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Synthesis and Microphase Separation Behavior of Random, Mixed Cylindrical Brush Copolymers Bearing Polystyrene and Poly(ε-caprolactone) Side Chains

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Chinese Journal of Polymer Science 2017年第12期35卷 1572-1586页

作者： Houluo Cong sen xu 郑思珣 Department of Polymer Science and Engineering and the State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University

A series of mixed, random cylindrical brush copolymers bearing polystyrene（PS） and poly（ε-caprolactone）（PCL） side chains were synthesized via the combination of ring-opening polymerization（ROP） and atom transfer radical polymerization（ATRP）. These novel cylindrical brush copolymers have been characterized by means of nuclear magnetic resonance（NMR） spectroscopy, gel permeation chromatography（GPC） and differential scanning calorimetry（DSC）. It was found that the mikto-armed cylindrical brush copolymers were microphase-separated in bulks and that the morphologies were dependent on the mass ratios of PS to PCL side chains. One of the cylindrical brush copolymers was employed to incorporate into epoxy thermoset to investigate effect of the mikto-armed cylindrical brush architecture on the reaction-induced microphase separation behavior. Depending on the concentration of the cylindrical brush in epoxy, the thermosets can display the morphologies with the spherical, worm-like and lamellar PS microdomains dispersing in continuous thermosetting matrices.

关键词： Cylindrical brush copolymers Block copolyrner Epoxy Reaction-induced microphase separation

Experimental research on charging characteristics of a pressure-controlled VRLA battery in high-temperature environments

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 418-422页

作者： Hua ZHU Jin-jun TAN Zhang-lu xu Ji-sen xu Institute of Thermal Science and Power Systems Zhejiang University Hangzhou 310027 China

Valve-regulated-lead-acid (VRLA) battery charging performed in high-temperature environments is extremely risky under overcharge conditions, and may lead to a subsequent thermal runaway. A new pressure-controlled charging method was adopted and the charging characteristics of the pressure-controlled VRLA battery in high-temperature environments were ex-perimentally studied. The concept was tested in a large temperature gradient to obtain more details about the effects of users' accustomed charging and discharging modes on battery capacity. The premature capacity loss (PCL) phenomenon under high temperature exposure was analyzed. The results showed that the capacity loss could be recovered by charging using a large current.

关键词： Valve-regulated-lead-acid (VRLA) battery Pressure-controlled charging method High-temperature environments Charging and discharging characteristics

Formation of Poly(ε-caprolactone) Networks via Supramolecular Hydrogen Bonding Interactions

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Chinese Journal of Polymer Science 2019年第3期37卷 197-207页

作者： sen xu Pengfei Chang Bingjie Zhao Muhammad Adeel Sixun Zheng Department of Polymer Science and Engineering and the State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University

In this contribution, we reported a novel approach to crosslink poly(ε-caprolactone)(PCL) via supramolecular hydrogen bonding interactions. First, a series of octa-armed poly(ε-caprolactone) stars with polyhedral oligomeric silsesquioxane(POSS) cores were synthesized via the ring-opening polymerizations. Thereafter, the arm ends of organic-inorganic star-shaped PCLs were reacted with 2-(6-isocyanatohexylaminocarbonylamino)-6-methyl-4[1 H]-pyrimidinone to obtain 2-ureido-4[1 H]-pyrimidone(UPy)-terminated PCL ***, the UPy-terminated PCL stars were physically crosslinked, which was evidenced by means of dynamic mechanical thermal analysis(DMTA) and rheological analysis. Owing to the formation of the physically-crosslinked networks, the organic-inorganic PCL stars displayed significant shape memory properties with about 100% of shape recovery, which was in marked contrast to the PCL stars without UPy termini.

关键词： POSS PCL Physical crosslinking Shape memory properties

Delivery methods for CRISPR/Cas9 gene editing in crustaceans

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Marine Life Science & Technology 2020年第1期2卷 1-5页

作者： sen xu Thinh Phu Pham Swatantra Neupane Department of Biology University of Texas at Arlington501 S.Nedderman Dr.ArlingtonTX 76019USA

In this mini-review,we provide an up-to-date overview of the delivery methods that have been used for CRISPR/Cas9 genomic editing in crustacean *** embryonic microinjection as the main workforce for delivering CRISPR/Cas9 reagents,biologists working with crustacean species have to tackle the technical challenges involved in *** use examples of three Crustacean species(the branchiopod Daphnia,amphipod Parhyale hawaiensis,and decapod Exopalaemon carinicauda)to provide a technical guide for embryonic ***,we outline two potentially useful new techniques for delivering CRISPR/Cas9 components into crustaceans,i.e.,Receptor-Mediated Ovary Transduction of Cargo(ReMOT Control)and electroporation.

