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Geopolymers for stabilizing soils with diverse compositions
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作者 Peng ZHOU Heyuan WANG +3 位作者 Changjie XU Tao FANG Guoliang MA Hanlong LIU 《Science China(Technological Sciences)》 2026年第3期294-307,共14页
One of the research hotspots in geotechnical engineering is the solidification of problematic soil foundations. However, the traditional materials, such as Portland cement, lime, and various types of chemical solution... One of the research hotspots in geotechnical engineering is the solidification of problematic soil foundations. However, the traditional materials, such as Portland cement, lime, and various types of chemical solutions, typically cause CO_(2) emissions and environmental pollution. Geopolymer is a newly proposed method for soil solidification, offering an environmentally friendly and effective solution. Given that soils typically consist of diverse compositions, an optimal soil stabilization technique should be versatile enough to be applied across various soil types, ensuring consistent strength outcomes with minimal variations among different soil compositions. In this study, three commonly used geopolymers(fly ash, ground granulated blast-furnace slag, and metakaolin) were utilized to stabilize silt, loess, silica sand, calcareous sand, and gravel, representing a diverse range of soils. The mechanical properties and microstructures of both geopolymers and geopolymerstabilized soils were analyzed. The findings indicated that the strength of stabilized coarse cohesionless soils was primarily influenced by the mechanical properties of the geopolymers themselves, with minimal impact from the inherent properties of the soil. However, the effectiveness of stabilizing cohesive soil may show significant discrepancies compared to the mechanical properties of geopolymer materials when certain types of geopolymers, like metakaolin, are employed. Higher strength is typically achieved through a denser structure(with fewer pores) and the presence of products with a higher degree of polymerization. Additionally, ground granulated blast-furnace slag exhibited excellent stability and superior strength when compared to other types of geopolymers. The present research establishes a basis for selecting geopolymers to stabilize a range of soils, including those with non-uniform compositions and diverse components. 展开更多
关键词 soil stabilization GEOPOLYMER soils with diverse compositions STRENGTH MICROSTRUCTURE
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Transmedia seepage characteristics of slope-concrete stabilizing piles interface systems in cold regions 被引量:1
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作者 FENG Xue WANG Boxin +2 位作者 WANG Qing CHEN Huie FU Lanting 《Journal of Mountain Science》 2025年第3期1015-1028,共14页
Understanding the factors triggering slope failure is essential to ensure the safety of buildings and transportation infrastructure on slopes. Specifically,the failure of stabilizing piles due to groundwater migration... Understanding the factors triggering slope failure is essential to ensure the safety of buildings and transportation infrastructure on slopes. Specifically,the failure of stabilizing piles due to groundwater migration and freeze–thaw(FT) cycles is a significant factor causing slope failure. This study aims to investigate the transmedia seepage characteristics at slope–concrete stabilizing pile interface systems by using silty clay and concrete with varying microstructure characteristics under FT cycles. To this end, a self-developed indoor test device for transmedia water migration, combined with a macro-meso-micro multiscale testing approach, was used to analyze the laws and mechanisms of transmedia seepage at the interface systems. The effect of the medium's microstructure characteristics on the transmedia seepage behavior at the interface systems under FT cycles was also assessed. Results indicated that the transmedia water migration exhibited particularity due to the migration of soil particles and the low permeability characteristics of concrete. The water content in the media increased significantly within the range of 1/3–2/3 of the height from the interface for soil and within 5 mm from the interface for concrete.FT cycles promoted the increase and penetration of cracks within the medium, enhancing the permeability of the slope-concrete stabilizing pile interface systems.With the increase in FT cycles, the porosity inside the medium first decreased and then increased, and the porosity reached the minimum after 25 FT cycles and the maximum after 75 FT cycles, and the water content of the medium after water migration was positively correlated with the porosity. FT cycles also significantly influenced the temporal variation characteristics of soil moisture and the migration path of water in concrete. The study results could serve as a reference for related research on slope stability assessment. 展开更多
