|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing,China显示文摘Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease(COVID-19)and the evidence of person-to-person transmission.Limited data are available for asymptomatic infections.This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers.Epidemiological investigations were conducted among all close contacts of COVID-19 patients(or suspected patients)in Nanjing,Jiangsu Province,China,from Jan 28 to Feb 9,2020,both in clinic and in community.Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples.Their clinical records,laboratory assessments,and chest CT scans were reviewed.As a result,none of the 24 asymptomatic cases presented any obvious symptoms while nucleic acid screening.Five cases(20.8%)developed symptoms(fever,cough,fatigue,etc.)during hospitalization.Twelve(50.0%)cases showed typical CT images of ground-glass chest and 5(20.8%)presented stripe shadowing in the lungs.The remaining 7(29.2%)cases showed normal CT image and had no symptoms during hospitalization.These 7 cases were younger(median age:14.0 years;P=0.012)than the rest.None of the 24 cases developed severe COVID-19 pneumonia or died.The median communicable period,defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests,was 9.5 days(up to 21 days among the 24 asymptomatic cases).Through epidemiological investigation,we observed a typical asymptomatic transmission to the cohabiting family members,which even caused severe COVID-19 pneumonia.Overall,the asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization.However,the communicable period could be up to three weeks and the communicated patients could develop severe illness.These results highlighted the importance of close contact tracing and longitudinally surveillance via virus nucleic acid tests.Further isolation recommendation and continuous nucleic acid tests may also be recommended to the patients discharged. | Zhiliang Hu Ci Song Chuanjun Xu Guangfu Jin Yaling Chen Xin Xu Hongxia Ma Wei Chen Yuan Lin Yishan Zheng Jianming Wang Zhibin Hu Yongxiang Yi Hongbing Shen | 2020 | Science China(Life Sciences)2020，63，5： | 77 |
| 2 | Pantograph-catenary electrical contact system of high-speed railways:recent progress,challenges,and outlooks显示文摘As the unique power entrance,the pantograph-catenary electrical contact system maintains the efficiency and reliability of power transmission for the high-speed train.Along with the fast development of high-speed railways all over the world,some commercialized lines are built for covering the remote places under harsh environment,especially in China;these environmental elements including wind,sand,rain,thunder,ice and snow need to be considered during the design of the pantograph-catenary system.The pantograph-catenary system includes the pantograph,the contact wire and the interface—pantograph slide.As the key component,this pantograph slide plays a critical role in reliable power transmission under dynamic condition.The fundamental material characteristics of the pantograph slide and contact wire such as electrical conductivity,impact resistance,wear resistance,etc.,directly determine the sliding electrical contact performance of the pantograph-catenary system;meanwhile,different detection methods of the pantograph-catenary system are crucial for the reliability of service and maintenance.In addition,the challenges brought from extreme operational conditions are discussed,taking the Sichuan-Tibet Railway currently under construction as a special example with the high-altitude climate.The outlook for developing the ultra-high-speed train equipped with the novel pantograph-catenary system which can address the harsher operational environment is also involved.This paper has provided a comprehensive review of the high-speed railway pantograph-catenary systems,including its progress,challenges,outlooks in the history and future. | Guangning Wu Keliang Dong Zhilei Xu Song Xiao Wenfu Wei Huan Chen Jie Li Zhanglin Huang Jingwei Li Guoqiang Gao Guozheng Kang Chuanjun Tu Xingyi Huang | 2022 | Railway Engineering Science2022，30，4： | 5 |
