检索结果-南通市图书馆

China Ocean Engineering 2024年第4期38卷 586-601页

作者： LIAN Ji-jian zhu Hang GUO yao-hua WANG Hai-jun YU Tong-shun State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China Tianjin University of Technology Tianjin 300384China College of Engineering Ocean University of ChinaQingdao 266100China

As offshore wind farms expand into deeper and farther ocean regions and the unit capacity of offshore wind turbines(OWTs)increases,there is a pressing need for a new foundation structure that can accommodate deep-sea conditions and support large capacities while maintaining economical and *** meet this goal of integrated transportation and one-step installation,a novel five-bucket jacket foundation(FBJF),with its suction installation and leveling methods in sand,has been proposed,analyzed and experimentally ***,seepage failure experiments of the FBJF at various depths were conducted,and a formula for calculating the critical suction of seepage failure suitable for the FBJF in sand was chosen and recommended for use with a range of values for the permeability coefficient ***,through leveling experiments of the FBJF at different depths,the maximum adjustable leveling angle during the sinking process was defined using seepage failure and the adjustable leveling angle of the foundation as control *** leveling control strategies were proposed and ***,an automatic sinking and leveling control system for the FBJF was developed and experimentally verified for feasibility.

关键词： offshore wind turbine(OWT) bucket foundation seepage failure suction installation

Improved observation of colonized roots reveals the regulation of arbuscule development and senescence by drought stress in the arbuscular mycorrhizae of citrus

在线全文

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2024年第2期10卷 425-436页

作者： Xilong Yin Wei Zhang Zengwei Feng Guangda Feng Honghui zhu Qing yao College of Horticulture South China Agricultural UniversityKey Laboratory of Biology and Genetic Improvement of Horticultural Crops(South China)Ministry of Agriculture and Rural AffairsGuangdong Province Key Laboratory of Microbial Signals and Disease ControlGuangzhouGuangdong 510642China Key Laboratory of Agricultural Microbiomics and Precision Application Ministry of Agriculture and Rural AffairsGuangdong Provincial Key Laboratory of Microbial Culture Collection and ApplicationKey Laboratory of Agricultural MicrobiomicsState Key Laboratory of Applied Microbiology Southern ChinaGuangdong Microbial Culture Collection Center(GDMCC)Institute of MicrobiologyGuangdong Academy of SciencesGuangzhouGuangdong 510070China

Citrus is the typical mycorrhizal fruit tree species establishing symbiosis with arbuscular mycorrhizal (AM) fungi. However, arbuscule development and senescence in colonized citrus roots, especially in response to drought stress, remain unclear, which is mainly due to the difficulty in clearing and staining lignified roots with the conventional method. Here, we improved the observation of colonized roots of citrus plants with the sectioning method, which enabled the clear observation of AM fungal structures. Furthermore, we investigated the effects of one week of drought stress on arbuscule development and senescence with the sectioning method. Microscopy observations indicated that drought stress significantly decreased mycorrhizal colonization (F%and M%) although it did not affect plant growth performance. Fluorescence probes (WGA 488 and/or Nile red) revealed that drought stress inhibited arbuscule development by increasing the percentage of arbuscules at the early stage and decreasing the percentages of arbuscules at the midterm and mature stages. Meanwhile, drought stress accelerated arbuscule senescence, which was characterized by the increased accumulation of neutral lipids. Overall, the sectioning method developed in this study enables the in-depth investigation of arbuscule status, and drought stress can inhibit arbuscule development but accelerate arbuscule senescence in the colonized roots of citrus plants. This study paves the way to elaborately dissecting the arbuscule dynamics in the roots of fruit tree species in response to diverse abiotic stresses.

关键词： Arbuscular mycorrhizae Citrus Drought stress Arbuscule development Arbuscule senescence Fruit tree species

Automatic detection and assessment of crack development in ultra-high performance concrete in the spatial and Fourier domains

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第3期18卷 350-364页

作者： Jixing CAO yao ZHANG Haijie HE Weibing PENG Weigang ZHAO Zhiguo YAN Hehua zhu School of Safety Engineering and Emergency Management Shijiazhuang Tiedao UniversityShijiazhuang 050043China College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China College of Civil and Architectural Engineering Taizhou UniversityTaizhou 318000China College of Civil Engineering and Architecture Zhejiang University of TechnologyHangzhou 310014China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

Automatic detection and assessment of surface cracks are beneficial for understanding the mechanical performance of ultra-high performance concrete(UHPC).This study detects crack evolution using a novel dynamic mode decomposition(DMD)*** this method,the sparse matrix‘determined’from images is used to reconstruct the foreground that contains cracks,and the global threshold method is adopted to extract the crack *** application of the DMD method to the three-point bending test demonstrates the efficiency in inspecting cracks with high ***,the geometric features,including the area and its projection in two major directions,are evaluated over *** relationship between the geometric properties of cracks and load-displacement curves of UHPC is *** to the irregular shape of cracks in the spatial domain,the cracks are then transformed into the Fourier domain to assess their *** indicate that crack patterns in the Fourier domain exhibit a distinct concentration around a central ***,the power spectral density of cracks exhibits an increasing trend over *** investigation into crack evolution in both the spatial and Fourier domains contributes significantly to elucidating the mechanical behavior of UHPC.

