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四水合1,1'-二羟基-5,5'-联四唑钠盐的合成、晶体结构及性能 被引量:7
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作者 黄海丰 杨军 +3 位作者 杨普 李晓强 李慧 俞艳 《含能材料》 EI CAS CSCD 北大核心 2014年第4期462-466,共5页
以二氯乙二肟为起始原料,通过一锅法合成了四水合1,1'-二羟基-5,5'-联四唑钠盐(SBTD·4H2O),并用红外、元素分析、扫描电子显微镜对其进行了表征,测试了目标化合物的单晶结构,结果表明其属于三斜晶系,P-1空间群,晶胞参数为a... 以二氯乙二肟为起始原料,通过一锅法合成了四水合1,1'-二羟基-5,5'-联四唑钠盐(SBTD·4H2O),并用红外、元素分析、扫描电子显微镜对其进行了表征,测试了目标化合物的单晶结构,结果表明其属于三斜晶系,P-1空间群,晶胞参数为a=5.6440(11),b=6.4476(17),c=8.303(11),α=100.131(5)°,β=96.789(3)°,γ=112.157(3)°,V=1,Dc=1.761 g·cm-3,F(000)=146,μ(Mo Kα)=0.227 mm-1。采用热重-差示扫描量热联用(TG-DSC)对其进行了热行为分析,在加热速率为10 K·min-1的条件下,该化合物从83.9℃开始失去结晶水,368.1℃开始分解,分解峰值温度为398.6℃,热稳定性良好。依据GJB772A-1997对SBT D·4H2O的感度进行了测试,撞击感度H50>100 cm,摩擦感度为0%,这表明其对机械撞击和摩擦不敏感。 展开更多
关键词 应用化学 四水合1 1'-二羟基-5 5'-联四唑钠盐(SBTD·4H2O) 热分解 晶体结构 感度 sodium 5 5'-bistetrazole-1 1'-diolate tetrahedrate (SBTD·4H2O)
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A combinatorial approach to surface reconstruction 被引量:1
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作者 XU Yan ZHANG Qiang +1 位作者 ZHOU Dongsheng WEI Xiaopeng 《Computer Aided Drafting,Design and Manufacturing》 2012年第4期21-28,共8页
This paper presents a reconstruction algorithm to build a surface mesh approximating an object from an unorganized point sampling of the boundary object. It combines 3D Delaunay tetrahedralization and mesh-growing met... This paper presents a reconstruction algorithm to build a surface mesh approximating an object from an unorganized point sampling of the boundary object. It combines 3D Delaunay tetrahedralization and mesh-growing method and uses only once Delau- nay triangulation. It begins with 3D Delaunay triangulation of the sampling. Then initialize the surface mesh with seed facets se- lected from Delaunay triangulation. Selection is based on the angle formed by the circumscribing ball of incident tetrahedral. Finally, grow until complete the surface mesh based on some heuristic rules. This paper shows several experimental results that demonstrate this method can handle open and close surfaces and work efficiently on various object topologies except non-manifold surface with self-intersections. It can reproduce even the smallest details of well-sampled surfaces but not work properly in every under-sampled situation that point density is too low. 展开更多
关键词 TRIANGULATION Delaunay tetrahedralization sharp features
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A Parallel Algorithm for Adaptive Local Refinement of Tetrahedral Meshes Using Bisection 被引量:30
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作者 Lin-Bo Zhang 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第1期65-89,共25页
Local mesh refinement is one of the key steps in the implementations of adaptive finite element methods. This paper presents a parallel algorithm for distributed memory parallel computers for adaptive local refinement... Local mesh refinement is one of the key steps in the implementations of adaptive finite element methods. This paper presents a parallel algorithm for distributed memory parallel computers for adaptive local refinement of tetrahedral meshes using bisection. This algorithm is used in PHG, Parallel Hierarchical Grid Chttp://lsec. cc. ac. cn/phg/), a toolbox under active development for parallel adaptive finite element solutions of partial differential equations. The algorithm proposed is characterized by allowing simukaneous refinement of submeshes to arbitrary levels before synchronization between submeshes and without the need of a central coordinator process for managing new vertices. Using the concept of canonical refinement, a simple proof of the independence of the resulting mesh on the mesh partitioning is given, which is useful in better understanding the behaviour of the biseetioning refinement procedure. 展开更多
关键词 Adaptive refinement BISECTION tetrahedral mesh parallel algorithm MPI.
