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Microstructure and Toughness of Seeded Hot-Pressed Si_3N_4 Ceramics

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Journal of Materials Science & Technology 2004年第3期20卷 241-244页

作者： D.Bucevac S.Boskovic M.Vlajic V.Krstic Institute of Nuclear Sciences vinca Materials Sci.Lab.POB 52211001 BelgradeSerbia and MontenegroInstitute of Nuclear Sciences vincaMaterials Sci.Lab.POB 52211001 BelgradeSerbia and MontenegroCentre for Manufacturing of Advanced Ceramics and NanomaterialsQueens UniversityNicol HallKingstonOntarioCanadaCentre for Manufacturing of Advanced Ceramics and NanomaterialsQueens UniversityNicol HallKingstonOntarioCanada

Densification, phase transformation and fracture toughness were studied in hot-pressed Si_3N_4 seeded by in-houseproduced large, elongated β-Si_3N_4 seeds. A mixture of Y_2O_3-Al_2O_3 was used as the sintering aid. Concentration ofseeds were varied from 0 to 6 wt pct and the sintering time at 1700℃ was varied from 1 to 4 h. Maximum fracturetoughness of 9.0 MPam^(1/2) was measured in samples containing 5 wt pct seeds, hot pressed at 1700℃ for 4 h.

关键词： In-situ composites Seeds Hot-pressing Silicon nitride

Battery Separators Functionalized with Edge-Rich MoS2/C Hollow Microspheres for the Uniform Deposition of Li2S in High-Performance Lithium-Sulfur Batteries

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Nano-Micro Letters 2019年第3期11卷 104-118页

作者： Nan Zheng Guangyu Jiang Xiao Chen Jiayi Mao Nan Jiang Yongsheng Li lab.of Low-Dimensional Materials Chemistry Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical Nanomaterials School of Materials Science and Engineering East China University of Science and Technology

As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy ***,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical *** this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of *** microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization *** obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of ***,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high *** a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg ***,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 *** work provides fresh insights into energy storage systems related to complex phase conversions.

关键词： Edge-rich MoS2/C Hollow microspheres Li2S Lithium-sulfur batteries

Microscale methods to assemble mammalian cells into tissue-like structures

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Science China(Life Sciences) 2012年第10期55卷 862-871页

作者： GONG PeiYuan ZHENG WenFu XIAO Dan JIANG XingYu College of Chemistry Sichuan UniversityChengdu 610064China Key lab.for Biological Effects of nanomaterials and Nanosafety National Center for Nanoscience and TechnologyBeijing 100190China

Different cell types make up tissues and organs hierarchically and communicate within a complex, three-dimensional (3D) en- vironment. The in vitro recapitulation of tissue-like structures is meaningful, not only for fundamental cell biology research, but also for tissue engineering (TE). Currently, TE research adopts either the top-down or bottom-up approach. The top-down approach involves defining the macroscopic tissue features using biomaterial scaffolds and seeding cells into these scaffolds. Conversely, the bottom-up approach aims at crafting small tissue building blocks with precision-engineered structural and functional microscale features, using physical and/or chemical approaches. The bottom-up strategy takes advantage of the repeating structural and functional units that facilitate cell-cell interactions and cultures multiple cells together as a functional unit of tissue. In this review, we focus on currently availab.e microscale methods that can control mammalian cells to assemble into 3D tissue-like structures.

关键词：哺乳动物细胞组织结构组装微尺度自底向上支架材料细胞生物学组织工程

Engineering of drug nanoparticles by HGCP for pharmaceutical applications

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Particuology 2008年第4期6卷 239-251页

作者： Ting-Ting Hua, Jie-Xin Wanga, Zhi-Gang Shena, Jian-Feng Chena,b, a Key lab.for nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, China b Research Center of Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029, China Key lab.for nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Research Center of Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical Technology Beijing 100029 China