关键词 SLOPE Concrete stabilizing piles Interface systems Transmedia seepage Freeze–thaw cycles MICROSTRUCTURE
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Stabilizing the solid-solution sodium storage in Cr-substituted Na_(3)V_(2)(PO_(4))_(3) cathode for aqueous sodium-ion batteries with long-term stability 被引量:1
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作者 Qinyan Jian Tinghong Gao +4 位作者 Wensheng Yang Xinhai Wang Lishan He Jiarui Liu Yunjun Ruan 《Journal of Energy Chemistry》 2025年第6期797-805,I0016,共10页
Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials ... Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries. 展开更多
关键词 Na_(3)V_(2)(PO_(4))_(3) Cr substitution Insertion/extraction mechanism Long-term cycling stability Aqueous sodium-ion battery
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Stabilizing Cu^(+)active sites by small molecule modulation on copper electrocatalyst for boosting semi-hydrogenation of alkynes in water
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作者 Ran Li Hui Li +7 位作者 Jing Luo Jie Zhou Qi Sui Yujie Gao Hongshuai Zheng Lixin Xia Fei Li Yi Jiang 《Journal of Energy Chemistry》 2025年第3期800-807,共8页
Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme ch... Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme challenges due to the susceptibility of the copper cathode in a reduction environment.Herein,a small molecule modulation electrodeposition strategy is introduced that regulates the structure of Cubased materials through modification with citric acid(CA)ligands,aiming for highly active and selective ECSH.The as-prepared EDCu-CA electrode achieves more than 97%alkyne conversion and 99%olefin selectivity.In-situ Raman and Auger electron spectroscopy(AES)data provide evidence that active Cu^(+)sites can stably exist in the EDCu-CA during the catalytic process.Density functional theory(DFT)calculations indicate that the modulation by CA contributes to maintaining Cu in a positive valence state,and Cu^(+)can inhibit the over-hydrogenation of olefins.Moreover,by utilizing a large-area electrode for longterm electrolysis,g-level conversion and a 92%separation yield of olefin can be achieved,demonstrating a viable application prospect.This study offers a promising route for designing Cu-based catalysts for the highly selective electrocata lytic conversion of organic substrates to value-added chemicals in water. 展开更多
关键词 Electrocatalysis Cu catalysts Alkyne semi-hydrogenation Citric acid modulation stabilizing Cu^(+)
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What signals does 2025 Action Plan for Stabilizing Foreign Investment send to the textile industry?
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作者 Zhao Xinhua 《China Textile》 2025年第2期24-25,共2页
ln order to improve the level of investment promotion and redouble effortsto enhance services,on February l9th,the 2025 Action Plan for StabilizingForeign lnvestment was released,proposing 20 measures in four aspects.... ln order to improve the level of investment promotion and redouble effortsto enhance services,on February l9th,the 2025 Action Plan for StabilizingForeign lnvestment was released,proposing 20 measures in four aspects.Cur-rently,with increasing uncertainties in the external environment,China facesmultple difficulties and challenges in attracting foreign investment. 展开更多
关键词 stabilizing Foreign Investment Investment Promotion Service Enhancement Textile Industry enhance serviceson improve level investment promotion Action Plan action plan
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Pushing working voltage of nickel-rich cathode to 4.6 V by stabilizing lattice oxygen redox via spinel Li_(4)Mn_5O_(12)coating
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作者 Yunting Wang Gaohui Du +11 位作者 Di Han Jiahao Deng Weihao Shi Huayu Li Yongle Wang Siyao Wang Zhan Gao Youqing Wang Shixian Chen Wenqi Zhao Qingmei Su Bingshe Xu 《Journal of Energy Chemistry》 2025年第4期692-702,共11页
Augmenting the working voltage is an effective way to maximize the energy density of Ni-rich layered Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(NCM)to approach its theoretical capacity.However,NCM suffers from structural degra... Augmenting the working voltage is an effective way to maximize the energy density of Ni-rich layered Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(NCM)to approach its theoretical capacity.However,NCM suffers from structural degradation in deep delithiation state,which is often accompanied by severe surface lattice oxygen loss and transition metal dissolution,leading to restricted cycle life.Herein,a facile and effective surfacestrengthening strategy is proposed,in which Mn(OH)_(2)nanoshells are uniformly grown on the