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ALGORITHMS FOR TETRAHEDRAL NETWORK(TEN) GENERATION 被引量:11
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作者 LI Qingquan LI Deren 《Geo-Spatial Information Science》 2000年第1期11-16,共6页
The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN appli... The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN application is automatic creating data structure. Although a raster algorithm has been introduced by some authors, the problems in accuracy, memory requirement, speed and integrity are still existent. In this paper, the raster algorithm is completed and a vector algorithm is presented after a 3-D data model and structure of TEN have been introducted. Finally, experiment, conclusion and future work are discussed. 展开更多
关键词 3-D GIS tetrahedral network(TEN) generation algorithm
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Effects of tetrahedral framework nucleic acid/wogonin complexes on osteoarthritis 被引量:10
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作者 Sirong Shi Yang Chen +7 位作者 Taoran Tian Songhang Li Shiyu Lin Yuxin Zhang Xiaoru Shao Tao Zhang Yunfeng Lin Xiaoxiao Cai 《Bone Research》 CAS CSCD 2020年第1期84-96,共13页
Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, ... Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, inflammation should be inhibited, and chondrocyte proliferation should be promoted. Tetrahedral framework nucleic acids can be internalized by chondrocytes(even inflammatory chondrocytes) and can enhance their proliferation and migration. Wogonin, a naturally occurring flavonoid,suppresses oxidative stress and inhibits inflammation. In this study, tetrahedral framework nucleic acids were successfully selfassembled and used to load wogonin. We confirmed the effective formation of tetrahedral framework nucleic acid/wogonin complexes by dynamic light scattering, zeta potential analysis, transmission electron microscopy, and fluorescence spectrophotometry. Tetrahedral framework nucleic acids, wogonin, and especially tetrahedral framework nucleic acid/wogonin complexes effectively alleviated inflammation in vitro and in vivo and prevented cartilage destruction. In addition, these materials remarkably downregulated the expression of inflammatory mediators and matrix metalloproteinases, upregulated chondrogenic markers, and promoted tissue inhibitor of metalloproteinase 1 and B-cell lymphoma 2 expression. In vivo, after treatment with tetrahedral framework nucleic acid/wogonin complexes, the bone mineral density in regenerated tissues was much higher than that found in the untreated groups. Histologically, the complexes enhanced new tissue regeneration, significantly suppressed chondrocyte apoptosis, and promoted chondrogenic marker expression. They also inhibited cell apoptosis, increased chondrogenic marker expression, and suppressed the expression of inflammatory mediators in osteoarthritis. Therefore, we believe that tetrahedral framework nucleic acid/wogonin complexes can be used as an injectable form of therapy for osteoarthritis. 展开更多
关键词 COMPLEXES TETRAHEDRAL promoted
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Tetrahedral Framework Nucleic Acid-Based Delivery of Resveratrol Alleviates Insulin Resistance:From Innate to Adaptive Immunity 被引量:4
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作者 Yanjing Li Shaojingya Gao +5 位作者 Sirong Shi Dexuan Xiao Shuanglin Peng Yang Gao Ying Zhu Yunfeng Lin 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第6期1-16,共16页
Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current... Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current therapeutic approaches lack efficacy and immunomodulatory capacity.Thus,a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance.Here,we synthesized a tetrahedral framework nucleic acid(tFNA)nanoparticle that carried resveratrol(RSV)to inhibit tissue inflammation and improve insulin sensitivity in obese mice.The prepared nanoparticles,namely tFNAs-RSV,possessed the characteristics of simple synthesis,stable properties,good water solubility,and superior biocompatibility.The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy.In high-fat diet(HFD)-fed mice,the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status.tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages.As for adaptive immunity,the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg,leading to the alleviation of insulin resistance.Furthermore,this study is the first to demonstrate that tFNAs,a nucleic acid material,possess immunomodulatory capacity.Collectively,our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice,suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases. 展开更多
关键词 Tetrahedral framework nucleic acid RESVERATROL Insulin resistance INFLAMMATION Innate immunity Adaptive immunity
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Pollen morphology of Rhododendron subgen. Tsutsusi and its systematic implications 被引量:4
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作者 Yue-Jiao ZHANG Xiao-Fen JIN +1 位作者 Bing-Yang DING Jing-Ping ZHU 《Journal of Systematics and Evolution》 SCIE CSCD 北大核心 2009年第2期123-138,共16页
Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentant... Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera (G. Don) Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi (Sweet) Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding & Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera. 展开更多
关键词 ERICACEAE Rhododendron subgen. Tsutsusi pollen morphology tetrahedral tetrads systematic implication.
