摘要：The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced thermal conductivity in contrast with the currently used yttria-partially stabilized zirconia (YSZ) in high operating temperature *** review summarizes the recent progress on rare earth zirconates for TBCs that insulate high-temperature gas from hot-section components in gas *** on the first principles,molecular dynamics,and new data-driven calculation approaches,doping and high-entropy strategies have now been adopted in advanced TBC materials *** this paper,the solid-state heat transfer mechanism of TBCs is explained from two aspects,including heat conduction over the full operating temperature range and thermal radiation at medium and high *** paper also provides new insights into design considerations of adaptive TBC materials,and the challenges and potential breakthroughs are further highlighted for extreme environmental *** for improving thermophysical performance are proposed in two approaches:defect engineering and material compositing.

摘要：Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains *** this work,the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO_(2).Structural characterizations revealed that a distinct TiO_(x) coating on the Ni nanoparticles(NPs)was evident for Ni/TiO_(2)-700 catalyst due to strong metal-support *** is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased,thereby enhancing the exposure of Ni active *** exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4,which led to the much elevated catalytic activity for Ni/TiO_(2)-950 in which rutile ***,the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ***/TiO_(2)-950,characterized by a predominant rutile phase,exhibited the highest DRM reactivity,with remarkable H2 and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h),*** rates were approximately 257 and 130 times higher,respectively,compared to those obtained on Ni/TiO_(2)-700 with *** study suggests that the optimization of crystal structure of TiO_(2) support can effectively enhance the performance of photothermal DRM reaction.

摘要：Due to their tunable acidity,shape selectivity,and excellent stability,zeolites are of great importance as solid acid materials in industrial *** the properties of the acid sites in zeolites allows for the rational design and fabrication of catalysts for target *** ether(DME)carbonylation,a critical chain-growth reaction for C1 resource utilization,is selectively catalyzed by the Brønsted acid sites within the eight-membered rings(8-MRs)of mordenite(MOR).It is anticipated that strengthening the Brønsted acidity—particularly in 8-MRs—will improve the catalytic performance of *** this work,density functional theory(DFT)calculations are first employed and the results used to design a modified MOR with stannum(Sn)and to predict the corresponding changes in *** by the theoretical studies,a series of Sn-modified MOR are synthesized via a defect-engineering and subsequent heteroatom-substitution *** partial desilication,isolated tetrahedral Sn species in an open configuration are successfully synthesized for the first time,within which tetrahedrally coordinated Al sites are *** acidic characterization is used to confirm that the acidity of the Brønsted acid sites is enhanced by the introduction of the Sn species;as a result,the sample exhibits excellent activity in DME carbonylation *** and DFT studies reveal that this strengthened acidity facilitates the adsorption of DME and reduces the activation barriers of DME dissociation and acetyl formation,accounting for the improved *** work demonstrates mechanistic insights into the promoting effects of strong acidity on DME carbonylation and offers a promising strategy to precisely control the acidic strength of zeolites.

摘要：In order to increase the productivity of microreactors, the parallelization of the microreactors is required. The performances of flow distributors can affect the product yield and fault detection ability when blockage *** this research, an optimal design method to calculate the channel diameters and to determine the flow sensor location is derived based on mass balance and pressure balance models of split-and-recombine-type flow distributors(SRFDs). The model accuracy is verified by experiment data. The proposed method is applied to optimal design of SRFDs under constant flow rate operation conditions. The maximum angle difference between normal and blockage conditions at one sensor to those at the other sensors is set to be the objective function and the uniformity of flow distribution in microreactors under normal condition is also required. The diameters of each pipe in SRFDs are selected as the design variables. Simulated annealing algorithm is used to solve the optimization problem. The effectiveness of the optimal design results is demonstrated by fluid dynamics simulations. The results show that using the optimal channel diameters of SRFDs, the pressure drop in SRFD section is lower than that of the microreactor section. Meanwhile, in the case studies, only a few sensors that are located inside the SRFDs can easily detect the blockage abnormal condition in the parallelized microreactor system.

