Multiple Targets Localization Algorithm Based on Covariance Matrix Sparse Representation and Bayesian Learning

The multi-source passive localization problem is a problem of great interest in signal pro-cessing with many applications.In this paper,a sparse representation model based on covariance matrix is constructed for the long-range localization scenario,and a sparse Bayesian learning algo-rithm based on Laplace prior of signal covariance is developed for the base mismatch problem caused by target deviation from the initial point grid.An adaptive grid sparse Bayesian learning targets localization(AGSBL)algorithm is proposed.The AGSBL algorithm implements a covari-ance-based sparse signal reconstruction and grid adaptive localization dictionary learning.Simula-tion results show that the AGSBL algorithm outperforms the traditional compressed-aware localiza-tion algorithm for different signal-to-noise ratios and different number of targets in long-range scenes.

Dynamic train dwell time forecasting:a hybrid approach to address the influence of passenger flow fluctuations

Train timetables and operations are defined by the train running time in sections,dwell time at stations,and headways between trains.Accurate estimation of these factors is essential to decision-making for train delay reduction,train dispatching,and station capacity estimation.In the present study,we aim to propose a train dwell time model based on an averaging mechanism and dynamic updating to address the challenges in the train dwell time prediction problem(e.g.,dynamics over time,heavy-tailed distribution of data,and spatiotemporal relationships of factors)for real-time train dispatching.The averaging mechanism in the present study is based on multiple state-of-the-art base predictors,enabling the proposed model to integrate the advantages of the base predictors in addressing the challenges in terms of data attributes and data distributions.Then,considering the influence of passenger flow on train dwell time,we use a dynamic updating method based on exponential smoothing to improve the performance of the proposed method by considering the real-time passenger amount fluctuations(e.g.,passenger soars in peak hours or passenger plunges during regular periods).We conduct experiments with the train operation data and passenger flow data from the Chinese high-speed railway line.The results show that due to the advantages over the base predictors,the averaging mechanism can more accurately predict the dwell time at stations than its counterparts for different prediction horizons regarding predictive errors and variances.Further,the experimental results show that dynamic smoothing can significantly improve the accuracy of the proposed model during passenger amount changes,i.e.,15.4%and 15.5%corresponding to the mean absolute error and root mean square error,respectively.Based on the proposed predictor,a feature importance analysis shows that the planned dwell time and arrival delay are the two most important factors to dwell time.However,planned time has positive influences,whereas arrival delay has negative influences.

Prediction of high-speed train delay propagation based on causal text information

The delay-causing text data contain valuable information such as the specific reasons for the delay,location and time of the disturbance,which can provide an efficient support for the prediction of train delays and improve the guidance of train control efficiency.Based on the train operation data and delay-causing data of the Wuhan-Guangzhou high-speed railway,the relevant algorithms in the natural language processing field are used to process the delay-causing text data.It also integrates the train operatingenvironment information and delay-causing text information so as to develop a cause-based train delay propagation prediction model.The Word2vec model is first used to vectorize the delay-causing text description after word segmentation.The mean model or the term frequency-inverse document frequency-weighted model is then used to generate the delay-causing sentence vector based on the original word vector.Afterward,the train operating-environment features and delay-causing sentence vector are input into the extreme gradient boosting(XGBoost)regression algorithm to develop a delay propagation prediction model.In this work,4 text feature processing methods and 8 regression algorithms are considered.The results demonstrate that the XGBoost regression algorithm has the highest prediction accuracy using the test features processed by the continuous bag of words and the mean models.Compared with the prediction model that only considers the train-operating-environment features,the results show that the prediction accuracy of the model is significantly improved with multi-ple regression algorithms after integrating the delay-causing feature.