NCM surface as a Li~+capturer and then converted to thin spinel Li_(4)Mn_(5)O_(12)layers during subsequent hightemperature sintering.The resultant Li_(4)Mn_(5)O_(12)layers can enhance cathode-electrolyte interface electrochemical stability with inhibited electrolyte corrosion and accelerated Li~+kinetics.The theoretical calculations confirms that the Mn-O bonds formed at the interfaces can effectively decrease the oxygen activity,thereby further inhibiting the lattice oxygen release and structural degradation caused by the irreversible phase transition.Consequently,the Li_(4)Mn_(5)O_(12)-coated NCM displays high capacity retention of 80.3%and 94.9%at 1 C and 5 C compared to the pristine NCM(52.5%and 10.1%)after 200 cycles and can operate stably at 2.7-4.6 V and 60℃.The spinel Li_(4)Mn_(5)O_(12)-coating demonstrates an effective route to enhance the structural/electrochemical stability of NCM for next-generation advanced lithium-ion batteries. 展开更多
关键词 Ni-rich cathode Interfacial stability Li_(4)Mn_5O_(12)coating High voltage stability
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Stabilizing P2-phase in layered oxides via electronic modulation for high-performance sodium-ion batteries
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作者 Zhipeng Xu Yulei Ren +4 位作者 Zhihong Xiao Xiangze Kong Zhongyu Sun Qingyin Zhang Zhiqiang Shi 《Journal of Energy Chemistry》 2025年第12期877-885,I0019,共10页
P2-type layered oxides are highly promising cathode candidates for sodium-ion batteries(SIBs)owing to their substantial theoretical capacity.Nevertheless,structural degradation caused by transition metal dissolution a... P2-type layered oxides are highly promising cathode candidates for sodium-ion batteries(SIBs)owing to their substantial theoretical capacity.Nevertheless,structural degradation caused by transition metal dissolution and irreversible phase transitions at high voltage severely compromises cycling stability.To address this limitation,we propose a Li/Ti co-doping strategy to design a Na_(0.67)Li_(0.06)Ni_(0.27)Mn_(0.5)7Ti_(0.1)O_(2)(NLMT) cathode for SIBs.In-situ X-ray diffraction(XRD) confirms that this deliberate strategy eliminates the adverse phase transition at high voltage and sustains the unitary P2phase throughout cycling.In addition,strengthened transition metal-oxygen(TM-O) bonding via electronic modulation suppresses transition metal dissolution and reinforces the layered oxide framework,contributing to exceptional electrochemical performance.Consequently,the NLMT cathode exhibits an outstanding capacity of 92.8 mA h g^(-1) within 2.5-4.3 V at 5 C(865 mA g^(-1)),with 87 % capacity retention over 200 cycles.Configured into a full cell,which achieves a competitive capacity of 107.7 mA h g^(-1) at0.1 C and retains 86.4 % capacity over 100 cycles at 0.5 C.This study validates co-doping as a potent strategy for significantly improving the long-term cyclability of layered oxide cathodes in SIBs. 展开更多
关键词 Sodium-ion battery Layered oxide Phase transition Cycling stability
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Hybrid non-fragile attitude takeover control of modular spacecraft with communication delay
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作者 Ziyu YANG Yibo DING +1 位作者 Ran TAO Xiaokui YUE 《Chinese Journal of Aeronautics》 2025年第11期469-486,共18页
The modular design pattern revolutionizes the monolithic morphology of traditional spacecraft into the reconfigurable combination of modular units.However,due to the morphological changes,the effective takeover contro... The modular design pattern revolutionizes the monolithic morphology of traditional spacecraft into the reconfigurable combination of modular units.However,due to the morphological changes,the effective takeover control of the combination through multiple independent modules,including the controller and actuator modules,remains a challenge.In this paper,a robust takeover control scheme with high allocation accuracy,independent of precise inertia,is proposed for the reconfigurable combination in the presence of the inertia uncertainty,model parameters uncertainty,communication delay,and external disturbance.By reregulating the conditions for performance synthesis into a symmetric form with similar structure,a hybrid non-fragile H_(2)/H_(∞)controller is designed for handling two types of controller gain perturbations,achieving superior performance with less energy consumption through simultaneous perturbation suppression.Moreover,through temporarily storing the allocation signals in the initial stage to cover the upper bound of the communication delay,the proposed distributed dynamic allocation scheme enables the actuator modules to implement the control signals jointly to stabilize the combination.Distinguished from general allocators,the proposed high-precision allocation scheme under communication delay can not only ensure full exploitation of controller performance,but also dynamically adjust allocation coefficients based on energy consumption index of controller modules to prevent actuator saturation.Numerical simulations demonstrate the superiority of the proposed hybrid non-fragile controller and the allocation scheme. 展开更多
