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Studies on Excitation and Rotational Temperatures of an Oxygen-shielded Argon Microwave Plasma Torch Source

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Chemical Research in Chinese Universities 2006年第5期22卷 560-565页

作者： WANG Shu-hua LI Guo-zhen ZHOU Jian-guang JIN qin-han Institute of Miniature Analytical Instrumentation College of Chemistry Jilin University Jilin Province Research Center for Engineering and Technology of Spectral Analytical Instruments Changchun 130021 P. R. China Department of Physics Bohai University Jinzhou 121000 P. R. China

Excitation（ Texc ） and rotation（ Trot ） temperatures were determined under different conditions for an oxygen-shielded argon microwave plasmsa torch source（OS-Ar-MPT）. The Texc value, which was shown to be between 4300 and 5250 K under different operating conditions, was calculated from the slope of the Boltzmann plot with Fe as the thermometric species. The Trot value, which was in the range of 2100-2500 K, was measured with OH molecular spectra. The influences of microwave power, flow rates of the support gas, cartier gas, and shielding gas, as well as the observation height on Texc and Trot were investigated and discussed. The detailed results of Texc and Trot provided a better understanding of the performance of an OS-ArMPT as a source for atomic emission spectrometry.

关键词： Microwave plasma torch (MPT) Excitation temperature Rotational temperature

Surface reconstruction from unorganized point clouds based on edge growing

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Advances in Manufacturing 2019年第3期7卷 343-352页

作者： Xu-Jia qin Zhong-Tian Hu Hong-Bo Zheng Mei-Yu Zhang College of Computer Science and Technology Zhejiang University of TechnologyHangzhou 310023People's Republic of China Key Laboratory of Visual Media Intelligent Processing Technology of Zhejiang Province Hangzhou 310023People's Republic of China

Owing to unorganized point cloud data,unexpected triangles,such as holes and slits,may be generated during mesh surface *** solve this problem,a mesh surface reconstruction method based on edge growing from unorganized point clouds is *** method first constructs an octree structure for unorganized point cloud data,and determines the k-nearest neighbor for each ***,the method searches for flat areas in the point clouds to be used as the initial mesh edge growth regions,to avoid incorrect reconstruction of the mesh surface owing to the growth of initial sharp ***,the optimal mesh surface is obtained by controlling the mesh edge growing based on compulsive restriction and comprehensive optimization *** experimental results of mesh surface reconstruction show that the method is feasible and shows high reconstruction performance without introducing holes or slits in the reconstructed mesh surface.

关键词： Mesh surface reconstruction Point clouds Edge growing Octree

Environmental factors influencing snowfall and snowfall prediction in the Tianshan Mountains, Northwest China

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Journal of Arid Land 2019年第1期11卷 15-28页

作者： ZHANG Xueting LI Xuemei LI Lanhai ZHANG Shan qin Qirui Faculty of Geomatics Lanzhou Jiaotong University Gansu Provincial Engineering Laboratory for National Geographic State Monitoring State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

Snowfall is one of the dominant water resources in the mountainous regions and is closely related to the development of the local ecosystem and economy. Snowfall predication plays a critical role in understanding hydrological processes and forecasting natural disasters in the Tianshan Mountains, where meteorological stations are limited. Based on climatic, geographical and topographic variables at 27 meteorological stations during the cold season(October to April) from 1980 to 2015 in the Tianshan Mountains located in Xinjiang of Northwest China, we explored the potential influence of these variables on snowfall and predicted snowfall using two methods: multiple linear regression(MLR) model(a conventional measuring method) and random forest(RF) model(a non-parametric and non-linear machine learning algorithm). We identified the primary influencing factors of snowfall by ranking the importance of eight selected predictor variables based on the relative contribution of each variable in the two models. Model simulations were compared using different performance indices and the results showed that the RF model performed better than the MLR model, with a much higher R^2 value(R^2=0.74; R^2, coefficient of determination) and a lower bias error(RSR=0.51; RSR, the ratio of root mean square error to standard deviation of observed dataset). This indicates that the non-linear trend is more applicable for explaining the relationship between the selected predictor variables and snowfall. Relative humidity, temperature and longitude were identified as three of the most important variables influencing snowfall and snowfall prediction in both models, while elevation, aspect and latitude were of secondary importance, followed by slope and wind speed. These results will be beneficial to understand hydrological modeling and improve management and prediction of water resources in the Tianshan Mountains.