Extraction Conditions of Essential Oil from Eucalyptus Leaves by Distillation

[Objectives]To explore the extraction conditions of essential oil from eucalyptus leaves.[Methods]The essential oil of eucalyptus leaves was extracted by steam distillation,and the yields of essential oil from eucalyptus leaves under different extraction times,soaking times and different solid-liquid ratios were analyzed through orthogonal test with three factors and three variables.[Results]The effects of various factors on extraction results were:distillation time>solid-liquid ratio>soaking time.When the extraction time and soaking time were 1.5 and 2 h,and the solid-liquid ratio of eucalyptus leaves to distilled water was 1:10,the yield of essential oil was the highest(0.8%).The yield of essential oil increased with the increase of extraction and soaking time,but when reaching the optimal value,the yield decreased with the extension of time.Increasing the solid-liquid ratio can improve the yield of essential oil,but beyond a certain value the yield increased gradually while the cost performance decreased.[Conclusions]The results will provide some reference for the recovery and utilization of eucalyptus leaves.

Dynamic response to climate change in the radial growth of Picea schrenkiana in western Tien Shan,China

Forests are important ecosystems for economic and social development.However,the response of tree radial growth to climate has produced‘divergent problems'at high latitudes under global warming.In this study,the response stability and trend of Picea schrenkiana radial growth to variability in climate factors were analyzed in the mid-latitudes of the western Tien Shan Mountains.Radial growth of P.schrenkiana was mainly limited by minimum and mean temperatures.The divergent responses of radial growth occurred in response to the minimum and mean temperatures at the beginning of the growing season(April–May)of the current year,but responses to drought occurred in July–September of the previous year.And the mean and minimum temperatures in June–September of the current year were both stable.Radial growth first increased and then decreased according to the basal area increment,with a gradual increase in temperature.Therefore,forest ecosystems in mountainous arid areas will be increasingly affected by future climate warming.

CD93 and GIPC expression and localization during central nervous system inflammation

CD93 and GAIP-interacting protein, C termius （GIPC） have been shown to interactively alter phagocytic processes of immune cells. CD93 and GIPC expression and localization during cen-tral nervous system inflammation have not yet been reported. In this study, we established a rat model of brain inlfammation by lipopolysaccharide injection to the lateral ventricle. In the brain of rats with inlfammation, western blots showed increased CD93 expression that decreased over time. GIPC expression was unaltered. Immunohistochemistry demonstrated extensive distribution of CD93 expression mainly in cell membranes in the cerebral cortex. After lipopoly-saccharide stimulation, CD93 expression increased and then reduced, with distinct staining in the cytoplasm and nucleus. Double immunolfuorescence staining in cerebral cortex of normal rats showed that CD93 and GIPC widely expressed in resting microglia and neurons. CD93 was mainly expressed in microglial and neuronal cell membranes, while GIPC was expressed in both cell membrane and cytoplasm. In the cerebral cortex at 9 hours after model establishment, CD93-immunoreactive signal diminished in microglial membrane, with cytoplasmic transloca-tion and aggregation detected. GIPC localization was unaltered in neurons and microglia. These results are the ifrst to demonstrate CD93 participation in pathophysiological processes of central nervous system inlfammation.

Statistics of cloud heights over the Tibetan Plateau and its surrounding region derived from CloudSat data

Cloud-radiation interaction has a large impact on the Earth＇s weather and climate change, and clouds with different heights cause different radiative forcing. Thus, the information on the statistics of cloud height and its variation in space and time is very important to global climate change studies. In this paper, cloud top height （CTH）, cloud base height （CBH） and cloud thickness over regions of the Tibetan Plateau, south slope of the plateau and South Asian Monsoon are analyzed based on CloudSat data during the period from June 2006 to December 2007. The results show that frequency of CTH and CBH in unit area over the studied regions have certain temporal-spatial continuity. The CTH and CBH of different cloud types have different variation scopes, and their seasonal variations are distinct. Cloud thickness is large （small） in summer （winter）, and the percentages of different cloud types also have certain regularity.

