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Effect of a Ti plus c Granule Size on combustion in a Nitrogen Flow

cOMBUSTION EXPLOSION AND SHOcK WAVES 2021年第1期57卷 60-66页

作者： Seplyarskii, B. S. Kochetkov, R. A. Lisina, T. G. Abzalov, N. I. Russian Acad Sci Merzhanov Inst Struct Macrokinet & Mat Sci Chernogolovka 142432 Russia

Dependence of the combustion of a Ti + c granular charge on a granule size is experimentally studied. It is revealed that the burning rate of a granular mixture of all fractions used in the work is higher than the burning rate of a bulk-density powder mixture. It is shown that, with a decrease in the granule size, the burning rate of the charge in the absence of gas decreases due to an increase in the number of boundaries between the granules per unit length of the sample. A strong influence of the nitrogen flow on the burning rate of both coarse and fine granules is established. It is shown that, in contrast to fine granules, an increase in the nitrogen flow rate of coarse granules up to 600 liters/h leads to a transition to convective combustion. The studies performed indicate that, despite the structural analogy between mechanically activated and granular mixtures, the relationship between the combustion time and the front transition time in granular mixtures is completely different. This means that the combustion of granular mixtures even in the absence of a gas flow cannot be explained within the framework of a microheterogeneous model.

关键词： SHS Ti + c granule size cocurrent gas flow convective combustion microheterogeneous model

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Laser flash photolysis of fullerols of c_(60) and of c_(70) in aqueous solutions

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Science china chemistry 1998年第3期41卷 259-265页

作者：陆长元姚思德王文锋童永彭林维真荣廷文林念芸 Laboratory of Radiation Chemistry Shanghai Institute of Nuclear Research Chinese Academy of Sciences Shanghai China Nuclear Analysis Center Shanghai Institute of Nuclear Research Chinese Academy of Sciences Shanghai China

Fullerols of c 60 and of c 70 \ [c 60 (OH)\-\%n\%, c 70 (OH)\-\%m\%], water\|soluble fullerene derivatives, unlike some other fullerene derivatives (such as c 60 (c\-4H\-6O), c 60 (c\-3H\-7N) and c 60 [c(cOOEt)\-2]\-\%x\%), do not result in excited triplet state but in ionization via monophotonic process in aqueous solutions with 248 nm laser. The quantum yields of formation of hydrated electron ( Φ e - ) are determined to be 0.08 and 0.11 for fullerols of c 60 and of c 70 respectively at room temperature (ca. 15℃) with KI solution used as reference. By laser flash photolysis and oxidation of sulfate radical anion SO -· \-4, the fullerol radical cation or neutral radical of c 60 is confirmed to be existent and the transient absorption spectra of fullerol radical cation of c 70 are observed for the first time.

关键词： fullerol of c 60 fullerol of c 70 laser flash photolysis monophotonic ionization radical.

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comparison of ESI-MS/MS and APcI-MS methods for the quantification of folic acid analogs in c. elegans

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JOURNAL OF MASS SPEcTROMETRY 2019年第4期54卷 316-327页

作者： Annibal, Andrea Tam, Hannah Latza, christian Antebi, Adam Max Planck Inst Biol Ageing Cologne Germany Univ Cologne Cologne Excellence Cluster Cellular Stress Respon Cologne Germany

Folic acid (FA) plays a vital role in central metabolism, including the one carbon cycle, nucleotide, and amino acid biosynthesis. The development of sensitive, accurate analytical methods to measure FA intermediates in tissues is critical to understand their biological roles in diverse physiological and pathological contexts. Here, we developed a highly sensitive method for the simultaneous quantification of FA intermediates in the nematode caenorhabditis elegans as a model to dissect metabolic networks. The method was further validated by analyzing the worm folate pool upon RNAi knockdown of the dihydrofolate reductase gene dhfr-1. comparative mass spectrometry behavior of the FA analogs using two different ion sources, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APcI), revealed ESI-MS/MS to be more sensitive, but APcI-MS provided more detailed structure inferences, which can elucidate chemical investigation and synthesis of FA analogs. Finally, we report on the use of in vitro oxidation coupled with high-resolution mass spectrometry as a tool to discover new endogenous FA derivatives in the nematode.