| 3 | The Effects of Polyphenol Oxidase and Cycloheximide on the Early Stage of Browning in Phalaenopsis Explants显示文摘Explant browning is one of the major problems in the tissue culture process, and polyphenol oxidase(PPO), is the major proteases involved in plant tissue browning. We investigated the effects of polyphenol oxidase on the early stage of browning in explants of the orchid Phalaenopsis. Our results show that PPO activity was significantly higher in explants cultured for 3 d than in the 0 h control. The levels of PPO transcripts and PPO protein were significantly higher in explants cultured for 6 h compared to the 0 h control; these high expression levels were maintained over increasing cultivation time. Cycloheximide(CHX) treatment reduced PPO transcript levels, PPO protein levels, and PPO enzyme activity. High levels of PPO m RNA and PPO protein were detected in the cytoplasm and vascular bundles of Phalaenopsis explants cultured for 6 h compared to explants cultured for 0 h, 24 h, and 3 d. CHX treatment did not significantly affect the distribution of PPO m RNA and PPO protein in explant tissues, but their levels were significantly lower than those of the untreated control. | XU Chuanjun RU Zhiwei LI Ling ZENG Biyu HUANG Junmei HUANG Wen HU Ou | 2015 | Horticultural Plant Journal2015，1，3： | 2 |
| 4 | Cloning and characterization ofperoxidase gene in Phalaenopsis显示文摘 | Xu Chuanjun Sun Xuzhuo Chert Dongyin Lai Yanyan Li Ling | | 0，，04： | 1 |
| 5 | Geological characteristics and metallogenesis of the Shilu Fe-ore deposit in Hainan Province, South China显示文摘 | Deru Xu Zhilin Wang Jianxin Cai Chuanjun Wu Nonna Bakun-Czubarow Li Wang Huayong Chen Michael J. Baker Monika Agnieszka Kusiak | 2012 | Ore Geology Reviews2012，，： | 1 |
| 6 | Transition metal carbonate anodes for Li-ion battery: fundamentals,synthesis and modification显示文摘Even though transition metal carbonates(TMCs, TM = Fe, Mn, Co, Ni etc.), show high theoretical capacities, rich reserves and environmental friendliness as anodes for lithium-ion batteries(LIBs), they suffer from sluggish electronic/ionic conductivities and huge volume variation, which severely deteriorate the rate capacities and cycling performances. Understanding the intrinsic reaction mechanism and further developing ideal TMC-based anode with high specific capacity, excellent rate capabilities, and longterm cycling stability are critical for the practical application of TMCs. In this review, we firstly focus on the fundamental electrochemical energy-storage mechanisms of TMCs, in terms of conversionreaction process, pseudocapacitance-type charge storage, valence change for charge storage and catalytic conversion mechanisms. Based on the reaction mechanisms, various modification strategies to improve the electrochemical performance of TMCs are summarized, covering:(i) micro-nano structural engineering, in which the influence factors on the morphology are discussed, and multiple architectures are listed;(ii) elemental doping, in which the intrinsic mechanisms of metal/nonmetal elements doping on the electrochemical performance are deeply explored;(iii) multifunctional compositing strategies, in which the specific affections on structure, electronic conductivity and chemo-mechanical stability are summarized.Finally, the key challenges and opportunities to develop high-performance TMCs are discussed and some solutions are also proposed. This timely review sheds light on the path towards achieving cost-effective and safe LIBs with high energy density and long cycling life using TMCs-based anode materials. | Rui Zhang Qingfeng Fu Peng Gao Wang Zhou Hui Liu Chaohe Xu Jian-Fang Wu Chuanjun Tu Jilei Liu | 2022 | Journal of Energy Chemistry2022，31，7： | 1 |
| 7 | Study of automobile exhaust particles by spectromicroscopy显示文摘In this paper,automobile exhaust particles of Gol and Santana 3000 were studied by spectromicroscopy.The STXM results show that the single particulate is sized at 500 nm,with the mass distribution reducing towards the center.The N 1s NEXAFS spectra of automobile exhaust particles have similar structure with those of nitrates,which can be deduced as the main chemical species of nitrogen in automobile exhaust particles.There are minor amounts of ammoniums and organic nitrogen compounds in automobile exhaust particles.A single Gol automobile exhaust particle was stack scanned in the energy range of 396-416 eV.By principal component analysis and cluster analysis,it can be deduced that there are main three chemical species of nitrogen.The particle surface consists of mainly nitrates,the inside consists of mainly ammonium and organic nitrogen compounds,and the middle layer is an intergradation consisting of mainly nitrates and organic nitrogen compounds. | YANG Chuanjun GUO Zhi ZHANG Xiangzhi WANG Yong XU Zhijian ZHANG Lijuan TAI Renzhong BAO Liangman LI Xiaolin ZHANG Guilin LI Yan | 2010 | Nuclear Science and Techniques2010，21，5： | 1 |