Stable isotope in precipitation in China:A review

The isotope ratios in precipitation are associated with various meteorological processes and display obvious spatial and temporal distributions, and thus can be used as impo~_nt techniques in inversing atmospheric processes, tracing vapor sources, and reflect- ing the local weather and climate conditions. The composition and distribution of stable isotopes in precipitation in China are summarized and the factors that influence isotope ratios are elucidated. An overview of related research progress in China during the past several decades is presented and the prospects for future work in this subject area are described.

Multiscale Analysis of the Effect of Debris on Fretting Wear Process Using a Semi-Concurrent Method

Fretting wear is a phenomenon,in which wear happens between two oscillatory moving contact surfaces in microscale amplitude.In this paper,the effect of debris between pad and specimen is analyzed by using a semi-concurrent multiscale method.Firstly,the macroscale fretting wear model is performed.Secondly,the part with the wear profile is imported from the macroscale model to a microscale model after running in stage.Thirdly,an effective pad’s radius is extracted by analyzing the contact pressure in order to take into account the effect of the debris.Finally,the effective radius is up-scaled from the microscale model to the macroscale model,which is used after running in stage.In this way,the effect of debris is considered by changing the radius of the pad in the macroscale model.Due to the smaller number of elements in the microscale model compared with the macroscale model containing the debris layer,the semi-concurrent method proposed in this paper is more computationally efficient.Moreover,the results of this semi-concurrent method show a better agreement with experimental data,compared to the results of the model ignoring the effect of debris.

Chemistry and environmental significance of aerosols collected in the eastern Tianshan

Aerosol samples were collected at altitudes from 584 m a.s.l.to 3,804 m a.s.l.at seven sites of the eastern Tianshan.The occurrence,distribution,and possible sources of 47 trace metals—including alkali metals and alkali earth metals,transition metals,lanthanoids,and heavy metals—were investigated.It was found that four sampling sites(Shuinichang,1,691 m a.s.l.;Urumqi City,809 m a.s.l.;Fu Kang Station,584 m a.s.l.;and Bogeda Glacier No.4,3,613 m a.s.l.)were contaminated mainly by heavy metals.Other three high-altitude sites(Urumqi Glacier No.1,3,804 m a.s.l.;Wang Feng road-maintenance station,3,039 m a.s.l.;and Tianshan Glaciology Station,2,135 m a.s.l.)were not polluted.The aerosol particles were clustered into two dominant types:crust-originated particles and pollution-derived particles.Aerosols from UG1,WF,and TGS were characterized by crust-originated particles such as clay,plagioclase,dolomite,alkali feldspar,and biotite;while those from SNC,Urumqi,FK,and BG4 were characterized by high content of Cl-rich particles,S-rich particles,and soot.The backward-trajectories results indicated that air masses arriving at SNC,Urumqi,FK,and BG4 were identified as the more polluted source,when compared to the short-range air mass transport from the North to UGI and WF.Relatively lower altitude,as well as terrain blocking,might be another important reason for the gradient difference in pollution influence among these seven places in the Urumqi River Basin.

Satellite-measured water vapor isotopologues across the Tianshan Mountains,central Asia

The satellite-based water vapor stable isotope measurements have been widely used in modern hydrological and atmospheric studies.Their use is important for arid areas where the precipitation events are limited,and below-cloud evaporation is strong.This study presents the spatial and temporal characteristics of water vapor isotopologue across the Tianshan Mountains in arid central Asia using the NASAAura Tropospheric Emission Spectrometer(TES).The near-surface water vapor stable isotopes are enriched in summer and depleted in winter,consistent with the seasonality of precipitation isotopes.From the surface to 200 hPa,the isotope values in water vapor show a decreasing trend as the atmospheric pressure decreases and elevation rises.The vapor isotope values in the lower atmosphere in the southern basin of the Tianshan Mountains are usually higher than that in the northern basin,and the seasonal difference in vapor isotopes is slightly more significant in the southern basin.In addition,bottom vapor isotopologue in summer shows a depletion trend from west to east,consistent with the rainout effect of the westerly moisture path in central Asia.The isotopic signature provided by the TES is helpful to understand the moisture transport and below-cloud processes influencing stable water isotopes in meteoric water.