This paper reviews our work on the fundamental principles of high gravity controlled precipitation (HGCP) technology, and its applications in the production of drug nanoparticles, which was carried out in a rotating packed bed (RPB). Several kinds of drug nanoparticles with narrow particle size distributions (PSDs) were successfully prepared via HGCP, including the 300-nm Cefuroxime Axetil (CFA) particles, 200–400-nm cephradine particles, 500-nm salbutamol sulfate (SS) particles (100 nm in width), and 850-nm beclomethasone dipropionate (BDP) particles, etc. Compared to drugs availab.e in the current market, all the drug nanoparticles produced by HGCP exhibited advantages in both formulation and drug delivery, thus improving the bioavailab.lity of drugs. HGCP is essentially a platform technology for the preparation of poorly water-soluble drug nanoparticles for oral and injection delivery, and of inhalab.e drugs for pulmonary delivery. Consequently, HGCP offers potential applications in the pharmaceutical industry due to its cost-effectiveness, efficient processing and the ease of scaling-up.

关键词： High gravity controlled precipitation Rotating packed bed Drug nanoparticle Poorly water-soluble drug Inhalab.e drug

Preparation of ultrafine chitosan particles by reverse microemulsion

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China Particuology 2007年第6期5卷 384-390页

作者： Guogen Liu Lei Shao Fei Ge Jianfeng Chen Key lab.for nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Research Center of Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical Technology Beijing 100029 China

Ultrafine chitosan particles were prepared by reverse microemulsion consisting of water, Triton X-100, octanol and cyclohexane. Two methods of preparing ultrafine chitosan particles were adopted and compared using TEM and IR, and possible mechanisms for the formation of ultrafine chitosan particles were proposed. Experimental results show that the method which combined ionic gelation and cross-linking gave uniformly sized chitosan nanoparticles with an average diameter of 92 nm, while the cross-linking without ionic gelation produced spindly chitosan particles with an average length of 943 nm and width of 188 nm.

关键词： Chitosan Ultrafine particles Microemulsion

TiO_2-modified nano-egg-shell Pd catalyst for selective hydrogenation of acetylene

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Particuology 2010年第3期8卷 251-256页

作者： Jin Gao Qiufeng Zhu Lixiong Wen Key lab.for nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical Technology Beijing 100029 China

Pd-based egg-shell nano-catalysts were prepared using porous hollow silica nanoparticles （PHSNs） as support, and the as-prepared catalysts were modified with TiO2 to promote their selectivity for hydro-genation of acetylene. Pd nanoparticles were loaded evenly on PHSNs and TiO2 was loaded on the active Pd particles. The effects of reduction time and temperature and the amount of TiO2 added on catalytic per-formances were investigated by using a fixed-bed micro-reactor. It was found that the catalysts showed better performance when reduced at 300 ℃ than at 500℃, and if reduced for 1 h than 3 h. When the amount of Ti added was 6 times that of Pd, the catalyst showed the highest ethylene selectivity.

关键词： Egg-shell nano-catalyst Porous hollow silica nanoparticles Modification Selective hydrogenation Acetylene

Preparation of mesoporous silica microspheres with multi-hollow cores and their application in sustained drug release

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Particuology 2010年第5期8卷 447-452页

作者： Chen Zhang Tian Hou Jianfeng Chen Lixiong Wen Key lab.for nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Research Center of the Ministry of Education for High Gravity Engineering & Technology Beijing University of Chemical Technology Beijing 100029 China

Mesoporous silica microspheres with multi-hollow cores （MSMMCs） were prepared by an O1/W/O2 double emulsion technique. When tetraethyl orthosilicate （TEOS） was hydrolyzed in the O1/W/O2 double emulsion with P123 （a triblock copolymer with a formula of HO（CH2CH20）20（CH2CH（CH3）O）70（CH2CH2O）20H） dissolved in the aqueous phase, the internal oil droplets would serve as templates for the empty hollow cores, P123 function as templates for the mesopores in the shell, and the aqueous phase act as space-limiting micro-reactors for the hydrolysis process, thus forming MSMMCs with controllab.e size and hollow cores. After further modification by a high-temperature aging process, the prepared MSMMCs had a diameter of 2-10 μm, with macromulti-hollow cores with a size of 100-1000 nm, mesopores in the shell with a size of 3.8-4.4 nm, and a surface area of 383-735 m2/g. In addition, MSMMCs were used as carriers to load avermectin through an immersing and evaporating process, and the loaded avermectin showed a well sustained release behavior from the MSMMCs matrix. This study demonstrated a promising and simple method for preparing silica micro-particles with porous multi-hollow core structure for sustained release applications.

