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The correlation of multi-angle thermal infrared data and the choice of optimal view angles

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Science china Earth Sciences 2004年第6期47卷 570-576页

作者： fan wenjie1 & xu xiru1,2 1.Institute of Remote Sensing and GIS of{1.,Beijing 1.0871.china 2.Center of Remote Sensing and GIS of Beijing Normal {3.,Beijing 1.0875,china Institute of Remote Sensing and GIS of peking university Beijing China Center of Remote Sensing and GIS of Beijing Normal university Beijing China

Based on the matrix formula of thermal infrared radiant system, the components temperature can be retrieved by the inversive matrix. Around the stability problem of retrieved result, the research work we did was focused on (i) the correlation of (wk,j) which is the key to affect the retrieval accuracy, (ii) a general method which can help us find the number of retrievable parameters and evaluate the retrieval error before its performance, (iii) the choice of “optimal viewing angle group” based on the formula of absolute error propagation. The row winter wheat field was chosen as an example. The results can provide a theoretical basis for multi-angle thermal infrared remote sensing and components temperature retrieval.

关键词： components temperature retrieval, correlation, number of retrievable parameters, optimal viewing angle group.

Solubility determination and comparison ofβ-HMX and RDX in two binary mixed solvents(acetonitrile+water,nitric acid+water)

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Chinese Journal of Chemical Engineering 2024年第5期69卷 238-249页

作者： Yuehua Yao fan Wang Yinguang {1. Zishuai {1. Lizhen Chen Jianlong Wang School of Chemistry and Chemical Engineering North University of ChinaTaiyuan 030051China Gansu Yinguang Chemical Industry Group Co.Ltd. Baiyin 730900China

In order to remove hexahydro-1.3.5-trinitro-1.3.5-triazine(RDX),the main impurity,in process of polymorphic transformation of octrahydro-1.3.5,7-tetranitro-1.3.5,7-tetrazocine(HMX),the solubility ofβ-HMX and RDX in acetonitrile(ACN)+water in the temperature range of 288.1.-3.3.1. K and in nitric acid(HNO_(3.)+water in the temperature range of 298.1.-3.3.1. K were measured by laser dynamic *** results showed that the solubility of bothβ-HMX and RDX in binary mixed solvents increased monotonously as the temperature increase at a given solvent composition or with increasing of mole fraction of solvent(ACN and nitric acid).Solubility data were well correlated by the modified Apelblat equation,Jouyban-Acree model,Yaws equation and van't Hoff equation,and the Yaws equation achieved the best fitting results according to the relative error and the mean square error ***,the solubility ofβ-HMX and RDX in binary mixed solvent was compared,based on the solubility difference and the solvent's own properties,the best separation degree ofβ-HMX and RDX was found when the mole fraction of nitric acid was 0.22 at room temperature,which provided data support for HMX crystallization in mixed *** solubility differences between RDX andβ-HMX in mixed solvents were explained from the formation of intermolecular and intramolecular hydrogen bonds.

关键词： Solubility Octrahydro-1.3.5,7-tetranitro-1.3.5,7-tetrazocine Hexahydro-1.3.5-trinitro-1.3.5-triazine Separation Model Hydrogen bond

A novel endorectal RF coil for high resolution MRI and spectroscopy of the prostate

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Progress in Natural Science:Materials International 2005年第5期15卷 472-476页

作者： ZHANG Hongjie 1.2, SONG Xiaoyu1. WANG Xiaoying3. xu Ping{1.g1.and BAO Shanglian1.*(1. Beijing Key Laboratory of Medical Physics & Engineering, peking university, Beijing 1.0871.{1. 2. Navy General Hospital, Beijing 1.003.,{1. 3. peking university First Hospital, Beijing 1.003.,{1.) Beijing Key Laboratory of Medical Physics & Engineering Peking University Beijing 100871 China Navy General Hospital Beijing 100037 China peking {1. First Hospital Beijing 100034 China

The diagnosis of prostate diseases by magnetic resonance imaging (MRI) in vivo is sometimes difficult for the lower signal to noise ratio (SNR). To increase the SNR of the prostate image, we designed a RF coil that can be inserted into rectum and was named endorectal coil. The properties of RF coil were evaluated using a network analyzer. Moreover the images and spectroscopy of a special phantom were acquired and the results were compared to those of the commercial TORSO coil (G.E. Medical Systems, USA). Our coil gave a significantly higher SNR at the region of interest (ROI). The achieved high local SNR and resulting high spatial resolution would add more anatomic and biochemical information to the diagnosis of prostate diseases.