Characteristics and source of aerosols at Shiyi Glacier,Qilian Mountains, China

Aerosol samples were collected in the Shiyi Glacier, Qilian Mountains from July 24 to August 19, 2012 and analyzed for major water-soluble ionic species(F-, Cl-, NO2-, NO3-, SO42-, Na+, NH4+, K+, Mg2+and Ca2+) by ion chromatography. SO42-and NH4+were the most abundant components of all the anions and cations, with average concentrations of 94.72 and 54.26 neq/m3, respectively, accounting for 34% and 20% of the total water-soluble ions analyzed. These mean ion concentrations were generally comparable with the background conditions in remote sites of the Qilian Mountains, but were much lower than those in certain cities in China. The particles were grouped into two dominant types according to their morphology and EDX signal: Si-rich particles and Fe-rich particles. Backward air mass trajectory analysis suggested that inland cities may contribute some anthropogenic pollution to this glacier, while the arid and semi-arid regions of central Asia were the primary sources of the mineral particles.

Research and Design of UUV Navigation and Control Integrative Simulation System Based on Component

This paper uses the component-based technology and the object oriented simulation technology to analyze the UUV navigation and control integration simulation system. We divide the system into components based on its structure, and describe every component using active diagram. By using the component-based technology, the system described here is easier to extended and be reused. At last, it realizes the whole UUV integrated navigation simulation course using the system to validate the availability.

Ultrafast photoexcitation dynamics behavior of hydrogen-bonded polyfluorenol

Exciton behavior is crucial to the exploitation of light-emitting conjugated polymer(LCPs)for optoelectronic devices.Singlet excitons are easily trapped by the intrinsically defect structures.Herein,we set a polyfluorenol(PPFOH)as an example to systematically investigate its photophysical behavior to check the role of defect structures in LCPs.According to time-resolved photoluminescence analysis,the feature emission peaks from individual chain of PPFOH in diluted DMF solution is effectively avoided the influence of fluorenone formation,but the residual green-band emission at 550nm is easily observed in the PL spectra of PPFOH dilute toluene solution obtained delay 1.5 ns,confirmed the formation of“guest”physical aggregation-induced defect structure.Remarkably,efficient and ultrafast energy transfer from individual chain to defect structure is observed in PPFOH films.Interestingly,the efficient energy transfer happened for the film obtained from DMF solution(200 ps)than those of toluene ones(600 ps).Meanwhile,compared to relatively stable green-band emission in PPFOH film from toluene solution,red-shifted emission peak(11 nm)of PPFOH film from DMF solutions exposed to saturated DNT vapor also confirmed their different aggregation-induced green-band emission.Therefore,this aggregation defect structures are influenced on the photophysical property of LCPs in solid states.

植原体tuf基因与其上游部分基因结构和相关基因启动子保守区域特征及活性分析

植原体寄主种类多,危害范围广,开展其遗传多样性、关键基因调控等方面研究有助于提高该病害综合防治水平。通过长片段PCR引物扩增我国PaWB-sdyz、PaWB-fjfz和LY-fjya1植原体株系tuf基因及其上游6个基因的片段,进行植原体基因启动子保守区域序列特征和多位点序列分析。利用启动子探针载体p SUPV4检测植原体tuf基因上游序列的启动子活性。扩增获得PaWB-sdyz、PaWB-fjfz、LY-fjya1株系tuf基因上游12,745–12,748 bp序列,比较分析发现Pa WB-sdyz、Pa WB-fjfz、LY-fjya1、OY-M、AYWB、PAa、SLY、AT植原体株系tuf与其上游6个基因的结构顺序皆为5’-rpl L-rpo B-rpo C-rps12-rps7-fus A-tuf-3’。推测出可能的植原体启动子保守区域模式序列:T_(90)T_(100)G_(92)T_(75)G_(67)A_(85)(-35区);T_(90)A_(96)T_(92)A_(98)T_(73)T_(90)(-10区)。基于8个植原体株系的rpl L-tuf核苷酸序列编码基因、非编码序列、氨基酸序列的多位点序列分析可将不同植原体株系以较高的支持率清晰地区分,不同植原体株系rpl L-tuf核苷酸非编码区变异水平更高。16SrI组植原体tuf基因上游序列存在3种变异类型,其代表株系PaWB-fjfz、LY-fjya1tuf基因上游130 bp片段和CWB-hnsy1 tuf基因上游129 bp片段皆具有启动子活性。

