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Reactive jet density distribution effect on its penetration behavior

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Defence Technology（防务技术） 2023年第6期24卷 190-202页

作者： Huan-guo guo Cheng-hai su Yi-qiang Cai suo He Qing-bo Yu haifu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

In this paper,the penetration mechanism of reactive jet with non-uniform density distribution is studied.The simulations show that the density deficit occurs in the whole reactive jet,and the density increases from the jet tip to tail.The density of jet tip is approximately 1.5 g/cm3,which is lower than that of the reactive liner materials.The X-ray experiments show similar results with the simulations.The density decreasing effect of jet tip has a significant influence on the penetration behavior when the reactive jet impacts steel plate.According to the simulation results,this paper assumes that the density gradient in the jet section has linear distribution.Then,the deflagration pressure generated by each jet element at the bottom of crater is introduced into the Bernoulli equation.Based on the virtual origin model and Szendrei-Held equation,the analytical models for penetration depth and radial cratering of reactive jet with the density reduction are obtained.Moreover,to further prove the validity of analytical models,the penetration experiments of the reactive liner shaped charge against steel plate under different standoffs are carried out.There is a convergence between the analytical crater profiles and experimental results when reactive jets penetrate steel plates under different standoffs,especially at standoff of 1.5 and 2.0charge diameters.

关键词： Shaped charge Reactive jet Density distribution Jet penetration Virtual origin

Applanoids A—E as the First Examples of C-15/C-20 Michael Adducts in Ganoderma Triterpenoids and Their PXR Agonistic Activity

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Chinese Journal of Chemistry 2022年第22期40卷 2633-2641页

作者： Hai-Guo Su Hang-Fei Liang Gui-Lin Hu Lin Zhou Xing-Rong Peng Hui-Chang Bi Ming-Hua Qiu Guangdong Provincial Key Laboratory of New Drug Design and Evaluation School of Pharmaceutical SciencesSun Yat-sen UniversityGuangzhouGuangdong510006China State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China NMPA Key Laboratory for Research and Evaluation of Drug Metabolism&Guangdong Provincial Key Laboratory of New Drug Screening School of Pharmaceutical SciencesSouthern Medical UniversityGuangzhouGuangdong 510515China

Ganoderma triterpenoids(GTs),a class of major active constituents of Ganoderma fungi,possess diverse structures and remarkable activities.In the present study,nine new GTs,namely applanoids A—I(1—9),were isolated from the medicinal fungus of Ganoderma applanatum.Their structures including absolute configurations were established by comprehensive spectroscopic analyses and ECD calculation.Applanoids A—E(1—5)represent the first example of GTs with 6/6/5/6/5 pentacyclic system and the formation of the ether ring between C-15 and C-20 involves Michael addition reaction.Furthermore,compounds 1—8 were evaluated for their human pregnane X receptor(hPXR)agonistic activity using dual-luciferase reporter gene assay,and the results showed that compounds 1,2 and 4 can dose-dependently activate hPXR.This investigation further illustrated the structural diversity of GTs and provided new insights for searching PXR agonists from GTs.

关键词： Ganoderma applanatum Lanostane triterpenoids Michael adducts Structure elucidation Pregnane X receptor

Design of Self‑Reconfigurable Multiarm Robot Mechanism Based on Deployable Kinematic Chains

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Chinese Journal of Mechanical Engineering 2020年第5期33卷 34-50页

作者： Fu‑Qun Zhao Sheng guo hai‑Jun su hai‑Bo Qu Ya‑Qiong Chen School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

As the structures of multiarm robots are serially arranged,the packaging and transportation of these robots are often inconvenient.The ability of these robots to operate objects must also be improved.Addressing this issue,this paper presents a type of multiarm robot that can be adequately folded into a designed area.The robot can achieve different operation modes by combining different arms and objects.First,deployable kinematic chains(DKCs)are designed,which can be folded into a designated area and be used as an arm structure in the multiarm robot mechanism.The strategy of a platform for storing DKCs is proposed.Based on the restrictions in the storage area and the characteristics of parallel mechanisms,a class of DKCs,called base assembly library,is obtained.subsequently,an assembly method for the synthesis of the multiarm robot mechanism is proposed,which can be formed by the connection of a multiarm robot mechanism with an operation object based on a parallel mechanism structure.The formed parallel mechanism can achieve a reconfigurable characteristic when different DKCs connect to the operation object.Using this method,two types of multiarm robot mechanisms with four DKCs that can switch operation modes to perform different tasks through autonomous combination and release operation is proposed.The obtained mechanisms have observable advantages when compared with the traditional mechanisms,including optimizing the occupied volume during transportation and using parallel mechanism theory to analyze the switching of operation modes.

