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Velocity Constraints Based Approach for Online Trajectory Planning of High‑Speed Parallel Robots

Chinese Journal of Mechanical Engineering 2022年第6期35卷 98-109页

作者： di Yang Fugui xie Xinjun Liu State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Beijing Key Lab of Precision/Ultra‑Precision Manufacturing Equipments and Control Tsinghua UniversityBeijing 100084China

High-speed parallel robots have been extensively utilized in the light industry.However,the influence of the nonlinear dynamic characteristics of high-speed parallel robots on system’s dynamic response and stable operation cannot be ignored during the high-speed reciprocating motion.Thus,trajectory planning is essential for efficiency and stability from pick-and-place(PAP)actions.This paper presents a method for planning the equal-height pick-and-place trajectory considering velocity constraints to improve the PAP efficiency and stability of high-speed parallel robots.The velocity constraints in the start-and-end points can reduce vibration from picking and placing,making the trajectory more suitable to complex beltline situations.Based on velocity constraints,trajectory optimization includes trajectory smoothness and joint torque to optimize cycle time is carried out.This paper proposes an online trajectory optimization solution.By using back propagation(BP)neural networks,the solution is simplified and can be solved in real-time.Simulation and experiments were carried out on the SR4 parallel robot.The results show that the proposed method improves the efficiency,smoothness,and stability of the robot.This paper proposes an online trajectory planning method which is velocity constraints based and can improve the efficiency and stability of high-speed parallel robots.The work of this research is conducive to finely applying high-speed parallel robots.

关键词： Trajectory planning High-speed parallel robot Velocity constraints BP neural network

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Lactic acid in tumor microenvironments causes dysfunction of NKT cells by interfering with mTOR signaling

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Science China(Life Sciences) 2016年第12期59卷 1290-1296页

作者： Di Xie Shasha Zhu Li Bai CAS Key Laboratory of lnnate lmmunity and Chronic disease CAS Center for Excellence in Molecular Cell Science School of Life Sciences and Medical Center University of Science and Technology of China Hefei 230027 China Innovation Center for Cell Signaling Network Hefei National Laboratory for Physical Sciences at Microscale Hefei 230027 China

Cellular metabolism has been shown to regulate differentiation and function of immune cells.Tumor associated immune cells undergo phenotypic and functional alterations due to the change of cellular metabolism in tumor microenvironments.NKT cells are good candidates for immunotherapies against tumors and have been used in several clinical trials.However,the influences of tumor microenvironments on NKT cell functions remain unclear.In our studies,lactic acid in tumor microenvironments inhibited IFNγ and IL4 productions from NKT cells,and more profound influence on IFNγ was observed.By adjusting the pH of culture medium we further showed that,dysfunction of NKT cells could simply be induced by low extracellular pH.Moreover,low extracellular pH inhibited NKT cell functions by inhibiting mammalian target of rapamycin(mTOR) signaling and nuclear translocation of promyelocytic leukemia zinc-finger(PLZF).Together,our results suggest that tumor acidic microenvironments could interfere with NKT cell functions through metabolic controls.

关键词： lactic acid NKT cell IFNγ mTOR PLZF

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Improving antioxidant activities of water-soluble lignin-carbohydrate complex isolated from wheat stalk through prolonging ball-milling pretreatment and homogeneous extraction

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Journal of Bioresources and Bioproducts 2024年第1期9卷 113-125页

作者： Di Xie Zhulan Liu Yunfeng Cao Sheng-I Yang Chen Su Mi Li Jiangsu Co-innovation Center for Efficient Processing and Utilization of Forest Products Nanjing Forestry UniversityNanjing 210037China International Innovation Center for Forest Chemicals and Materials Nanjing Forestry UniversityNanjing 210037China Center for Renewable Carbon School of Natural ResourcesUniversity of TennesseeKnoxvilleTN 37996USA Shandong Huatai Paper Co. Ltd.Dongying 257000China School of Natural Resources University of TennesseeKnoxvilleTN 37996USA Key Lab of Biomass Energy and Material Institute of Chemical Industry of Forest ProductsChinese Academy of ForestryJiangsu ProvinceNanjing 210042China

Water-soluble lignin-carbohydrate complex(LCC)rich in polysaccharides exhibits benign in vitro antioxidant activities and distinguishes high biocompatibility from lignin-rich LCC and lignin.However,the antioxidant activity of water-soluble LCCs remains to be improved and its structure-antioxidant relationship is still uncertain.Herein,structurally diversified water-soluble LCCs were isolated under different ball-milling pretreatment durations(4,6,8 h),extraction pathways(ho-mogeneous and heterogeneous),and isolation routines(water extracts and residues after water extraction).Their structures were characterized by wet chemistry,chromatography and spec-troscopies.Antioxidant activities were evaluated by ferric reducing antioxidant power and 1,1-diphenyl-2-picrylhydrazyl radicals scavenging rate(RDPPH).Results show that altering ball-milling duration and isolation procedures cause varied structures and antioxidant activities of the water-soluble LCCs.Specifically,prolonging ball-milling duration to 8 hours and homogeneous extrac-tion can enhance their antioxidant activity through releasing more phenolic structures and pro-moting the extraction of high-molecular-weight LCCs via reducing mass-transfer resistance,re-spectively.As a result,the RDPPH of water-soluble LCCs reaches up to 97.35%,which is associated with the arabinan content with statistical significance(P<0.05).This study provides new insights into the structure-antioxidation relationship of herbaceous LCC as potential antioxidants.