关键词： snowfall prediction snowfall fraction random forest multiple linear regression predictor variables Tianshan Mountains

Efficient nitric oxide capture and reduction on Ni-loaded CHA zeolites

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Green Energy & Environment 2024年第12期9卷 1857-1865页

作者： Bin Yue Jianhua Wang Shanshan Liu Guangjun Wu Bin qin Landong Li School of Materials Science and Engineering Nankai UniversityTianjin300350China College of Chemistry Nankai UniversityTianjin300071China

As a prominent contributor to air pollution,nitric oxide(NO)has emerged as a critical agent causing detrimental environmental and health *** mitigate emissions and facilitate downstream utilization,adsorption-based techniques offer a compelling approach for direct NO capture from both stationary and mobile *** this study,a comprehensive exploration of NO capture under oxygen-lean and oxygenrich conditions was conducted,employing Ni ion-exchanged chabazite(CHA-type)zeolites as the ***,Ni/Na-CHA zeolites,with Ni loadings ranging from 3 to 4 wt%,demonstrate remarkable dynamic uptake capacities and exhibit exceptional NO capture efficiencies(NO-to-Ni ratio)for both oxygen-lean(0.17-0.31 mmol/g,0.32-0.43 of NO/Ni)and oxygen-rich(1.64-1.18 mmol/g)under ambient *** NH3 reduction methodology was designed for the regeneration of absorbents at a relatively low temperature of 673 *** insights into the NO_(x) adsorption mechanism were obtained through temperature-programmed desorption experiments,in situ Fourier transform infrared spectroscopy,and density functional theory *** is unveiled that NO and NO_(2) exhibit propensity to coordinate with Ni^(2+) via N-terminal or O-terminal,yielding thermally stable complexes and metastable species,respectively,while the low-temperature desorption substances are generated in close proximity to Na^(+).This study not only offers micro-level perspectives but imparts crucial insights for the advancement of capture and reduction technologies utilizing precious-metal-free materials.

关键词： Nitrogen oxides Capture Zeolite Lean/rich condition Adsorption mechanism

Morphological traits for sex identification of the oriental armyworm,Mythimna separata(Lepidoptera:Noctuidae)

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Journal of Integrative Agriculture 2020年第6期19卷 1458-1463页

作者： CHEN Lin PAN qin-jian Muhammad Saad WAQAS LIU Tong-xian State Key Laboratory of Crop Stress Biology for Arid Areas/Key Laboratory of Integrated Pest Management on the Loess Plateau Ministry of AgricultureNorthwest A&F UniversityYangling 712100P.R.China State Key Laboratory of Rice Biology/MOA Key Lab of Molecular Biology of Crop Pathogens and Insects/Institute of Insect Sciences Zhejiang UniversityHangzhou 310058P.R.China

The oriental armyworm,Mythimna separata(Lepidoptera:Noctuidae)is a harmful pest which causes heavy loss in agricultural *** identification of *** is very important for understanding the biology and management of this *** of fast and convenient methods to identify *** female and male is the necessary prerequisite for con ducting gender-related *** this study,new methods to differentiate sex of *** at pupal and adult stages were *** results showed that posterior abdominal segments containing genital organs which are morphological traits to differentiate female and *** openings are important characters for the female and male pupae *** female pupa,it locates on the ventral side of eighth and ninth abdominal segments and appears as a visible longitudinal suture;for male pupa,it locates on the ventral side of the ninth abdominal segment and appears as a short slit surrounded by a pair of visible semicircular *** numbers are another indicator for sex differentiation of *** female has three-bristled frenulum and each male has one bristled-frenulum near the base of hind wing of each side of moth *** confirmed the two sex differentiation methods manually by dissecting genitalia of adults and found their genger was as same as what we examined the sex of pupae and adults using the morphological methods.

关键词： sex identification pupa and adult genital opening frenulum genitalia

Versatile functionalization of amylopectin for effective biomedical applications

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Science China Chemistry 2015年第9期58卷 1461-1470页

作者： Ranran Wang Hao Hu qin Cai Nana Zhao Yun Zhu Fujian Xu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education Beijing Laboratory of Biomedical Materials Chongqing Academy of Agricultural Science

Successful gene vectors should be with high transfection efficiency and minimal cytotoxicity. Natural polysaccharides, due to their good biocompatibility and biodegradability, have been widely studied and applied. Amylopectin is one of polysaccharides with dendritic structure and numerous hydroxyl groups that could be used for subsequent modification. In this work, a series of dendritic cationic gene vectors comprising amylopectin backbones and poly(2-(dimethylamino) ethyl methacrylate)(PDMAEMA) side chains with different lengths(termed as AMY-PDs) were readily prepared by atom transfer radical polymerization(ATRP). The gene condensation ability, cytotoxicity and gene transfection of AMY-PDs carriers were investigated. In comparison with "gold-standard" poly(ethyleneimine)(PEI, 25 k Da), the AMY-PDs exhibited higher transfection efficiency with lower cytotoxicity. AMY-PDs could be further modified with Au nanoparticles(termed as AMY-PD@Au). The potential of the AMY-PD@Au vectors to be utilized as a CT contrast agent for imaging of cancer cells was investigated. Such AMY-PD@Au vectors may realize gene therapy with the ability of real-time imaging.