关键词： Design Multiarm robot Deployable kinematic chain Parallel mechanism Motion set

Cucurbitane-Type Triterpene Glycosides from Momordica charantia and Their α-Glucosidase Inhibitory Activities

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Natural Products and Bioprospecting 2020年第3期10卷 153-161页

作者： Ya Gao Jian-Chao Chen Xing-Rong Peng Zhong-Rong Li Hai-Guo Su Ming-Hua Qiu State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201People’s Republic of China University of the Chinese Academy of Sciences Beijing 100049People’s Republic of China Yunnan Key Laboratory of Natural Medicinal Chemistry Chinese Academy of SciencesKunming 650201People’s Republic of China

Ten cucurbitane-type triterpene glycosides,including five new compounds named charantosides H(1),J(2),K(3),momor-characoside A(4),goyaglycoside-l(5),and five known compounds(6-10),were isolated from the EtOAc extract of Momor-dica charantia fruits.The chemical structures of these compounds were identified by 1D and 2D NMR and HRESIMS spectroscopic analyses.Configurations of new compounds were determined by ROESY correlations and comparison of their 13C NMR data with literature reported values.All compounds were evaluated for their inhibition againstα-glucosidase,in which compounds 2,5,7,8,9 showed moderate inhibitory activities with IC50 values ranging from 28.40 to 63.26μM comparing with the positive control(acarbose,IC5087.65±6.51μM).

关键词： Momordica charantia Cucurbitane-type triterpene glycosides α-Glucosidase inhibitory activity

Enantioselective recognition based on aggregation-induced emission

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Chinese Chemical Letters 2023年第6期34卷 70-80页

作者： Pu Chen Panpan Lv Chang-Sheng guo Rui-Peng Wang Xiaolong su hai-Tao Feng Ben Zhong Tang AIE Research Center Shaanxi Key Laboratory of PhytochemistryCollege of Chemistry and Chemical EngineeringBaoji University of Arts and SciencesBaoji 721013China Shenzhen Institute of Aggregate Science and Technology School of Science and EngineeringThe Chinese University of Hong KongShenzhen 518172China

Chirality is one of the most important features of the nature.The recognition of enantiomers plays significant roles in the field of life science,pharmaceutical analysis and food chemistry.Among various recognition methods,fluorescence spectrometry has attracted much attention of researchers thanks to its high sensitivity and easy operation.Compared with traditional fluorescent probes,chiral molecules with aggregation-induced emission(AIE)have drawn increasing interests due to their huge potential in high-efficiency chemo/biosensors and solid emitters.Chiral AIE luminogens(AIEgens)can not only discriminate two enantiomers with excellent enantioselectivity,but also show general applicability for many chiral analytes,such as chiral acids,amino acids,amines,alcohols.In this review,we mainly summarized the recent development of chiral probes with AIE properties,including chiral tetraphenylethylene(TPE)derivatives,α-cyanostilbene derivatives,Schiff base derivatives and other AIEgens.Their synthetic routes,recognition capabilities and possible working mechanisms were well discussed.It is envisioned that the present review can give some significant guidance for design and synthesis of chiral AIEgens with good enantioselectivity and inspire more readers to join the research of chiral AIE.

关键词： Aggregation-induced emission Enantioselective recognition Fluorescent probe Host-guest interaction Tetraphenylethylene derivatives α-Cyanostilbene derivatives Schiff base derivatives

Differentially Private Precision Matrix Estimation

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Acta Mathematica Sinica,English Series 2020年第10期36卷 1107-1124页

作者： Wen Qing su Xiao guo hai ZHANG School of Mathematics Northwest UniversityXi'an 710127P.R.China Faculty of Information Technology Macao University of Science and TechnologyMacao 999078P.R.China Key Laboratory of Advanced Theory and Application in Statistics and Data Science(East China Normal University) Ministry of EducationShanghai 200062P.R.China

In this paper, we study the problem of precision matrix estimation when the dataset contains sensitive information. In the differential privacy framework, we develop a differentially private ridge estimator by perturbing the sample covariance matrix. Then we develop a differentially private graphical lasso estimator by using the alternating direction method of multipliers(ADMM) algorithm.Furthermore, we prove theoretical results showing that the differentially private ridge estimator for the precision matrix is consistent under fixed-dimension asymptotic, and establish a convergence rate of differentially private graphical lasso estimator in the Frobenius norm as both data dimension p and sample size n are allowed to grow. The empirical results that show the utility of the proposed methods are also provided.