关键词： LCC Homogeneous extraction Ball-milling Structure-antioxidation relationship Wheat straw

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Tuning heat transport via coherent structure manipulation:recent advances in thermal turbulence

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National Science Review 2023年第6期10卷 245-257页

作者： Ke-Qing Xia Shi-di Huang Yi-Chao xie Lu Zhang Center for Complex Flows and Soft Matter Research and Department of Mechanics and Aerospace Engineering Southern University of Science and Technology State Key Laboratory for Strength and Vibration of Mechanical Structures and School of Aerospace Xi'an Jiaotong University

Tuning transport properties through the manipulation of elementary structures has achieved great success in many areas,such as condensed matter physics.However,the ability to manipulate coherent structures in turbulent flows is much less explored.This article reviews a recently discovered mechanism of tuning turbulent heat transport via coherent structure manipulation.We first show how this me chanism can be realized by applying simple geometrical confinement to a classical thermally driven turbulence, which leads to the condensation of elementary coherent structures and significant heat-transport enhancement,despite the resultant slower flow.Some potential applications of this new paradigm in passive heat management are also discussed.We then explain how the heat transport behaviors in seemingly different turbulence systems can be understood by this unified framework of coherent structure manipulation.Several future directions in this research area are also outlined.

关键词： coherent structure turbulent flow heat transport geometrical confinement dynamical constraint

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Na2V6O16·2.14H2O nanobelts as a stable cathode for aqueous zinc-ion batteries with long-term cycling performance

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Journal of Energy Chemistry 2019年第11期28卷 185-191页

作者： Fang Hu Di Xie Depeng Zhao Guihong Song Kai Zhu School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870LiaoningChina Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150010HeilongjiangChina

Aqueous zinc-ion batteries(ZIBs) have been considered as one of the most promising electrochemical devices for large-scale energy storage system owing to their low cost and high safety. Herein, Na2V6O16·2.14H2O nanobelts are synthesized and applied as cathode material for ZIBs. The sample displays a high capacity of 466 m Ahg^-1 at 100 mAg^-1 and stable cycling performance with a capacity retention of 90% over 20 0 0 cycles at the 20 Ag^-1. Moreover, Na2V6O16·2.14H2O presents a capable rate ability and a high energy density of 312 Wh kg^-1 at a specific power of 70 Wkg^-1. The superior electrochemical performance is attributed to the large interlayer spacing and outstanding structure stability, which promise the highly reversible intercalation and extraction of zinc ion. The electrochemical kinetics and zinc ion storage mechanism are also investigated. This work demonstrates that nanoscale electrode materials with large interlayer spacing can effectively enhance the electrochemical performance of aqueous ZIBs, which can be extended to other metal ion batteries, such as magnesium ion batteries and aluminum ion batteries.

关键词： Aqueous zinc-ion batteries Nanobelts Sodium vanadates Electrochemical performance

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One-step synthesis of triazine-based covalent organic frameworks at room temperature for efficient photodegradation of bisphenol A under visible light irradiation

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Frontiers of Materials Science 2023年第4期17卷 159-169页

作者： Pin Chen Siyuan di Weixin xie Zihan Li Shukui Zhu State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China Huizhou Port Customs Huizhou 516080China

Herein,a novel visible-light-responsive photocatalyst with high efficiency was firstly synthesized at room temperature.The mild synthetic method resulted in a uniform spherical triazine-based covalent organic framework(TrCOF2)with ultra-high specific surface area as well as chemical stability.Due to the synergistic effect between the self-assembled uniform spherical structure and the abundant triazine-based structure,photoelectron–hole pairs were efficiently separated and migrated on the catalysts.On this basis,TrCOF2 was successfully applied to efficiently degrade bisphenol A(BPA).More than 98%of BPA was deraded after 60 min of visible light treatment,where the active specie of•O_(2)^(−)played a vital role during the degradation of BPA.The holes of TrCOF2 could produce O_(2)by direct reaction with water or hydroxide ions.Simultaneously,photoelectrons can be captured by O_(2)to generate•O_(2)^(−).Moreover,density functional theory(DFT)calculations proved the outstanding ability of the exciting electronic conductivity.Remarkably,a reasonable photocatalytic mechanism for TrCOF2 catalysts was proposed.This research can provide a facile strategy for the synthesis of TrCOFs catalysts at room temperature,which unfolds broad application prospects in the environmental field.

