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Ammonium affects cell viability to inhibit root growth in Arabidopsis

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第6期12卷 477-484页

作者： cheng QIN Ke-ke YI ping WU State Key Laboratory of Plant Physiology and Biochemistry College of Life Sciences Zhejiang University Hangzhou 310058 China Zhejiang Academy of Agricultural Sciences Hangzhou 310021 China

Ammonium （NH4^＋） is an important form of nitrogen nutrient for most plants, yet is also a stressor for many of them. However, the primary events of NH4^＋ toxicity at the cellular level are still unclear. Here, we showed that NH4^＋ toxicity can induce the root cell death in a temporal pattern which primarily occurs in the cells of root maturation and elongation zones, and then spreads to the ceils in the meristem and root cap. The results from the NH4^＋-hypersensitive mutant hsn1 further confirmed our findings. Taken together,NH4^＋ toxicity inhibits primary root growth by inhibiting cell elongation and division and inducing root cell death.

关键词： Ammonium toxicity Root Cell viability GDP-mannose pyrophosphorylase Arabidopsis

Characteristics and clinical role of bronchoscopy in diagnosis of childhood endobronchial tuberculosis

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World Journal of Pediatrics 2017年第6期13卷 599-603页

作者： An-Xia Jiao Lin Sun Fang Liu Xiao-Chun Rao Yu-Yan Ma Xi-cheng Liu Chen shen Bao-ping Xu A-Dong shen Kun-Ling shen Key Laboratory of Major Diseases in Children Ministry of EducationNational Clinical Research Center for Respiratory DiseasesNational Key Discipline of Pediatrics(Capital Medical University)Department of Interventional PulmonologyBeijing Children's HospitalCapital Medical UniversityNational Center for Children's Health Beijing Key Laboratory of Pediatric Respiratory Infection Diseases Beijing Pediatric Research InstituteBeijing Children's HospitalCapital Medical UniversityNational Center for Children's Health Department of Respiratory Diseases Beijing Children's HospitalCapital Medical UniversityNational Center for Children's Health

Background:Endobronchial tuberculosis (EBTB) is the most frequent complication of primary pulmonary tuberculosis (PTB) in *** aim of the study was to analyze characteristics and clinical role of bronchoscopy in diagnosis of childhood ***:A retrospective,descriptive study was undertaken in 157 children with EBTB undergone flexible bronchoscopy (FB) between January 2006 and June ***:The median age of the enrolled patients was 3.4 years,with 73.2% of patients under five years *** most common subtype was tumorous type (145/157,92.4%).If only involved bronchus were considered,the common affected sites were right middle lobe bronchus (49/228,21.5%),left upper lobe bronchus (41/228,18.0%),right upper lobe bronchus (41/228,18.0%),right main bronchus (35/228,15.4%),*** younger than five years old were at higher risk to have multiple endobronchial lesions (P=0.044),with an odds ratio of 2.313 (95% confidence interval:1.009-5.299).Before the bronchoscopy,only 16 (10.2%)patients were highly suspected of EBTB,while the others were diagnosed as PTB without EBTB (69.4%),or misdiagnosed as pneumonia or foreign body aspiration (20.4%) on ***:The patients under five years old are at high risk to progress to EBTB and have multiple endobronchial *** most frequent subtype of EBTB in children is tumorous *** lesions are seen in the right bronchial system more *** should be performed to detect the endobronchial lesions in suspected patients as soon as possible.

关键词： diagnosis endobronchial tuberculosis flexible bronchoscopy

Shu-szi Sin: A Chinese pioneer biologist, ancient agronomist, and educator

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Protein & Cell 2021年第7期12卷 515-517页

作者： Qun Xie Yan-ping cheng Lei Fu Teacher Education College Zhejiang Normal UniversityJinhua 321000China

Shu-szi Sin(辛树枳,1894-1977)(Fig.1),a Chinese pioneer biologist and ancient agronomist,initiated the earliest scientific biological investigation of the Dayao mountain in both Guangxi and Guangdong provinces,discovering more than 20 new species that have been acknowledged *** was one of the founders and initiators of the China Botanical Society and the China Zoological *** was also a great educator Among one of those who first introduced the scientific method into agricultural history research,*** helped to set up the National Northwest Agriculture and Forestry College(now Northwest A&F University)and the Lanzhou *** devoted himself to the development of higher education in Northwest China.