术前行短程或常规放化疗的ⅢB期直肠癌患者术后疗效及组织标本中Runx3、Ki-67表达的差异

目的分析术前行短程放化疗或常规放化疗对ⅢB期直肠癌患者的手术效果及切除的组织标本中Runt相关转录因子3(Runx3)、细胞增殖核抗原Ki-67(简称Ki-67)表达的差异。方法前瞻性研究2019年1至12月于河北北方学院附属第一医院确诊的100例ⅢB期直肠癌患者的临床资料,其中男性52例、女性48例,年龄38~79(58.56±9.11)岁。将所有患者按电脑随机数字表法分为对照组和观察组,每组50例。对照组术前接受常规调强适形放疗+化疗,观察组术前接受短程放疗+化疗,分别比较2组患者手术的一般临床资料、术后病理T分期降期率、病理学完全缓解(pCR)率、不良反应发生情况、局部复发率、远处转移率和生存率,对切除的直肠癌组织标本采用免疫组化方法分别计算Runx3和Ki-67表达的评分。2组间计量资料的比较采用独立样本t检验;2组间的计数资料进行比较时,当例数<40或理论频数T≤1时采用Fisher's确切概率法,当例数≥40且理论频数T≥5(未校正)或1<T<5(校正)时采用χ^(2)检验。结果观察组与对照组患者的手术时间[(165.89±18.73)min对(158.14±23.57)min]、术中出血量[(215.63±56.89)mL对(227.84±60.75)mL]、术后排气时间[(62.28±16.47)h对(59.28±12.04)h]、住院时间[(13.97±7.11)d对(15.01±5.29)d]、吻合口瘘率[6%(3/50)对2%(1/50)]、肠梗阻率[4%(2/50)对0(0/50)]、感染率4%(2/50)对[8%(4/50)]的差异均无统计学意义(t=0.854~1.820,χ^(2)=0.260、0.177,Fisher's确切概率法,均P>0.05)。2组患者术后T分期降期率和pCR率的差异均无统计学意义(χ^(2)=0.160、0.000,均P>0.05)。观察组放射性皮炎总发生率(12%,6/50)低于对照组(30%,15/50),且差异有统计学意义(χ^(2)=4.883,P<0.05)。观察组术中切除标本中Runx3表达的评分为(2.56±0.51)分,高于对照组的(1.87±0.72)分,且差异有统计学意义(t=5.530,P<0.01),Ki-67表达的评分为(2.39±1.03)分,低于对照组的(3.94±0.46)分,且差异有统计学意义(t=9.716,P<0.01);观察组局部复发率(2%,1/50)低于对照组(17%,8/48),且差异有统计学意义(χ^(2)=5.936,P<0.05)。结论对ⅢB期直肠癌术前行短程放化疗,不会增加全直肠系膜切除术的难度与风险,可减少不良反应的发生,降低局部复发率。手术切除标本中Runx3和Ki-67的表达存在差异。

Deformation-induced martensitic transformation kinetics and correlative micromechanical behavior of medium-Mn transformation-induced plasticity steel