关键词： dynamic mode decomposition ultra-high performance concrete crack detection geometric features Fourier domain

Effect of dynamic loading orientation on fracture properties of surrounding rocks in twin tunnels

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 393-409页

作者： Ze Deng Zheming zhu Lei Zhou Leijun Ma Jianwei Huang yao Zhang Key Laboratory of Deep Earth and Engineering(Ministry of Education) College of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province College of Architecture and EnvironmentSichuan UniversityChengdu610065China Institute for Disaster Management and Reconstruction Sichuan UniversityChengdu610065China

For expedited transportation,vehicular tunnels are often designed as two adjacent tunnels,which frequently experience dynamic stress waves from various orientations during blasting *** analyze the impact of dynamic loading orientation on the stability of the twin-tunnel,a split Hopkinson pressure bar(SHPB)apparatus was used to conduct a dynamic test on the twin-tunnel *** two tunnels were rotated around the specimen’s center to consider the effect of dynamic loading ***-DYNA software was used for numerical simulation to reveal the failure properties and stress wave propagation law of the twin-tunnel *** findings indicate that,for a twin-tunnel exposed to a dynamic load from different orientations,the crack initiation position appears most often at the tunnel corner,tunnel spandrel,and tunnel *** the impact direction is created by a certain angle(30°,45°,60°,120°,135°,and 150°),the fractures are produced in the middle of the line between the left tunnel corner and the right tunnel *** the impact loading angle(a)is 90°,the tunnel sustains minimal damage,and only tensile fractures form in the surrounding *** orientation of the impact load could change the stress distribution in the twin-tunnel,and major fractures are more likely to form in areas where the tensile stress is concentrated.

关键词： Twin-tunnel Dynamic load Split Hopkinson pressure bar(SHPB) Fracture mode Stress distribution Displacement field distribution

Phosphorous-doped carbon nanotube/reduced graphene oxide aerogel cathode enabled by pseudocapacitance for high energy and power zinc-ion hybrid capacitors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 570-576页

作者： Junjun yao Fuzhi Li Ruyi Zhou Chenchen Guo xinru Liu Yirong zhu Hunan Key Laboratory of Green Metallurgy and New Energy Materials College of Materials and Advanced ManufacturingHunan University of TechnologyZhuzhou 412007China College of packaging and Material Engineering Hunan University of TechnologyZhuzhou 412007China

The design and development of energy storage device with high energy/power density has become a research ***-ion hybrid capacitors(ZHCs)are considered as one of the most promising ***,the application of ZHCs is hindered by their low energy density at high power density due to the unsatisfactory cathode *** this study,a novel 3D phosphorus-doped carbon nanotube/reduced graphene oxide(P-CNT/rGO)aerogel cathode is synthesized through a synergistic modification strategy of CNT insertion and P doping modification combined with 3D porous *** as-obtained P-CNT/rGO aerogel cathode manifests significantly increased surface aera,expanded interlayer spacing,and enhanced pseudocapacitance behavior,thus leading to significantly enhanced specific capacitance and superb ions transport *** as-assembled ZHC based on P-CNT/rGO cathode delivers a superior energy density of 42.2 Wh/kg at an extreme-high power density of 80 kW/kg and excellent cycle ***-depth kinetic analyses are undertaken to prove the enhanced pseudocapacitance behavior and exceptional power output capability of ***,the reaction mechanism of physical and chemical adsorption/desorption of electrolyte ions on the P-CNT/rGO cathode is revealed by systematic ex-situ *** work can provide a valuable reference for developing advanced graphene-based cathode for high energy/power density ZHCs.