关键词： China. Northwest devoted

Effects of content and particle size of TiH2 powders on the energy output rules of RDX composite explosives

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Defence Technology（防务技术） 2024年第2期32卷 297-308页

作者： Hao Wang Yangfan cheng Shoujun Zhu Zihan Li Zhaowu shen School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001China Anhui Engineering Laboratory of Explosive Materials and Technology Anhui University of Science and TechnologyHuainan 232001China School of Engineering Science University of Science and Technology of ChinaHefei 230027China

In order to improve the detonation characteristics of RDX,a RDX-based composite explosive with TiH_(2)powders was *** effects of content and particle size of TiH_(2)powders on thermal safety,shock wave parameters and thermal damage effects of RDX-based composite explosive were studied with the C80 microcalorimeter,air blast experiment system and colorimetric thermometry *** results showed that TiH_(2)powders could enhance the thermal stability of RDX-based composite explosive and increase its ultimate decomposition *** content and particle size of TiH_(2)powders also had significant effects on the thermal safety,detonation velocity,shock wave parameters,fireball temperature and duration of RDX-based composite ***,the differences of TiH_(2)and Ti powders on the detonation energy output rules of RDX-based composite explosives were also compared,showing that TiH_(2)powders had better influences on improving the explosion power and thermal damage effect of RDX-based composite explosives than Ti powders,for the participation of free H_(2)released by TiH_(2)powders in the detonation ***_(2)powders have important research values as a novel energetic additive in the field of military composite explosives.

关键词： RDX Hydrogen storage alloy Air blast After-burn reaction Colorimetric thermometry

Science Letters:A new coding scheme in coded ultrasound using staggering repetition interval

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第8期10卷 1213-1216页

作者： cheng JIN Si-ping CHEN Zheng-di QIN School of Biomedical Engineering and Instrument Science Zhejiang University Hangzhou 310027 China School of Medicine Shenzhen University Shenzhen 518060 China Nokia Corporation Tampere 33100 Finland

The increase of frame rate,though with the potential in a coded ultrasound system,is generally concomitant with the simultaneous transmission of a number of apertures,and in consequence leads to increased cross-talks between different *** view of this,a new coding scheme using staggering repetition interval was *** transmitting signals were constructed by repeating the two(or more) modulated codes using staggering repetition interval,and then allocated to and transmitted simultaneously among different *** decoding process was based on the subsection-matched filter under the assistance of different matched filters for different *** last the outputs of subsection-matched filtering were added *** changed the positions of cross-correlation(CC) peaks from coinciding,which resulted in an effective reduction of *** theoretical analysis and simulations showed that,the coding scheme can be used to reduce cross-talk,and a good cross-talk reduction will be achieved if the staggering delay is kept in an appropriate range.

关键词： Coded ultrasound Frame rate Cross-correlation (CC) Staggering Ultrasonic imaging

Deflagration characteristics of freely propagating flames in magnesium hydride dust clouds

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Defence Technology（防务技术） 2024年第1期31卷 471-483页

作者： Qiwei Zhang Yangfan cheng Beibei Zhang Danyi Li Zhaowu shen School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001AnhuiPR China School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001AnhuiPR China Anhui Engineering Laboratory of Explosive Materials and Technology Anhui University of Science and TechnologyHuainan 232001AnhuiPR China School of Engineering Science University of Science and Technology of ChinaHefei 230027AnhuiPR China

The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed *** dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were *** experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,*** dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were *** flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of *** falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,*** the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the ***,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)*** combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg *** micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.

