Pdxcuy/ccatalysts combinations were employed to cH4 partial oxidation in mild condition using a solid electrolyte reactor-alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor...
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Pdxcuy/ccatalysts combinations were employed to cH4 partial oxidation in mild condition using a solid electrolyte reactor-alkaline fuel cell type. The differential mass spectroscopy on line method was used to monitor the oxidation products obtained as methanol, dimethyl ether, methyl formate and potassium formate. It was observed that as the electrical potential of the reactor increases, the generation of products decreases. The best results for conversion of methane into methanol and energy co-generation was obtained from Pd90cu10/c and Pd50cu50/c due to better H2O activation effects and adsorption site for cH4 oxidation.
In this study, the effect of the silicon carbide (Sic) matrix content on the mechanical behaviour of a threedimensional needled carbon fibre-reinforced Sic matrix composite (c/Sic) was investigated. The Sic matrix con...
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In this study, the effect of the silicon carbide (Sic) matrix content on the mechanical behaviour of a threedimensional needled carbon fibre-reinforced Sic matrix composite (c/Sic) was investigated. The Sic matrix content was controlled by the infiltration time, and it can be divided into two stages for the evolution of matrix densification, leading to different mechanical responses. In the first stage, with an increase in the Sic matrix content from 12 to 39 vol%, the matrix was filled into a non-woven cloth, leading to an improvement in the loading efficiency of the fibre bundles. Thus, flexural strength and fracture toughness increased sharply from 54 to 218 MPa and 1.3-13.0 MPa m1/2, respectively. As the Sic matrix content increases to 59 vol% in the second stage, the flexural strength and fracture toughness increased to 256 MPa and 15.4 MPa m1/2, respectively. The infiltration ability of the Sic matrix into the non-woven cloth reached the threshold in this stage, and the Sic matrix filled the short-cut web layer, resulting in a slightly increasing tendency of strength and toughness.
A combination method of precursor infiltration and pyrolysis (PIP), chemical vapor infiltration (cVI) and liquid silicon infiltration (LSI) was proposed to prepare PIP-Sic modified c/c?Sic brake materials. The Siccer...
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A combination method of precursor infiltration and pyrolysis (PIP), chemical vapor infiltration (cVI) and liquid silicon infiltration (LSI) was proposed to prepare PIP-Sic modified c/c?Sic brake materials. The Sicceramic matrix pyrolyzed by polymethysilane (PMS) homogeneously dispersed in the fiber bundles region, which improved the plough resistance of local c/c region and the wear resistance of c/c?Sic brake materials. When the braking speed rises to 28 m/s, the fluctuation range of friction coefficient was limited to 0.026. The linear wear rate of the as-prepared composites was could be -50% less than that of c/c?Sic, when the braking speed was above 15 m/s (for instance, the wear rate of 1.02 ?m/(side?cycle) at 28 m/s less than 2.02 ?m/(side?cycle) of traditional c/c? Sic). The fading ratio D of coF under wet conditions was -11%. The results showed that introducing PIP-Siccould stabilize the braking process and effectively prolong the service life of c/c?Sic brake materials.
Using nanoclusters and single atoms with unique activity to replace nanoparticles is a promising strategy to enhance catalyst activity. However, stable loading of nanoclusters and single atoms remain a challenge. This...
