检索结果-南通市图书馆

Stress relaxation properties of calcium silicate hydrate:a molecular dynamics study

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 97-115页

作者： Zhicheng GENG Shengwen TANG Yang WANG Hubao A zhen HE kai WU Lei WANG State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and EngineeringTongji UniversityShanghai200092China College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

The time-dependent viscoelastic response of cement-based materials to applied deformation is far from fully understood at the atomic *** silicate hydrate(C-S-H),the main hydration product of Portland cement,is responsible for the viscoelastic mechanism of cement-based *** this study,a molecular model of C-S-H was developed to explain the stress relaxation characteristics of C-S-H at different initial deformation states,Ca/Si ratios,temperatures,and water contents,which cannot be accessed *** stress relaxation of C-S-H occurs regardless of whether it is subjected to initial shear,tensile,or compressive deformation,and shows a heterogeneous *** plays a crucial role in the stress relaxation process.A large Ca/Si ratio and high temperature reduce the cohesion between the calcium-silicate layer and the interlayer region,and the viscosity of the interlayer region,thereby accelerating the stress relaxation of *** effect of the hydrogen bond network and the morphology of C-S-H on the evolution of the stress relaxation characteristics of C-S-H at different water contents was elucidated by nonaffine mean squared *** results shed light on the stress relaxation characteristics of C-S-H from a microscopic perspective,bridging the gap between the microscopic phenomena and the underlying atomic-level mechanisms.

关键词： Calcium silicate hydrate(C-S-H) Stress relaxation Ca/Si ratio Temperature Water content Atomic simulation

Reducing Operation Emissions and Improving Work Efficiency Using a Pure Electric Wheel Drive Tractor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2024年第6期37卷 230-245页

作者： Chang-kai Wen Wen Ren Qing-zhen Zhu Chun-Jiang Zhao zhen-Hao Luo Sheng-Li Zhang Bin Xie Zhi-Jun Meng Research Center of Intelligent Equipment Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China State Key Laboratory of Intelligent Agricultural Power Equipment Beijing 100097China BYD Company Limited Shenzhen 518118China College of Agricultural Engineering Jiangsu UniversityZhenjiang 212013China College of Engineering China Agricultural UniversityBeijing 100083China

In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction efficiency of conventional diesel tractors in the field,a purely electric wheel-side drive tractor was studied,including an electric motor drive system,a battery ballast system,and an electro–hydraulic suspension *** paper develops a dynamics model of an electric tractor-ploughing unit under complex soil conditions,leading to the proposal of an active control method for drive wheel torque and a joint control method for the traction force of the suspension system and the front-and rear-axle loads of a ***,the tractor is prototyped and assembled,and ploughing tests are carried *** ploughing results show that the active torque-distribution control method proposed in this study reduces the tractor slip by 14.83.and increases the traction efficiency by 10.28%compared with the average torquedistribution *** with the conventional traction control mode,the joint control method for traction and ballast proposed in this paper results in a 3.7%increase in traction efficiency,a 15.05%decrease in slip,and a 4.9%reduction in total drive motor energy *** study will help to improve the operation quality and traction efficiency of electric tractors in complex soil conditions.

关键词： Electric tractor Ploughing unit Torque distribution Active ballast Traction performance

Examining the evolution of tidal creeks in the Huanghe River delta using multi-temporal Landsat images

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 Oceanology and Limnology 2024年第4期42卷 1061-1073页

作者： zhen HAN kai JIN Quanli ZONG Peng QIN Chunxia LIU Xiuzhi ZHU Xinyue LI College of Resources and Environment Qingdao Agricultural UniversityQingdao 266109China

