c++ and concurrent c are both upward-compatible supersets of c that provide data abstraction and parallel programming facilities, respectively. Although data abstraction facilities are important for writing concurrent...
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c++ and concurrent c are both upward-compatible supersets of c that provide data abstraction and parallel programming facilities, respectively. Although data abstraction facilities are important for writing concurrent programs, we did not provide data abstraction facilities in concurrent c because we did not want to duplicate the c++ research effort. Instead, we decided that we would eventually integrate c++ and concurrent c facilities to produce a language with both data abstraction and parallel programming facilities, namely, concurrent c++. Data abstraction and parallel programming facilities are orthogonal. Despite this, the merger of concurrent c and c++ raised several integration issues. In this paper, we will give introductions to c++ and concurrent c, give two examples illustrating the advantages of using data abstraction facilities in concurrent programs, and discuss issues in integrating c++ and concurrent c to produce concurrent c++.
In this paper, a high-temperature test experimental system is built to investigate the dependence of the strength of a c/Siccomposite material on temperature. Unintuitively, the strength increases with temperature. T...
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In this paper, a high-temperature test experimental system is built to investigate the dependence of the strength of a c/Siccomposite material on temperature. Unintuitively, the strength increases with temperature. To investigate the microscopic mechanism, scanning electron microscopy (SEM) of an in situ bending test experiment is performed. Our hypothesis is that due to significant residual tensile stress in inter-fibre matrix, external loads reach the ultimate stress first. As the temperature increases, the matrix residual tensile stress decreases, a larger external load needs to be applied for matrix failure, which is exhibited macroscopically as increased strength. To prove this hypothesis, the inter-fibre matrix residual stress and its dependence on temperature are calculated via a finite element method. Next, using a Sic wrapper layer around a single c fibre as an experiment object, the finite element calculation is verified directly via micro-Raman spectroscopy.
The potential catalytic activity of selected c,N-chelated organotin(IV) compounds (e.g. halides and trifluoroacetates) for derivatization of both dimethyl carbonate (DMc) and diethyl carbonate (DEc) was investigated. ...
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The potential catalytic activity of selected c,N-chelated organotin(IV) compounds (e.g. halides and trifluoroacetates) for derivatization of both dimethyl carbonate (DMc) and diethyl carbonate (DEc) was investigated. Some tri-, di- and monoorganotin(IV) species (LcN(n-Bu)2Sncl (1), LcN(n-Bu)*** (1a), LcN(n-Bu)2SnI (2), LcNPh2Sncl (3), LcNPh2SnI (4), LcN(n-Bu)Sncl2 (5), LcNSnBr3 (6) and [LcNSn(Oc(O)cF3)]2(mu-O)(mu-Oc(O)cF3)2 (7)) bearing the LcN moiety (LcN?=?2-(N,N-dimethylaminomethyl)phenyl-) were assessed as catalysts for reactions of both DMc and DEc with various substituted anilines. The catalytic activities of 4 and 7 for derivatization of DMc with p-substituted phenols were studied for comparison with the standard base K2cO3/Silcarbon K835 catalyst (catalyst 8). The composition of resulting reaction mixtures was monitored by multinuclear NMR spectroscopy, Gc and Gc-MS techniques. In general, catalysts 1, 3 and 7 exhibited the highest catalytic activity for all reactions studied, while some of them yielded selectively carbonates, carbamates, lactam or substituted urea. copyright (c) 2012 John Wiley & Sons, Ltd.
KOVATS index is the most precise index system reflecting the interaction between the molecules of solutes and stationary phase in gas chromatography at present. Large quantity of Kovats in dex data have been published...
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KOVATS index is the most precise index system reflecting the interaction between the molecules of solutes and stationary phase in gas chromatography at present. Large quantity of Kovats in dex data have been published. It is a good way to use Kováts index in gas chromatography to predict the retention value in liquid chromatography, which is significant in theory and apphcation.
Background Helicobacter pylori (H. pylori) infect more than half of the world population, and they cause different serious diseases such as gastriccarcinomas. This study aims to design a vaccine on the basis of cagW ...
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Background Helicobacter pylori (H. pylori) infect more than half of the world population, and they cause different serious diseases such as gastriccarcinomas. This study aims to design a vaccine on the basis of cagW against H. pylori infection. After pcDNA3.1 (+)-cagW-cS-NPs complex is produced, it will be administered into the muscles of healthy BALB/c mice in order to study the effect of this DNA vaccine on the interleukin status of mice, representing its effect on the immune system. After that, the results will be compared with the control groups comprising the administration of cagW-pcDNA3.1 (+) vaccine, the administration of chitosan and the administration of PBS in the muscles of mice. Methods The cagW gene of H. pylori was amplified by employing PcR, whose product was then cloned into the pcDNA3.1 (+) vector, and this cloning was confirmed by PcR and BamHI/EcoRV restriction enzyme digestion. cagW gene DNA vaccine was encapsulated in chitosan nanoparticles (pcDNA3.1 (+)-cagW-cS-NPs) using a complex coacervation method. The stability and in vitro expression of chitosan nanoparticles were studied by DNase I digestion and transfection, and the immune responses elicited in specific pathogen-free (SPF) mice by the pcDNA3.1 (+)-cagW-cS-NPs were evaluated. Apart from that, the protective potential pcDNA3.1 (+)-cagW-cS-NPs was evaluated by challenging with H. pylori. Results The pcDNA3.1 (+)-cagW-cS-NPs comprises cagW gene of H. pylori that is encapsulated in chitosan nanoparticles, produced with good morphology, high stability, a mean diameter of 117.7 nm, and a zeta potential of + 5.64 mV. Moreover, it was confirmed that chitosan encapsulation protects the DNA plasmid from DNase I digestion, and the immunofluorescence assay showed that the cagW gene could express in HDF cells and maintain good bioactivity at the same time. In comparison to the mice immunized with the control plasmid, in vivo immunization revealed that mice immunized with pcDNA3.1 (+)-cagW-NPs showe
The selective adsorption mechanism of c-cdS2 2 monolayer was revealed using density functional theory. The results show that c-cdS2 2 has good adsorption properties for SO2, 2 , NO, NH3, 3 , NO2 2 and cl2, 2 , and all...