关键词： Microinjection Electroporation Vitellogenesis Daphnia Parhyale hawaiensis Exopalaemon carinicauda

A nonprofiled side-channel analysis based on variational lower bound related to mutual information

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Science China(Information Sciences) 2023年第1期66卷 277-295页

作者： Chi ZHANG Xiangjun LU Pei CAO Dawu GU Zheng GUO sen xu School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Zhi xun Crypto Testing and Evaluation Technology Co. Ltd. 3. Viewsource Information Science and Technology Co. Ltd.

In this paper, we attempt to improve the practical performance of the nonprofiled side-channel analysis(Non SCA) with the help of neural networks. We first derive a variational lower bound related to mutual information(VLBRMI) optimized for the context of Non SCA, which possesses a set of adjustable parameters and whose maximum value linearly depends on the mutual information. Then, we propose a new Non SCA method called neural mutual information analysis(NMIA) that exploits the maximum VLBRMI as the distinguisher. We present an estimator of the maximum VLBRMI, which uses neural networks to instantiate the VLBRMI and trains the neural networks to approximate the maximum VLBRMI so that we can implement the NMIA efficiently. Finally, we evaluate the NMIA on several datasets. The experimental results show that NMIA outperforms the correlation power analysis, the mutual information analysis(MIA)based on histograms, the MIA based on kernel density estimation, and the state-of-the-art Non SCA method based on neural networks.

关键词： side-channel analysis nonprofiled method variational lower bound mutual information neural networks

Automatically Identifying Calling-Prone Higher-Order Functions of Scala Programs to Assist Testers

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Journal of Computer Science & Technology 2020年第6期35卷 1278-1294页

作者： Yi-sen xu Xiang-Yang Jia Fan Wu Lingbo Li Ji-Feng xuan School of Computer Science Wuhan UniversityWuhan 430072China Turing Intelligence Technology Limited LondonEC2Y 9STU.K.

For the rapid development of internetware, functional programming languages, such as Haskell and Scala, can be used to implement complex domain-specific applications. In functional programming languages, a higher-order function is a function that takes functions as parameters or returns a function. Using higher-order functions in programs can increase the generality and reduce the redundancy of source code. To test a higher-order function, a tester needs to check the requirements and write another function as the test input. However, due to the complex structure of higher-order functions, testing higher-order functions is a time-consuming and labor-intensive task. Testers have to spend an amount of manual effort in testing all higher-order functions. Such testing is infeasible if the time budget is limited, such as a period before a project release. In practice, not every higher-order function is actually called. We refer to higher-order functions that are about to be called as calling-prone ones. Calling-prone higher-order functions should be tested first. In this paper, we propose an automatic approach, namely PHOF, which predicts whether a higher-order function of Scala programs will be called in the future, i.e., identifying calling-prone higher-order functions. Our approach can assist testers to reduce the number of higher-order functions of Scala programs under test. In PHOF, we extracted 24 features from source code and logs to train a predictive model based on known higher-order function calls. We empirically evaluated our approach on 4832 higher-order functions from 27 real-world Scala projects. Experimental results show that PHOF based on the random forest algorithm and the Synthetic Minority Oversampling Technique Processing strategy (SMOTE) performs well in the prediction of calls of higher-order functions. Our work can be used to support the scheduling of limited test resources.

关键词： higher-order function testing tool test management Scala program internetware

In-situ carbonizing of coal pitch on the surface of silica sphere as quasi-graphitized carbon stationary phase for liquid chromatography

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Chinese Chemical Letters 2023年第7期34卷 219-221页

作者： sen xu Zhihua Zhong Yu Wang Lingyi Zhang Weibing Zhang Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry&Molecular EngineeringEast China University of Science and Technology.Shanghai200237China

A novel chromatography stationary phase with a quasi-graphitized carbon modified shell has been developed. Coal pitch was directly carbonized on the surface of porous silica with in-situ carbonization. The carbonized coal pitch coating exhibits some degree of graphitization with a 78 nm-thick layer on the surface of silica and a 0.5 nm-thick layer on the inner surface of the mesopores. Based on the special structure of the graphitized carbon coating, the novel stationary phase can provide multiple interactions such as hydrophobic interaction, π-π interaction and dipole-dipole interaction. The novel composite material exhibited unique separation selectivity and excellent separation efficiency for polar compounds, including imidazoles, nucleosides and pesticides. Besides, the packed column also exhibited great repeatability with the RSDs of the retention time of nucleosides between 0.07%-0.50%(n = 5). Finally, satisfied result was achieved in the separation of fullerenes on the new column, suggesting the great potential in the industrial-scale purification of fullerenes.