关键词 Attitude stabilization Communication delay Hybrid non-fragile Modular spacecraft takeover control
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Suppressing catalyst reconstruction in neutral electrolyte: stabilizing Co-O-Mo point-to-point connection of cobalt molybdate by tungsten doping for oxygen evolution reaction
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作者 Zhouzhou Wang Qiancheng Zhou +9 位作者 Li Luo Yaran Shi Haoran Li Chunchun Wang Kesheng Lin Chengsi Wang Libing Zhu Linyun Han Zhuo Xing Ying Yu 《Chinese Journal of Catalysis》 2025年第9期146-158,共13页
Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-dope... Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-doped cobalt molybdate(WDCMO)catalyst was synthesized for efficient and durable OER under neutral electrolyte.It is demonstrated that catalyst reconstruction is suppressed by W doping,which stabilizes the Co-O-Mo point-to-point connection in CoMoO_(4) architecture and stimulates to a lower valence state of active sites over the surface phase.Thereby,the surface structure maintains to avoid compound dissolution caused by over-oxidation during OER.Meanwhile,the WDCMO catalyst promotes charge transfer and optimizes*OH intermediate adsorption,which improves reaction kinetics and intrinsic activity.Consequently,the WDCMO electrode exhibits an overpotential of 302 mV at 10 mA cm^(-2) in neutral electrolyte with an improvement of 182 mV compared with CoMoO4 electrode.Furthermore,W doping significantly improves the electrode stability from 50 h to more than 320 h,with a suppressive potential attenuation from 2.82 to 0.29 mV h^(-1).This work will shed new light on designing rational electrocatalysts for neutral OER. 展开更多
关键词 Neutral oxygen evolution reaction Suppressive catalyst reconstruction Cobalt molybdate Tungsten doping Stability
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Double nano-emulsions for stabilizing Vitamin C and enhancing antioxidant capacity with macadamia oil and tea tree essential oil
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作者 Dinh Quan Nguyen Ngoc Thien Phuc Nguyen +4 位作者 Thi Trinh To Le Minh Dat Nguyen Thi Khanh Van Pham Gia Man Vu Long Phuoc Lieu 《Oil Crop Science》 2025年第3期177-185,共9页
Vitamin C,a potent antioxidant with broad therapeutic applications,is limited by rapid degradation under environmental stressors,which compromises its stability and bioactivity.This study addresses these limitations b... Vitamin C,a potent antioxidant with broad therapeutic applications,is limited by rapid degradation under environmental stressors,which compromises its stability and bioactivity.This study addresses these limitations by formulating a double nano-emulsion(W/O/W)system incorporating macadamia oil and tea tree oil,using homogenization and phase inversion temperature(PIT)techniques.Comprehensive physicochemical charac-terization,including droplet size,polydispersity index(PDI),zeta potential,turbidity,Fourier transform infrared spectroscopy(FTIR),and SEM,was conducted alongside stability assessments under varying pH,temperature,and storage conditions.The optimized nano-emulsions exhibited nanoscale droplet sizes(10-40 nm),low PDI values(indicating high uniformity),and robust stability.Interestingly,the formulation with 2%W/O loading,with a particle size of 11.57 nm and a PDI of 0.04,demonstrated an antioxidant capacity of 4622.62μg ascorbic acid equivalents(AA)/g,which was significantly higher(p<0.05)compared to both natural oils(macadamia oil:20.91μg AA/g,tea tree oil:16.86μg AA/g)and a 10%Vitamin C aqueous solution(592.94μg AA/g).FTIR analysis confirmed the molecular integrity of Vitamin C and its successful encapsulation with macadamia and tea tree oils,while SEM images revealed uniformly spherical and well-dispersed droplets.Moreover,the formulation retained its structural integrity and antioxidant functionality under diverse pH and thermal conditions.These findings underscore the potential of double nano-emulsion systems to overcome the stability challenges of Vitamin C,offering a promising approach to enhance its bioavailability and therapeutic performance in phar-maceutical and cosmetic applications. 展开更多
关键词 Double nano-emulsions Vitamin C stabilization Antioxidant capacity Macadamia oil Tea tree essential oil
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Stabilizing the dual electrode interface via a crosslinked gelatin nonwoven separator for durable lithium metal batteries