关键词： photocatalysis triazine-based covalent organic framework visible light pollutant degradation catalytic mechanism

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Smoking Behavior Among Secondary School Students--China, 2021

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China CDC weekly 2022年第21期4卷 441-447页

作者： Xinying Zeng Xinbo di Shiwei Liu Huiyu xie Zida Meng Lin Xiao Tobacco Control Office Chinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?In 2019,China CDC conducted the National Youth Tobacco Survey among secondary school students,and the prevalence rates of ever,current,and frequent smoking were 17.9%,5.9%,and 1.8%,respectively.What is added by this report?The prevalence rate of cigarette use in males decreased largely from 2019 to 2021 in China,while it increased in 18 provincial-level administrative divisions(PLADs)for females.The tobacco control situation remains challenging among vocational senior high school(VSHS)students.Significant geographical disparities existed in cigarette use.What are the implications for public health practice?Targeted tobacco control policies aimed at VSHS students are needed,specifically those PLADs with higher smoking rates.Additionally,close attention should be paid to female smokers.

关键词： smoke cigarette tobacco

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A Unified Method Based on SPA and Timing Attacks on the Improved RSA

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China Communications 2016年第4期13卷 89-96页

作者： JIA Fan xie di Beijing Jiaotong University China Information Technology & Security Test and Evaluation Center Beijing China

Nowadays the modular multiplications in many kinds of smartcards are utilized Montgomery's algorithm modular multiplier, so traditional SPA to RSA becomes invalid. An improved attack method is proposed based on SPA which just depends on the fact that there exist some subtle differences in each loop during the operation of cd mod n. At same time, compared with the traditional SPA, it doesn't need to select the clear text or some known message. Using this method, attacks can easy to discover the mode of RSA implementation and extract the bits of decryption key just based on a few collected traces. From the real attack test on several main kinds of smartcard, the private keys of RSA stored inside can be analyzed successfully.

关键词： power analysis SPA RSA attack SCA

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Artificial Cycle with or without a Depot Gonadotropin-releasing Hormone Agonist for Frozen-thawed Embryo Transfer： An Assessment of Infertility Type that Is Most Suitable

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Current Medical Science 2018年第4期38卷 626-631页

作者： Di Xie Fan CHEN Shou-zhen xie Zhi-lan CHEN Ping TUO Rong ZHOU Juan ZHANG Reproductive Medical Centre Wuhan General Hospital of Guangzhou Military Region Wuhan 430070 China Key Laboratory of Agricultural Animal Genetics Breeding and Reproduction Education Ministry of China College of Animal Science and Technology Huazhong Agricultural University Wuhan 430070 China

The clinical outcomes of five groups of infertility patients receiving frozen- thawed, cleavage-stage embryo transfers with exogenous hormone protocols with or without a depot gonadotropin-releasing hormone （GnRH） agonist were assessed. A retrospective cohort analysis was performed on 1003 cycles undergoing frozen-thawed, cleavage-stage embryo transfers from January 1, 2012 to June 31, 2015 in the Reproductive Medicine Center of Wuhan General Hospital of Guangzhou Military Region. Based on the infertility etiologies of the patients, the 1003 cycles were divided into five groups： tubal infertility, polycystic ovary syndrome （PCOS）, endometriosis, male infertility, and unexplained infertility. The main outcome was the live birth rate. Two groups were set up based on the intervention： group A was given a GnRH agonist with exogenous estrogen and progesterone, and group B （control group） was given exogenous estrogen and progesterone only. The results showed that the baseline serum hormone levels and basic characteristics of the patients were not significantly different between groups A and B. The live birth rates in groups A and B were 41.67% and 29.29%, respectively （P〈0.05）. The live birth rates in patients with PCOS in groups A and B were 56.25% and 30.61%, respectively （P〈0.05）. The clinical pregnancy, implantation and on-going pregnancy rates showed the same trends as the live birth rates between groups A and B. The ectopic pregnancy rate was significantly lower in group A than in group B. We concluded that the live birth rate was higher and other clinical outcomes were more satisfactory with GnRH agonist co- treatment than without GnRH agonist co-treatment for frozen-thawed embryo transfer. The GnRH agonist combined with exogenous estrogen and progesterone worked for all types of infertility tested, especially for women with PCOS.

关键词： frozen-thawed embryo transfer gonadotropin-releasing hormone agonist polycystic ovary syndrome

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Tobacco Use and Cessation Among College Students--China, 2021

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China CDC weekly 2022年第21期4卷 448-451页

作者： Huiyu xie Xinbo di Shiwei Liu Xinying Zeng Zida Meng Lin Xiao Tobacco Control Office Chinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?Previous studies about tobacco use among college students in China were conducted at the school level or city level,with fewer than 5,000 students participating.What is added by this report?In 2021,China CDC conducted a national tobacco survey targeting students enrolled in the public higher education system.Overall,124,119 students from 220 colleges and universities in 31 provincial-level administrative divisions participated in this survey.Current cigarette smoking,current daily smoking,willingness to quit,and smoking cessation among college students were explored.What are the implications for public health practice?The current daily cigarette smoking rate of college students was significantly higher than that of senior high school students,especially higher vocational college students.Tobacco control interventions,such as a smoke-free school policy and smoking cessation services,need to be reinforced on college campuses.

关键词： smoke college smoking

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