检索结果-南通市图书馆

Explosion characteristics of aluminum-based activated fuels containing fluorine

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

Defence Technology（防务技术） 2023年第2期20卷 34-43页

作者： Jin-tao Xu Lei Huang Hai-peng Jiang tian-jiao zhang Feng-qi Zhao Jian-kan zhang Wei Gao State Key Laboratory of Fine Chemicals Department of Chemical Machinery and Safety EngineeringDalian University of TechnologyDalian116024China Beijing Institute of Aerospace Testing Technology Beijing100074China Science and Technology on Combustion and Explosion Laboratory Xi'an Modern Chemistry Research InstituteXi'an710065China

Measuring the dust explosion characteristics of aluminum-based activated fuels was a prerequisite for developing effective prevention and control measures.In this paper,ignition sensitivity,flame propagation behaviors and explosion severity of aluminum/polytetrafluoroethylene(Al/PTFE)compositions including 2 PT(2.80 wt.%F),4 PT(7.18 wt.%F)and 8 PT(11.90 wt.%F)were studied.When the content of F increased from 2.80 wt.%to 11.90 wt.%,the minimum explosive concentration MEC decreased from380 g/m^(3)to 140 g/m^(3),due to the dual effects of increased internal active aluminum and enhanced reactivity.The average flame propagation velocities increased as the percentage of F increased.The maximum explosion pressure Pmof 500 g/m3aluminum-based activated fuels increased from 247 k Pa to299 kPa.Scanning electron microscopy demonstrated that with the increase of PTFE content,the reaction was more complete.On this basis,the explosion mechanism of aluminum-based activated fuels was revealed.

关键词： Aluminum-based activated fuels Ignition sensitivity Flame propagation Explosion severity Explosion mechanism

Investigation and Analysis of Hemoglobin Alc Measurement Systems＇ Performance for 135 Laboratories in China

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2017年第9期130卷 1079-1084页

作者： Hai-Jian Zhao tian-jiao zhang Jie Zeng Cui-Hua Hu Rong Ma Chuan-Bao zhang National Center for Clinical Laboratories Beijing Hospital National Center of Gerontology Beijing Engineering Research Center of Laboratory Medicine Beijing 100730 China

Background： Hemoglobin A 1 c （HbA1 c） measurement is of great value for the diagnosis and monitoring of diabetes. Many manufacturers have developed various experiments to determine the HbAlc concentration. However, the longitudinal use of these tests requires strict quality management. This study aimed to analyze the quality of HbAlc measurement systems in China using six sigma techniques to help improve their performances. Methods： A total of 135 laboratories were involved in this investigation in 2015. Bias values and coefficients of variation were collected from an HbA 1 c trueness verification external quality assessment program and an internal quality control program organized by the National Center of Clinical Laboratories in China. The sigma （σ） values and the quality goal index （QGI） were used to evaluate the performances of different groups, which were divided according to principles and instruments. Results： The majority of participants （88, 65.2%） were scored as ＂improvement needed （σ 〈 3）＂, suggesting that the laboratories needed to improve their measurement performance. Only 8.2% （11/135） of the laboratories were scored as ＂world class （σ≥ 6）＂. Among all the 88 laboratories whose σ values were below 3, 52 （59.1%） and 23 （26.1%） laboratories needed to improve measurement precision （QGI 〈8.0） and trueness （QGI 〉 1.2）, respectively; the remaining laboratories （13, 14.8%） needed to improve both measurement precision and trueness. In addition, 16.1% （5/31） and 15.0% （3/20） of the laboratories in ＂TO SOH＂ and ＂ARKRAY＂ groups, respectively, were scored as ＂world class＂, whereas none of the laboratories in ＂BIO-RAD＂ group were scored as ＂world class＂. Conclusions： This study indicated that, although participating laboratories were laboratories with better performance in China, the performances were still unsatisfactory. Actions should be taken to improve HbAlc measurement performance before we can include HbAlc assays in diabetes diagnosis in China.