关键词： SilicaPreparationHollow structureSustained release

Diffusion of H2, CO, N2,O2 and CH4 Through Nanoporous Carbon Membranes

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Chinese Journal of Chemical Engineering 2008年第5期16卷 709-714页

作者：吴志强刘志平汪文川范益群徐南平 Division of Molecule and Materials Simulation Key Lab for Nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China Membrane Science and Technology Research Center Nanjing University of Technology Nanjing 210009 China

通过 nanoporous 碳膜的纯 H2，公司， N2， O2 和 CH4 气体的散开被执行非平衡调查分子的动力学(NEMD ) 模拟。为与各种各样的毛孔宽度通过碳膜扩散的纯气体的流动，运输扩散性和激活精力被调查。模拟结果表明那运输扩散性与温度和毛... 详细信息

通过 nanoporous 碳膜的纯 H2，公司， N2， O2 和 CH4 气体的散开被执行非平衡调查分子的动力学(NEMD ) 模拟。为与各种各样的毛孔宽度通过碳膜扩散的纯气体的流动，运输扩散性和激活精力被调查。模拟结果表明那运输扩散性与温度和毛孔宽度增加，并且它的价值有 10 的大小 ? 7 m2 路 s ? 1 为在 273 ～ 300 K 的大约 0.80 ～ 1.21 nm 的毛孔宽度。为通过有各种各样的毛孔宽度的膜的气体散开的激活精力是大约 1 鈥吗？kJ 路 m ol ? 1。运输扩散性的结果与 Rao 和政府的是可比较的(J。Membr。Sci， 1996 ) ，显示 NEMD 模拟方法是为在多孔的材料为气体预言运输扩散性的一个好工具，它精确地总是是困难的是由实验测量了。

关键词： H2 CO N2 O2 CH4 碳膜扩散化工过程

A zwitterionic polymer-inspired material mediated efficient CRISPR-Cas9 gene editing

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Asian Journal of Pharmaceutical Sciences 2022年第5期17卷 666-678页

作者： Lingmin Zhang Langyu Yang Jionghua Huang Sheng Chen Chuangjia Huang Yinshan Lin Ao Shen ZhouYikang Zheng Wenfu Zheng Shunqing Tang Key lab.ratory of Molecular Target&Clinical Pharmacology and the State&NMPA Key lab.ratory of Respiratory Disease School of Pharmaceutical Sciences&The Third and Fifth Affiliated HospitalGuangzhou Medical UniversityGuangzhou 511436China Department of Biomedical Engineering Jinan UniversityGuangzhou 510632China CAS Key lab.for Biological Effects of nanomaterials and Nanosafety National Center for NanoScience and TechnologyBeijing 100190China

The typeⅡ prokaryotic CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR/Cas9) adaptive immune system is a cutting-edge genome-editing ***,its applications are still limited by its inefficient ***,we present a novel gene vector,the zwitterionic polymer-inspired material with branched structure (ZEBRA) for efficient CRISPR/Cas9 ***-like kinase 1 (PLK1) acts as a master regulator of mitosis and overexpresses in multiple tumor *** Cas9 and single guide sgRNA (sgRNA)-encoded plasmid was transduced to knockout Plk1 gene,which was expected to inhibit the expression of *** studies demonstrated that ZEBRA enabled to transduce the CRISPR/Cas9 system with large size into the cells *** transduction with ZEBRA was cell line dependent,which showed~10-fold higher in CD44-positive cancer cell lines compared with CD44-negative ***,ZEBRA induced highlevel expression of Cas9 proteins by the delivery of CRISPR/Cas9 and efficient gene editing of Plk1 gene,and inhibited the tumor cell growth *** zwitterionic polymerinspired material is an effective and targeted gene delivery vector and further studies are required to explore its potential in gene delivery applications.

关键词： CRISPR/Cas9 Gene editing Zwitterionic polymers CD44 PLK1