关键词： MRI RF coil endorectal coil.

Microwave-assisted pyrolysis of plastics for aviation oil production:energy and economic analyses

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 141-153页

作者： Sichen fan Yifan Liu Yaning Zhang Wenke Zhao Chunbao xu School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Energy and Environment City University of Hong KongHong Kong SARChina

Microwave-assisted pyrolysis is an effective method for recycling plastic wastes into oils that can be used for aviation fuels. In this study, energy and economic analyses of aviation oil production from microwave-assisted pyrolysis of polystyrene were performed. The total energy efficiency, recovered energy efficiency, unitary cost, unitary energy economic cost, relative cost difference, and energy economic factor were detailed. And the effects of microwave power, pyrolysis temperature, microwave absorbent loading, and microwave absorbent type on these parameters were covered. It was found that pyrolysis temperature has the most significant effect on the unitary cost and unitary energy economic cost of aviation oil, and-microwave absorbent type has a significant influence on energy economic factor during the whole microwave-assisted pyrolysis process. The optimum reaction conditions at the tonnage system for pyrolysis of 1.t polystyrene were microwave power of 650 W, pyrolysis temperature of 460 ℃, and silicon carbide (microwave absorbent) at a loading of 2 t (twice than feedstock loading). At these optimal conditions, the total energy efficiency, recovered energy efficiency, unitary cost, unitary energy economic cost, relative cost difference, and energy economic factor were 62.78%, 96.51., 3.21.× 1.^(4) yuan·t^(-1., 779 yuan·GJ^(-1., 1.49, and 71.02%, respectively.

关键词： energy analysis economic analysis microwave-assisted pyrolysis polystyrene aviation oil

Pole assignment in descriptor periodic systems

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Science china Mathematics 2005年第10期48卷 1309-1332页

作者： fan Hung-Yuan~1.LIN Wen-Wei~1.& {1. Shufang~2 1. Department of Mathematics,Tsing Hua university,Hsinchu 3.043.{1. 2. LMAM,School of Mathematical Sciences,peking university,Beijing 1.0871.{1. Department of Mathematics Tsing Hua University Hsinchu China LMAM School of Mathematical Sciences Peking University Beijing China

In this paper a pole assignment problem is considered for the descriptor linear discrete-time periodic systems, which is using the periodic proportional-derivative feedback to modify a given system such that the closed loop system has a specified selfconjugate set of eigenvalues. It is shown that the complete reachability of an open loop periodic system is equivalent to the possibility of assigning an arbitrary set of the eigenvalues to the system by choosing the suitable periodic proportional-derivative feedback.A computational approach is also proposed to solve the problem, which uses the reliable numerical techniques based on the orthogonal transformations. Numerical examples are presented to illustrate the effectiveness of the proposed approach.

关键词： descriptor linear periodic system, pole assignment, proportional and derivative feedback, numerical method, periodic Schur decomposition.

Impaired Spatial Firing Representations of Neurons in the Medial Entorhinal Cortex of the Epileptic Rat Using Microelectrode Arrays

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Research 2024年第2期2023卷 541-552页

作者： Zhaojie xu {1. Mo Gucheng Yang Penghui {1. Botao Lu Wei Liang {1.li Kong Luyi Jing Wei xu Juntao Liu Mixia Wang Yirong Wu Xinxia Cai State Key Laboratory of Transducer Technology Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China university of Chinese Academy of Sciences Beijing 100049China

Epilepsy severely impairs the cognitive behavior of *** remains unclear whether epilepsy-induced cognitive impairment is associated with neuronal activities in the medial entorhinal cortex(MEC),a region known for its involvement in spatial *** explore this neural mechanism,we recorded the spikes and local field potentials from MEC neurons in lithium-pilocarpine-induced epileptic rats using self-designed microelectrode *** the open field test,we identified spatial cells exhibiting spatially selective firing properties and assessed their spatial representations in relation to the progression of ***,we analyzed theta oscillations and theta modulation in both excitatory and inhibitory ***,we used a novel object recognition test to evaluate changes in spatial cognitive ability of epileptic *** the epilepsy modeling,the spatial tuning of various types of spatial cells had suffered a rapid and pronounced damage during the latent period(1.to 5 d).Subsequently,the firing characteristics and theta oscillations were *** the chronic period(>1. d),the performance in the novel object experiment *** conclusion,our study demonstrates the detrimental effect on spatial representations and electrophysiological properties of MEC neurons in the epileptic latency,suggesting the potential use of these changes as a"functional biomarker"for predicting cognitive impairment caused by epilepsy.