关键词： Graphene aerogel Phosphorus doping Pseudocapacitance Zinc-ion hybrid capacitors Energy storage mechanism

The Astrometric Performance of the China Space Station Telescope(CSST)Sky Survey in Extending the Gaia Celestial Reference Frame

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第8期24卷 133-140页

作者： Jun yao Jia-Cheng Liu Niu Liu Zi zhu Zhen-Wei Wang School of Astronomy and Space Science Key Laboratory of Modern Astronomy and Astrophysics(Ministry of Education)Nanjing UniversityNanjing 210023China University of Chinese Academy of Sciences Nanjing 211135China

The multi-color imaging sky survey conducted by the China Space Station Telescope(CSST)holds significant promise for advancing the development of the celestial reference *** this study,we focus on assessing the astrometric performance of the CSST celestial reference frame(CSST-CRF)in extending the Gaia Celestial Reference Frame 3(Gaia-CRF3).First,the orientation precision of the CSST reference frame is evaluated using a simulated set of extragalactic sources with CSST g magnitudes ranging from 18 to 25 *** estimated orientation uncertainty caused by random error insignificantly affects the alignment between Gaia-CRF3 and the ***,the systematic effect of incomplete CSST sky coverage on the alignment between CSST-CRF and Gaia-CRF3 is discussed by analyzing the differences between the subset of Gaia-CRF3 in the CSST observation region(Gaia-CRF3′)and Gaia-CRF3 as a *** the third International Celestial Reference Frame(ICRF3)S/X band as an intermediate reference frame,the orientation offset between Gaia-CRF3′and GaiaCRF3 is estimated to be 20μ*** offset is marginally larger than the orientation offset between Gaia-CRF3 and the ICRF3,approximately 15μ*** residual spin and glide rate of Gaia-CRF3′are derived from the proper motions,consistent with that of Gaia-CRF3 within the formal ***,we explore the role of CSST in establishing a multi-band celestial reference frame by comparing its limiting magnitude and observation accuracy with existing catalogs in the infrared and ultraviolet *** to its broad wavelength coverage and highprecision measurements,CSST is well-positioned to make significant contributions to the development of a multiband celestial reference frame.

关键词： astrometry-reference systems-surveys

The interaction mechanism between zein and folic acid in alkaline aqueous solutions:an experimental and molecular simulation study

在线全文

学校读者我要写书评

暂无评论

Food Quality and Safety 2024年第1期8卷 166-178页

作者： Jun zhu Yiling yao Yuying Liao Lala Cai Wenqi Zhang Nuo Hong Wenlin Sun Chunhua Xiong Lanying yao School of Food Science and Biotechnology Zhejiang Gongshang UniversityHangzhouChina

Objectives:Folic acid is a vitamin that is not highly soluble in water and is sensitive to the ***,it is important to find suitable *** study aimed to exemplify the interaction of folic acid with zein in alkaline aqueous solutions and shed light on how zein can be used as a carrier for folic *** and Methods:Zein and folic acid were separately dissolved in NaOH solutions with a PH of *** solution and folic acid solution were combined in specific *** methods including multi-spectroscopy,dynamic light scattering,and electron microscopy combining with molecular dynamics simulations were used to study the interaction mechanism between zein and folic acid in alkaline aqueous ***:Fluorescence spectroscopy showed that the quenching of zein by folic acid was mainly static,and the main driving force behind this interaction was van der Waals forces and hydrogen *** formation of zein–folic acid complexes was confirmed by ultraviolet–visible spectroscopy,Fourier transform infrared spectroscopy,and circular dichroism *** results also showed that the structure of zein changed when it interacted with folic *** light scattering analysis revealed that the addition of folic acid caused proteins to *** aggregates of the complexes had an irregular shape and were large,as observed by scanning electron microscopy and transmission electron *** simulation was used to further investigate the interaction *** to these findings,the folic acid molecule interacted with zein in a shallow recess near the protein *** dominant forces at play in the zein–folic acid interaction were van der Waals forces and electrostatic forces,including hydrogen ***:The zein alkali-soluble system is very suitable for folic acid delivery.

关键词： Zein folic acid alkaline aqueous solutions molecular simulation interaction mechanism.

Berberine alleviates ovarian tissue damage in mice with hepatolenticular degeneration by suppressing ferroptosis and endoplasmic reticulum stress

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第4期22卷 493-502页

作者： Qian-zhuo Liu Hui Han xin-ru Fang Lu-yao Wang Dan Zhao Miao-zhu Yin Nian Zhang Peng-yu Jiang Zhi-hui Ji Li-min Wu Department of Neurology the First Affiliated Hospital of Anhui University of Chinese MedicineHefei 230031Anhui ProvinceChina Center for Reproduction and Genetics the First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230031Anhui ProvinceChina