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Using nanoclusters and single atoms with unique activity to replace nanoparticles is a promising strategy to enhance catalyst activity. However, stable loading of nanoclusters and single atoms remain a challenge. This paper reports atomically dispersed Pt bridged with metal-organic framework (MOF)-derived ZnO/c through carbon atoms (Pt-ZnO/c), by impregnation combined with calcination, for photocatalytic oxidation of NO. The MOF-derived ZnO/c has a larger specific surface area than pure ZnO. The presence of c enhances the visible light absorption, promotes the migration of photogenerated carriers, and more importantly facilitates the stabilization of Pt single atoms through Pt-c interactions. The Pt species present in the Pt-ZnO/ccatalysts in the form of single atoms and nanoclusters. The Pt-ZnO/ccatalysts show high NO conversion rates and selectivity towards NO3 /NO2 ions formation. Specifically, the NO conversion rate of 81.9% is much higher than those of ZnO/c (31.4%) and Pt nanoparticles loaded ZnO/c (Pt NPs-ZnO/c, 58.6%). In addition, the selectivity of NO3 /NO2 (i. e., 98.6%) formation over the Pt-ZnO/ccatalyst is much higher than that of NO2 (i.e., 1.4%). Furthermore, the photocatalysis tests and ESR results suggest that the Pt single atoms and nanoclusters can enhance the oxidation of NO by promoting the production of O2 & BULL;- and OH & BULL;. The DFT results also reveal that single Pt atoms promote the adsorption of O2 and H2O to form O2 & BULL;- and OH & BULL;. More importantly, OH & BULL;can promote the selective oxidation of NO to NO3 /NO2 ions. In addition, the projected density of states of single Pt atoms loaded on the ZnO/ccatalysts show that the presence of c atom bridge favors the stability of single Pt atoms because of the interaction between c and Pt atoms. This work provides a new strategy for the design of single-atom-loaded metal oxide catalysts.
A Mo-doping LiFe1-xMoxPO4/ccathode material was synthesized via carbothermal reduction route, and the effect of the content of Mo on the structure and electrochemical performance of LiFePO4/c was studied. XRD results...
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A Mo-doping LiFe1-xMoxPO4/ccathode material was synthesized via carbothermal reduction route, and the effect of the content of Mo on the structure and electrochemical performance of LiFePO4/c was studied. XRD results revealed doping of Mo did not change the olivine structure of LiFePO4/c, but also formed the Li+ vacancies, which contribute to increase the diffusion rate of Li+. The experimental results further demonstrated that among the Mo-doping samples, the LiFe0.98Mo0.02PO4/c exhibited the best cycle performance and rate performance. After 100 cycles at 0.1 c, its discharge specificcapacity reached 143.2 mAh center dot g(-1), which was about 10 mAh center dot g(-1) higher than that of pure phase LiFePO4/c. The capacity retention rate was 98%. When cycling at a rate of up to 5 c, the discharge specificcapacity of LiFe0.98Mo0.02PO4/ccan still be maintained above 90 mAh center dot g(-1), indicating that Mo doping was an effective method to improve LiFePO4/c electrochemical performance.
作者：
Visentin, Jonathancouzi, LionelTaupin, Jean-LucCHU Bordeaux
Lab Immunol & Immunogenet Hop Pellegrin Pl Amelie Raba Leon F-33076 Bordeaux France Univ Bordeaux
CNRS ImmunoConcEpT Bordeaux France CHU Bordeaux
Hop Pellegrin Serv Nephrol Transplantat Dialyse & Aphereses Pl Amelie Raba Leon Bordeaux France Hop St Louis
Lab Immunol & Histocompatibilite 1 Ave Claude Vellefaux Paris France Univ Paris
INSERM UMR976 Paris France Univ Paris
Inst Rech St Louis Paris France
In solid organ transplantation (SOT), the clinical relevance of donor-specific antibodies (DSA) directed at anti-HLA-A, -B, -DR and -DQ antigens is largely recognized while it is still a matter of debate for DSA direc...