An in situ high-energy X-ray diffraction(HE-XRD) technique was mainly used to investigate the micromechanical behavior of medium-Mn Fe-0.12 C-10.16 Mn-1.87 Al(in wt%) transformation-induced plasticit(TRIP) steel subjected to intercritical annealing at 625℃, 650℃, 675℃ and 700℃ for 1 h. As the intercritical annealing temperature increased, the volume fraction of retained austenite(RA) and ultimate tensilstress(UTS) increased, while the Lüders strain and yield stress(YS) decreased. The incremental workhardening exponent of experimental steel increased with increasing intercritical annealing temperatureThe overall trend of the transformation kinetics of the RA with respect to the true strain followed thsigmoidal shape predicted by the Olson and Cohen(OC) model. Load partitioning occurred among the ferrite, austenite and martensite immediately after entering the yielding stage. Because the stability of thRA decreased with increasing intercritical annealing temperature, the load undertaken by the martensitincreased. The moderate transformation kinetics of the RA and effective load partitioning among constituent phases were found to contribute to a favorable combination of strength and ductility for thimedium-Mn TRIP steel.

Virus-like supramolecular assemblies formed by cooperation of base pairing interaction and peptidic association

A peptide nucleic acid(PNA)-peptide conjugated molecule, T′_3(AKAE)_2, was designed to have both a PNA segment for oligonucleotide binding and an ionic self-complementary peptide sequence for self-association. T′_3(AKAE)_2 could co-assemble with oligoadenines(d(A)_x) to form virus-like supramolecular structures whose morphology showed dependence on the chain length and rigidity of the d(A)_x molecules. Smaller nanospheres with diameters of 13.0±2.0 nm were produced in the case of d(A)_6. Wormlike aggregates with lengths of 20–50 nm and diameters of 15.0±2.5 nm were found in the cases of d(A)_(12), d(A)_(18), d(A)_(24) and d(A)_(30). And larger spherical aggregates with diameters of 18±5 nm came into presence in the cases of d(A)_(36) and d(A)_(42). These nanostructures were suggested to be formed under a cooperative effect of base pair recognition and peptidic association. The study provides insights into the programmed assembly of a multi-components system as well as control of the size and shape of the co-assembled structures, which is of great significance in developing gene/drug delivery systems.

Dynamic simulation of the tractor HMCVT under typical working conditions based on AMESim

In order to study the dynamic characteristics of hydro-mechanical continuously variable transmission(HMCVT)under ploughing and sowing conditions,a complete simulation model of HMCVT is established based on AMESim software,including mechanical transmission model,pump controlled hydraulic motor speed control model and section changing hydraulic system model.In addition,the dynamic model of tractor is established.In order to verify the correctness of the simulation model,a test-bed is established.The test of tractor running speed and the test of pump controlled hydraulic motor system were carried out on the test-bed.The test results show that the simulation model of pump control hydraulic system can correctly reflect the change of transmission ratio of pump controlled hydraulic motor,and the simulation model can reflect the actual working condition change of clutch.Thus,the correctness of the previous simulation model based on AMESim is verified.Based on the simulation model established by AMESim,the dynamic characteristics of HMCVT under ploughing and sowing conditions are studied.The results show that:Under ploughing condition,the planetary platoon will have strong impact at the moment of throttle opening and changing section.Under sowing condition,the HMCVT will have a great impact at the time of variable cross section,but the variation range of rodent force decreases and the changing trend tends to be stable.

Effect of wear debris on fretting fatigue crack initiation

Both wear and fatigue occur in fretting condition,and they interact with one another during the whole process.Fretting fatigue is commonly analysed without considering the effect of wear in partial slip regime,although wear affects the lifetime of crack initiation.This paper investigates,for the first time,the effect of wear debris on fretting fatigue crack initiation.To investigate the effect of debris,first fretting wear characteristics in partial slip regime are analysed for loading conditions.Then,the effect of wear on fretting fatigue crack initiation is investigated using Ruiz parameters and critical plane methods without considering the debris effect.Through the results,we can see that loading conditions affect the wear profiles in different ways.Moreover,wear has a significant effect on the fatigue in partial slip regime without considering debris especially on the crack initiation location.Finally,considering wear debris in the analysis,its effect on critical plane parameters is investigated.It is found that by considering the wear debris effect,the frtting fatigue crack initiation location is shifted towards the trailing edge.The predictions of both crack initiation location and lifetime show a good agreement with the experimental data.