Rapid Detection of Accelerants in Fire Debris Using a Field Portable Mid-Infrared Quantum Cascade Laser Based Analyzer

Arson presents a challenging crime scene for fire investigators worldwide. Key to the investigation of suspected arson cases is the analysis of fire debris for the presence of accelerants or ignitable liquids. This study has investigated the application and method development of vapor phase mid-Infrared (mid-IR) spectroscopy using a field portable quantum cascade laser (QCL) based system for the detection and identification of accelerant residues such as gasoline, diesel, and ethanol in fire debris. A searchable spectral library of various ignitable fluids and fuel components measured in the vapor phase was constructed that allowed for real-time identification of accelerants present in samples using software developed in-house. Measurement of vapors collected from paper material that had been doused with an accelerant followed by controlled burning and then extinguished with water showed that positive identification could be achieved for gasoline, diesel, and ethanol. This vapor phase mid-IR QCL method is rapid, easy to use, and has the sensitivity and discrimination capability that make it well suited for non-destructive crime scene sample analysis. Sampling and measurement can be performed in minutes with this 7.5 kg instrument. This vibrational spectroscopic method required no time-consuming sample pretreatment or complicated solvent extraction procedure. The results of this initial feasibility study demonstrate that this portable fire debris analyzer would greatly benefit arson investigators performing analysis on-site.

The research progress of an E//B neutral particle analyzer

An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.

Broadband third-order optical nonlinearities of layered franckeite towards mid-infrared regime

The study of nonlinear optical responses in the mid-infrared(mid-IR)regime is essential for advancing ultrafast mid-IR laser applications.However,nonlinear optical effects under mid-IR excitation are rarely reported due to the lack of suitable nonlinear optical materials.The natural van derWaals heterostructure franckeite,known for its narrow bandgap and stability in air,shows great potential for developing mid-IR nonlinear optical devices.We have experimentally demonstrated that layered franckeite exhibits a broadband wavelength-dependent nonlinear optical response in the mid-IR spectral region.Franckeite nanosheets were prepared using a liquid-phase exfoliation method,and their nonlinear optical response was characterized in the spectral range of 3000 nm to 5000 nm.The franckeite nanosheets exhibit broadband wavelengthdependent third-order nonlinearities,with nonlinear absorption and refraction coefficients estimated to be about 10^(-7)cm/W and 10^(-11)cm^(2)/W,respectively.Additionally,a passively Q-switched fluoride fiber laser operating around a wavelength of 2800 nm was achieved,delivering nanosecond pulses with a signal-to-noise ratio of 43.6 dB,based on the nonlinear response of franckeite.These findings indicate that layered franckeite possesses broadband nonlinear optical characteristics in the mid-IR region,potentially enabling new possibilities for mid-IR photonic devices.

Mid-infrared Optical Frequency Comb-based Fourier Transform Spectrometer for Broadband Molecular Spectroscopy

Optical frequency combbased Fourier transform spectroscopy has the features of broad spectral bandwidth,high sensitivity,andmultiplexed trace gas detection,which has valuable application potential in the fields of precision spectroscopy and trace gas detection.Here,we report the development of a mid-infrared Fourier transform spectrometer based on an optical frequency comb combined with a Herriott-type multipass cell.Using this instrument,the broadband absorption spectra of several important molecules,including methane,acetylene,water molecules and nitrous oxide,are measured by near real-time data acquisition in the 2800-3500 cm^(-1)spectral region.The achieved minimum detectable absorption of the instrument is 4.4×10^(-8)cm^(-1)·Hz^(-1/2)per spectral element.Broadband spectra of H_(2)0 are fited using the Voigt profile multispectral fitting technique and the consistency of the concentration inversion is 1%.Our system also enables precise spectroscopic measurements,and it allows the determination of the spectral line positions and upper state constants of N_(2)O in the(0002)-(1000)band,with results in good agreement with those reported by Toth[Appl.Opt.30,5289(1991)].

