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Smart heat isolator with hollow multishelled structures

Green Energy & Environment 2023年第4期8卷 1154-1160页

作者： Kun wang Lekai Xu Jiao wang Shaojun Zhang Yanlei wang Nailiang Yang Jiang Du dan wang Henan Province Industrial Technology Research Institute of Resources and Materials Zhengzhou UniversityZhengzhou450001China State Key Laboratory of Biochemical Engineering Key Laboratory of Science and Technology on Particle MaterialsInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou450000China University of Chinese Academy of Sciences 19A Yuquan RoadBeijing100049China Beijing Key Laboratory of Ionic Liquids Clean Process Institute of Process EngineeringChinese Academy of SciencesBeijing100190China

Safe, green and efficient industrial production has always been the pursuit of the chemical industry. Since thermal energy is the driving force for most of chemical reactions, an ideal reaction tank would have the capacity to automatically regulate heat conduction rate. In detail, this reaction tank should endow an ability that resists the heat loss when the reaction temperature is lower than the target, while accelerating the heat dissipation when the system is overheated. In this case, this smart reactor can not only minimize energy consumption but also reduce safety *** structures are known to reduce heat conductivity. Particularly, the hollow structure with multishells can provide more interfaces and thus further inhibit heat transmission, which would be more favorable for heat isolation. Step forward, by coupling HoMSs with temperature-sensitive polymer, a smart heat isolation material has been fabricated in this work. It performs as a good heat isolator at a relatively lower temperature. A heat insulation effect of 6.5℃ can be achieved for the TSPU/3S–TiO_(2)HoMSs with a thickness of 1 mm under the temperature field of 50℃.The thermal conductivity of composite material would be raised under overheating conditions. Furthermore, this composite displays an unusual two-stage phase transformation during heating. Benefiting from the unique multishelled structure, energy is found to be gradually guided into the hollow structure and stored inside. This localized heat accumulation enables the composite to be a potential coating material for intelligent thermal-regulator and site-defined micro-reactor.

关键词： Hollow multishelled structures Thermal insulation Smart material

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Optimal multi-photon entanglement concentration with the photonic Faraday rotation

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Chinese Physics B 2017年第2期26卷 56-62页

作者： Lan Zhou dan-dan wang Xing-Fu wang Shi-Pu Gu Yu-Bo Sheng College of Mathematics & Physics Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology (Ministry of Education) Nanjing University of Posts and Telecommunications Nanjing 210003 China College of Electronic Science and Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

We put forward an optimal entanglement concentration protocol（ECP） for recovering an arbitrary less-entangled multi-photon Greenberger–Horne–Zeilinger（GHZ） state into the maximally entangled GHZ state based on the photonic Faraday rotation in low-quality（Q） cavity. In the ECP, only one pair of less-entangled multi-photon GHZ state and one auxiliary photon are required, and the concentration task can be realized by local operations. Moreover, our ECP can be used repeatedly to further concentrate the discarded items of conventional ECPs, which can increase its success probability largely. Under the practical imperfect detection condition, our protocol can still work with relatively high success probability. This ECP has application potential in current and future quantum communication.

关键词： quantum communication entanglement concentration photonic Faraday rotation low-Q cavity

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Selective synthesis of triacetin from glycerol catalyzed by HZSM-5/MCM-41 micro/mesoporous molecular sieve

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Chinese Journal of Chemical Engineering 2019年第5期27卷 1073-1078页

作者： Jiangyong Liu Zihao wang Yunlin Sun Ruiqi Jian Panming jian dan wang School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou225002China School of Medicine Stanford UniversityStanfordCA 94304USA State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

HZSM-5/MCM-41 molecular sieve (H-ZM) catalysts with well-defined micro/mesoporous structures were synthesized and showed high performance for selective synthesis of triacetin via the esterification reaction of glycerol with acetic acid. The conversion of glycerol was demonstrated to be 100% and the triacetin selectivity was over 91%, which can be attributed to the synergistic effect regarding suitable acidic property, excellent diffusion efficiency and good stability derived from the combined advantages of microporous molecular sieve HZSM-5 and mesoporous molecular sieve MCM-41.

