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Experimental and numerical investigation of the flexural performance of channel steel-bolt joint for prefabricated subway stations

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 918-935页

作者： Lei WANG Shengyang ZHOU Xiangsheng CHEN Xian LIU Shuya LIU Dong SU Shouchao JIANG Qikai ZHU Haoyu YAO College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Coastal Urban Resilient Infrastructures(MOE) Shenzhen UniversityShenzhen 518061China Shenzhen Key Laboratory of Green Efficient and Intelligent Construction of Underground Metro StationShenzhen UniversityShenzhen 518061China College of Civil Engineering Tongji UniversityShanghai 200092China Shenzhen Municipal Design&Research Co. Ltd.Shenzhen 518029China Shenzhen Metro Group Co. Ltd.Shenzhen 518026China

Flexural performance of joints is critical for prefabricated *** study presents a novel channel steel-bolt(CB)joint for prefabricated subway ***-scale tests are carried out to investigate the flexural behavior of the CB joint under the design loads of the test-case *** addition,a three dimensional(3D)finite element(FE)model of the CB joint is established,incorporating viscous contact to simulate the bonding and detachment behaviors of the interface between channel steel and *** on the 3D FE model,the study examines the flexural bearing mechanism and influencing factors for the flexural performance of the CB *** results indicate that the flexural behavior of the CB joint exhibits significant nonlinear characteristics,which can be divided into four *** illustrate the piecewise linearity of the bending moment-rotational angle curve,a four-stage simplified model is proposed,which is easily applicable in engineering *** study reveals that axial force can enhance the flexural capacity of the CB joint,while the preload of the bolt has a negligible *** flexural capacity of the CB joint is approximate twice the value of the designed bending moment,demonstrating that the joint is suitable for the test-case station.

关键词： channel steel-bolt joint flexural performance full-scale test numerical simulation prefabricated subway station

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Near Infrared Spectroscopy (NIRS) Model-Based Prediction for Protein Content in Cowpea

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American Journal of Plant Sciences 2024年第3期15卷 145-160页

作者： Kavera Biradar Waltram Ravelombola Aurora Manley Caroline Ruhl Texas A&M AgriLife Research Vernon TX USA University of Agricultural Sciences Dharwad India Department of Soil and Crop Sciences Texas A&M University College Station TX USA

Cowpea (Vigna unguiculata L. Walp) is a multi-purpose legume with high quality protein for human consumption and livestock. The objective of this work was to develop near-infrared spectroscopy (NIRS) prediction models to estimate protein content in cowpea. A total of 116 cowpea breeding lines with a wide range of protein contents (19.28 % to 32.04%) were selected to build the model using whole seed and ground seed samples. Partial least-squares discriminant analysis (PLS-DA) regression technique with different pre-treatments (derivatives, standard normal variate, and multiplicative scatter correction) were carried out to develop the protein prediction model. Results showed: 1) spectral plots of both the whole seed and ground seed showed higher spectral scatter at higher wavelengths (>1450 nm), 2) data pre-processing affects prediction accuracy for bot whole seed and ground seed samples, 3) prediction using ground seed samples (0.64 R2 0.85) is better than the whole seed (0.33 R2 0.78), and 4) the data pre-processing second derivative with standard normal variate has the best prediction (R2_whole seed = 0.78, R2_ground seed = 0.85). The results will be of interest in cowpea breeding programs aimed at improving total seed protein content.

关键词： Cowpea Germplasm Protein Near-Infrared Spectroscopy (NIRS) Partial Least Squares (PLS)

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养分回收加剧了氮沉降背景下盐渍化草地优势植物内在氮磷的失衡

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Journal of Plant Ecology 2024年第1期17卷 111-120页

作者： Yuan Su Shuaikai Wu Jie Hao Huajie Diao Kuanhu Dong Changhui Wang Shanxi Key Laboratory of Grassland Ecological Protection and Native Grass Germplasm Innovation College of Grassland ScienceShanxi Agricultural UniversityTaigu 030801China Youyu Loess Plateau Grassland Ecosystem National Research station Shanxi Agricultural UniversityTaigu 030801China

在落叶之前,从衰老组织中重新吸收养分被认为是植物适应养分缺乏的一种策略。然而,养分重吸收如何调节植物体内氮(N)和磷(P)的平衡仍不清楚,特别是在土壤氮有效性增加的情况下。本文研究了不同速率(0、1、2、4、8、16、24和32 g N m^(-2... 详细信息