关键词： APcI c elegans dhfr-1 ESI folic acid

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Tribological behavior and wear mechanism of c/c-Sic brake discs based on third-body layer

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INTERNATIONAL JOURNAL OF APPLIED cERAMIc TEcHNOLOGY 2023年第2期20卷 1310-1326页

作者： Hui, Yang Liu, Guimin Shi, Ruidong Zhang, Yong Yan, Tao Acad Army Armored Forces Dept Equipment Maintenance & Remfg Engn Beijing 100072 Peoples R China

c/c-Sic composites are promising candidates for heavy-duty tracked vehicle brake discs. A third-body layer (TBL) can be formed on the surface of c/c-Sic self-mated brake discs, which has an important impact on tribological behavior and wear mechanism of brake discs. Herein, the formation conditions and evolution process of TBL and its effect on friction and wear properties were investigated. An appropriate braking pressure and speed (P and V) are beneficial to the cutting of asperities and refinement of wear debris on the contact surface, which are preconditions for the formation of original TBL. The original TBL can be formed under the P center dot V of 12, 15, and 16, which effectively improve braking stability and reduce the wear rate. During the continuous braking process, the original TBL undergoes growth, stabilization, destruction, and regeneration. Under the frictional heat and compressive stress, wear debris gradually evolves into a uniform and dense TBL. The average coefficient of friction and wear rate reach to the lowest value of .446 and 38.5 x 10(-3) cm(3)/MJ, respectively. A continuous high temperature in the later stages of braking leads to severe oxidative wear. The newly formed TBL covers the original surface to form a multilayered structure, indicating the TBL undergoes destruction and regeneration.

关键词： c c-Sic friction third-body layer tribological behavior wear mechanism

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combustion synthesis of c/MgAl2O4 composite powders using magnesium oxalate as carbon source

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INTERNATIONAL JOURNAL OF APPLIED cERAMIc TEcHNOLOGY 2019年第3期16卷 1253-1263页

作者： Lv, Lihua Xiao, Guoqing Ding, Donghai Ren, Yun Yang, Shoulei Yang, Pan Hou, Xing Xian Univ Architecture & Technol Coll Mat & Mineral Resources Xian Shaanxi Peoples R China

In order to solve the bottleneck problems including uniform distribution, and oxidation resistance of nano carbons in oxide ceramics, c/MgAl2O4 composite powders were prepared with Mgc2O4 center dot 2H(2)O, MgO2, Al2O3, and Al as raw materials via combustion method under argon atmosphere. The maximum adding amount of Mgc2O4 center dot 2H(2)O is 34.34 wt%. The phase compositions and microstructures of combustion products were characterized through X-ray diffraction (XRD), scanning electron microscope (SEM)/EDX, and Raman spectroscopy. The results showed that the phases of products are mainly composed of MgAl2O4 and carbon. The prepared MgAl2O4 has granular and rod-like morphologies, and the free carbon (1.172 wt%) exists between particles of MgAl2O4. Moreover, the addition of Fec2O4 as catalyst in raw materials ratio would be beneficial for improving crystallization of in situ carbon generated in the products. The oxidation activation energy of the prepared c/MgAl2O4 composite powders was calculated as 143.01 kJ/mol which was 22.17% higher than that of carbon black/MgAl2O4 powders (117.06 kJ/mol), suggesting that the c/MgAl2O4 composite powders prepared by combustion synthesis have excellent oxidation resistance.

关键词： c MgAl2O4 composite powders combustion synthesis microstructure

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A sound polymorphic type system for a dialect of c

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ScIENcE OF cOMPUTER PROGRAMMING 1998年第1-3期32卷 49-72页

作者： Smith, G Volpano, D Florida Int Univ Sch Comp Sci Miami FL 33199 USA USN Postgrad Sch Dept Comp Sci Monterey CA 93943 USA

Advanced polymorphic type systems have come to play an important role in the world of functional programming. But, so far, these type systems have had little impact upon widely used imperative programming languages like c and c++. We show that ML-style polymorphism can be integrated smoothly into a dialect of c, which we call Polymorphic c. It has the same pointer operations as c, including the address-of operator &, the dereferencing operator *, and pointer arithmetic. We give a natural semantics for Polymorphic c, and prove a type soundness theorem that gives a rigorous and useful characterization of what can go wrong when a well-typed Polymorphic c program is executed. For example, a well-typed Polymorphic c program may fail to terminate, or it may abort due to a dangling pointer error. Proving such a type soundness theorem requires a notion of an attempted program execution;we show that a natural semantics gives rise quite naturally to a transition semantics, which we call a natural transition semantics, that models program execution in terms of transformations of partial derivation trees. This technique should be generally useful in proving type soundness theorems for languages defined using natural semantics. (c) 1998 Elsevier Science B.V. All rights reserved.