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Assessment of k–ε models using tetrahedral grids to describe the turbulent flow field of a PBT impeller and validation through the PIV technique 被引量:3
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作者 Victor X. Mendoza-Escamilla Alejandro Alonzo-Garcia +3 位作者 Helvio R. Mollinedo Israel Gonzalez-Neria J. Antonio Yanez-Varela Sergio A. Martinez-Delgadillo 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期942-956,共15页
In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has ... In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has an impact on the convergence and solution in STRs, and they are used in mixing, multiphase modeling or as starting solution of transient models as DES and LES. Although there are several studies with the pitched blade turbine(PBT) impeller, most of them used the Standard model as representative of all k–ε models, using structured hexahedral grids composed of low number of cells, and in some cases under axial symmetry assumptions.Accordingly, in this work the assessment of the Standard, RNG and Realizable models to describe the turbulent flow field of this impeller, using the Multiple Reference Frame(MRF) and Sliding Mesh(SM) approaches with tetrahedral domains in dense grids, is presented. This kind of cell elements is especially suitable to reproduce complex geometries. Flow velocities and turbulent parameters were verified experimentally by PIV and torque measurements. The three models were capable of predicting fairly the pumping number, the power number based on torque, and velocities. Although the RNG improved the predictions of the turbulent kinetic energy and dissipation rate, the Realizable model presented better performance for both approaches. All models failed in the prediction of the total dissipation rate, and a dependence of its value on the number of cells for the MRF was found. 展开更多
关键词 Tetrahedral grids PIV Turbulent flow k-ε models Stirred vessel
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Effect of Substrate Bias on Microstructure and Properties of Tetrahedral Amorphous Carbon Films 被引量:1
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作者 Jiaqi ZHU Jiecai HAN Songhe MENG Qiang LI Manlin TAN 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第z1期109-111,共3页
The microstructure and properties of tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum arc technology has been investigated by visible Raman spectroscopy, AFM and Nano-indentor. The R... The microstructure and properties of tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum arc technology has been investigated by visible Raman spectroscopy, AFM and Nano-indentor. The Raman spectra have been fitted with a single skewed Lorentzian lineshape described by BWF function defining coupling coefficient, which characterizes the degree of asymmetry and is correlated with the sp3 content. When the substrate bias is -80 V, the sp3 content is the most and simultaneously the coupling coefficient is the least, following with the minimum root mean square surface roughness (Rq=0.23 nm) and the highest hardness (51.49 GPa), Young′s modulus (512.39 GPa), and critical scratching load (11.72 mN). As the substrate bias is increased or decreased, the sp3 content and other properties lower correspondingly. 展开更多
关键词 TETRAHEDRAL AMORPHOUS carbon Filtered cathodic VACUUM arc Substrate BIAS
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Advances in regenerative medicine applications of tetrahedral framework nucleic acid-based nanomaterials: an expert consensus recommendation 被引量:1
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作者 Yunfeng Lin Qian Li +10 位作者 Lihua Wang Quanyi Guo Shuyun Liu Shihui Zhu Yu Sun Yujiang Fan Yong Sun Haihang Li Xudong Tian Delun Luo Sirong Shi 《International Journal of Oral Science》 SCIE CAS CSCD 2022年第4期439-460,共22页
With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versati... With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids(t FNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, t FNAs have been widely applied in the biomedical field as threedimensional DNA nanomaterials. Surprisingly, t FNAs exhibit positive effects on cellular biological behaviors and tissue regeneration,which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity,t FNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization,intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic t FNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic t FNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone,cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases. 展开更多