在落叶之前,从衰老组织中重新吸收养分被认为是植物适应养分缺乏的一种策略。然而,养分重吸收如何调节植物体内氮(N)和磷(P)的平衡仍不清楚,特别是在土壤氮有效性增加的情况下。本文研究了不同速率(0、1、2、4、8、16、24和32 g N m^(-2)yr^(-1))氮添加对中国北方盐渍化草地优势植物赖草(Leymus secalinus)叶片和茎秆养分回收的影响,以及养分回收在调控植物内部氮磷平衡的作用。研究结果表明:氮添加6年后,随着施氮量的增加,绿色和衰老组织(叶和茎)的N浓度和氮磷比均呈上升趋势。随着施氮量的增加,绿色组织中P浓度降低,而衰老组织中P浓度无显著变化。N重吸收效率(NRE)、P重吸收效率(PRE)和NRE:PRE比值沿N添加梯度显著降低。此外,我们发现衰老组织(叶和茎)氮磷比比绿色组织(叶和茎)氮磷比对氮素添加的响应更敏感,植物内在氮磷失衡的加剧主要是由于不成比例的减少养分重吸收,尤其是NRE。总的来说,我们的研究表明,NRE和PRE的差异进一步加剧了植物凋落物内部氮磷的失衡。

关键词：生态化学计量学氮添加氮磷失衡重吸收效率重吸收能力重吸收比盐渍化草地

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Electrochemical performance of nano-scale β-Ni(OH)_2 prepared at different transformations of pH value

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Journal of Harbin Institute of Technology(New Series) 2008年第2期15卷 160-163页

作者：赵力张利军韩喜江张翠芬 Postdoctoral station of Material Science and Engineering Harbin Institute of Technology Postdoctoral work station Jiangsu Shuangdeng Group Co.LtdJiangyan 225526China Dept of Applied Chemistry Harbin Institute of Technology

The influence of transforming pH values on the electrochemical performance of nano-scale Ni （OH）2 was analyzed. The measurement results of XRD indicate that the nano-scale Ni （OH） 2 prepared at different transformations of pH value is β （ Ⅱ ）-phase with different crystal lattice parameters. Cyclic voltammograms （CV） and electrochemical impedance spectroscopy（EIS） measurement results show that transformations of pH value affect the proton diffusion coefficient （D） and charge-transfer resistance （Re,） of the material. The simulation *** experiment shows that the sample prepared at a pH of 10. 1 exhibits the maximum specific capacity （327.8 mAh/g） and higher discharge platform, the discharge performance of electrodes depends on both D and Rct, so the kinetics characteristics that electrodes reaction is controlled by both mass-transfer step and charge- transfer step are put forward.

关键词： nano-material Ni(OH)2 electrochemical transformations of pH value

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Effects of impregnation sequence on the NH_(3)-SCR activity and hydrothermal stability of a Ce-Nb/SnO_(2) catalyst

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Journal of Environmental Sciences 2024年第4期138卷 450-457页

作者： Ying Zhu Wenpo Shan Zhihua Lian Jingjing Liu Yan Zhang Hong He Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control Ningbo Urban Environment Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesNingbo 315800China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Hydrothermal stability is crucial for the practical application of deNO_(x)catalyst on diesel vehicles,for the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR).SnO_(2)-based materials possess superior hydrothermal stability,which is attractive for the development of NH_(3)-SCR *** this work,a series of Ce-Nb/SnO_(2)catalysts,with Ce and Nb loading on SnO_(2)support,were prepared by impregnation *** was found that,the NH_(3)-SCR activities and hydrothermal stabilities of the Ce-Nb/SnO_(2)catalysts significantly varied with the impregnation sequences,and the Ce-Nb(f)/SnO_(2) catalyst that firstly impregnated Nb and then impregnated Ce exhibited the best *** characterization results revealed that CeNb(f)/SnO_(2)possessed appropriate acidity and redox ***,the strong synergistic effect between Nb and Sn species stabilized the structure and maintained the dispersion of acid *** study may provide a new understanding for the effect of impregnation sequence on activity and hydrothermal stability and a new environmental-friendly NH_(3)-SCR catalyst with potential applications for NO_(x)removal from diesel and hydrogenfueled engines.