关键词： amylopectin ATRP gene carriers CT imaging

Combustion Stabilization based on a Center Flame Strut in a Liquid Kerosene Fueled Supersonic Combustor

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Journal of Thermal Science 2013年第5期22卷 497-504页

作者： Jichao Hu Jiang qin Juntao Chang Wen Bao Youhai Zong qingchun Yang Harbin Institute of Technology

A newly designed strut is proposed in this paper for fuel injection and flame holding in a liquid-kerosene-fueled supersonic combustor. The thickness of the strut is 8ram and the front blockage is about 8%. The characteristic of this strut is that extra oxygen can be injected through a set of orifices at the back of the strut, which can change the local flow field structure and ER （Equivalence Ratio）. Based on the above mentioned strut, a stable local flame is generated at the back of the strut and the main combustion can be organized around this local fire. Nu- merical simulation is conducted to compare the local flow field distribution at the back of the strut with/without extra oxygen injection. Experiments are conducted to test the combustion characteristics based on this fuel injec- tion and flame holding strategy. The temperature distribution which can reflect the local flame characteristic has been measured in the experiments conducted under cold incoming supersonic air flow condition. In addition, the overall combustion performance in a full-scale supersonic combustor has been evaluated in the experiments con- ducted under hot incoming supersonic air flow condition. Results show that this strut strategy is very promising since it can organize stable supersonic combustion at the center of the combustor without any cavity or rearward facing step. Besides that, even with the 8ram thick strut, the combustion can be stable in a wide range of ER from 0.25-1 by using liquid room-temperature kerosene.

关键词： strut center flame oxygen liquid-kerosene-fueled supersonic combustor

Comprehensive analyses of initiation and failure mechanisms of the 2017 Xinmo catastrophic rockslide

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Journal of Mountain Science 2022年第6期19卷 1525-1540页

作者： ZHOU Jia-wen FAN Gang CHEN qin YANG Xing-guo State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China State Key Laboratory of Geohazard Prevention and Geoenvironment Chengdu University of TechnologyChengdu 610059China College of Water Resource and Hydropower Sichuan UniversityChengdu 610065China

The failure of the 2017 Xinmo catastrophic rockslide in Maoxian County, Sichuan, Southwest China was a combined effect of long-term and shortterm triggering factors. Field investigation, historical data collection, laboratory tests, chemical and microstructure analysis and numerical simulations were adopted herein to reveal the initiation and failure mechanism of the Xinmo rockslide. The analytical results showed that this failure involved the coupling of several triggering factors. The initial cracks in the rock mass were induced by historical earthquakes due to the convex topography and the direction effect. Rock masses from the source area of the Xinmo rockslide contain water-sensitive minerals, i.e., albite and chamosite, and the easily oxidized chemical element Fe, resulting in obvious strength deterioration under the action of water. The scanning electron microscopy(SEM) experimental results indicated that the internal structure of the rock mass is conducive to weathering. The compressive and shear strengths of the rock mass were reduced due to freeze-thaw cycles and weathering. The antecedent rainfall further deteriorated the stability of the slope, and stress and deformation accumulated continually in the locked section. Finally, the locked section sheared out, and the slope failed. An entrainment effect was observed in the Xinmo rockslide due to the presence of old landslide deposits and the antecedent rainfall, resulting in an amplification of the catastrophic rockslide. A simplified three dimensional analysis model was established in this study to reveal the influence of the triggering factors on the failure mechanism of the Xinmo rockslide.

关键词： Xinmo Rockslide Landslide Failure mechanism Long-term evolution Rainfall Entrainment effect

Origin of beaded tafoni in cliffs of Danxia landscapes,Longhushan Global Geopark, South China

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Journal of Mountain Science 2018年第11期15卷 2398-2408页

作者： GUO Fu-sheng CHEN Liu-qin XU Huan LIU Xin State Key Laboratory of Nuclear Resources and Environment East China University of Technology Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Minerals Shandong University of Science and Technology School of Earth Sciences East China University of Technology

The tafoni that develop in sandstone cliffs have attracted the interest of both scientists and the general public. A necklace-like tafone system, referred to here as beaded tafoni, has developed in the prominent cliffs of the Danxia landscapes within the Longhushan Global Geopark in the subtropical zone of South China. This paper presents a new model of the formation of this system of extraordinary beaded tafoni. The cliffs of the Danxia landscapes of the study area are composed of an alluvial conglomerate(i.e.,red beds). These Danxia landscapes have subrounded summits that are covered by vegetation and experience a nearly vertical water flow induced by gravity. Erosion and collapse of the outsized gravels and concentrated pebbles in the red beds give rise to the initial development of the beaded tafoni. The tafoni then become rounded and beaded as a result of reworking and decay by fluvial outwash. During storms, intense water flows run vertically down the cliffs and generate a whirling motion in the ***, the inside walls of the tafoni gradually become wider and smoother. During the late development stage, the beaded tafoni tend to become indistinct or disappear because of the interconnection of the tafoni and subsequent merging with the bedding-controlled cavities.

关键词： Beaded tafoni Alluvial red beds Danxia landscape Longhushan Global Geopark