摘要：The exact solution for the bending problem of a free-end point loaded film- substrate cantilever with arbitrary film-to-substrate thickness ratio is obtained by using the basic mechanical equilibrium equation. And then the problem of design and optimization for microactuator buildup of film-substrate cantilever is discussed by taking into account the effect of geometrical and physical parameters of the cantilever components. Furthermore, the optimal condition for actuator application is presented and some theoretical problems are clarified. The results show that, in general, the greater the film-to-substrate thickness ratio, the higher the ability of taking load, namely the larger the exerted force of the cantilever when the thickness of substrate is kept constant. When the total thickness of the cantilever is kept constant, however, the free-end exerted force will experience a maximum and this maximum value of the exerted force will decrease with the increasing film-to-sub- strate stiffness ratio. Meanwhile, the optimal thickness ratio corresponding to this maximum exerted force also decreases with the increasing stiffness ratio. Whether for the cases of fixed substrate or fixed total thickness, the influence of Poisson’s ratio of two cantilever components on the exerted force is remarkable, and should not be neglected.

摘要：Crimping is widely adopted in the production of large-diameter submerged-arc welding pipes. Traditionally, designers obtain the technical parameters for crimping from experience or by trial and error through experiments and the finite element(FE) method. However, it is difficult to achieve ideal crimping quality by these approaches. To resolve this issue, crimping parameter design was investigated by multi-objective optimization. Crimping was simulated using the FE code ABAQUS and the FE model was validated experimentally. A welding pipe made of X80 high-strength pipeline steel was considered as a target object and the optimization problem for its crimping was formulated as a mathematical model and crimping was optimized. A response surface method based on the radial basis function was used to construct a surrogate model; the genetic algorithm NSGA-II was adopted to search for Pareto solutions; grey relational analysis was used to determine the most satisfactory solution from the Pareto solutions. The obtained optimal design of parameters shows good agreement with the initial design and remarkably improves the crimping quality. Thus, the results provide an effective approach for improving crimping quality and reducing design times.

摘要：Cobalt nanoparticles(NPs)catalysts are extensively used in heterogeneous catalytic reactions,and the addition of alkali metal promoters is a common method to modulate the catalytic performance because the catalyst's surface structures and morphologies are sensitive to the addition of ***,the underlying modulation trend remains ***,the adsorption of alkali metal promoters(Na and K)on the surfaces of face-centered-cubic(FCC)and hexagonal-closest packed(HCP)polymorphous cobalt was systematically investigated using density functional ***,the effect of alkali promoters on surface energies and nanoparticle morphologies was revealed on the basis of Wulff *** FCC-Co,the exposed area of the(111)facet in the nanoparticle increases with the adsorption coverage of alkali metal ***,the(311),(110),and(100)facets would disappear under the higher adsorption coverage of alkali *** HCPCo,the Wulff morphology is dominated by the(0001)and(1011)facets and is independent of the alkali metal adsorption *** work provides insights into morphology modulation by alkali metal promoters for the rational design and synthesis of cobalt-based nanomaterials with desired facets and morphologies.

摘要：This paper describes a large tuning range low phase noise voltage-controlled ring oscillator （ring VCO） based on a different cascade voltage logic delay cell with current-source load to change the current of output node. The method for optimization is presented. Furthermore, the analysis of performance of the proposed ring VCO is confirmed by the measurement results. The three-stage proposed ring VCO was fabricated in the 180-nm CMOS process of SMIC. The measurement results show that the oscillator frequency of the ring VCO is from 0.77O to 5.286 GHz and the phase noise is 97.93 dBc/Hz at an offset of 1 MHz from 5.268 GHz with a total power of 15.1 mW from a 1.8 V supply while occupying only 0.00175 mm2 of the core die area.

摘要：为非强迫的优化，一个新混合设计算法在纸被介绍。这个算法有一些吸引人的集中性质。Convergencetheory 能在▽ f (x) 是一致地连续的条件下面被获得。如果▽ f (x) 是连续地可辨的伪 convex，整个顺序重申没有任何另外的假设，收敛到这个问题的一个答案。而且，在适当条件下面，一个人证明顺序重申有一个簇点如果并且仅当Ω ~* ≠ 0。数字例子在这篇论文的结束被给。