关键词 TETRAHEDRAL summarized VERSATILE
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Structural Characterization of Chiral Sulfido Cluster(η~5-C_5H_5) WFeCo(CO)_8 (μ_3-S) 被引量:1
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作者 XU Feng SUN Wen-Hua +1 位作者 YANG Shi-Yan YIN Yuan-Qi (State Key Laboratory for OXO Synthesis and Selected Oxidation Annzhou Institute of Chemical Physics, the Chinese Academy of Sciences , Lanzhou 730000)WU Qiang-Jin(Fujnin Institute of Research on the S 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1997年第1期59-63,共5页
The chiral sulfido cluster (η5-C5H5)WFeCo(CO)8(μ3--S) was synthesized by refluxing a solution of HFe2Co(CO)9 (μ3,--S) and (η5-C5H5)Fe(CO)3Cl in tetrahydrofuran. It was characterized by elemental analysis, IR and 1... The chiral sulfido cluster (η5-C5H5)WFeCo(CO)8(μ3--S) was synthesized by refluxing a solution of HFe2Co(CO)9 (μ3,--S) and (η5-C5H5)Fe(CO)3Cl in tetrahydrofuran. It was characterized by elemental analysis, IR and 1H/13C--NMR. Theproposal concerning mechanism was discussed herewith and the structure was reportedas well. Crystallographic data: Mr= 563. 85, monoclinicl P21/n(# 14); a= 8. 009(2), b= 17. 600(5), c=12. 003(4) A; β=95. 91(2)°; V= 1683. 0 (9) A3; Z=4;Dc=2. 22 g. cm-3; F(000) = 1048, μ=89. 27 cm-1 ; final R=0. 039 and Rw=0. 049for 2121 observable reflections with (I≥3. cσ(I) ). The crystal structure determinationshows that S atom coordinates to all three metal (W,Fe,Co) atoms in a μ3,-fashion,thetitle cluster core has the tetrahedral skeleton. 展开更多
关键词 heterometallic cluster CARBONYL SULFIDO tetrahedral framework
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Optical Properties of Tetrahedral Amorphous Carbon Films and Their Potential for Lab-on-a-Chip 被引量:1
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作者 Katja Guenther Frank Sonntag +1 位作者 Teja Roch Andrés Fabián Lasagni 《Materials Sciences and Applications》 2015年第5期445-455,共11页
In this study, tetrahedral amorphous carbon (ta-C) films with thicknesses between several 100 nm and several micrometers have been deposited onto polished tungsten carbide and steel substrates by pulsed laser depositi... In this study, tetrahedral amorphous carbon (ta-C) films with thicknesses between several 100 nm and several micrometers have been deposited onto polished tungsten carbide and steel substrates by pulsed laser deposition (PLD) using an excimer laser (248 nm wavelength). We investigate the optical properties (e.g. the refractive index (n) and extinction coefficient (k) in the visible and near-infrared wavelength range) of these layers in dependence of the used laser ablation fluence on the target. It is shown that n of ~2000 nm thick ta-C films can be tuned, depending on the sp3-content, between n = 2.5 and 2.8 at a wavelength of 632 nm. Besides of this k reduces with the sp3-content and is as low as 0.03 at sp3-contents of more than 75%. We proof that this gives the opportunity to prepare coating with tailored optical properties. Furthermore, it is shown that the ta-C films have low background fluorescence in the wavelengths range of 380 - 750 nm, which make this thin films attractive for certain optical, medical and biotechnological applications. We present for the first time that one possible application is the use in Lab-on-a-Chip-systems (LOC). Within these systems, the ultrasensitive detection of fluorescence markers and dyes is a challenge. In order to increase the signal-to-noise-ratio, a setup was developed, that used the specific optical properties of ta-C films produced by PLD. We used the ta-C film as an integrated reflector that combined low background fluorescence, a low reflectivity at the excitation wavelength and the high reflectivity at the emission wavelength. We prove that this setup improves the detection of fluorescence photons. 展开更多
关键词 TETRAHEDRAL AMORPHOUS CARBON PULSED Laser Deposition Thin Films DIAMOND-LIKE CARBON LAB-ON-A-CHIP
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Un-thorough Delaunay Approach for Tetrahedral Mesh Generation 被引量:1
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作者 LI Yang FENG Wei ZHOU Hua-min 《Computer Aided Drafting,Design and Manufacturing》 2007年第2期82-90,共9页