关键词： c type systems polymorphism variables pointers type soundness natural semantics transition semantics

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Ultrasensitive Detection of Hepatitis c Virus DNA Subtypes Based on cucurbituril and Graphene Oxide Nano-composite

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chemical Research in chinese Universities 2020年第2期36卷 307-312页

作者： JIANG Ping LI Yifei JU Ting cHENG Wenbo XU Jianhua HAN Kun University of Science and Technology of China Hefei 230027P.R.China C/LS Key Lab of Bio-medical Diagnostics Suzhou Institute of Biomedical Engineering and TechnologyChinese Academy of SciencesSuzhou 215163P.R.China University of Chinese Academy of Sciences Beijing 100049P.R China Institute of Optics and Electronics Chengdu 610209P.R.China Laboratory of Oncology Science and Molecular Biology Shunde Hospital of Guangzhou University of Chinese MedicineFoshan 528333P.R.China

Infectious of hepatitis c viruses(HcVs)lead to hepatic fibrosis,cirrhosis even *** rapid and sensitive diagnostic method for HcV is of great *** on the host-and-guest interaction between cucurbit[7]uril(cB[7])and methylene blue(MB),a cB[7]-graphene nano-composite(cB[7]-N3-GO)is raised for the electrochemical detection of HcV *** method is able to linearly detect the HcV nucleic acid in the range of 0.2—10 nmol/L with detection limit as low as 160.4 pmol/*** proposed detection strategy is able to discriminate the lb and 6k subtypes of HcV and has a prospective potential in the blood screen for HcV in clinical diagnosis.

关键词： Hepatitis c virus cucurbituril Graphene Nano-composite Assay

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SELEcTIVE HYDROGENATION OF 3,4-DIMETHOXYBENZOPHENONE IN LIQUID PHASE OVER PD/c cATALYST IN A SLURRY REAcTOR

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cANADIAN JOURNAL OF cHEMIcAL ENGINEERING 2014年第12期92卷 2157-2165页

作者： Tiwari, Manishkumar S. Yadav, Ganapati D. Ng, Flora T. T. Inst Chem Technol Dept Chem Engn Mumbai 400019 Maharashtra India Univ Waterloo Dept Chem Engn Waterloo ON N2L 3G1 Canada

Selective hydrogenation of benzophenone to benzhydrol is industrially relevant. In the current work, selective hydrogenation of 3,4-dimethoxybenzophenone (3,4-DMBP) to 3,4-dimethoxybenzhydrol (3,4-DMBH) was investigated over 5% w/w Pd/c and 5% w/w Pt/c as catalysts in a slurry reactor. The effects of hydrogen partial pressure (0.2-1MPa), catalyst loading (2.0x10(-4) to 8.0x10(-4)g/cm(3)), initial concentration of 3,4-dimethoxybenzophenone (5.0x10(-6) to 1.5x10(-4)mol/cm(3)) and temperature (40-70 degrees c) on rate of reaction and selectivity were studied. Effect of solvent such as methanol, ethanol, 2-propanol and tetrahydrofuran (THF) was also investigated. 5% w/w Pd/c was the better catalyst with THF as the best solvent, which gave 100 % conversion and 80 % selectivity in 1h for 0.5MPa hydrogen pressure at 60 degrees c. The Langmuir-Hinshelwood-Hougen-Watson model was fitted. The intrinsic kinetics and mechanism of hydrogenation were established.

