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Selective synthesis of the B_(11)H_(14)^(-) and B_(12)H_(12)^(2-) borane derivatives and the general mechanisms of the B-H bond condensation

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Science China Chemistry 2024年第3期67卷 876-881页

作者： Yi Jing xinghua Wang Hui Han xin-ran liu xing-Chao Yu Xi-Meng Chen Donghui Wei Lai-Sheng Wang Xuenian Chen College of Chemistry Green Catalysis CenterZhengzhou UniversityZhengzhou 450001China School of Chemistry and Chemical Engineering Henan Key Laboratory of Boron Chemistry and Advanced Energy MaterialsHenan Normal UniversityXinxiang 453007China Department of Chemistry Brown UniversityProvidenceRI 02912USA

Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic ***,the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B-H bond condensation reaction,critical for the synthesis of the polyhedral boranes,is not well *** we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate(1-)(B_(11)H^(-)_(14)) and dodecahydrido-dodecaborates(2-)(B_(12)H_(12)^(2-)) anions by employing commercially available and inexpensive starting *** theoretical and experimental investigations are carried out to elucidate the reaction *** have found that the nature of the B-H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens(bridged hydrogens) play a crucial *** current study has not only led to more effective and selective synthetic methods for B_(11)H^(-)_(14) and B_(12)H_(12)^(2-) but also unveiled the nature of the B-H bond condensation and the general formation mechanisms of polyhedral *** finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.

关键词： Boranes polyhedral boranes dihydrogen bond nucleophilicity

LES investigation of the tip vortex cavitating flow with special emphasis on the interaction between cavitation and vorticity by a modified cavitation model

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水动力学研究与进展B辑:英文版 2023年第3期35卷 594-606页

作者： xin-ran liu Tao Wang Xiao-yang Zhao Tai-ran Chen School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Vehicle Engineering Department Army Academy of Armored ForcesBeijing 100072China China Ship Research and Development Academy Beijing 100085China

Cavitation within the tip vortex(TV)flow remains a challenging issue in the design of high-speed and low-noise hydraulic *** this paper,the TV cavitating flow around an elliptical hydrofoil is calculated by using large eddy simulation(LES)combined with a modified Schnerr-Sauer(S-S)cavitation *** original S-S cavitation model is modified by taking into account the typical effect of vortex *** partial pressure term which can describe the vortex quantitatively and qualitatively is confirmed asρ_(m)ω^(2) x r _(c)^(2) ,and is considered into the R-P equation of the modified S-S cavitation *** between the numerical and experimental results shows good agreement in the form and evolution of cavities,including attached cavities(AC)and tip vortex cavities(TVC).The vorticity transport equation is utilized to investigate the dynamic mechanisms of the vortex development around the *** analyses indicate that cavitation in the TV flow influences the pressure in the core of the cavity and the local flow *** vortex structures in the TV cavitating flow include TV,secondary vortex(SV)and wake vortex(WV).The direction and magnitude of the rotation effect can be described by axial vorticity which is drawn on the iso-surface of Q=1×105 s−*** development of the TV cavitating flow can be divided into two stages:Stage I,the development and fusion of TV,SV,stage II,the dissipation of *** stretching term dominates the evolution of TV,and the dilatation term is the main reason in the mergence process of SV.

关键词： Cavitating flow tip vortex(TV) large eddy simulation(LES) cavitation model

Time and Temperature Dependence of the Structural Evolution for Polyamide 1012

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Chinese Journal of Polymer Science 2020年第9期38卷 993-998,I0007页

作者： xin-ran liu Yu Wang Li-Yuan liu Xia Dong Du-Jin Wang CAS Key Laboratory of Engineering Plastics CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China

The rheological property evolution of polyamide 1012(PA1012)in the isothermal process in molten state has been *** results show that the viscosity increases and crosslinking reaction occurs simultaneously together with the increase of temperature,thus causing the variation of storage modulus(G')and loss modulus(G")in the repeated frequency sweeps with residual *** research has pointed out that the superposition is valid for monitoring the complex behavior composed of the viscosity increasing and crosslink occurring process by tracing the variation behavior of the crossover points of G'and G"with time,revealing the same time-temperature dependence of the two reactions in the isothermal process.A normalized master curve has been proposed to describe the melt behavior at a given temperature.