An integrated tetrahedrization algorithm in 3D domain which combines the Delaunay tetrahedral method with un-Delaunay tetrahedral method is described. The algorithm was developed by constructing Delaunay Tetrahedrons ... An integrated tetrahedrization algorithm in 3D domain which combines the Delaunay tetrahedral method with un-Delaunay tetrahedral method is described. The algorithm was developed by constructing Delaunay Tetrahedrons from a scattered point set, recovering boundaries using Delaunay and un-Delaunay method, inserting additional nodes in unsuitable tetrahedrons, optimizing tetrahedrons and smoothing the tetrahedral mesh with the 2D-3D Laplacian method. The algorithm has been applied to the injection molding CAE preprocessing. 展开更多
关键词 boundary constraints boundary recovery Delaunay tetrahedrization inserting nodes optimizing tetrahedrons
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SYNTHESES OF TETRAHEDRAL METAL CLUSTER COMPOUNDS
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作者 Yuan Qi YIN Hong Sui SUN Zhuan Yun ZHAO 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第7期551-554,共4页
The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2... The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2Mo(μ_3-CC_6H_5) Br(CO)_9(Py)_2 (3) and Mn_2Mo(μ_3-CC_6H_5)Br(CO)_(10) (Py)_2 (4) respectively. Tri-metal cluster compound Co_2Mo(μ_3-CC_6H_5)Br(CO)_8-(bipy) (bipy=α,α'dipyridyl) (5) is prepared in a similar reaction sequence from [Br(CO)_2(bipy)Mo(≡CC_6H_5)] (1b) and Co_2(CO)_8. IR, ~1H and ^(13)C NMR spectral data of these compounds are reported and discussed. The crystal structure of compound (5) has been determined by X-ray diffraction. 展开更多
关键词 CO BR Hs SYNTHESES OF TETRAHEDRAL METAL CLUSTER COMPOUNDS CO HO
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^(27)Al MAS-NMR study of inorganic polymer formation at ambient temperature
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作者 Sang-Wook AHN Hee-Soo LEE +2 位作者 Wan-Hee YANG Jung-Woo LEE Young-Keun JEONG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第A01期182-187,共6页
Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alka... Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and AI atoms to dissolve from a feedstock such as aluminosilicate. A study of 27A1 MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy (SEM) and X-ray diflYactometry (XRD) were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different A1/Si mole ratios from the starting materials. The higher the AI content, the more sufficient the AI atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si--O--A1--O polymer structure, and then the higher the A1 content, the fewer the octahedral A1 with a uniform Si--O--A1--O structure in four directions, because four AI atoms are combined with SiO4, resulting in a uniform Si--O--AI--O structure in four directions. The results show that they have an amorphous microstructure. 展开更多
关键词 inorganic polymer AMORPHOUS TETRAHEDRAL
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ENHANCING ADHESION OF TETRAHEDRAL AMORPHOUS CARBON FILMS
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作者 赵玉清 林毅 +2 位作者 王晓艳 王炎武 魏新宇 《Journal of Pharmaceutical Analysis》 SCIE CAS 2005年第1期33-35,39,共4页
Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method... Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method, scratch method, heating and shaking method as well as boiling salt solution method is used to test the adhesion of the TAC films on various material substrates. Results The test results show that the adhesion is increased as the ion bombardment energy increases. However, if the bombardment energy were over the corresponding optimum value, the adhesion would be enhanced very slowly for the harder material substrates and drops quickly, for the softer ones. Conclusion The optimum values of the ion bombardment energy are larger for the harder materials than that for the softer ones. 展开更多
关键词 tetrahedral amorphous carbon filtered cathode vacuum arc ion bombardment ADHESION
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Application of High Performance Liquid Chromatography to Separation of Novel Chiral Tetrahedral Heterometal Clusters
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作者 Xin Yi ZHU, Wei Qiang ZHANG, Yu Hua ZHANG, Li Ren CHEN, Yong Min LI Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第9期942-945,共4页
A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mo... A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mobile phase with various alcohols as modifiers. 展开更多
关键词 Chiral stationary phase cellulose tris-(3 5-dimethylphenylcarbamate) mobile-phase composition chiral tetrahedral clusters enantioseparation.
