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Asymmetric Hydrogenation of Phenanthridines with Chiral Boranes

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Chinese Journal of Chemistry 2024年第6期42卷 631-635页

作者： Guangyu cui Xiangqing feng Haifeng Du Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionInstitute of ChemistryChinese Academy of SciencesBeijing100190 China University of Chinese Academy of Sciences Beijing100049 China

The asymmetric hydrogenation of N-heteroarenes provides an efficient method for the synthesis of optically active cyclic secondary *** this paper,we described an asymmetric hydrogenation of phenanthridines using a chiral mono-alkene-derived borane.A variety of dihydrophenanthridines were furnished in high yields with up to 93%*** current catalytic system was very sensitive for the steric hindrance of *** substituents at one phenyl group of phenanthridines were required to obtain the high *** large substituents on the carbon of the C=N bonds would diminish the reactivity sharply.

关键词： Asymmetric catalysis Hydrogenation Nitrogen heterocycles Phenanthridines Frustrated Lewis pairs Chiral boranes

Pre-reduction of WO_(3)-Co_(3)O_(4)by H_(2)-C_(2)H_4 in a fluidized bed

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Chinese Journal of Chemical Engineering 2024年第2期66卷 273-284页

作者： Huijun Shang Hengli Li Weijun Li feng Pan zhan Du State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China College of Chemical Engineering Nanjing Technology UniversityNanjing 211816China School of Chemistry and Chemical Engineering Shihezi UniversityShihezi 832003China College of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Chinalco Environmental Protection and Energy Conservation Group Co. Ltd.Xiong’an 071700China

In order to avoid the formation ofηphase(W_(6)Co_(6)C or W_(3)Co_(3)C)that adversely affects the sintering process and its products in the preparation process of ultra-fine WC-Co powder,a technical route of prereduction of WO_(3)-Co_(3)O_(4)to WO_(2)-Co and then deep reduction carbonization to WC-Co powder has been *** study mainly investigates the influence of gas partial pressure on the pre-reduction process of WO_(3)-Co_(3)O_(4)under a mixed atmosphere of H_(2)-C_(2)H_(4)-Ar at 600℃and establishes the kinetic equations of pre-reduction and carbon *** results indicate that increasing the partial pressure of hydrogen is conducive to the rapid and complete conversion of WO_(3) to WO_(2).High carbon content can be generated by the deposition of C_(2)H_(4),and it hinders the diffusion of the reducing gas;WO_(3)still cannot be completely reduced to WO_(2)as the partial pressure of C_(2)H_(4) increases to 60%.For the carbon evolution of C_(2)H_(4),the carbon amount is positively related to the H_(2)partial pressure,but it shows the highest amount and evolution rate when the ethylene partial pressure is 20%.Based on the reduction rate curves of WO_(3) and carbon evolution rate curves of C_(2)H_(4),the rate equations of pre-reduction and carbon evolution of WO_(3)-Co_(3)O_(4)system at 600℃are *** pre-reduction reaction belongs to the first-order reaction,and its equation is expressed as follows:r=-(dw_(WO_(3)))/dt=(9±0.15)×10^(-2)×P_(H_(2))^(0.44)P_(C_(2)H_(4))&(0.57)The carbon deposition rate equation of C_(2)H_(4) can be expressed as follows:r=-(dc_C)/dt=r_f-r_b≌7.35×10^(-2)×P_(C_(2)H_(4))^(0.31)

关键词： Fluidization WO_(3)-Co_(3)O_(4) Reduction Carbon deposition Rate equation

A Piezoelectrically Driven Microrobot Using a Novel Monolithic Spatial Parallel Mechanism as Its Hip Joint

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Journal of Bionic Engineering 2024年第2期21卷 803-820页

作者： Guangping Wu Ziyang Wang Jiaxin Zhao feng cui Xinghan Cai National Key Laboratory of Advanced Micro and Nano Manufacture Technology Shanghai Jiao Tong UniversityShanghai200240China Department of Micro-Nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai200240China

Inspired by the fast,agile movements of insects,we present a 1.9 g,4.5 cm in length,piezoelectrically driven,quadrupedal *** microrobot uses a novel spatial parallel mechanism as its hip joint,which consists of two spatially orthogonal slider-crank *** mechanism maps two inputs of two independent actuators to the decoupled swing and lift outputs of a leg,and each leg can produce the closed trajectories in the sagittal plane necessary for robot ***,the kinematics of the transmission are analyzed,and the parameters of the flexure hinges are designed based on geometrical constraints and yield *** hip joints,legs and exoskeletons are integrated into a five-layer standard laminate for monolithic fabrication which is composed of two layers of carbon fiber,two layers of acrylic adhesive and a polyimide *** measured output force(15.97 mN)of each leg is enough to carry half of the robot’s weight,which is necessary for the robot to move *** has been proven that the robot can successfully perform forward and turning *** to the microrobot fabricated with discrete components,the monolithically fabricated microrobot is more capable of maintaining the original direction of locomotion when driven by a forward signal and has a greater speed,whose maximum speed is 25.05 cm/s.