关键词： Hemoglobin Alc Quality Assurance Six Sigma Metric

Spanning tree trajectory optimization in the galaxy space

在线全文

学校读者我要写书评

暂无评论

Astrodynamics 2021年第1期5卷 27-37页

作者： tian-jiao zhang Dietmar Wolz Hong-Xin Shen Ya-Zhong Luo State Key Laboratory of Astronautic Dynamics Xi’an Satellite Control CenterXi’an 710043China University of Jena Jena 07737Germany National University of Defense Technology Changsha 410073China

The 10th edition of the Global Trajectory Optimization Competition considered the problem of the galaxy settlement wherein competitors from all over the world were expected to design the trajectories of different settler vessels to maximize the given multi-faceted merit function.The synthesis methods used by the winning team,led jointly by the National University of Defense Technology(NUDT)and Xi’an Satellite Control Center(XSCC),are described along with a greedy search method and the improved solution obtained by University of Jena.Specifically,we presented a layout-first topology-second approach that allows an efficient settlement tree search guided by the pre-specified ideal spatial distribution.We also explained how the problem of constructing settlement trees can be modeled as the widely studied minimum spanning tree problem.Furthermore,University of Jena explored the possibility that a greedy search can generate even better settlement trees,based on the same initial conditions,when compared to that of the winning solution.

关键词： trajectory optimization Settlers of the Galaxy minimum spanning tree ant colony optimization greedy search

Inductively Coupled Plasma Mass Spectrometry as a Reference Method to Evaluate Serum Calcium Measurement Bias and the Commutability of Processed Materials during Routine Measurements

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

Chinese Medical Journal 2018年第13期131卷 1584-1590页

作者： Hai-Jian Zhao Meng-Lei Ge Yin Yan tian-jiao zhang Jie Zeng Wei-Yan Zhou Yu-Fei Wang Qing-Hui Meng Chuan-Bao zhang National Center for Clinical Laboratories Beijing Hospital National Center of Gerontology Beijing Engineering Research Center of Laboratory Medicine Beijing 100730 China Department of Clinical Laboratory Children's Hospital Capital Institute of Pediatrics Beijing 100020 China Graduate School Peking Union Medical College Chinese Academy of Medical Sciences Beijing 100730 China

Background： Measuring total serum calcium is important for the diagnosis of diseases. Currently, results from commercial kits for calcium measurement are variable. Generally, the performance of serum calcium measurements is monitored by external quality assessment （EQA） or proficiency testing schemes. However, the commutability of the EQA samples and calibrators is often unknown, which limits the effectiveness of EQA schemes. The aim of this study was to evaluate the bias of serum calcium measurements and the commutability of processed materials. Methods： Inductively coupled plasma mass spectrometry was applied as a comparative method, and 14 routine methods were chosen as test methods. Forty-eight serum samples from individual patients and 25 processed materials were quantified. A scatter plot was generated from patient samples, and 95% prediction intervals were calculated to evaluate the commutability of the processed materials and measurement bias at three concentration levels was used to determine the accuracy of routine assays. Results： All assays showed high precision （total coefficient of variation [CV] 〈2.26%） and correlation coefficients （r 〉 0.99）. For all assays, the mean bias for the 48 patient samples ranged from 0.13 mmol/L to 0.00 mmol/L （-5.61 0.01%）, and the ranges for the three concentrations were 0.10-0.04 mmoUL （-5.71-2.35%）, -0.14-0.01 mmol/L （-5.80-0.30%）, and -0.19-0.04 mmol/L （-6.24-1.22%）. The EQA samples, calibrators, and animal sera exhibited matrix effects in some assays; human serum pools were commutable in all assays; certificate reference materials were commutable in most assays, and only GBW09152 exhibited a matrix effect in one assay： and aqueous reference materials exhibited matrix effects in most assays. Conclusions： Biases for most assays were within the acceptable range, although the accuracy of some assays needs improvement. Human serum pools prepared from patient samples were commutable, and the other tested materials exhibited a matrix effect.

关键词： Calibration Bias Commutability Inductively Coupled Plasma Mass Spectrometry Matrix Effect Serum Calcium

Unsteady aerodynamics modeling for flight dynamics application

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2012年第1期28卷 14-23页

作者： Qing Wang Kai-Feng He. Wei-Qi Qian tian-jiao zhang Yan-Qing Cheng Kai-Yuan Wu State Key Laboratory of Aerodynamics 621000 MianyangChina Computational Aerodynamics Institute China Aerodynamics Research and Development Center621000 MianyangChina Scientific Research Base of Flight Technology and Safety Civil Aviation Flight University of China618307 GuanghanChina