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An h-Adaptivity DG Method on Locally Curved Tetrahedral Mesh for Solving Compressible Flows
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作者 AN Wei HUANG Zenghui LYU Hongqiang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第5期702-712,共11页
For the numerical simulation of compressible flows,normally different mesh sizes are expected in different regions.For example,smaller mesh sizes are required to improve the local numerical resolution in the regions w... For the numerical simulation of compressible flows,normally different mesh sizes are expected in different regions.For example,smaller mesh sizes are required to improve the local numerical resolution in the regions where the physical variables vary violently(for example,near the shock waves or in the boundary layers)and larger elements are expected for the regions where the solution is smooth.h-adaptive mesh has been widely used for complex flows.However,there are two difficulties when employing h-adaptivity for high-order discontinuous Galerkin(DG)methods.First,locally curved elements are required to precisely match the solid boundary,which significantly increases the difficulty to conduct the"refining"and"coarsening"operations since the curved information has to be maintained.Second,h-adaptivity could break the partition balancing,which would significantly affect the efficiency of parallel computing.In this paper,a robust and automatic h-adaptive method is developed for high-order DG methods on locally curved tetrahedral mesh,for which the curved geometries are maintained during the h-adaptivity.Furthermore,the reallocating and rebalancing of the computational loads on parallel clusters are conducted to maintain the parallel efficiency.Numerical results indicate that the introduced h-adaptive method is able to generate more reasonable mesh according to the structure of flow-fields. 展开更多
关键词 h-adaptivity discontinuous Galerkin(DG)method curved mesh tetrahedral mesh compressible flows
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Synthesis and Re-refinement of Cu_3PSe_4
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作者 马宏伟 郭国聪 +4 位作者 周国伟 王明盛 林善伙 董振超 黄锦顺 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第3期288-291,共4页
The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space g... The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.685(2), b = 6.656(1), c = 6.377(1) , V = 326.2(1) 3, Z = 2, Dc = 5.472 g/cm3, Mr = 537.43, F(000) = 476, m = 32.12 mm-1, R = 0.0642, wR = 0.1481 and S = 1.037. The 3-D structure can be regarded as constructed from the alternately stacking of [Cu(2)Se4] tetrahedral layers and Cu(1)PSe tetrahedral layers along the b direction, in which the Cu(2)Se layer is comprised of corner-sharing [Cu(2)Se4] tetrahedra along the a and c directions, and the Cu(1)PSe layer is consisted of alternately corner-sharing [Cu(1)Se4] tetrahedra and [PSe4] tetrahedra along the a and c directions. 展开更多
关键词 solid state reaction normal tetrahedral structure metal chalcogenophosphide
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Synthesis and Structure of Ag_3PSe_4
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作者 马宏伟 郭国聪 +4 位作者 陈文通 邓镭 周国伟 董振超 黄锦顺 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2003年第2期161-164,共4页
The title compound Ag3PSe4 was synthesized by the reaction of Ag powder, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, sp... The title compound Ag3PSe4 was synthesized by the reaction of Ag powder, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.689(4), b = 6.660(3), c = 6.379(4) , V = 326.7(3) 3, Z = 2, Dc = 6.816 g/cm3, Mr = 670.42, F(000) = 584, m = 31.302 mm-1, R = 0.0606, wR = 0.1289 and S = 1.012. The 3-D structure can be regarded as constructed from the stacking of puckered AgPSe honeycomb-like sheets along the c direction, in which the Ag, P and Se atoms are bonded to each other to form a chair-like six-membered ring, and the rings then build the sheets by sharing edges. 展开更多
关键词 solid state reaction normal tetrahedral structure metal chalcogenophosphide
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