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作者 Weijie Cai Xinxin Han +8 位作者 Min Chen Haoyuan Chen Hao Wang Zhixiang Chen Mengmeng Shao Ke Zheng Wenlong Wang Rui Hong Xiaodong Shi 《Chinese Chemical Letters》 2025年第12期410-414,共5页
The uncontrollable dendrite growth of lithium anode and active material dissolution of transition metal oxides cathodes severely hinder the development of lithium metal batteries.An effective strategy to address these... The uncontrollable dendrite growth of lithium anode and active material dissolution of transition metal oxides cathodes severely hinder the development of lithium metal batteries.An effective strategy to address these issues is optimizing the separator to regulate ion transport and trap the lost active component.Herein,a crosslinked gelatin nonwoven(CGN)separator is elaborately fabricated through electrospinning and in-situ vapor phase crosslinking process to manipulate the dual electrode interface.Benefitting from the characteristic composition of gelatin,and porous structure of electrospun nonwoven,the CGN separator exhibits excellent interface wettability and low interface resistance,featuring a high Li^(+)transference number of 0.70 and high ionic conductivity of 3.75 m S/cm.As expected,the symmetrical Li/Li cells present stable cycling behavior for 1900 h at 0.5 mA/cm^(2)with low overpotential of 20 mV.The optimized LiMn_(2)O_(4)/Li cells deliver high reversible capacity of 103 m Ah/g as well as high capacityretention ratio of 83.7%after 100 cycles at 0.3 C,which can be effectively attributed to the strong interaction between CGN separator and Mn ions to prevent the loss of active Mn component.This study indicates the application potential of protein-based electrospun membrane for high-performance lithium metal batteries. 展开更多
关键词 Crosslinked gelatin nonwoven separator Dendrite growth Active material dissolution Dual-interface stability Lithium metal batteries
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Effects of stabilizing heat treatment on microstructures and creep behavior of Zn-10Al-2Cu-0.02Ti alloy 被引量:3
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作者 林高用 张锐 +2 位作者 王莉 雷玉霞 贺家健 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期86-91,共6页
The microstructures of as-extruded and stabilizing heat-treated Zn-10Al-2Cu-0.02Ti alloys were observed by scanning electron microscopy,transmission electron microscopy,electron probe microanalysis and X-ray diffracti... The microstructures of as-extruded and stabilizing heat-treated Zn-10Al-2Cu-0.02Ti alloys were observed by scanning electron microscopy,transmission electron microscopy,electron probe microanalysis and X-ray diffraction analysis techniques.The change in structure after heat treatment and its effects on room temperature creep behavior were investigated by creep experiments at constant stress and slow strain rate tensile tests.The results show that after stabilizing heat treatment((350℃,30 min,water-cooling)+(100℃,12 h,air-cooling)),the amount of α+η lamellar structure decreases,while the amount of cellular and granular structure increases.The heat-treated Zn-10Al-2Cu-0.02Ti alloy exhibits better creep resistance than the as-extruded alloy,and the rate of steady state creep decreases by 96.9% after stabilizing heat treatment. 展开更多
关键词 Zn-10Al-2Cu-0.02Ti alloy stabilizing heat treatment microstructure creep behavior
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INERTIAL INTEGRATED SYSTEM OF NORTH SEEKING/SIGHT STABILIZING ON VEHICLE 被引量:2
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作者 刘建业 徐珍 +1 位作者 杨莉 肖纪立 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2000年第2期157-162,共6页
A brand new method of automatic north seeking/sight stabilizing is introduced for usage in land fighting vehicles such as tank, etc. Some inertial devices are installed additionally on the platform along with relat... A brand new method of automatic north seeking/sight stabilizing is introduced for usage in land fighting vehicles such as tank, etc. Some inertial devices are installed additionally on the platform along with relative control circuits to make its function of North seeking possible. Double position calculation is adopted in this method, and by alignment at two sites the azimuth angle can be figured out. Also the orientation and the horizontal shifts of the gyro are simultaneously measured and compensated so as to improve the accuracy of north seeking. The system can automatically seek north when the vehicle is immobile. And the time consumption is no more than 5.5 min. Besides, the system can keep azimuth angle and provide tilt angle and pitch angle of the vehicle. 展开更多
关键词 north seeking sight stabilizing inertial platform shift measurement and compensation land fighting vehicle
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Dynamics of the perturbed Calogero-Moser system:well-posedness,stability and blow up