关键词： Magnesium hydride dust Flame combustion mechanism Particle size Dust explosion Two-color pyrometer

A perspective on influences of cathode material degradation on oxygen transport resistance in low Pt PEMFC

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Nano Research 2023年第1期16卷 377-390页

作者： Huiyuan Li Xiaojing cheng Xiaohui Yan Shuiyun shen Junliang Zhang Institute of Fuel Cells School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Power&Machinery Engineering Shanghai Jiao Tong UniversityShanghai 200240China

A large-scale industrial application of proton exchange membrane fuel cells(PEMFCs)greatly depends on both substantial cost reduction and continuous durability ***,compared to effects of material degradation on apparent activity loss,little attention has been paid to influences on the phenomena of mass *** this review,influences of the degradation of key materials in membrane electrode assemblies(MEAs)on oxygen transport resistance in both cathode catalyst layers(CCLs)and gas diffusion layers(GDLs)are comprehensively explored,including carbon support,electrocatalyst,ionomer in CCLs as well as carbon material and hydrophobic polytetrafluoroethylene(PTFE)in *** is analyzed that carbon corrosion in CCLs will result in pore structure destruction and impact ionomer distribution,thus affecting both the bulk and local oxygen transport *** the catalyst degradation,an eventual decrease in electrochemical active surface area(ECSA)definitely increases the local oxygen transport resistance since a decrease in active sites will lead to a longer oxygen transport *** is also noted that problems concerning oxygen transport caused by the degradation of ionomer chemical structure in CCLs should not be *** cation contamination and chemical decomposition will change the structure of ionomer,thus worsening the local oxygen ***,it is found that the loss of carbon and PTFE in GDLs lead to a higher hydrophilicity,which is related to an occurrence of water flooding and increase in the oxygen transport resistance.

关键词： proton exchange membrane fuel cells(PEMFC) oxygen transport resistance degradation cathode catalyst layer gas diffusion layer

MXene Quantum Dots/Copper Nanocomposites for Synergistically Enhanced N_(2)Electroreduction

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Energy & Environmental Materials 2023年第1期6卷 192-198页

作者： Yonghua cheng Xingchuan Li Peng shen Yali Guo Ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrocatalytic N_(2) reduction reaction(NRR)represents an appealing solution for sustainable ammonia production,whereas exploring high-efficiency NRR catalysts is highly desired but extremely ***,we combine Ti_(3) C_(2)T_(x)-MXene quantum dots(MQDs)with porous Cu nanosheets to design a novel heterostructured MQDs/Cu as an effective and durable NRR ***,MQDs/Cu showed a synergistically enhanced NRR activity with an NH_(3) yield of 78.5 lg h^(-1) mg^(-1)(-0.5 V)and a Faradaic efficiency of 21.3%(-0.4 V),far superior to pure MQDs and Cu,and outperforming the majority of the state-of-the-art NRR *** function theory computations demonstrated that the synergy of MQDs and Cu enabled the creation of interfacial Cu-Ti dimer as dual-active-centers to strongly activate the absorbed N 2 and promote the*N_(2)H formation,consequently resulting in the much reduced energy barriers and greatly enhanced NRR performance.

关键词： density functional theory electrocatalytic nitrogen fixation heterostructure MXene quantum dots

Collaborative eye tracking based code review through real-time shared gaze visualization

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Frontiers of Computer Science 2022年第3期16卷 163-173页

作者： Shiwei cheng Jialing WANG Xiaoquan shen Yijian CHEN Anind DEY School of Computer Science and Technology Zhejiang University of TechnologyHangzhou 310023China Information School University of WashingtonSeattle 98195-9440USA

Code review is intended to find bugs in early development phases,improving code quality for later integration and ***,due to the lack of experience with algorithm design,or software development,individual novice programmers face challenges while reviewing *** this paper,we utilize collaborative eye tracking to record the gaze data from multiple reviewers,and share the gaze visualization among them during the code review *** visualizations,such as borders highlighting current reviewed code lines,transition lines connecting related reviewed code lines,reveal the visual attention about program functions that can facilitate understanding and bug *** can help novice reviewers to make sense to confirm the potential bugs or avoid repeated reviewing of code,and potentially even help to improve reviewing *** built a prototype system,and conducted a user study with paired *** results showed that the shared real-time visualization allowed the reviewers to find bugs more efficiently.

关键词： computer supported collaborative learning computer supported cooperative work social computing fixation human computer interaction