关键词： epilepsy impaired involvement

Soil bacterial and fungal communities resilience to long-term nitrogen addition in subtropical forests in china

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Journal of Forestry Research 2024年第2期35卷 95-108页

作者： Xinlei Fu Yunze Dai Jun Cui Pengfei Deng Wei fan Xiaoniu {1. School of Forestry and Landscape Architecture Anhui Agricultural UniversityHefei 230036AnhuiPeople’s Republic of China Suzhou Polytechnic Institute of Agriculture Suzhou 215008JiangsuPeople’s Republic of China College of Life and Environment Sciences Huangshan UniversityHuangshan 245041AnhuiPeople’s Republic of China

Atmospheric nitrogen(N)deposition is predicted to increase,especially in the ***,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have not been clarified.A long-term nutrient addition experiment was conducted in a subtropical evergreen old-growth forest in *** four treatments were:control,low N(50 kg N ha^(-1.a^(-1.),high N(1.0 kg N ha^(-1.a^(-1.),and combined N and phosphorus(P)(1.0 kg N ha^(-1.a^(-1.+50 kg P ha^(-1.a^(-1.).Metagenomic sequencing characterized diversity and composition of soil microbial communities and used to construct bacterial/fungal co-occurrence ***-treated soils were more acidic and had higher levels of dissolved organic carbon than *** were no significant differences in microbial diversity and community composition across *** addition of nutrients increased the abundance of copiotrophic bacteria and potentially beneficial microorganisms(e.g.,Gemmatimonadetes,Chaetomium,and Aureobasidium).Low N addition increased microbiome network *** rare fungi were identified as module hubs under nutrient addition,indicating that low abundance fungi were more sensitive to increased *** results indicate that the overall composition of microbial communities was stable but not static to long-term N *** findings provide new insights that can aid predictions of the response of soil microbial communities to long-term N addition.

关键词： Long-term nitrogen addition Old-growth subtropical forest Metagenomics Beneficial microorganisms Co-occurrence network

β-delayed proton decays near the proton drip line

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： xu Shuwei 1., LI Zhankui 1., XIE Yuanxiang 1., HUANG Wenxue 1., SHU Nengchuan 2 , CHEN Yongshou 2 , xu Furong 3., WANG Kun 4 , PAN Qiangyan 1., WANG xudong 1., YU Yong 1.& XING Yebing 1.1. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73.000,{13. 2. Nuclear Physics Department,{13. Institute of Atomic Energy, Beijing 1.241.,{13. 3. Department of Technical Physics,{3., Beijing 1.0871.{13. 4. Shanghai Institute for Nuclear Research, Shanghai 201.00,{13. Institute of Modern Physics Chinese Academy of Sciences Lanzhou China Nuclear Physics Department China Institute of Atomic Energy Beijing China Department of Technical Physics Peking University Beijing China Shanghai Institute for Nuclear Research Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1.96―2004, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 1. nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1. The experimental half-lives for 85Mo and 92Rh as well as the predicted “waiting point” nuclei 89Ru and 93.d are 5―1. times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2) The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 1.2Ho and 1.8Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3. The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

Investigating spatial distribution of tourist attractions’inlinks: A case study of three mountains

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Science china(Technological Sciences) 2010年第S1期53卷 126-133页

作者： ZHANG Yi 1.QI LiNa 2,YANG AnRan 1.SHI Lei 1.& {3. Li 1.1.Institute of RS and GIS,{1. {1.,Beijing 1.0871.china 2 Center for Recreation and Tourism Research,{1. {1.,Beijing 1.0871.china Institute of RS and GIS Peking University Beijing China Center for Recreation and Tourism Research Peking University Beijing China

In hyperlink analysis,most researchers focus on interpreting hyperlink counts,they seldom concern themselves enough about the significance of spatial distribution of *** this paper,we argue that not only can the inlink count to a tourist attraction’s official website reflect its attractiveness,but also the spatial distribution of its inlinks can reflect the distribution of its tourist source *** mountains in Anhui Province,china,are chosen for the case ***,the correlation between the spatial distributions of an attraction’s tourist source markets and its official website’s inlinks is ***,the tourism indexes such as the spatial concentration index(SCI)and the attraction radius(AR),which are calculated by inlinks,are compared to the real indexes based on tourist ***,the detailed discussion and analysis are presented and an improved model,which is used to calculate the distribution of inlinks,is proposed.

关键词： tourist attractiveness hyperlink analysis spatial distribution of hyperlinks tourist source market