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作者 LIU Qianle WANG Zhong ZHU Weipeng 《中山大学学报(自然科学版)(中英文)》 北大核心 2026年第1期157-168,共12页
We investigate a class of non-integrable two-particle Calogero-Moser systems modulated by a power-law external potential.The local well-posedness of the Cauchy problem is established under the strict initial separatio... We investigate a class of non-integrable two-particle Calogero-Moser systems modulated by a power-law external potential.The local well-posedness of the Cauchy problem is established under the strict initial separation condition for the particles.For suitably prepared initial configurations,local solutions can be extended globally via energy conservation;conversely,negative energy conditions induce(in)finite-time blowup.The linear(in)stability of stationary solutions is analyzed,with their energy serving as a threshold.Numerical investigations employ a fourth-order Runge-Kutta scheme with adaptive step-size control.Simulations demonstrate that the trajectories either converge to steady states or exhibit blowup,depending on the power exponent α and initial conditions.Increasingαaccelerates the convergence rate and dampens oscillatory dynamics,promoting a transition from periodic behavior to static equilibrium. 展开更多
关键词 Calogero-Moser system WELL-POSEDNESS blow up STABILITY
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Systematic evaluation of reference gene stability across tissues and sexes in cuttlefish(Sepiella japonica)
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作者 LI Shuang GU Min +5 位作者 YE Xiaowen YE Bin LIU Siyu YU Jia ZHOU Xu CHI Changfeng 《水产学报》 北大核心 2026年第2期26-49,共24页
Quantitative real-time PCR(qPCR)is widely used for gene expression analysis,but its accuracy critically depends on stable internal reference genes for normalization.In marine invertebrates,especially non-model taxa su... Quantitative real-time PCR(qPCR)is widely used for gene expression analysis,but its accuracy critically depends on stable internal reference genes for normalization.In marine invertebrates,especially non-model taxa such as cephalopods,systematic evaluation of reference genes is limited,leading to potential bias.The cuttlefish Sepiella japonica is ecologically and economically important in China,yet previous molecular studies have often relied on single unvalidated reference genes,which may compromise data reliability.This study aimed to systematically evaluate the stability of five commonly used reference genes(18S,ef-1α,ef-1γ,gapdh,andβ-actin)across multiple tissues and sexes of S.japonica,and to identify the most suitable reference genes and optimal number for qPCR normalization.Fifteen to sixteen tissue types were collected from ten healthy adults(five males and five females).Total RNA was extracted,reverse-transcribed,and analyzed by qPCR.Gene stability was assessed using four algorithms(geNorm,NormFinder,BestKeeper,andΔCt)integrated with RefFinder,and the optimal gene number was determined using geNorm pairwise variation(V_(n/n+1)<0.15).Four transcriptome-derived genes(creld2,cd109,acy1,and miox)were used for validation.The C_(t)values of the five genes ranged from 15.47 to 20.83.β-actin and gapdh showed pronounced variability in expression stability among tissues and sexes,indicating their limited suitability for normalization.18S exhibited the highest expression(mean C_(t):15.47-16.29)and lowest variability but displayed sex-biased expression,whereas ef-1αand ef-1γremained consistently stable across most tissues in both sexes,with ef-1αbeing the most robust and showing no sex-related bias.Although specific rankings varied among tissues and sexes,the comprehensive results indicated that ef-1αand ef-1γpossessed the highest overall stability,followed by 18S,whileβ-actin and gapdh were the least stable.The final comprehensive rankings were ef-1γ>ef-1α>18S>gapdh>β-actin(male)and ef-1α>ef-1γ>18S>gapdh>β-actin(female).geNorm analysis(V2/3<0.15)indicated that two genes,mainly ef-1αand ef-1γ,were generally sufficient for reliable normalization in most tissues.Validation confirmed that normalization using the stable ef-1αand ef-1γaccurately reflected the expression differences among tissues,whereasβ-actin and gapdh can bias or confound statistical analyses.ef-1αand ef-1γare identified as the most reliable reference gene combination for qPCR analysis in S.japonica,while 18S can serve as an auxiliary gene for within-sex comparisons.The use ofβ-actin or gapdh alone is not recommended.This study establishes a systematic framework for selecting reliable reference genes in S.japonica,thereby facilitating robust qPCR normalization and providing a foundation for future gene expression research in S.japonica and other cephalopods. 展开更多
关键词 Sepiella japonica reference genes qPCR expression stability RefFinder
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Preparation of Ultrafine Copper Powders by Ethanol Solvothermal Method and Properties Study