Coastal tidal creeks are important channels for exchanges of material and energy between sea and land,and play an important role in the ecological protection of tidal *** tidal creeks have evolved differently in various regions,the evolutionary process of tidal creeks in the Huanghe(Yellow)River delta of China,one of the most active deltas worldwide,is not entirely ***,the evolution of tidal creeks in the delta from 1981 to 2021 was investigated by quantitatively analysing the tidal creeks and developing a standard for dividing their evolution *** interpretation and supervised classification methods were applied to the Landsat images to extract the tidal creek network,and 17 groups of tidal creek systems were *** indicate that Creek S 1 was the most developed creek for having 113.tidal creeks totaling 65.8 km in length,while Creek E 3.had the fastest growth rate for having average annual increase of 1.9 ***,the level of tidal creeks increased,the average and median lengths of tidal creeks increased,and the number of tidal creeks decreased since *** evolution of the tidal creek system could be divided into four stages,namely,rising,developing,stabilizing,and *** of a representative tidal creek show that there was no degenerated tidal creek during the rising period,with an increase in the number of 50 and a length increase of 57.9 km between 1981 and *** proportion of new tidal creeks in the developing period was more than 50%and the new tidal creeks in the stabilizing period were equal to the degraded tidal *** tidal creeks were greater than 50%during the degrading *** was no fixed order of tidal creek evolution in each period,and there may be a skip in *** findings provided a reference for studying the evolution of tidal creeks.

关键词： tidal creek evolution pattern remote sensing Huanghe(Yellow)River delta

Strengthening effect of prefabrication(10-12)tensile twinning on AZ80+0.4%Ce magnesium alloy and inhibition mechanism of discontinuous precipitation

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第5期12卷 1918-1930页

作者： zhen Wang Xi Zhao Zhimin Zhang Yaojin Wu kai Chen Xianwei Ren Dengkui Wang Wei Wang School of Mechanical and Electrical Engineering North University of ChinaTaiyuan 030051China Engineering Technology Research Center for Integrated Precision Forming of Shanxi Province North University of ChinaTaiyuan 030051China

This paper provided an effective method to further improve the mechanical properties of the AZ80+0.4%Ce magnesium alloy wheel *** effect of high strength and ductility was obtained with a yield strength of 295.3. MPa,an elongation of 10%,by the combination of pre-deformation(7%deformation)and two-stage aging treatment(120℃/9 h+175℃/24 h).The evolution of the microstructure and properties of the alloy was explored under the coupling conditions of different pre-deformation degrees and multi-stage *** results show that,pre-deformation introduced a large number of(1012)tensile twinning and dislocations,which greatly promoted the probability of continuous precipitates(CPs)*** the contrary,the discontinuous precipitates(DPs)were limited by the vertical and horizontal twin *** a result,the pre-nucleation method of two-stage aging increased the proportion of CPs by 3.%-3.%.Owing to the DPs was effectively suppressed,the alloy's yield strength has been greatly ***,under multi-stage aging,the twin boundaries induce protruding nucleation to form static recrystallization by hindering the migration of dislocations,and the matrix swallows the twins,then the texture gradually tilts from the two poles to the basal *** an important supplement,the grain refinement and oblique texture promoted the improvement of the yield strength of the component.

关键词： Magnesium alloy Pre-deformed Two-stage aging Tensile twinning Continuous precipitates Texture

Differential bonding behaviors of sodium/potassium-ion storage in sawdust waste carbon derivatives

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第4期35卷 496-501页

作者： Jun-Ming Cao kai-Yang Zhang Jia-Lin Yang zhen-Yi Gu Xing-Long Wu MOE Key Laboratory for UV Light-Emitting Materials and Technology Northeast Normal UniversityChangchun 130024China Department of Chemistry Northeast Normal UniversityChangchun 130024China

Sodium-ion batteries(SIBs) and potassium-ion batteries(PIBs) are the most promising alternatives to lithium-ion batteries, and thus have drawn intensive research attention. Porous carbon materials from different precursors have been widely used as anode materials owing to their compatible storage effectiveness of both larger radii sodium and potassium ions. However, the differential bonding behaviors of Na and K ions with porous carbon-based anode are the significant one worth investigating, which could provide a clean picture of alkali ions storage mechanism. Therefore, in this work, we prepare a porous carbon network derived from sawdust(SDC) wastes, to further analyze the differences on sodium and potassium ions storage behaviors in terms of bond-forming process. It is found that, as-prepared SDC anodes could deliver stable sodium and potassium storage capacities, however, there are notable distinctions in terms of electrochemical behaviors and diffusion processes. By virtue of ex-situ XRD and Raman spectroscopy, the phase transition reaction of potassium ions could be well-observed, and the results shows that the multiple intercalated compounds was formed in SDC network during ions insertion, further resulting in slower diffusion kinetics and larger resistance compared to non-bonded process of sodium ions storage. This study provides more insights into the differences between sodium and potassium ions storage, as well as the energy storage mechanism of porous carbon as anodes for secondary batteries.