| 8 | Blood pressure monitoring via double sandwich-structured triboelectric sensors and deep learning models显示文摘Real-time blood pressure monitoring is essential for the timely diagnosis and treatment of cardiovascular disease.Many traditional prediction methods estimate blood pressure by measuring multiple sets of physiological signals with energyconsuming sensors.Herein,a continuous,cuffless and self-powered blood pressure monitoring system was developed based on a new double sandwich-structured triboelectric sensor and a novel blood pressure method estimation.A pyramid-patterned sensor based on the double sandwich structure realizes a sensitivity of 0.89 V/kPa in a linear range of 0–35 kPa,which is more than twice of the conventional single electrode structure.The sensor processes a low pressure detection limit of 1 g andfast response time of 32 ms.Hence,it can easily capture the pulse signal at the radial artery.Furthermore,a novel method for estimating blood pressure using pulse waves accompanied by the user’s background information was proposed.This method measures only one set of pulse signals and is portable.A deep learning model with multi-network structures was developed to improve the estimation accuracy.The mean absolute error and standard deviation of error for systolic and diastolic blood pressure(SBP and DBP)estimations were 3.79±5.27 and 3.86±5.18 mmHg,respectively.This work reveals a new sensing structure of triboelectric sensors and offers a novel method for blood pressure estimation. | Xu Ran Fangyuan Luo Zhiming Lin Zhiyuan Zhu Chuanjun Liu Bin Chen | 2022 | Nano Research2022，15，6： | 0 |
| 9 | A CPK-Based Identity Authentication Scheme for IoT显示文摘As the power Internet of Things(IoT)enters the security construction stage,the massive use of perception layer devices urgently requires an identity authentication scheme that considers both security and practicality.The existing public key infrastructure(PKI)-based security authentication scheme is currently difficult to apply in many terminals in IoT.Its key distribution and management costs are high,which hinders the development of power IoT security construction.Combined Public Key(CPK)technology uses a small number of seeds to generate unlimited public keys.It is very suitable for identity authentication in the power Internet of Things.In this paper,we propose a novel identity authentication scheme for power IoT.The scheme combines the physical unclonable function(PUF)with improved CPK technology to achieve mutual identity authentication between power IoT terminals and servers.The proposed scheme does not require third-party authentication and improves the security of identity authentication for power IoT.Moreover,the scheme reduces the resource consumption of power IoT devices.The improved CPK algorithm solves the key collision problem,and the third party only needs to save the private key and the public key matrix.Experimental results show that the amount of storage resources occupied in our scheme is small.The proposed scheme is more suitable for the power IoT. | Mingming Zhang Jiaming Mao Yuanyuan Ma Liangjie Xu Chuanjun Wang Ran Zhao Zhihao Li Lu Chen Wenbing Zhao | 2022 | Computer Systems Science & Engineering2022，40，3： | 0 |
| 10 | Two-Way Coupling Vortex Method and Its Application显示文摘Because of the success of the discrete vortex method for the simulation of large-scale vortex structure.many researchers extend this method to two-phase flow simulations,especially,to the simulation of particle dispersion in mixing layer,which is characterized by large-scale vortex structure,But the previous work is limited to one-way couplin,which neglects the effect of particles on fluid flow.In this paper a discrete vortex method involving two-way coupling for two-phase flows is frist proposed and then used in numerical simulation of two-dimensional gas-particle mixin layers The numerical results show that the introduction of particles into the mixing layer has significant effects on the creation,development and merging process of large-scale vortex structures.It makes the mean size of large-scale vortex stucture large and the distance needed for development of large-scale vortex sturcture shorter. | Chenggang Xu (1) Chuanjun Yan (1) Hongji Wang (1) | 1992 | Journal of Thermal Science1992，1，3： | 0 |