关键词： Polyamide 1012 Rheology Crosslinking Viscosity increasing Time-temperature superposition

Effects of Ferulic Acid on Regulating the Neurovascular Unit:Implications for Ischemic Stroke Treatment

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World Journal of Traditional Chinese Medicine 2022年第2期8卷 210-217页

作者： Xiang Wang xin-ran liu Ke-xin Li Xiang Fan Yang liu Graduate School Tianjin University of Traditional Chinese MedicineTianjinChina School of Chinese Materia Medic Tianjin University of Traditional Chinese MedicineTianjinChina Zhejiang Chinese Medical University ZhejiangChina Chinese Medical College Tianjin University of Traditional Chinese MedicineTianjinChina

Ferulic acid(FA)is a phenolic phytochemical with antioxidant and anti-inflammatory pharmacological *** recent years,the neuroprotective effects of FA have been studied *** researchers have attempted to use FA to prevent and treat neurological diseases and have made some *** paper mainly collated the study of the protective effect of FA on stroke and summarized the protective effect of FA on ischemic stroke and the potential protective effects of FA on neurovascular units.

关键词： Ferulic acid ischemic stroke neuroprotective effects neurovascular unit

Self-adaptive hydrogel for breast cancer therapy via accurate tumor elimination and on-demand adipose tissue regeneration

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Chinese Chemical Letters 2024年第1期35卷 371-378页

作者： ran Tian xinyu Qiu Wenyun Mu Bolei Cai Zhongning liu Shiyu liu xin Chen School of Chemical Engineering and Technology Department of Chemical EngineeringShaanxi Key Laboratory of Energy Chemical Process IntensificationXi'an Jiao Tong UniversityXi'an 710049China School of Stomatology State Key Laboratory of Military Stomatology&National Clinical Research Center for Oral Diseases&Shaanxi Clinical Research Center for Oral DiseasesDepartment of Preventive DentistryThe Fourth Military Medical UniversityXi'an 710032China School of Stomatology State Key Laboratory of Military StomatologyDepartment of Oral and Maxillofacial SurgeryThe Fourth Military Medical UniversityXi'an 710032China Department of Prosthodontics Peking University School and Hospital of StomatologyNational Clinical Research Center for Oral DiseasesNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital StomatologyBeijing 100081China School of Stomatology State Key Laboratory of Military StomatologyNational Clinical Research Center for Oral DiseasesShaanxi International Joint Research Center for Oral DiseasesCenter for Tissue EngineeringThe Fourth Military Medical UniversityXi'an 710032China

The irregular defects and residual tumor tissue after surgery are challenges for effective breast cancer ***,a smart hydrogel with self-adaptable size and dual responsive cargos release was fabricated to treat breast cancer via accurate tumor elimination,on-demand adipose tissue regeneration and effective infection *** hydrogel consisted of thiol groups ended polyethylene glycol(SH-PEG-SH)and doxorubicin encapsulated mesoporous silica nanocarriers(DOX@MSNs)double crosslinked hyaluronic acid(HA)after loading of antibacterial peptides(AP)and adipose-derived stem cells(ADSCs).A pH-cleavable unsaturated amide bond was pre-introduced between MSNs and HA frame to perform the tumor-specific acidic environment dependent DOX@MSNs release,meanwhile an esterase degradable glyceryl dimethacrylate cap was grafted on MSNs,which contributed to the selective chemotherapy in tumor cells with over-expressed *** bond cleavage between MSNs and HA would also cause the swelling of the hydrogel,which not only provide sufficient space for the growth of ADSCs,but allows the hydrogel to fully fill the irregular defects generated by surgery and residual tumor atrophy,resulting in the on-demand regeneration of adipose ***,the sustained release of AP could be simultaneously triggered along with the size change of hydrogel,which further avoided bacterial infection to promote tissue regeneration.

关键词： Smart hydrogel with self-adaptable size Breast cancer therapy Dual responsive cargoes release Selective tumor elimination On-demand adipose tissue regeneration Effective bacteria inhibition

Quantum control for time-dependent noise by inverse geometric optimization

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 51-57页

作者： Xiaodong Yang Yingcheng Li ran liu xinfang Nie Tao xin Dawei Lu Jun Li Institute of Quantum Precision Measurement State Key Laboratory of Radio Frequency Heterogeneous IntegrationCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China State Key Laboratory of Surface Physics Department of PhysicsCenter for Field Theory and Particle Physicsand Institute for Nanoelectronic Devices and Quantum ComputingFudan UniversityShanghai 200433China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen 518045China

Quantum systems are exceedingly difficult to engineer because they are sensitive to various types of *** particular,timedependent noises are frequently encountered in experiments but how to overcome them remains a challenging *** this work,we propose a flexible robust control technique to resist time-dependent noises based on inverse geometric optimization working in the filter-function *** basic idea is to parameterize the control filter function geometrically and minimize its overlap with the noise spectral *** then effectively reduces the noise susceptibility of the controlled system *** show that the proposed method can produce high-quality robust pulses for realizing desired quantum evolutions under realistic noise ***,we demonstrate this method in examples including dynamical decoupling and quantum sensing protocols to enhance their performances.