关键词： Porous carbon Sodium-ion storage Potassium-ion storage Bonding behaviors Batteries

Adsorption behavior of CO2/H2S mixtures in calcite slit nanopores for CO2 storage:An insight from molecular perspective

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2444-2456页

作者： Cheng Qian zhen-Hua Rui Yue-Liang Liu kai Du Chen Liu Yang Zhao Xiao-Min Ma State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum College of Petroleum Engineering China University of Petroleum College of Carbon Neutrality Future Technology China University of Petroleum College of Petroleum China University of Petroleum-Beijing at Karamay College of Mining Engineering Taiyuan University of Technology

It is acknowledged that injecting CO2into oil reservoirs and saline aquifers for storage is a practical and affordable method for *** CO2produced from industrial exhaust contains impurity gases such as H2S that might impact CO2sequestration due to competitive *** study makes a commendable effort to explore the adsorption behavior of CO2/H2S mixtures in calcite slit *** Canonical Monte Carlo（GCMC） simulation is employed to reveal the adsorption of CO2,H2S as well as their binary mixtures in calcite *** show that the increase in pressure and temperature can promote and inhibit the adsorption capacity of CO2and H2S in calcite nanopores,***2exhibits stronger adsorption on calcite surface than *** energy plays the dominating role in the adsorption *** energy accounts for 97.11% of the CO2-calcite interaction energy and 56.3.% of the H2S-calcite interaction energy at 10 MPa and 3.3.15 *** presence of H2S inhibits the CO2adsorption in calcite nanopores due to competitive adsorption,and a higher mole fraction of H2S leads to less *** quantity of CO2adsorbed is lessened by approximately 3.% when the mole fraction of H2S reaches ***2molecules preferentially occupy the regions near the po re wall and H2S molecules tend to reside at the center of nanopore even when the molar ratio of CO2is low,indicating that CO2has an adsorption priority on the calcite surface over *** addition,moisture can weaken the adsorption of both CO2and H2S,while CO2is more *** interestingly,we find that pure CO2is more suitable to be sequestrated in the shallower formations,i.e.,500-1500 m,whereas CO2with H2S impurity should be settled in the deeper reservoirs.

关键词： Adsorption behavior CO2/H2S binary mixtures Molecular perspective Calcite slit nanopores CO2 sequestration

Towards overcoming obstacles of type Ⅱ photodynamic therapy:Endogenous production of light,photosensitizer,and oxygen

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2024年第3期14卷 1111-1131页

作者： Lin Yu zhen Liu Wei Xu kai Jin Jinliang Liu Xiaohui Zhu Yong Zhang Yihan Wu Department of Chemical and Environmental Engineering Shanghai UniversityShanghai 200433China School of Medicine Shanghai UniversityShanghai 200433China Department of Biomedical Engineering City University of Hong KongHong KongChina

Conventional photodynamic therapy(PDT)approaches face challenges including limited light penetration,low uptake of photosensitizers by tumors,and lack of oxygen in tumor *** promising solution is to internally generate light,photosensitizers,and *** can be accomplished through endogenous production,such as using bioluminescence as an endogenous light source,synthesizing genetically encodable photosensitizers in situ,and modifying cells genetically to express catalase ***,these strategies have been reinforced by the recent rapid advancements in synthetic *** this review,we summarize and discuss the approaches to overcome PDT obstacles by means of endogenous production of excitation light,photosensitizers,and *** envision that as synthetic biology advances,genetically engineered cells could act as precise and targeted“living factories”to produce PDT components,leading to enhanced performance of PDT.