Intra-and interobserver reliability of ocular surface analyzer LacryDiag

AIM:To invastigate intra-and interobserver reliability of interferometry,tear meniscus height(TMH)measurement and meibography(MBG)of an ocular surface analyzer,LacryDiag(Quantel Medical,France).METHODS:Five consecutive measurements and subsequent analysis of interferometry,TMH,and MBG were recorded by two examiners using the LacryDiag.To assess intra-and interobserver reliability,we used Cohen’s kappa for categorical variables(interferometry),or intraclass correlation coefficient for continuous variables(TMH,MBG).RESULTS:Thirty eyes of 30 examinees were included.For both observers,there was excellent intraobserver reliability for MBG(0.955 and 0.970 for observer 1 and 2,respectively).Intraobserver reliability for observer 1 was substantial for interferometry(0.799),and excellent for TMH(0.863).Reliability for observer 2 was moderate for interferometry(0.535)and fair to good for TMH(0.431).Interobserver reliability was poor for interferometry(0.074)and fair to good for TMH(0.680)and MBG(0.414).CONCLUSION:LacryDiag ocular surface analyzer in our study proves to be a reliable noninvasive tool for the evaluation of TMH and MBG.As for interferometry,poor interobserver reliability,fair to good intraobserver reliability for observer 1,and moderate for observer 2,leave room for improvement.

Research on power improvement of a LD directly-pumped mid-infrared pulse solid-state laser

An LD directly-pumped solid-state laser is considered to be one of the most promising mid-infrared light sources because of its simple principle,small size,and compact structure for the generation of mid-infrared(MIR)lasers in the 3-5µm band.However,the quantum defect of LD directly-pumped MIR solid-state lasers will be much larger than that of ordinary near-infrared LD pumped solid-state lasers,which may lead to thermal damage and limit their development.In order to solve this problem,the methods of reducing the specific surface area of the crystal and improving the thermal energy released by the crystal structure are discussed,and the opti⁃mal length of the laser crystal is determined.The cooling structures of barium yttrium fluoride laser crystals(Ho^(3+):BY_(2)F_(8))of different lengths were studied by thermal simulation using COMSOL software.The experimen⁃tal results show that the output power can be increased and the thermal stress in the laser crystal can be alleviated by using the laser crystal whose length is slightly shorter than that of the cooler.The final experiment shows that when the pump repetition rate is 15 Hz and the pulse width is 90µs,the single pulse energy is 7.28 mJ at the out⁃put wavelength of 3.9µm,which is about 3 times as large as that of the crystal with the length of 10 mm(2.81 mJ).Such results should be another breakthrough of our team since the first directly-pumped solid-state MIR laser was realized more than a year ago.It might pave the way for the construction of a feasible MIR laser in the near future.

The Application of Digital Optical 3D Image Analyzer Evaskin in The Evaluation of Wrinkles

To verify the effectiveness of digital optical 3D image analyzer EvaSKIN in the objective and quantitative evaluation of wrinkles.A total of 115 subjects were recruited,the facial images of the subjects were collected by digital optical 3D image analyzer and manual camera,the changes of crow’s feet with age were analyzed.Pictures obtained by manual photography can be directly used for observation and preliminary grading of wrinkles.However,the requirements for evaluators are high,and the results are prone to errors,which will affect the accuracy of the evaluation.Therefore,skilled raters are needed.Compared with the manual photography method,the digital optical 3D image analyzer EvaSKIN can realize three-dimensional extraction of wrinkles,and obtain the change trend of crow’s feet with age.20~30 years old,wrinkles begin to appear slowly;wrinkles will increase rapidly at the age of 30~50;The length of 50~60 year old wrinkles is basically fixed,the wrinkles develop longitudewise,gradually widen and deepen,and the area,depth and volume increase is obvious,and the skin aging condition is intensified.the digital optical 3D image analyzer EvaSKIN realizes the 3D extraction of wrinkles,quantifies the circumference,area,average depth,maximum depth and volume of wrinkles,realizes the objective and quantitative evaluation of wrinkle state,is more accurate in the measurement of wrinkles,and provides a new instrument and method for the evaluation of wrinkles.it is a perfect and supplement to the traditional evaluation methods,and to a certain extent,it helps the research and development and evaluation institutions of cosmetics to obtain more abundant and three-dimensional data support.