关键词： NO_(x)emission control NH_(3)-SCR Hydrothermal stability Ce-Nb/SnO_(2)catalyst Impregnation sequence

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Acoustic localization scheme and accuracy analysis for underwater vertical moving target using seabed stations

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Chinese Journal of Acoustics 2019年第2期38卷 145-166页

作者： ZHANG Xu SUN Ao XIN Jian HAN Xu Unit 91550 of PLA Postdoctoral Scientific Research work station in Unit 92493 of PLA

To measure the trajectory of an underwater vertical moving target(UVMT) in transient motion with high accuracy and high frame rate,an acoustic localization model using seabed stations with an acoustic beacon was presented.A solution algorithm based on the Gauss-Newton method was derived,which was shown to satisfy the local linear *** analysis of the numerical simulation indicated that the station location,sound velocity,and signal time delay estimation errors were propagated to location parameters through measurement ranges,and the main affecting factors included the station geometry,target relative location,and acoustic *** accuracy was improved using a supplemental surface station coupled with the seabed *** characteristics were indicated by accuracy distribution from the full test sea area.A 14-station array composed of 13 seabed stations and 1 surface station in a test sea of 1 km x 1 km and 60 m in depth demonstrated that the average root mean square errors(RMSEs) in the x,y,and z directions were 0.30,1.47,and0.34 m,respectively,in the vertical range of 35-60 *** work provided a technical approach for UVMT localization,which would be useful for designing related measurement systems.

关键词： Acoustic localization scheme and accuracy analysis for underwater vertical moving target using seabed stations

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Fabricating bio-inspired high impact resistance carbon nanotube network films for multi-protection under an extreme environment

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Nano Research 2024年第9期17卷 7793-7802页

作者： Mingquan Zhu Kailu Xiao Wei Zhang Xudong Lei Yunxiang Bai Shijun Wang Peng Zhang Feng Gao Congying Wang Wenqiang Xu Huiyong Li Xianqian Wu Chao Wang Hui Zhang Luqi Liu Zhong Zhang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Materials Science and Engineering Texas A&M UniversityCollege StationTexas 77840USA Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Astronautics Harbin Institute of TechnologyHarbin150001China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China

The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme *** nanotubes(CNTs),one of the strongest and toughest materials ever found,also have good conductivity,chemical stability,and thermal stability,etc,making them a competitive candidate as building blocks to help achieve the above *** this work,a kind of CNT network was prepared by using chlorosulfonic acid(CSA)to release the internal stress of super-aligned carbon nanotube films(SA-CNTF)and dendritic polyamide amine(PAMAM)to further introduce multiple hydrogen bonds and interlocking *** fabricated bioinspired carbon nanotube network films(PAMAM@C-CNTF)have a high toughness of 45.97 MJ/m3,showing an increase of 420%compared to neat *** importantly,the anti-impact performance of the films(e.g.,with a maximum specific energy absorption of 1.40 MJ/kg under 80-100 m/s projectile impact)is superior to that of conventional protective materials from steel and Kevlar fiber,and also exceeds that of any other reported carbon-based *** hierarchical energy dissipation mechanism was further revealed through experiment and *** functions including intelligent heating/anti-icing,ultraviolet protection,as well as electromagnetic interference shielding properties make these network films have great potential in practical multi-protection applications,especially under an extreme environment.

关键词： carbon nanotubes composites mechanical properties multi-function

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碳中和背景下基于g-C_(3)N_(4)光催化CO_(2)还原的研究进展与挑战

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Science China Materials 2024年第6期67卷 1740-1764页

作者：展海银周睿人刘可望马志辉王鹏飞展思辉周启星 Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria Carbon Neutrality Interdisciplinary Science Centre/College of Environmental Science and EngineeringNankai UniversityTianjin 300350China Department of Biological and Agricultural Engineering Texas A&M University126 Hobgood2117 TAMUCollege StationTX 77843-2117USA

全球变暖对人类的生产生活造成了严重的威胁,已成为当今世界面临的重大挑战之一.碳中和这一重要举措能够有效缓解全球变暖的进程,在这一背景下光催化CO_(2)还原可有效减少碳排放且促进碳循环.g-C_(3)N_(4)因其制备工艺简单、稳定性高、... 详细信息