关键词： Photodynamic therapy Cancer Biogenesis Biosynthesis Engineered bacteria Phototherapy Photosensitizers Catalase

Designing silver niobate-based relaxor antiferroelectrics for ultrahigh energy storage performance

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第8期13卷 1282-1290页

作者： zhengdong Hu zhen Liu Bing Han Haonan Peng kai Da Zequan Xu zhengqian Fu Zhigao Hu Genshui Wang Key Laboratory of Inorganic Functional Materials and Devices Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Physics and Electronic Science East China Normal UniversityShanghai 200241China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China

AgNbO_(3.(AN)and modified AgNbO_(3. have been extensively investigated as promising lead-free antiferroelectric(AFE)energy storage *** studies have focused mainly on the use of an ion dopant at the A/B site to obtain a stabilized AFE phase;however,simultaneous improvements in the recoverable energy storage density(Wrec)and efficiency(n)are stll difficult to ***,we innovatively constructed a AgNbO_(3.-NaNbO_(3.-(Sr_(0.7)Bi_(0.2))TiO_(3.(AN-NN-SBT)ternary solid solution to achieve a relaxor AFE in AgNbO_(3.-based *** coexistence of antiferroelectric(M3.and paraelectric(O)phases in 0.8(0.7AgNbO_(3.-0.3.aNbO_(3.)-0.2(Sro.7Bio.2)TiO_(3. confirms the successful realization of a relaxor AFE,attributed to multiple ion occupation at the A/B ***,a high Wrec of 7.53.***^(-3. and n of 74.0% are acquired,together with superior stability against various temperatures,frequencies,and cycling ***,a high power density(298.7 MW·cm^(-3.)and fast discharge speed(41.4 ns)are also demonstrated for the AgNbO_(3.-based relaxor *** work presents a promising energy storage AgNbO_(3.-based ternary solid solution and proposes a novel strategy for AgNbO_(3.-based energy storage via the design of relaxor AFE materials.

关键词： AgNbO_(3.(AN)-based ceramics relaxor antiferroelectric(RAFE) paraelectric(PE) energy storage performance

High pressure phase boundaries of AgNbO_(3.

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 Materiomics 2024年第2期10卷 431-439页

作者： kai Dai Anyang Cui Yafang Li zhen Liu Yuting Yan kai Jiang Jinzhong Zhang Liyan Shang Liangqing Zhu Yawei Li Genshui Wang Zhigao Hu Technical Center for Multifunctional Magneto-Optical Spectroscopy(Shanghai) Engineering Research Center of Nanophotonics&Advanced Instrument(Ministry of Education)Department of PhysicsSchool of Physics and Electronic ScienceEast China Normal UniversityShanghai200241China Key Laboratory of Optoelectronic Material and Device Department of PhysicsShanghai Normal UniversityShanghai200234China Chongqing Key Laboratory of Precision Optics Chongqing Institute of East China Normal UniversityChongqing401120China Key Laboratory of Inorganic Functional Materials and Devices Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuanShanxi030006China

The external pressure is one of the essential parameters for regulating the structure and energy con-version properties of antiferroelectric AgNbO_(3..For pure AgNbO_(3.,however,there has been still a blank of its real lattice structure under the stress ***,high-pressure lattice structures and phase transitions of AgNbO_(3.have been explored by spectroscopic experiments and theoretical models.A successive phase transition process from Pbcm to C222_(1) to P2_(1) has been observed at the pressure range of 0-3. GPa,associated with displacive-type characterized by soft-mode *** that the paraelectric phase cannot be achieved under high-pressure at room ***,the competition of long-range Coulomb force,short-range interatomic interaction,and covalent interaction in AgNbO_(3.lattice were demonstrated under the stress *** present work can provide fundamental guidelines to reveal the high-pressure phase transitions of AgNbO_(3.,which will open up possibilities for the designing device with functional properties at extremes.

关键词： temperature. field. phase