关键词： Mesoscale Porous materials Molecular sieve Triacetin Glycerol esterification

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Micro-macro fracture mechanism of heterogeneous granite in percussive drilling

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Petroleum Science 2023年第5期20卷 3131-3142页

作者： Wei-Ji Liu Yan-Fei wang Zhao-wang dan Xiao-Hua Zhu School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500SichuanChina Geothermal Energy Research Center Southwest Petroleum UniversityChengdu610500SichuanChina Powerchina Sinohydro Bureau 7 Co. LTDChengdu610500SichuanChina

The conventional rotary rock breaking method faces a technical bottleneck in improving the rate of penetration(ROP)in deep hard *** drilling is the most potential approach to increase rock-breaking efficiency and ***,the rock-breaking mechanism of percussive drilling is still unclear enough,especially the micro-fracture mechanism of rock under confining pressure(under lateral pressure and hydraulic pressure).In this paper,the impact rock breaking experiments by four kinds of Polycrystalline Diamond Compact(PDC)cutters are carried out using a drop-weight impact testing machine and an acoustic emission(AE)recording system,the influence of parameters such as cutter shape,rake angle,and impact energy on rock-breaking are systematically *** study includes a numerical simulation to examine the process of crack initiation,propagation,and cuttings formation during the impact process with the consideration of confining *** results show the conicalshaped cutter is the most aggressive with high breaking *** penetration depth of the cutter is mainly influenced by the impact energy and cutter shape than the rake angle of the *** exists critical impact energy makes the rock breaking efficiency the *** critical impact energy is about 40 J when using the conical-shaped cutter with a rake angle of 15°.The rock mainly failed in tensile mode,and the inter-grain crack is the main *** pressure can inhibit the formation of horizontal cracks,while lateral pressure can inhibit the formation of vertical cracks and reduce the proportion of tensile *** research results can provide some reference and basis for improving the rock-breaking efficiency in deep hard formations.

关键词： Percussive drilling PFC Rock fragmentation characteristics Rock breaking efficiency

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A General Strategy for Efficiently Constructing Multifunctional Cluster Fillers Using a Three-Fluid Nozzle Spray Drying Technique for Dental Restoration

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Engineering 2022年第1期8卷 138-147页

作者： dan-Lei Yang dan wang Hao Niu Rui-Li wang Mei Liu Fei-Min Zhang Jie-Xin wang Mei-Fang Zhu State Key Laboratory of Organic–Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Jiangsu Key Laboratory of Oral Diseases Department of ProsthodonticsAffiliated Hospital of StomatologyNanjing Medical UniversityNanjing 210029China

Multifunctional fillers are greatly required for dental resin composites(DRCs).In this work,a spray dryer with a three-fluid nozzle was applied for the first time to construct high-performance complex nanoparticle clusters(CNCs)consisting of different functional nanofillers for dental *** application of a three-fluid nozzle can effectively avoid the aggregation of different nanoparticles with opposite zeta potentials before the spray drying process in order to construct regularly shaped *** a SiO_(2)–ZrO_(2) binary system,the SiO_(2)–ZrO_(2) CNCs constructed using a three-fluid nozzle maintained their excellent mechanical properties((133.3±4.7)MPa,(8.8±0.5)GPa,(371.1±13.3)MPa,and(64.5±0.7)HV for flexural strength,flexural modulus,compressive strength,and hardness of DRCs,respectively),despite the introduction of ZrO_(2) nanoparticles,whereas their counterparts constructed using a two-fluid nozzle showed significantly decreased mechanical ***,heat treatment of the SiO_(2)-ZrO_(2) CNCs significantly improved the mechanical properties and radiopacity of the *** DRCs containing over 10%mass fraction ZrO_(2) nanoparticles can meet the requirement for radiopaque *** importantly,this method can be expanded to ternary or quaternary *** filled with SiO_(2)-ZrO_(2)-ZnO CNCs with a ratio of 56:10:4 displayed high antibacterial activity(antibacterial ratio>99%)in addition to excellent mechanical properties and ***,the three-fluid nozzle spray drying technique holds great potential for the efficient construction of multifunctional cluster fillers for DRCs.

关键词： Multifunctional cluster fillers Three-fluid nozzle spray drying Mechanical properties Antibacterial activity Radiopacity Dental resin composites

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CURVATURE-BASED INTERACTION POTENTIAL BETWEEN MICRO/NANO PLANAR CURVE AND PARTICLE LOCATED OUTSIDE THE CURVE

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Acta Mechanica Solida Sinica 2015年第4期28卷 331-346页

作者： Xugui wang Yajun Yin Jiye Wu Kun Huang dan wang Qinshan Fan Department of Engineering Mechanics School of Aerospace Tsinghua University

Based on the negative exponential pair-potential （I/R）n, the interaction potential between the micro/nano planar curve and the particle located outside the curve is studied. We verified that, whatever the value of exponent n may be the potential of particle/plane-curve is always of unified curvature form. Furthermore, we proved that the driving forces acted on the particle may be induced by the highly curved micro/nano curve, and the curvature and gradient of curvature are confirmed to be the essential factors forming the driving force. Through the idealized numerical experiments, the accuracy and reliability of the curvature-based potential are examined.