Objective:Hepatolenticular degeneration (HLD) is an autosomal recessive disorder that manifests as multiorgan damage due to impaired copper (Cu) metabolism. Female patients with HLD often experience reproductive impairments. This study investigated the protective effect of berberine against ovarian damage in toxic-milk (TX) mice, a murine model for ***:Mice were categorized into control group, HLD TX group (HLD group), penicillamine (Cu chelator)-treated TX group and berberine-treated TX group. Body weight, ovary weight and the number of ovulated eggs were recorded. Follicular morphology and cellular ultrastructure were examined. Total iron, ferrous iron (Fe2+) and trivalent iron (Fe3+) levels, as well as malondialdehyde (MDA), glutathione(GSH) and oxidized glutathione (GSSG), were measured in the ovaries. Western blot analysis was used to analyze the expression of proteins related to ferroptosis and endoplasmic reticulum (ER) ***:Ovarian tissue damage was evident in the HLD group, with a significant increase in ferroptosis and ER stress compared to the control group. This damage was inhibited by treatment with penicillamine,a Cu chelator. Compared with the HLD group, berberine increased the number of ovulations, and improved ovarian morphology and ultrastructure. Further, we found that berberine reduced total iron,Fe2+, MDA and GSSG levels, elevated GSH levels, decreased the expression of the ferroptosis marker protein prostaglandin-endoperoxide synthase 2 (PTGS2), and increased glutathione peroxidase 4 (GPX4)expression. Furthermore, berberine inhibited the expression of ER stress-associated proteins mediated by the protein kinase RNA-like ER kinase (PERK) ***:Ferroptosis and ER stress are involved in Cu-induced ovarian damage in TX mice. Berberine ameliorates ovarian damage in HLD TX mice by inhibiting ferroptosis and ER stress.

关键词： Berberine Hepatolenticular degeneration Copper deposition Ferroptosis Endoplasmic reticulum stress

Volume-averaged modeling of multiphase solidification with equiaxed crystal sedimentation in a steel ingot

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 229-238页

作者： Xiao-lei zhu Shuang Cao Rui Guan Ji Yang Zhe Ning xin-gang Ai Sheng-li Li xin-cheng Miao The key Laboratory of Material Forming and Structure Property Control Anshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

Macrosegregation is a critical factor that limits the mechanical properties of *** impact of equiaxed crystal sedimentation on macrosegregation has been extensively studied,as it plays a significant role in determining the distribution of alloying elements and impurities within a *** improve macrosegregation in steel connecting shafts,a multiphase solidification model that couples melt flow,heat transfer,microstructure evolution,and solute transport was established based on the volume-averaged Eulerian-Eulerian *** this model,the effects of liquid phase,equiaxed crystals,columnar dendrites,and columnar-to-equiaxed transition(CET)during solidification and evolution of microstructure can be considered *** sedimentation of equiaxed crystals contributes to negative macrosegregation,where regions between columnar dendrites and equiaxed crystals undergo significant A-type positive macrosegregation due to the ***,noticeable positive macrosegregation occurs in the area of final solidification in the *** improvement in macrosegregation is beneficial for enhancing the mechanical properties of connecting *** mitigate the thermal convection of molten steel resulting from excessive superheating,reducing the superheating during casting without employing external fields or altering the design of the ingot mold is indeed an effective approach to control macrosegregation.

关键词： ingot casting multiphase solidification model equiaxed crystal sedimentation microstructure macrosegregation

Reorientation and obstacle avoidance control of free-floating modular robots using sinusoidal oscillator

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 262-275页

作者： Zhiyuan YANG Mingzhu LAI Jian QI Ning ZHAO xin SUI Jie ZHAO Yanhe zhu State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China

This paper presents that a serpentine curve-based controller can solve locomotion control problems for articulated space robots with extensive flight phases,such as obstacle avoidance during free floating or attitude adjustment before *** proposed algorithm achieves articulated robots to use closed paths in the joint space to accomplish the above *** snakes,which can shuttle through gaps and adjust their landing posture by swinging their body during gliding in jungle environments,inspired the design of two *** first maneuver generates a rotation of the system by varying the moment of inertia between the joints of the robot,with the magnitude of the net rotation depending on the controller *** maneuver can be repeated to allow the robot to reach arbitrary *** second maneuver involves periodic undulations,allowing the robot to avoid collisions when the trajectory of the global Center of Mass(CM)passes through the *** maneuvers are based on the improved serpenoid curve,which can adapt to redundant systems consisting of different numbers of ***,the simulation illustrates that combining the two maneuvers can help a free-floating chain-type robot traverse complex *** proposed algorithm can be used with similar articulated robot models.

关键词： Collision avoidance Modularrobots Reorientation Free-floating space robots Nonholonomic systems Biologically inspired controllers Serpenoid curve