关键词： Insect-like Crawling microrobot Piezoelectric drive Parallel mechanism Monolithic fabrication

Dual-aligned porous electrodes for enhanced hydrogen evolution in alkaline water electrolysis

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Nano Research 2024年第5期17卷 3835-3843页

作者： Yuqi zhang Wenzhi cui Longjian Li Chongbo Wang Chen zhan Xiaojun Quan School of Energy and Power Engineering Chongqing UniversityChongqing 400030China Key Laboratory of Low-grade Energy Utilization Technologies and Systems Chongqing UniversityChongqing 400030China School of Mechanical Engineering Shanghai Jiao-Tong UniversityShanghai 200240China

The efficiency of water electrolysis is significantly affected by the bubbles on the surface and inside the *** enhance the gas-liquid transfer within the porous electrodes,we developed an innovative design termed dual-aligned porous electrode(D-APE),achieved by integrating magnetic alignment with freeze casting *** paper investigates the hydrogen evolution performance of porous electrodes prepared using four different methods:evaporation,magnetic-aligned evaporation,freeze casting,and dual-aligned *** findings demonstrate that the magnetic-aligned process effectively alters the electrode structure,resulting in improved hydrogen evolution ***,among all the examined electrodes,the D-APE exhibits the highest hydrogen evolution performance,with further enhancements observed with prolonged the time of magnetic ***,a comparison is made between electrodes prepared using the freeze casting method and the dual-aligned method at various *** results show that the thinner D-APE exhibits excellent hydrogen evolution performance at high current ***,the D-APE demonstrates significantly improved material utilization rates compared to the conventional freeze casting method,offering promising prospects for enhancing the efficiency of water electrolysis.

关键词： hydrogen evolution reaction dual-aligned magnetic-aligned freeze casting

A Study on the Role of Tourism in Enhancing Personal Mental Health in the Post-Epidemic Era

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International Journal of Mental Health Promotion 2024年第4期26卷 325-334页

作者： Ruiqin Tian Yue feng Lingqi zhan School of Mathematics Hangzhou Normal UniversityHangzhou311121China

With the advent of the post-epidemic era,a great wave of tourism has been ushered in *** relationship between tourism and mental health has become a hot topic in *** paper investigates the enhancement of people’s mental health after tourism through social *** Hangzhou as the sample collection site,this paper conducted a study on the role of tourism in enhancing personal mental health through descriptive analysis,factor analysis and structural equation modeling,and further specifically analyzed the role of mediating *** results showed that:(1)The purpose of tourism is to relax and relieve stress,and the effectiveness of tourism is mainly reflected in the alleviation of emotional conditions;(2)Factor Analysis reduced the dimensionality of personal mental health indicators,and finally obtained four factors,among which the comprehensive behavioral ability and physiological manifestation had the best improvement effect after tourism;(3)The structural equation model shows that the enhancing effect of tourism on mental health originates from the factor of inner psychological characteristic,and this factor works through two paths:Inner Psychological Characteristic-Social Adaptability-Physiological Manifestations-Enhancement of Mental Health by Tourism,and Inner Psychological Characteristic-Comprehensive Behavioral Ability-Enhancement of Mental Health by Tourism;(4)Tourism has an enhancing effect on personal mental health,and the enhancing effect is most significant among the middle-aged and young people who are unmarried and do not have children *** results have been reasonably analyzed and explained,and relevant suggestions are put forward.

关键词： Tourism mental health factor analysis structural equation model enhancement

Dimensional reduction enhances photocatalytic carbon dioxide reduction performance of metal-organic frameworks

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Nano Research 2024年第5期17卷 3653-3659页

作者： Kaiyue Ma Jixin Li Jinlu Liu Chunguang Li zhan Shi Shouhua feng State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China

Metal-organic frameworks(MOFs)have shown significant potential as *** has been widely assumed that all catalytic active sites within MOFs are functional in photocatalytic reactions but for a three-dimensional MOF,whether the internal catalytic active sites can effectively absorb light and actively contribute to photocatalytic reactions remains to be *** this context,we synthesized a two-dimensional nanosheet MOF(2D-MOF)and a three-dimensional bulk MOF(3D-MOF)composed of Zr^(6) clusters and tetracarboxylic porphyrin(TCPP)by the approach described in the ***(bpy)(CO)^(3)Cl(bpy=2,2’-bipyridine),which has remarkable CO_(2) photoreduction ability,was introduced to the two MOFs to create two new photocatalysts 2D-MOF-Re and 3D-MOF-Re,*** CO_(2) reduction experiments show that based on the equal number of catalytic active sites,the CO turnover number(TON)of 2D-MOF-Re reaches 27.8 in 6 h,which is 50 times that of *** result shows that certain catalytic active sites inside the bulk MOF are inactive due to the inability to absorb *** study illuminates the potential of the dimensional reduction approach in the design of photocatalysts to exploit the capabilities fully.