关键词： micro/nano planar curve curvature-based potential driving force curvature andthe gradient of curvature

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Regioselective synthesis of α-bromo-α,β-unsaturated carbonyl compounds via photocatalytic α-bromination reactions

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Science China Chemistry 2016年第2期59卷 190-194页

作者： dan wang Yating Zhao Chao Yang Wujiong Xia State Key Laboratory of Urban Water Resource and Environment Shenzhen Graduate School Harbin Institute of Technology

A visible light-mediated approach for the preparation of α-bromo-α,β-unsaturated ketones and aldehydes was developed. In comparison to traditional methods that generally take two steps to afford the above compounds, this protocol was highlighted by its operational simplicity, avoiding using hazardous bromine and mild reaction conditions.

关键词： visible light α-bromination α β-unsaturated ketones and aldehydes operational simplicity

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Probabilistic total transfer capability analysis based on static voltage stability region integrated with a modified distributed-level nodal-loading model

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Science China(Technological Sciences) 2015年第12期58卷 2072-2084页

作者： wang dan ZHOU Yue JIA HongJie wang ChengShan LU Ning FAN MengHua Key Laboratory of Smart Grid of Ministry of Education Tianjin University Department of Electrical and Computer Engineering North Carolina State University State Grid Energy Research Institute

In this paper, a new evaluation method of probabilistic TTC based on SVSR calculation is developed through a hierarchical simulation. A smooth technology based on the non-parametric kernel estimator is adapted to obtain the time-dependent probabilistic density function of the feeder-head load data. In order to describe possible operating change directions of the operating point, the original hyper-cone-like(HCL) model is constructed to consider the probabilistic distribution function(PDF) extracted from feeder-head load data to replace the simple Normal Distribution model and the uncertain generator outputs. To realize the fast TTC calculation of the current operating point in random conditions, a sub-hyper-cone-like(SHCL) model in full power injections space is proposed, which is a similarity transformation of the original one.

关键词： voltage stability enhancement demand response demand-side management indirect load control heat pump regulation service

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High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersion with high solids content

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Frontiers of Chemical Science and Engineering 2020年第6期14卷 1087-1099页

作者： Weihong Zhang dan wang Jie-Xin wang Yuan Pu Jian-Feng Chen State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Centre of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China

In this work,we developed a continuous preparation strategy for the production of high-solidscontent waterborne polyurethane(WPU)emulsions via high-gravity-assisted emulsification in a rotating packed bed(RPB)*** adjusting the experimental parameters and formula,WPU emulsions with a high solids content of 55%and alow viscosity were *** applications of the high-solids-content WPU as a thermally insulating material were *** emulsification is an economical and environmentally friendly production strategy because of the low energy consumption,short emulsification time,and effective *** study demonstrated an effective method for preparation of high-solids-content WPU,moving toward commercialization and industrialization.

关键词： waterborne polyurethane rotating packed bed emulsification nanodispersion high solids content

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Channel Capacity Optimization Based on Riemannian Trust Region Algorithm in IRS-Aided Communication System

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China Communications 2022年第10期19卷 21-37页

作者： Jinzhi Liu dan wang Jiamin Liang Zhiqiang Mei College of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Intelligent Reflecting Surface (IRS) can offer unprecedented channel capacity gains since it can reconfigure the signal propagation environment. We decide to maximize the channel capacity by jointly optimizing the transmit-power-constrained precoding matrix at the base station and the unit-modulus-constrained phase shift vector at the IRS in IRS-assisted multi-user downlink communication. We first convert the resulting non-convex problem into an equivalent problem, then use the alternate optimization algorithm. While fixing the phase shift vector, we can obtain the optimal precoding matrix directly by adopting standard optimization packages. While fixing the precoding matrix, we propose the Riemannian Trust-Region (RTR) algorithm to solve this optimization problem. And the key of the RTR algorithm is the solution of the trust-region sub-problem. We first adopt the accurate solution based on Newton's (ASNT) method to solve this sub-problem, which can obtain the global solution but cannot guarantee that the solution is optimal since the initial iteration point is difficult to choose. Then, we propose the Improved-Polyline (IPL) method, which can avoid the difficulty of the ASNT method and improve convergence speed and calculation efficiency. The numerical results show that the RTR algorithm has more significant performance gains and faster convergence speed compared with the existing approaches.

关键词： intelligent reflecting surface(IRS) multi-user MIMO channel capacity unit modulus constraint Riemannian manifold optimization

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