| 11 | Petrology and geochemistry of the Shilu Fe-polymetallic ore deposit in Hainan Province of South China: Implications for the origin of Neoproterozoic BIFs显示文摘The Shilu Fe-polymetallic ore deposit,a famous hematite-rich Fe-ore deposit,is situated at the western Hainan Province of south China.The deposit characterizes the upper Fe ores and the lower Co-Cu ores,which are mainly hosted within a low-grade to medium-grade,dominantly submarine metamorphosed siliciclastic and carbonate sedimentary succession of the Neoproterozoic Shilu Group.Three facies types of metamorphosed BIFs,i.e.the oxide facies,the silicate-oxide facies and the sulfide-carbonate facies BIFs,are identified within the sixth sequence of the Shilu Group.The oxide facies BIF(i.e.the Fe-rich itabirites or ores)consists of alternating hematite-rich microbands with quartz-rich microbands;the silicate-oxide facies BIF(i.e.the Fe-poor itabirites or ores)comprises alternating millimeter-to a few tens meter-scale,magnetite-hematite-rich bands with calcsilicate-rich(garnet+actinolite+diopside+epidote+quartz)meso-to microbands;and the sulfide-carbonate facies BIF(i.e.the Co-Cu ores)contains alternating macro-to mesobands of Co-bearing pyrite and pyrrhotite,and chalcopyrite with mesobands of dolomite+calcite+diopside+quartz and/or chlorite+sericite+quartz.The blastooolitic,blastopelletoid blastocolloidal and blastopsammitic textures,and blasobedding structures which most likely represent primary sedimentation are often observed in these BIF facies.The interbedded host rocks with the BIFs mainly are the pyroxene-amphibole rocks and the banded or impure dolostones,and also contain banded or laminated structures,and lepido-gra-noblastic,nematoblastic and/or blastoclastic textures.Compositionally,the main host rocks,the pyroxene-amphibole rocks contain basic-intermediate SiO_2(~54.00 wt.%),CaO(~14.19 wt.%),MgO(~9.68 wt.%)and Al_2O_3(~8.49 wt.%)with a positive correlation between Al_2O_3 and TiO_2.The UCC-like Zr and Hf abundances,high Ba content andεNd(t)value(^-5.99)as well as the ratios of La/YbPAAS(0.17~1.00),δEuPAAS(0.88~1.12)andδCePAAS(0.93~1.13)commonly reveal that the protoliths to this type rocks are hydrogenic with a large contribution of terrigenous sediments and minor hydrothermal input.The high CaO+MgO+LOI contents and the extremely low trace element and REEconcentrations as well as the ratios of Y/Ho(44~45),δEuPAAS(1.13~1.57)andδCePAAS(0.69~0.98)reflect a marine origin with minor terrigenous materials for the banded or impure dolostones.Moreover,this type rocks also account for a negativeεNd(t)value(^-7.49).The oxide facies BIF is dominated by Fe_2O_3+FeO(~75.59wt.%)and SiO_2(~20.47 wt.%)with aεNd(t)value of^-6.10.The variable contents in Al_2O_3,TiO 2,K2O,Na2O,Zr,Hf and∑REE,and variable ratios of Y/Ho(24~39)andδEuPAAS(0.86~11.07)suggest the precursor sediments to this facies BIF are admixtures of sea-floor hydrothermal fluids and seawaters with minor involvement of detrital components.Compared to the oxide facies BIF,the silicate-oxide facies BIF is lower in Fe_2O_3+Fe O(~39.81wt.%)and Ba but higher in SiO_2(~42.54 wt.%),Al2O3(~3.60 wt.%),TiO_2(~0.19 wt.%),MgO(~1.12 wt.%),CaO(~9.06 wt.%),K_2O(~0.98 wt.%),Mn and Zr.The ratios of Y/Ho(25~34),La/YbPAAS(0.14-0.74)andδEuPAAS(0.91~1.12)most likely are linked to higher degree of detrital contamintants.While the sulfide-caronate facies BIF is main but variable in Fe_2O_3+Fe O(15.79~57.91 wt.%),SiO 2(0.54~61.52 wt.%),MgO(0.12~16.09wt.%),CaO(0.17~23.41 wt.%)and LOI(8.28-30.06 wt.%).The generally low contents in trace elements(including REE)except for an obvious enrichment in Pb,and the positive Ce anomalies(δCePAAS=1.04~1.95)and negative Pr anomalies(δPrPAAS=0.67~0.93),as well as the variable ratios ofδEuPAAS(0.72~1.71),La/YbPAAS(0.26~1.60)and Y/Ho(26~57)suggest that the precursors to the sulfide-carbonate facies BIF mainly are metalliferious sediments from deep-marine hydrotheral source with minor detrital components.The T2DM ages(ca.2.0 Ga)imply that the Shilu BIFs and interbedded host rocks contain a component with Paleoproterozoic crustal residence age due to a significant crustal accretion event at ca.2.0 Ga in Hainan Island.In connection with the petrographical and mineralogical relationship,we conclude that the precursor precipitates to the Shilu BIFs are variable degree of admixtures of the Fe-Co-Cu-(Si)-rich hydrothermal fluids and detrital components from seawater and fresh water carring continental landmass;whereas the protolith to the main interbedded host rocks,i.e.the pyroxene-amphibole rocks,most likely was terrigenous,fine-grained clastic-sediments but with significant input of hydrothermal fluids in a seawater environment.As a result,a continent marginal marine basin is proposed for deposition of the Shilu BIFs and interbedded host rocks.Sea-level fluctuations caused by marine transgression–regressions possibly contributed to changes in the composition and varied input of the terrigenous sediments. | Deru Xu Zhilin Wang Jianxin Cai Chuanjun Wu Wangwei Fu Nonna Bakun-Czubarow | 2012 | 矿床地质2012，31，S1： | 0 |
| 12 | Basic Relationship on Capacity of Bluetooth Piconets显示文摘 | Gang Xu Chuanjun Tian | 2006 | 通讯和计算机(中英文版)2006，3，8： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员