In view of engineering application, it is practicable to decompose the aerodynamics into three components： the static aerodynamics, the aerodynamic increment due to steady rotations, and the aerodynamic increment due to unsteady separated and vortical flow. The first and the second components can be presented in conventional forms, while the third is described using a one-order differential equation and a radial-basis-function （RBF） network. For an aircraft configuration, the mathematical models of 6- component aerodynamic coefficients are set up from the wind tunnel test data of pitch, yaw, roll, and coupled yawroll large-amplitude oscillations. The flight dynamics of an aircraft is studied by the bifurcation analysis technique in the case of quasi-steady aerodynamics and unsteady aerodynam- ics, respectively. The results show that：（1） unsteady aerodynamics has no effect upon the existence of trim points, but affects their stability; （2） unsteady aerodynamics has great effects upon the existence, stability, and amplitudes of periodic solutions; and （3） unsteady aerodynamics changes the stable regions of trim points obviously. Furthermore, the dynamic responses of the aircraft to elevator deflections are inspected. It is shown that the unsteady aerodynamics is beneficial to dynamic stability for the present aircraft. Finally, the effects of unsteady aerodynamics on the post-stall maneuverability

关键词： Unsteady aerodynamics High angle of attack Mathematical model Flight dynamics - Bifurcation analysis Post-stall maneuver

Heterogeneous integration of 2D materials on Si charge-coupled devices as optical memory

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第6期67卷 190-197页

作者： Zheng BIAN Feng tian Zongwen LI Xiangwei SU tianjiao zhang Jialei MIAO Bin YU Yang XU Yuda ZHAO College of Integrated Circuits Hangzhou Global Scientific and Technological Innovation CentreZhejiang University

Optical memory integrates the function of optical sensing in memory devices, remarkably promoting the interconnection between sensory and memory terminals. Silicon charge-coupled photodetectors and floating gate memory have been widely used in imaging and storage technologies, respectively. However,the heterogeneous integration of the two devices requires technological innovation and complex electrical connections. In this work, we adopt a three-dimensional layer stacking method to design a novel optical memory device. On the top of Si charge-coupled photodetectors, we successively deposit two-dimensional graphene,hexagonal boron nitride, and molybdenum disulfide as a floating gate layer, a tunneling layer, and a readout layer, respectively. By applying a gate bias on lightly doped Si, a deep depletion layer is formed with a high voltage potential drop. Under dark conditions, the depletion layer cannot be filled, and the electric field across the h-BN tunnel barrier is relatively small. Under light irradiation, the deep depletion layer is gradually filled, and the h-BN tunneling layer withstands the increasing electric field, resulting in charge storage in the floating gate layer. Based on this mechanism, the device exhibits a gate voltage-dependent operation mode, including an integrated optical sensing-memory mode and an electrically driven storage mode. Under moderate gate voltage, the device can effectively detect the optical information with varied intensity and store the optical information in the floating gate, displaying optically controlled memory characteristics. Our work demonstrates a compact device structure for optical memory and displays excellent optically controlled memory performance, which can be applied in artificial vision systems.

关键词： heterogeneous integration charge-coupled device floating gate optical memory molybdenum disulfide lightly doped silicon

A Possible γ-Ray Pulsation from PSR J1740-5340B in the Globular Cluster NGC 6397

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第1期24卷 285-291页

作者： jiao Zheng Pengfei zhang Li zhang Department of Astronomy School of Physics and AstronomyKey Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China

Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is detected.Considering that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris.

关键词： gamma-rays:galaxies (stars:)pulsars:individual(PSR J1740-5340B) (Galaxy:)globular clusters:individual(NGC 6397)

Robust adaptive radar beamforming based on iterative training sample selection using kurtosis of generalized inner product statistics

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第1期35卷 24-30页

作者： tian Jing zhang Wei School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Electromagnetic Space Security Chengdu 610036China

In engineering application,there is only one adaptive weights estimated by most of traditional early warning radars for adaptive interference suppression in a pulse reputation interval(PRI).Therefore,if the training samples used to calculate the weight vector does not contain the jamming,then the jamming cannot be removed by adaptive spatial filtering.If the weight vector is constantly updated in the range dimension,the training data may contain target echo signals,resulting in signal cancellation effect.To cope with the situation that the training samples are contaminated by target signal,an iterative training sample selection method based on non-homogeneous detector(NHD)is proposed in this paper for updating the weight vector in entire range dimension.The principle is presented,and the validity is proven by simulation results.

关键词： adaptive radar beamforming training sample selection non-homogeneous detector electronic jamming jamming suppression

Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第8期16卷 102-147页

作者： Fujuan Wang tianyun zhang tian zhang tianqi He Fen Ran State Key Laboratory of Advanced Processing and Recycling of Non‑Ferrous Metals Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China

Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion batteries.The present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials,explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials,and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based materials.This review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials,with particular focuses on their molecular,crystalline,and aggregation structures.Furthermore,the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization analyses.Finally,future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted.

关键词： Cellulose Hard carbon Anode materials Rate performance Sodium-ion batteries