全球变暖对人类的生产生活造成了严重的威胁,已成为当今世界面临的重大挑战之一.碳中和这一重要举措能够有效缓解全球变暖的进程,在这一背景下光催化CO_(2)还原可有效减少碳排放且促进碳循环.g-C_(3)N_(4)因其制备工艺简单、稳定性高、能带位置适宜以及优异的光催化性能而备受关注.因此,提高g-C_(3)N_(4)光催化CO_(2)还原效率是当前研究的热点问题.本文重点探究了碳中和对于全球生态平衡和环境可持续发展的重要性以及在碳中和背景下g-C_(3)N_(4)光催化CO_(2)还原的重要作用和发展前景;综述了目前解决限制g-C_(3)N_(4)光催化CO_(2)还原瓶颈问题的方法和技术手段.对g-C_(3)N_(4)在光催化CO_(2)还原领域存在的问题进行讨论,提出了未来的研究方向,并进行展望.本综述旨在为碳中和背景下基于g-C_(3)N_(4)催化剂光催化CO_(2)还原的应用提供理论支持,为基于g-C_(3)N_(4)高效CO_(2)还原光催化剂的设计提供思路.

关键词： carbon neutral photocatalysis CO_(2)reduction gra-phitic carbon nitride modification strategy

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Formulation of Organic Fertilizer Standard in Jiaxing City Based on NY525-2012

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Asian Agricultural Research 2013年第4期5卷 124-125,132页

作者： Jinfa HUANG Xiongwei NI Jianping XIE Yanping SHI Jiaxing work station of Soil and Fertilizer

On the basis of research, analysis and argumentation, we conduct analysis and research on the current situation of quality of commercial organic fertilizer in Jiaxing City, and carry out the inspection and testing of organic matter indicators using the laboratory. Based on the standard of NY525-2012 Organic Fertilizer by the Ministry of Agriculture, this paper formulates the quality level indicators of local commercial organic fertilizer and adding specifications of raw materials.

关键词： Organic fertilizer Jiaxing Local standard

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N-acetylcysteine ameliorates erectile dysfunction in rats with hyperlipidemia by inhibiting oxidative stress and corpus cavernosum smooth muscle cells phenotypic modulation

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Asian Journal of Andrology 2024年第1期26卷 99-106页

作者： Wei Ding Jun-Hong Fan Li-Ren Zhong Nan-Xiong Wang Lu-Hao Liu Hai-Bo Zhang Li Wang Ming-Qiang Wang Bing-Lin He An-Yang Wei Department of Urology The First Affiliated Hospital of Guizhou University of Traditional Chinese MedicineGuiyang 550002China Department of Urology Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou 510000China Department of Urology Nanfang HospitalSouthern Medical UniversityGuangzhou 510000China Department of Urology Shenzhen Immigration Inspection General Station HospitalShenzhen 518000China Department of Organ Transplantation The Second Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510000China Department of Endocrinology The First Affiliated Hospital of Guizhou University of Traditional Chinese MedicineGuiyang 550002China

Hyperlipidemia is a major risk factor for erectile dysfunction(ED).Oxidative stress and phenotypic modulation of corpus cavernosum smooth muscle cells(CcSMCs)are the key pathological factors of ED.N-acetylcysteine(NAC)can inhibit oxidative stress;however,whether NAc can alleviate pathological variations in the corpus cavernosum and promote erectile function recovery in hyperlipidemic rats remains unclear.A hyperlipidemia model was established using 27 eight-week-old male Sprague-Dawley(SD)rats fed a high-fat and high-cholesterol diet(hyperlipidemic rats,HR).In addition,9 male SD rats were fed a normal diet to serve as controls(NC).HR rats were divided into three groups:HR,HR+normal saline(NS),and HR+NAC(n=9 for each group;NS or NAc intraperitoneal injections were administered daily for 16 weeks).Subsequently,the lipid profiles,erectile function,oxidative stress,phenotypic modulation markers of ccsMCs,and tissue histology were *** experimental results revealed that erectile function was significantly impaired in the HR and HR+NS groups,but enhanced in the HR+NAC *** lipid levels,over-activated oxidative stress,and multi-organ lesions observed in the HR and HR+NS groups were improved in the HR+NAC ***,the HR group showed significant phenotypic modulation of CCSMCs,which was also inhibited by NAC *** report focuses on the therapeutic effect of NAc in restoring erectile function using a hyperlipidemic rat model by preventing CcSMC phenotypic modulationand attenuating oxidativestress.

关键词： erectile dysfunction hyperlipidemia N-acetylcysteine oxidative stress henotypic modulation

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