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作者 XU Yite ZHANG Xiang +6 位作者 HE Junpeng WANG Keke CAO Lei ZHU Qian LIU Baixiong LIU Jianfeng XIONG Shixian 《有色金属(中英文)》 北大核心 2026年第1期31-39,共9页
The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing... The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing agent.Specifically,by exploiting the weak reducing property of ethanol,the copper precursor is first converted to copper oxide and then further reduced to cuprous oxide and pure copper.Such a method can effectively control the morphology and particle size of the copper powder,reduce particle aggregation,and enhance oxidation resistance.It is cost-effective and produces fewer toxic by-products.Spherical copper particles with an average particle size of about 180 nm were obtained.The initial oxidation temperature is approximately 150℃,and the resulting copper powders can be stored stably under ambient conditions for at least 5 months,demonstrating excellent oxidation resistance and thermal stability. 展开更多
关键词 alcohol-solvent heat ultrafine copper powder oxidation resistance thermal stability
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Ecological Dynamics of a Logistic Population Model with Impulsive Age-selective Harvesting
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作者 DAI Xiangjun JIAO Jianjun 《应用数学》 北大核心 2026年第1期72-79,共8页
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy... In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting. 展开更多
关键词 The logistic population model Selective harvesting Asymptotic stability EXTINCTION
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Manganese‑doped poly(1,5‑diaminonaphthalene)based high‑performance supercapacitors
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作者 XU Mengying LI Wen +5 位作者 MEI Junzhong ZHANG Cheng Palanisamy Kannan LU Lei ZHANG Lianpeng WANG Peng 《无机化学学报》 北大核心 2026年第2期387-397,共11页
Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport ... Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1). 展开更多
关键词 poly(1 5‑diaminonaphthalene) transition metal long‑cycle stability SUPERCAPACITOR
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U.K.Prime Minister’s China Visit Signals a Pragmatic Turn in Bilateral Relations
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作者 JOHN QUELCH 《China Today》 2026年第3期20-22,共3页
British Prime Minister Keir Starmer’s visit to China underscores economic cooperation and strategic stability amid global uncertainties.U.K.Prime Minister Keir Starmer’s visit to China in January marks a significant... British Prime Minister Keir Starmer’s visit to China underscores economic cooperation and strategic stability amid global uncertainties.U.K.Prime Minister Keir Starmer’s visit to China in January marks a significant shift of Britain toward a more pragmatic and stability-oriented approach in Sino-British relations.After years of political tensions and limited high-level engagement,this trip underscores London’s intent to rebuild ties based on mutual economic and strategic interests. 展开更多
关键词 economic cooperation economic cooperation strategic stability bilateral relations UK strategic stability China rebuild ties political tensions
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Underscoring the polyimide-linkage in covalent organic frameworks and related applications
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作者 Qi Li Minqiao Liang +5 位作者 Huifen Zhuang Zhengyang Chen Yuxiang Jiang Xiaofei Chen Yifa Chen Ya-Qian Lan 《Chinese Chemical Letters》 2026年第2期6-18,共13页
Polyimide-linkage covalent organic frameworks(PI-COFs),as a subclass of the COFs material family,featuring the unique combination of excellent thermal stability of polyimide,tunable pore sizes,as well as high crystall... Polyimide-linkage covalent organic frameworks(PI-COFs),as a subclass of the COFs material family,featuring the unique combination of excellent thermal stability of polyimide,tunable pore sizes,as well as high crystallinity and surface area of COFs,are expected to be a novel type of promising crystalline porous material with potential applications in adsorption and separation,catalysis,chemical sensing,and energy storage.Therefore,it is increasingly important to summarize polyimide-linkage in COFs and related applications and provide in-depth insight to accelerate future development.In this review,we offer a comprehensive overview of recent advancements in PI-COFs,emphasizing their synthesis methods,design principles and applications.Finally,our brief outlooks on the current challenges and future developments of PI-COFs are provided.Overall,this review aims to guide the recent and future development of PI-COFs. 展开更多
关键词 Covalent organic frameworks Polyimide-linkage Heteroatomic sites Chemical stability Thermal stability
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