关键词： Graphitized carbon Coal pitch High performance liquid chromatography Chromatographic separation Fullerenes

Hazard evaluation of ignition sensitivity and explosion severity for three typical MH_(2) (M=Mg,Ti,Zr)of energetic materials

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Defence Technology（防务技术） 2021年第4期17卷 1262-1268页

作者： Xing-liang Wu sen xu Ai-min Pang Wei-guo Cao Da-bin Liu Xin-yu Zhu Fei-yang xu xu Wang School of Chemical Engineering Nanjing University of Science and TechnologyNanjingJiangsu210094PR China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechnologyXiangyang441003PR China School of Environmental and Safety Engineering North University of ChinaTaiyuan030051ShanxiPR China

MgH_(2),TiH_(2),and ZrH_(2) are three typical metal hydrides that have been gradually applied to composite explosives and propellants as additives in recent *** evaluate ignition sensitivity and explosion severity,the Hartmann device and spherical pressure vessel were used to test ignition energy and explosion pressure,*** results showed that the ignition sensitivity of ZrH_(2),TiH_(2) and MgH_(2) gradually *** the concentration of MgH_(2) is 83.0 g/m^(3) in Hartmann device,the ignition energy attained a minimum of 10.0 *** explosion pressure of MgH_(2) were 1.44 times and 1.76 times that of TiH_(2) and ZrH_(2),respectively,and the explosion pressure rising rate were 3.97 times and 9.96 times that of TiH_(2) and ZrH_(2),respectively,through the spherical pressure *** indicated that the reaction reactivity and reaction rate of MgH_(2) were higher than that of TiH_(2) and ZrH_(2).In addition,to conduct in edepth theoretical analysis of ignition sensitivity and explosion severity,gas production and combustion heat per unit mass of ZrH_(2),TiH_(2) and MgH_(2) were tested by mercury manometer and oxygen bomb *** experimental results revealed that MgH_(2) had a relatively high gas production per unit mass(5.15 mL/g),while TiH_(2) and ZrH_(2) both had a gas production of less than 2.0 mL/*** thermal stability gradually increased,leading to a gradual increase in ignition ***,compared with theoretical combustion heat,the combustion ratio of MgH_(2),TiH_(2) and ZrH_(2) was more than 96.0%,with combustion heat value of 29.96,20.94 and 12.22 MJ/kg,respectively,which was consistent with the explosion pressure and explosion severity test results.

关键词： Ignition energy Explosion pressure Reaction activity Combustion heat

Procyanidins Inhibit Tumor Angiogenesis by Crosslinking Extracellular Matrix

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Chinese Journal of Cancer Research 2011年第2期23卷 99-106页

作者： Wan-yin Zhai Chun-ping Jia Hui Zhao Yuan-sen xu State Key Lab of Transducer Technology Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200068 China Graduation School Chinese Academy of Sciences Beijing China Biomaterials and Tissue Engineering Research Center Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai China

Objective： Procyanidins （PC） are widely available natural polyphenols. The present study is designed to investigate if PC can inhibit angiogenesis in lung adenocarcinoma xenografts through crosslinking vascular extracellular matrix （ECM） and preventing proteolysis by matrix metalloproteinases （MMPs）. Methods： Using the in vitro MMP-2 proteolysis and in vivo subcutaneous implantation models, we investigated if PC crosslinking inhibits MMP-mediated proteolysis. Using a cultured cell detachment assay, an in vitro angiogenesis assay, and a cell proliferation assay, we investigated if PC inhibits MMP-2-mediated endothelial cell detachment, angiogenesis, and cell proliferation, respectively. Using tumor xenografts, we evaluated if PC can inhibit growth of lung adenocarcinoma. Results： PC crosslink vascular ECM proteins, protecting them against proteolysis by MMPs in vitro and in vivo, protecting cultured human umbilical vein endothelial cells from detachment by MMP-2, and inhibiting in vitro angiogenesis. However, PC （0.75-100 μg/mL） did not inhibit vascular and tumor cells proliferation. PC injections （30 mg PC/kg bodyweight） in situ had anticancer effects on xenografts of lung adenocarcinoma, most likely by inhibiting angiogenesis during ECM proteolysis by MMPs. Conclusion： The results suggest that PC may be important MMP inhibitors that can be used as therapeutic anticancer agents.

关键词： Procyanidins Crosslinking Extracellular matrix Matrix metalloproteinases Angiogenesis