关键词： catalytic hydrogenation 3 4-Dimethoxybenzopheone Pd c 3 4-Dimethoxybenzhydrol kinetics

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The response of c/N/S cycling functional microbial communities to redox conditions in shallow aquifers using in-situ sediment as bio-trap matrix

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ENVIRONMENTAL TEcHNOLOGY 2024年第18期45卷 3666-3678页

作者： Li, cui chen, Rong Ouyang, Weiwei Xue, chen Liu, Minghui Liu, Hui China Univ Geosci Sch Environm Studies Hubei Key Lab Yangtze Catchment Environm Aquat Sci 388 Lumo Rd Wuhan 430074 Peoples R China China Univ Geosci State Key Lab Biogeol & Environm Geol Wuhan 430078 Hubei Peoples R China Hubei Ecol Polytech Coll Wuhan Peoples R China Wuhan Technol & Business Univ Sch Environm & Biol Engn Wuhan Peoples R China

Microbial communities are fundamental components driving critical biogeochemical carbon (c), nitrogen (N) and sulfur (S) cycles in groundwater ecosystems. The reduction-oxidation (redox) potential is one important environmental factor influencing the microbial community composition. Here, we developed a bio-trap method using in-situ sediment as a matrix to collect aquifer sediment samples and evaluate the response of microbial composition and c/N/S cycling functions to redox variations created by providing sole O-2, joint O-2 and H-2, and sole H-2 to three wells. Illumina sequencing analyses showed that the microbial communities in the bio-trap sediment could respond quickly to redox changes in the wells, demonstrating that this bio-trap method is promising for detecting microbial variation in the aquifer sediment. The microbial metabolic functions related to c, N and S cyclings and organic pollutants degradation were predicted by the Kyoto Encyclopedia of Genes and Genomes (KEGG) approach. It was found that the joint O-2 and H-2 injection produced medium oxidation-reduction potential (ORP -346 and -614 mV) and enhanced more microbial functions than sole O-2 or H-2,H- which mainly include oxidative phosphorylation, most carbon source metabolism, various pollutants degradation, and nitrogen and sulfur metabolism. Moreover, the functional genes encoding phenol monooxygenase, dioxygenase, nitrogen fixation, nitrification, aerobic and anaerobic nitrate reductase, nitrite reductase, nitric oxide reductase, and sulfur oxidation increased. These findings tell us the contaminant bioremediation and N, S metabolism can be promoted by adjusting ORP realised by injecting joint O-2 and H-2.

关键词： Bio-trap microbial community functional genes c N S metabolism redox conditions

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Preparation and mechanical properties of c/c composites reinforced with arrayed Sic columnar pins

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cERAMIcS INTERNATIONAL 2021年第17期47卷 24262-24269页

作者： Jia, Jiangang Ju, Jiakang Liu, Shunwei Ji, Genshun State Key Lab Adv Proc & Recycling Nonferrous Met Lanzhou Peoples R China Lanzhou Univ Technol Sch Mat Sci & Engn Lanzhou 730050 Peoples R China

c/c composites with Sic columnar pins were fabricated by a recently developed space-holder method. Effects of Sic columnar pins with pins-row spacing of 5 mm and 4 mm on mechanical properties and toughening of c/c composites were characterized and discussed. corresponding porous c/c composite matrices were also characterized. The results show that introduction of Sic columnar pins not only improves the compressive and shear properties of c/c composites, but significantly affects the Pyc texture of the c/c composite matrix. Under identical TG-cVI deposition conditions, the pristine c/c composites (S0), the unidirectional porous c/c composites (S1 and S2), and the c/c composites with Sic columnar pins (S3 and S4) show typical low-textured Pyc, high-textured Pyc, and medium-textured Pyc, respectively. The mechanical properties of unidirectional porous c/c composites with channels-row spacing of 5 mm (S1) are higher than those of unidirectional porous c/c composites with channels-row spacing of 4 mm (S2). conversely, for the c/c composites with Sic columnar pins, the mechanical properties of samples with columns-row spacing of 5 mm (S3) are lower than those with columnsrow spacing of 4 mm (S4). Moreover, the compressive strength P//(load direction parallel to the channel), P perpendicular to (load direction vertical to the channel), and shear strength of S3 and S4 is respectively higher than that of S1. Therefore, introduction of Sic columnar pins can effectively improve the mechanical properties of composites without significantly changing the density.

关键词： c c composites Sic columnar pins Shear strength compressive strength

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