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In solid organ transplantation (SOT), the clinical relevance of donor-specific antibodies (DSA) directed at anti-HLA-A, -B, -DR and -DQ antigens is largely recognized while it is still a matter of debate for DSA directed at HLA-c. In this review, we summarize the peculiarities of HLA-c among class I HLA antigens as well as their immunogenicity, which underlie the clinical relevance of HLA-c locus and anti-HLA-c DSA in SOT. Many factors, both intrinsic and extrinsic to the HLA-c gene and HLA-c protein, explain its lower expression in comparison with HLA-A and -B. This lower expression can explain the apparent lower immunogenicity of HLA-c leading to a lower prevalence and strength of anti-HLA-c antibodies. Nevertheless, HLA-c antigens are truly immunogenic and preformed anti-HLA-c DSA are clinically relevant. Indeed, anti-HLA-c DSA are able to bind donor cells and to activate the complement pathway both ex vivo and in vivo. In line with this, numerous clinical studies now show that preformed DSA directed at native HLA-c molecules induce poorer graft outcomes. We then plead for the inclusion of HLA-c in all transplant allocation systems and we propose a strategy to cope with anti-HLA-c DSA in SOT. Beyond SOT, anti-HLA-c antibodies generate a growing interest in the allo-HcT, transfusion and obstetrics fields, while new concepts such as the role of the "missing-self" in solid organ rejection places HLA-c as an inescapable actor in transplant tolerance.
For finite-strain problems of quasi-incompressible materials, with hyperelastic and hyperelasto-plastic behavior, we develop a mixed polynomial-enriched radial-basis function (RBF) interpolation. It is characterized b...
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For finite-strain problems of quasi-incompressible materials, with hyperelastic and hyperelasto-plastic behavior, we develop a mixed polynomial-enriched radial-basis function (RBF) interpolation. It is characterized by decoupling quadrature and polynomials for the deviatoric and volumetric terms of the right cauchy-Green tensor. With an enriched interpolation, first and second derivatives of the deformation gradient are continuous. A finite-element mesh is employed for quadrature purposes with the corresponding distribution of Gauss points. In terms of discretization, linear, quadratic and cubic polynomials are combined and function support is established from the number of pre-assigned nodes. Due to the adoption of a Lagrangian kernel, finite strain elasto-plasticconstitutive developments are based on the Mandel stress. combined with the c technique, these developments are found to be convenient from an implementation perspective, as RBF formulations for finite strain plasticity have been limited in terms of generality and amplitude of deformations in the quasi -incompressibility case. Three benchmark tests are successfully solved, and it was found that a combination of reduced integration with a deviatoriccubic basis and volumetric quadratic basis provides superior results in the quasi-incompressible case. Numerical testing shows very good convergence behavior of the results. Besides absence of locking with selective interpolation, outstanding Newton convergence was observed regardless of strain levels.
Deep vein thrombosis (DVT) is common in patients following gynecological surgery. coagulation factor VIII (FVIII) is an important part of the human coagulation system, and FVIII:c is a component of FVIII with anticoag...
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Deep vein thrombosis (DVT) is common in patients following gynecological surgery. coagulation factor VIII (FVIII) is an important part of the human coagulation system, and FVIII:c is a component of FVIII with anticoagulant activity. 800 patients who underwent gynecological surgery were enrolled. General clinical data were harvested, and pre - and postoperative serum FVIII levels were determined. Lower-extremity ultrasound examination and/or postoperative pulmonary angiography were performed. Related data were analyzed statistically. DVT was the first manifestation of venous thromboembolism in all cases. There were a total of 46 cases, and the incidence of DVT was 5.8%. Progression to pulmonary embolism was confirmed in 16 cases, with an incidence of 2.0%. The independent risk factors for DVT after gynecological surgery were postoperative FVIII:c levels (odds ratio [OR] = 1.01), age (OR = 6.57), and operation time >= 3 hours (OR = 2.90) (P < 0.05). When the FVIII:c level was greater than the 75th centile (>= 150 IU/dL), the risk of DVT was 2.99 times higher than that below the 25th centile (<100 IU/dL) (P < 0.05). When combined with the risk factor of operation time >= 3 hours, the risk increased to 3.17 times (P = 0.10). When combined with age >= 60 years, the risk was significantly increased, reaching 12.0 times (P < 0.05). Serum FVIII:c levels are an independent risk factor for DVT after gynecological surgery. Higher levels increase the risk of DVT after gynecological surgery, and they may have a dose-dependent relationship. A synergistic effect exists in combination with other risk factors, which further increases the risk.
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