关键词： Differential privacy graphical model ADMM algorithm

Nontrivial topological states in the tantalum dipnictides TaX_(2)(X = As, P)

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Tungsten 2020年第3期2卷 251-260页

作者： Xiao‑Lei Liu Hong‑Yuan Wang Hao su Zhen‑hai Yu Yan‑Feng guo School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China CAS Center for Excellence in superconducting Electronics(CENSE) Chinese Academy of SciencesShanghai 200050China

The intriguing quasiparticles in solids,known as Dirac,Weyl,and Majorana fermions,etc.with properties akin to those theoretically predicted but never realized in high-energy physics,have excited intensive research activities in recent years.The transition metal dipnictides are attractive because of their extremely large magnetoresistance that is usually attributed to the carrier compensation effect.We briefly review herein the crystal growth,magneto-transport measurements,and theoretical studies of tantalum dipnictides TaAs_(2) and TaP_(2),with the emphasis being put on discussion of the nontrivial topological states in both materials.The analysis of quantum oscillations of the magnetoresistance unveils nonzero Berry phase.The chiral negative longitudinal magnetoresistance further points to possible Weyl state,which was recently theoretically sug-gested as the result of the magnetic field-induced Zeeman splitting effect no matter how large the field is.The analysis of these intriguing behaviors could brush up our understanding about the family of materials and would be valuable for future work on investigating the magnetic field-induced topological phase transition in such semimetals.

关键词： Tantalum dipnictides Semimetal Crystal growth Nontrivial topological states

Design of Self-Recon gurable Multiarm Robot Mechanism Based on Deployable Kinematic Chains

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Chinese Journal of Mechanical Engineering 2020年第5期 44-60页

作者： Fu-Qun Zhao Sheng guo hai-Jun su hai-Bo Qu Ya-Qiong Chen School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Department of Mechanical and Aerospace Engineering The Ohio State University

As the structures of multiarm robots are serially arranged, the packaging and transportation of these robots are often inconvenient. The ability of these robots to operate objects must also be improved. Addressing this issue, this paper presents a type of multiarm robot that can be adequately folded into a designed area. The robot can achieve different operation modes by combining different arms and objects. First, deployable kinematic chains(DKCs) are designed, which can be folded into a designated area and be used as an arm structure in the multiarm robot mechanism. The strategy of a platform for storing DKCs is proposed. Based on the restrictions in the storage area and the character-istics of parallel mechanisms, a class of DKCs, called base assembly library, is obtained. subsequently, an assembly method for the synthesis of the multiarm robot mechanism is proposed, which can be formed by the connection of a multiarm robot mechanism with an operation object based on a parallel mechanism structure. The formed parallel mechanism can achieve a reconfigurable characteristic when different DKCs connect to the operation object. Using this method, two types of multiarm robot mechanisms with four DKCs that can switch operation modes to perform different tasks through autonomous combination and release operation is proposed. The obtained mechanisms have observable advantages when compared with the traditional mechanisms, including optimizing the occupied volume during transportation and using parallel mechanism theory to analyze the switching of operation modes.

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Efficient p-doping of P3HT for hole transporting materials in perovskite solar cells

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Rare Metals 2022年第8期41卷 2575-2581页

作者： su-Peng Liu Xin-Can Qiu Jing guo Ping-An Chen Yu Liu Huan Wei Jiang-Nan Xia hai-Hong Xie Yuan-Yuan Hu Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education and International Science and Technology Innovation Cooperation Base for Advanced Display Technologies of Hunan Province School of Physics and ElectronicsHunan UniversityChangsha410082China Shenzhen Research Institute of Hunan University Shenzhen518063China

Developing hole transporting materials(HTMs)appropriate for large-area and high-performance perovskite solar cells(PSCs)is an important issue.In this work,we report using a widely used organic semiconductor P3 HT in combination with an efficient organic salt dopant trityl tetrakis(pentafluorophenyl)borate(TrTFPB)as HTM in PSCs.It is shown that the dopant can significantly enhance the conductivity of P3 HT while slightly change the film morphology.By doping P3 HT with different doping levels.

关键词： morphology. doping perovskite