m A under a 3.3 V power supply.The sine degree of phase current is immaculate,and the repeat positioning accuracy can reach 2μm.Moreover,it is possible to further shrink the bill of devices and the layout area of the Printed Circuit Board,especially in sizesensitive applications.This device has been developed under the new generation of The Large Sky Area MultiObject Fiber Spectroscopic Telescope.

用于视向速度测量的法珀标准具性能测试(特邀)

通过国家天文台兴隆观测基地2.16 m望远镜高色散光纤光谱仪,对一套置于真空恒温系统中的标准具进行测试分析。实测定标谱线频率间距~29.87 GHz,波长覆盖500~685 nm,波长范围内共有5425条谱线,谱线自身宽度小于光谱仪最小分辨单元。与激光频率梳同步对比测试表明,稳定后法布里-珀罗标准具谱线超过5 h的稳定性好于0.61 m/s,可以满足天文观测一个观测夜的稳定性需求。使用这些谱线对此光谱仪重新进行波长定标,并将激光频率梳作为已知的波长标准对定标结果进行检验,法布里-珀罗标准具波长解的残差标准差约为钍氩灯波长解的一半,说明其定标精度更高。

酒煎瓜蒌薤白半夏汤治疗冠心病多靶点作用机制的交互网络分析

目的:采用质谱分析与网络药理学和分子对接技术探究酒煎瓜蒌薤白半夏汤治疗冠心病(CHD)的作用机制。方法:使用超高效液相色谱-四级杆飞行时间串联质谱仪(UPLC-Q-TOF/MS)对酒煎瓜蒌薤白半夏汤的成分进行鉴别,根据Gene Cards数据库、DisGeNET数据库寻找CHD疾病作用靶点,并通过Metascape在线分析网站聚类分析基因靶点、通路,构建中药-活性成分-靶点相互作用机制网络图,使用AutoDockTools软件完成靶基因与关键活性成分的分子对接。结果:酒煎瓜蒌薤白半夏汤通过质谱分析共鉴别出76个化学成分,数据库筛选获得药物相关靶点751个,疾病相关靶点1249个,药物相关靶点与疾病相关靶点取交集后获得潜在作用靶点190个。基因本体(GO)富集分析显示,生物过程结果主要涉及激素反应、对炎症反应的调节作用、细胞迁移的正向调控等;细胞组成结果主要集中于膜筏、膜侧等;分子功能结果主要涉及丝氨酸水解酶活性、脂质结合、血红素结合等。京都基因与基因组百科全书(KEGG)富集分析结果主要涉及脂质与动脉粥样硬化、流体剪应力与动脉粥样硬化、cGMP-PKG通路、钙信号通路、PPAR信号通路。分子对接结果显示,在共同调控激素反应与脂质结合的靶点基因中过氧化物酶体增殖物激活受体δ(PPARD)、过氧化物酶体增殖物激活受体γ(PPARG)、血小板活化因子受体(PTAFR)、雌激素受体2(ESR2)、雄激素受体(AR)、维甲酸X受体α(RXRA)所代表的蛋白与美迪紫檀素、肉叶芸香碱、环(亮氨酸-酪氨酸)显示出了良好的结合能力。结论:酒煎瓜蒌薤白半夏汤可能通过激活PPARA、PPARG、PPARD、ESR2、AR、RXRA靶点与脂质与动脉粥样硬化、流体剪应力与动脉粥样硬化、cGMP-PKG通路、钙信号通路、PPAR信号通路实现对CHD的治疗作用。

黏土-砂混合物三轴压缩超声波特性研究

为研究核废料缓冲回填材料的超声波特征,本文利用岩石三轴压缩伺服仪和超声波测试系统,开展侧限压缩和常规三轴压缩2种应力路径和2种超固结比状态OCR=0.83和2.9的压实黏土-砂混合物的三轴压缩试验和超声波测试。结果表明:侧限压缩试验的纵、横波波速(V_(p)、V_(s))曲线表现出与轴压-轴向应变曲线相似的3阶段特征,但V_(p)曲线具有滞后效应;常规三轴压缩试验的V_(p)增加,V_(s)降低,V_(p)和V_(s)变化与围压有关。动剪切模量和动泊松比(G_(d)和μ_(d))的曲线分别与V_(s)和V_(p)的曲线相似,围压主要影响动剪切模量的大小;V_(p)和V_(s)与有效平均压力(p)有关,V_(p)和V_(s)与p的关系可用二次函数较好描述;横波信号的主频逐渐增大,主振幅先减小后增大,主频变得不易分辨,围压越大,横波信号衰减越强;Ⅰ和Ⅱ区随偏压加载而逐渐融合,横波分裂效应减弱。研究结果可为核废料缓冲回填材料的配比设计提供参考。

High-resolution X-ray focusing concave (elliptical) curved crystal spectrograph for laser-produced plasma

The X-ray spectrum emitted, from laser-produced plasma contains plentiful information. X-ray spectrometer is a powerful tool for plasma diagnosis and studying the information and evolution of the plasma. X-ray concave (elliptical) curved crystals analyzer was designed and manufactured to investigate the properties of laser-produced plasma. The experiment was carried out on Mianyang Xingguang-Ⅱ Facility and aimed at investigating the characteristics of a high density iron plasma. Experimental results using KAP, LIF, PET, and MICA curved crystal analyzers are described, and the spectra of Au, Ti laser-produced plasma are shown. The focusing crystal analyzer clearly gave an increase in sensitivity over a flat crystal.

The effects of spectrograph slit modes on the accuracy of stellar radial velocity measurement and atmospheric parameter estimation

Spectrograph slit is conventionally used to enhance the spectral resolution ~md manage how much light can be allowed to enter spectrograph. The narrow slit provides a higher resolution but sacrifices efficiency of spectrograph and results in a low signal to noise ratio （S/N） spectra product. We take GuoShouJing telescope as an example and carry out a series of experiments to study how its 2/3 slit mode affects the precision of stellar radial velocity measurement and atmosphere parameters estimate. By transforming the resolution and adding a Gaussian White Noise to the extremely high quality spectra from the Sloan Digital Sky Survey, we generate synthetic stellar spectra of various brightness with different S/Ns. Comparing the measurements on these noise added spectra with the original high quality ones, we summarize the influences of the 2/3 slit mode on the meas- urement accuracy of stellar radial velocity and atmospheric parameters.

Research on spectrographic oil analysis of 12VE-230ZC diesel engine

With the spectrographic analysis, this paper analyzes the concentration of elements inoil, such as Fe, Cu, Cr, Al, Si etc. In order to monitor conditions and diagnose faults, the correlationcoefficient of main elements in oil has been used to study wear characteristics of friction pairs inrunning-in and working periods.