关键词： time-dependent noise robust control quantum gates and states dynamical decoupling quantum sensing

Prediction for permeability index of blast furnace based on VMD-PSO-BP model

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Journal of Iron and Steel Research International 2024年第3期31卷 573-583页

作者： Xiao-jie liu Yu-jie Zhang xin Li Zhi-feng Zhang Hong-yang Li ran liu Shu-jun Chen School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina Chengde Branch HBIS Group Co.Ltd.Chengde 067000HebeiChina

The permeability index is one of the important production indicators to monitor the operation of blast *** is crucial to grasp the trends of changes in the new permeability index in *** the complex vibration spectrum of the permeability index,a prediction model of the permeability index based on the VMD-PSO-BP(variational mode decomposition-particle swarm optimization-back propagation)method was ***,the key factors that affect the permeability index of blast furnace were studied from multiple ***,the permeability index was divided into multiple sub-modes based on the difference of frequency bands by the VMD algorithm,and a PSO-BP prediction model was established for each ***,the prediction results of each sub-mode were summed to obtain the final *** results show that the composite prediction accuracy by using the VMD algorithm is 3%higher than that of the traditional prediction method,which has better applicability.

关键词： Big data-Blast furnace Air permeability Variational mode decomposition Particle swarm optimization Back propagation Model prediction

MFCC based real-time speech reproduction and recognition using distributed acoustic sensing technology

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Optoelectronics Letters 2024年第4期20卷 222-227页

作者： ZHOU ran ZHAO Shuai LUO Mingming MENG xin MA Jie liu Jianfei School of Electronic Information Engineering Hebei University of TechnologyTianjin 300401China Tianjin Key Laboratory of Electronic Materials and Devices Hebei University of TechnologyTianjin 300401China Hebei Key Laboratory of Advanced Laser Technology and Equipment Hebei University of TechnologyTianjin 300401China

The distributed acoustic sensing technology was used for real-time speech reproduction and recognition,in which the voiceprint can be extracted by the Mel frequency cepstral coefficient(MFCC)method.A classic ancient Chinese poem“You Zi Yin”,also called“A Traveler’s Song”,was analyzed both in time and frequency domains,where its real-time reproduction was achieved with a 116.91 ms time *** smaller scaled MFCC0 at 1/12 of MFCC matrix was taken as a feature vector of each line against the ambient noise,which provides a recognition method via cross-correlation among the 6 original and recovered verse *** averaged cross-correlation coefficient of the matching pairs is calculated to be 0.5806 higher than 0.1883 of the nonmatched pairs,promising an accurate and fast method for real-time speech reproduction and recognition over a passive optical fiber.

关键词： MFCC passive coefficient

Tracked robot with underactuated tension-driven RRP transformable mechanism:ideas and design

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Frontiers of Mechanical Engineering 2024年第1期19卷 85-104页

作者： ran XU Chao liu School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Key Laboratory of Vehicle Advanced Manufacturing Measuring and Control Technology(Ministry of Education)Beijing Jiaotong UniversityBeijing 100044China

Robots with transformable tracked mechanisms are widely used in complex terrains because of their high adaptability,and many studies on novel locomotion mechanisms have been conducted to make them able to climb higher *** underactuated transformable mechanisms for tracked robots could decrease the number of actuators used while maintaining the flexibility and obstacle-crossing capability of these robots,and increasing their cost ***,the underactuated tracked robots have appreciable research *** this paper,a novel tracked robot with a newly proposed underactuated revolute‒revolute‒prismatic(RRP)transformable mechanism,which is inspired by the sit-up actions of humans,was *** newly proposed tracked robot has only two actuators installed on the track pulleys for moving and does not need extra actuators for ***,it could concentrate the track belt’s tension toward one side,and the unbalanced tension would drive the linkage mechanisms to change its *** this method,the proposed underactuated design could change its external shape to create support points with the terrain and move its center of mass actively at the same time while climbing obstacles or crossing other kinds of terrains,thus greatly improving the climbing capability of the *** geometry and kinematic relationships of the robot and the crossing strategies for three kinds of typical obstacles are *** the basis of such crossing motions,the parameters of links in the robot are designed to make sure the robot has sufficient stability while climbing ***-crossing dynamic simulations were run and analyzed to prove the feasibility of the robot.A prototype was built and *** show that the proposed robot could climb platforms with heights up to 33.3%of the robot’s length or cross gaps with widths up to 43.5%of the robot’s length.

关键词： mechanical design tracked robot underactuated mechanisms RRP mechanism obstacle crossing strategy