关键词： photocatalysis CO_(2)reduction metal-organic frameworks(MOFs) nanosheets light absorption

Plasma-assisted aerogel interface engineering enables uniform Zn^(2+)flux and fast desolvation kinetics toward zinc metal batteries

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Journal of Energy Chemistry 2024年第8期95卷 29-38,I0002页

作者： Zijian Xu Zhenhai Shi zhan Chang Fan feng Zhuanyi Liu Dongkun Chu Jianguo Ren Zi-feng Ma Suli Chen Tianxi Liu Key Laboratory of Synthetic and Biological Colloids Ministry of Education School of Chemical and Material EngineeringJiangnan UniversityWuxi 214122JiangsuChina Shanghai Electrochemical Energy Devices Research Center Department of Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China BTR New Material Group Co. LTD.Shenzhen 518000GuangdongChina

The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal *** address these issues,a plasmaassisted aerogel(PAG)interface engineering was proposed as efficient ion transport modulator that can simultaneously regulate uniform Zn^(2+)flux and desolvation behavior during battery *** PAG with ordered mesopores acted as an ion sieve to homogenize Zn deposition and accelerate Zn^(2+)flux,which is favorable for corrosion resistance and dendrite ***,the plasma-assisted aerogel with abundant hydrophilic groups can facilitate the desolvation kinetics of Zn^(2+)due to the multiple hydrogen-bonding interaction with the activated water molecules,thus accelerating the Zn^(2+)migration ***,the Zn/Zn cell assembled with PAG-modified separator demonstrates stable plating and stripping behavior(over 1400 h at 1 mA cm^(-2))and high Coulombic efficiency(99.8%at1 mA cm^(-2)after 1100 cycles),and the Zn‖MnO_(2)full cell shows excellent long-term cycling stability and maintains a high capacity of 154.9 mA h g^(-1)after 1000 cycles at 1 A g^(-1).This study provides a feasible approach for the large-scale fabrication of aerogel functionalized separators to realize ultra-stable Zn metal batteries.

关键词： Zn metal batteries Aerogel interface Plasma Zn^(2+)migration kinetics Dendrite growth

Is appendoscope a new option for the treatment of acute appendicitis?

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World Journal of Gastroenterology 2024年第28期30卷 3386-3392页

作者： Shu-Jiong feng Yi-feng Zhou Jian-feng Yang Hong-zhang Shen Guang-Xing cui Xiao-feng zhang Department of Gastroenterology Affiliated Hangzhou First People’s HospitalSchool of MedicineWestlake UniversityHangzhou 310000Zhejiang ProvinceChina Department of Gastroenterology Key Laboratory of Integrated Traditional Chinese and Western Medicine for Biliary and Pancreatic Diseases of Zhejiang ProvinceHangzhou 310000Zhejiang ProvinceChina Department of Gastroenterology Hangzhou Institute of Digestive DiseasesHangzhou 310000Zhejiang ProvinceChina

Acute appendicitis is a common surgical *** is commonly caused by obstruction of the appendiceal lumen due to fecaliths,tumors,or lymphoid *** over a century,appendectomy has been the primary treatment for acute *** Groves performed the first open appendectomy in *** 1983,Kurt Semm completed the first laparoscopic appendectomy,heralding a new era in ***,appendectomy is associated with certain complications and a rate of negative *** have suggested controversy over the impact of appendectomy on the development of inflammatory bowel disease and Parkinson’s disease,but an increasing number of studies indicate a possible positive correlation between appendectomy and colorectal cancer,gallstones,and cardiovascular *** the recognition that the appendix is not a vestigial organ and the advancement of endoscopic technology,Liu proposed the endoscopic retrograde appendicitis *** is an effective minimally invasive alternative for treating uncomplicated acute *** team has developed an appendoscope with a disposable digital imaging system operated through the biopsy channel of a colonoscope and successfully applied it in the treatment of *** article provides an overview of the progress in endoscopic treatment for acute appendicitis and offers a new perspective on the future direction of appendiceal disease treatment.

关键词： Acute appendicitis Endoscopic technology Endoscopic retrograde appendicitis therapy Appendoscope Appendiceal disease treatment

Collaborative positioning for swarms:A brief survey of vision,LiDAR and wireless sensors based methods

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Defence Technology（防务技术） 2024年第3期33卷 475-493页

作者： Zeyu Li Changhui Jiang Xiaobo Gu Ying Xu feng zhou Jianhui cui College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao266590China Geoloc Laboratory Universite Gustave EiffelParis77454France School of Automation Guangdong University of TechnologyGuangzhou510006China

As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other *** receiving spatial information from both its environment and other agents,an agent can use various methods and sensor types to localize *** its high flexibility and robustness,collaborative positioning has become a widely used method in both military and civilian *** paper introduces the basic fundamental concepts and applications of collaborative positioning,and reviews recent progress in the field based on camera,LiDAR(Light Detection and Ranging),wireless sensor,and their *** paper compares the current methods with respect to their sensor type,summarizes their main paradigms,and analyzes their evaluation ***,the paper discusses the main challenges and open issues that require further research.

关键词： Collaborative positioning Vision LiDAR Wireless sensors Sensor fusion