Study on the Hook Effect in the Detection of Beta2-Microglobulin with Different Reagents in Fully Automated Biochemical Analyzers

Objective:To investigate the hook effect in the detection of beta2-microglobulin(β2-MG)with different reagents as well as on two fully automated biochemical analyzers and their solutions.Methods:Using immunoturbidimetric assay forβ2-MG as the research object,β2-MG levels were detected by different concentration gradients ofβ2-microglobulin samples in Liedemann,Mack,and Myriad reagents of three manufacturers on two automatic biochemical analyzers,and the difference of the hook effect was comparatively analyzed.Results:Leadman reagent showed the hook effect on the Beckman AU5800 automated biochemistry analyzer,while both Maccura and Mindray reagents did not show the hook effect.After the experiments,we found the limit value of the pre-zone check of Leadman reagent,and changed the parameters of the instrument,when the limit value of the pre-zone check was reached,the instrument automatically diluted the specimen five times and then detected it again.After changing the parameters of the instrument,the correlation between the three methods of detecting samples of different concentrations was r>0.99.Conclusion:Before selecting the application of immunoturbidimetric reagents,we have to carry out the risk assessment of the hook effect and selectively set the parameters of the pre-zone check based on the highest concentration that may occur in the clinic;for the items that may have the hook effect,we have to selectively set the parameters of the pre-zone check when the ratio of average reaction rate and the immediate reaction rate is at the limit value,and the phenomenon of antigen excess may occur,the instrument will carry out automatic dilution before detection,so as to avoid the issuance of erroneous results of high-value samples due to the hook effect.

索尼正式发布mocopi PC应用程序及移动端Data Analyzer

6月13日,索尼正式对便携动作捕捉产品mocopi发布几项更新,改善创作者基于PC(个人电脑)的工作流程,并将持续拓展PC端更多功能,助力3D内容创作。本次更新内容包括:(1)发布mocopi的Windows版PC应用程序,实现了PC端的动作捕捉,以支持电影、动画制作现场或使用3D虚拟形象进行直播等专业3DCG制作;(2)将mocopi移动应用程序的强大功能带到桌面环境,可以在PC上完成动作捕捉、文件保存、预览和发送等一系列工作,因此无需从智能手机迁移文件到PC,使用外部直播软件可以直接直播mocopi PC应用程序的屏幕。

语音分析软件Speech Analyzer和Praat在上海市区方言鼻化韵单一化演变研究中的应用

目前我国方言语音演变研究中音位的确定主要以传统意义上的研究方法为多,音位归纳主要凭个人经验。若记音人本身记音能力有限,可能造成记录结果与方言实际读音存在偏差。因此,如果在传统记音方法的基础上,辅以语音分析软件,将使方言语音研究更为精密、客观。以Speech Analyzer和Praat语音分析软件为例,結合上海市区方言鼻化韵单一化,即鼻化韵中前a后ɑ的对立完全消失,发成中A这一语音演变现象,以Speech Analyzer确定鼻化元音位置,以Praat做共振峰分析,为这一语音演变现象的确定提供证据。

使用Thomson Data Analyzer进行专利分析的几点研究

专利分析软件作为专利数据挖掘的工具,可以用作行业趋势分析、技术追踪、竞争对手监视等,目前正得到企业越来越广泛的重视。Thomson DataAnalyzer作为一款基于Derwent世界专利数据库基础上开发的专利分析软件,具有其独特的优势。本文在对TDA软件介绍的基础上,对使用中如何进行数据整理,以及如何进行技术领域分析进行了研究。

Rapid Determination of Lysine Content in Maize Kernel by Amino-acid Analyzer

In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize kernels was carried out using Hitachi L-8900 Automatic Amino-acid Analyzer, to know the effect of the Analyzer in distinguishing the lysine contents between common maize kernels and high-lysine maize kernels. The results showed that the lysine contents of high-lysine maize kernels were among 0.34%-0.42%, while of common maize kernels were a- mong 0.24%-0.25%, and the difference was significant. Compared with other tradi- tional methods, this method is rapid, simple, sensitive, highly reproductive and needs fewer maize kernels, thus it is applicable in maize breeding.