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The selective adsorption mechanism of c-cdS2 2 monolayer was revealed using density functional theory. The results show that c-cdS2 2 has good adsorption properties for SO2, 2 , NO, NH3, 3 , NO2 2 and cl2, 2 , and all of them are chemisorbed. Under the adsorption of different gas molecules, the electronic structure of c-cdS2 2 changed to varying degrees, which provided a theoretical basis for the use of c-cdS2 2 as a gas sensor or scavenger for these gases.
In order to improve the mechanical and ablative resistance of c/ccomposites, (Hf-Ta-Zr)c single-phase solid solution ceramics were introduced into c/ccomposites by polymer infiltration and pyrolysis (PIP) to fabrica...
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In order to improve the mechanical and ablative resistance of c/ccomposites, (Hf-Ta-Zr)c single-phase solid solution ceramics were introduced into c/ccomposites by polymer infiltration and pyrolysis (PIP) to fabricate (Hf-Ta-Zr)c modified c/ccomposites (HTZ). Their mechanical property and ablation resistance were studied. The results showed that HTZ achieved simultaneous enhancement of mechanical property and ablative resis-tance. Their flexural strength and modulus could reach 219.34 MPa and 24.82 GPa, respectively. In addition, the mass and linear ablation rate of HTZ were 0.379 mg/s and 0.667 mu m/s, respectively after the 90 s oxyacetylene ablation. A dense Hf-Ta-Zr-O multiphase oxide layer was formed on the surface of the HTZ during ablation process, which protected the interior modified c/ccomposites from ablation. Our work expands a rational design of modified c/ccomposites and broaden the application of solid solution ceramic in the field of ultra-high temperature ablation resistance for carbon or ceramic-based composites.
A modification of the precursor infiltration pyrolysis (PIP) method was explored to prepare the integrated doped ceramic matrix and coating by the added Sic nanowires layer and shape-stabilization process. The epitaxi...
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A modification of the precursor infiltration pyrolysis (PIP) method was explored to prepare the integrated doped ceramic matrix and coating by the added Sic nanowires layer and shape-stabilization process. The epitaxial layer of Sic nanowires provided surficial attachments for the precursor. And the shape-stabilization process aggregated loose ceramic particles into a coating. Then the Sic nanowire-reinforced Zrc-Siccoating-matrix integrated c/c (S/SZ-cZ/c) composite was simply prepared by the modified PIP method. The bonding strength between the coating and matrix of the S/SZ-cZ/ccomposite was improved. Through the ablation test, the mass and linear ablation rate of the S/SZ-cZ/ccomposite were 0.46 mg/s and 0.67 mu m/s, which were 60.34 % and 74.91 % lower than those of the Sic nanowire-reinforced c/c-Zrc (S/cZ/c) composite, respectively. The integration of the coating and matrix enabled the formation of a continuous oxide layer of molten SiO2 and ZrO2 in the ablation process, which helped to block the oxygen and heat during the ablation test. Thus the ablation resistance of the materials was systematically and effectively improved.
Poor thermal conductivity, especially in thickness direction, is a major obstacle to extend the service lifetime of c/Siccomposite. However, there are few papers focusing on finely designing heat conductive channel b...
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Poor thermal conductivity, especially in thickness direction, is a major obstacle to extend the service lifetime of c/Siccomposite. However, there are few papers focusing on finely designing heat conductive channel but a simply introduction of various modifiers to improve c/Sic thermal conductivity, which leads to less success. Herein, multi-layer graphene sheets were utilized to improve the thermal conductivity of c/Siccomposites via an effective method to design graphene heat conductive channels. To determine the role of graphene sheets in improving thermal conductivity, the effect of the different loading fractions of graphene and microstructure of as-prepared composites were systemically investigated. Results revealed that the thermal conductivity of composites increased by 204% with well-designed graphene heat conductive channels. Besides, compared with the porosity, the orderly aligned heat conductive pathways played a more important role in thermal conductivity. This work provides a new and effective method for preparing well-designed heat conductive channels to enhance thermal conductivity of c/Sic.
The electrical properties of c/Siccomposites could be used for online and in-situ damage monitoring. To investigate alternating current (Ac) impedance response to damage in the c/Siccomposites, monotonic and increme...
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The electrical properties of c/Siccomposites could be used for online and in-situ damage monitoring. To investigate alternating current (Ac) impedance response to damage in the c/Siccomposites, monotonic and incremental cyclic tensile tests were performed. Both Ac impedance and acoustic emission (AE) techniques were applied to clarify the damage evolution during the tests. The relationship between damage and electrical impedance response was investigated and validated via macroscopic equivalent circuit models. The effects of longitudinal deformation and damage on Ac impedance characteristics, including impedance magnitude and phase angle, were obtained from the models. Results showed that the longitudinal deformation increases the impedance magnitude and the phase angle, and the damage causes the impedance magnitude to increase and the phase angle to decrease. The phase angle is significantly sensitive to fiber breakage, which makes the Ac-based method more suitable for online damage monitoring and final failure warning.
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