Rapidly determining kinematic viscosity of aviation lubricating oil 50-1-4Φ by mid-infrared spectrometry

This paper analyzed 11 lubricating oil 50-1-4Ф samples of different base oil content （standard oil） and 28 used oil samples by Fourier transform mid-infrared spectrometer （FTIR）. First, the absorption peak of 1 465 cm 1 was selected as the characteristic peak for determining their kinematic viscosities. And then correlation of the kinematic viscosity and the absorbance at characteristic peaks of corresponding infrared spectrum of standard oil and used oil samples was analyzed, re- spectively, and two regression equations were proposed. Finally, the regression equation of standard oil was corrected through other 20 new oil samples. The results show that determining kinematic viscosity of new lubricating oil 50-1-4Ф and the used one by FTIR is feasible and reliable.

Rapidly determining fuel pollution level of aviation lubricating oil 50-1-4Φby mid-infrared spectrometry

A series of aviation lubrication oil 50-1-4φ samples were prepared with different RP-3 content, and then these sam- ples were analyzed by Fourier transform mid-infrared spectrometer （FTIR）. The infrared region of 805--755 cm-1 was selected as quantitative area for determining fuel pollution level of aviation lubrication oil. Finally, correlation of the testing peak area and the fuel pollution level of corresponding samples were analyzed, and the regression equation was proposed. The results show that determining jet fuel pollution level of aviation lubricating oil by FTIR is feasible and reliable.

PLC Analyzer在多工位快速液压机中的应用

介绍快速液压机工作原理以及PLC Analyzer软件的使用,通过PLC Analyzer软件在多工位快速压机中的使用,实现了对各种信号的数据采集与存储功能,便于分析、解决调试过程中出现的不定期的异常故障,优化了压机调试参数。借助该软件可快速、准确地发现设备故障点,弥补传统PLC无法对瞬时故障信号记录以及判断的缺陷。

基于Analyzer的城市水环境设施管理综合分析评估体系构建

本文以城市水环境设施预警监控信息为基础,构建面向行业主管部门的城市水环境设施综合分析评估体系,包括信息上报评价体系、检验合格评价体系、基础建设评价体系和突发事故评价体系,并采用BI技术-analyzer分析软件进行了实现,能够有效降低开发和维护难度。

Aspen Energy Analyzer软件在凝析油蒸馏装置改造的应用

辽宁某公司原凝析油蒸馏装置加工能力10万t/a,2013年将其加工能力改造至22万t/a。装置在改造设计过程中,为降低能耗,对换热网络采用Aspen Energy Analyzer软件进行优化设计,换热网络优化改造后各换热单元冷端温差均大于夹点温差20℃,热负荷均大于4.186 8×105k J/h;投资费有所降低,虽然改造后加热负荷和冷却负荷均有所增加,但换热网络符合能量松弛的原则,总体上,凝析油蒸馏装置的换热网络得到了优化,满足了换热网络投资费用和操作费用最小的要求。

基于EventLog Analyzer的日志服务器配置

计算机网络是学校基础设施中的核心。服务器与网络设备会产生大量的日志记录,这些日志记录在进行账号行为的审计、留存系统运行信息分析和发现黑客入侵行为方面具有重要作用,但这些日志记录并不能长期存在这些设备中。如何保存并管理这些日志记录以便发挥作用成为网络管理工作的重点。该文介绍通过EventLog Analyzer创建日志服务器的配置过程以及对服务器和网络设备的管理。

Digital Differential Analyzer,Bresenham算法的比较分析

本文主要阐述了Digital Differential Analyzer及Bresenham两类算法原理、伪代码编写、运行速度比较等内容。本文的研究对于计算机图形技术从业人员具有一定借鉴意义及参考价值。

采用库仑滴定法—康宁Chloride Analyzer 925型测定血清氯化物含量

目前人体氯化物测定普遍采用化学滴定法，火焰光度计法。但因这些方法操作繁冗，在分析中易引入较大误差，常常影响实验结果的精确性。近来我们使用美国康宁925型氯化物分析仪采用库仑滴定法测定氯化物含量，获得较为满意的效果。认为该法具有简单、