摘要：Covalent organic frameworks(COFs)are garnering significant interest in photocatalytic CO_(2) ***,their limited efficiency in separating photogenerated carriers and the scarcity of catalytic sites lead to suboptimal photocatalytic *** we develop a molecular engineering approach to design a pyrene-based COF(PyTa-H COF)confined cobalt single atoms photocatalyst(Co SACs)for CO_(2) *** moiety is introduced to enhance visible-light harvesting capability and improve charge separation in the ***,Co SACs enhance the photocatalytic activity by accelerating the migration of photo-induced carriers and reducing the reaction energy of the rate-determining ***,PyTa-H@Co achieves a CO production rate of 18.36 mmol g^(−1) h^(−1) and a selectivity of 94%in 4 h under visible light irradiation,which is comparable to the reported best-performing *** functional theory calculations reveal that the Co SACs greatly stabilize*COOH and significantly reduce the energy of the decisive step,leading to outstanding photocatalytic *** work,through molecular engineering design,highlights the critical relationship between catalyst structure and function in enhancing photocatalytic efficiency.

摘要：Classical transonic hodograph-based design methods are employed and revitalized using modern numerical tools to illustrate the design of a symmetrical accelerating-decelerating nozzle throat design. The concept of Elliptic Continuation is applied to solve transonic boundary value problems avoiding the inherently nonlinear nature of the basic equations and obtaining transonic flow examples using the Method of Characteristics in an inverse mode. Purpose of the present paper, besides describing a new special flow example, is to keep these classical methods alive for education of a new generation of creative engineers.

摘要：Fish mortality assessments for turbine passages are currently performed by live-animal testing with up to a hundred thousand fish per year in Germany.A propelled sensor device could act as a fish *** this context,the study presented here investigates the state of the art via a thorough literature review on propulsion systems for aquatic *** evaluation of propulsion performance,weight,size and complexity of the motion achievable allows for the selection of an optimal concept for such a fish mimicking device carrying the *** the second step,the design of a bioinspired soft robotic fish driven by an unconventional drive system is *** is based on piezoceramic actuators,which allow for motion with five degrees of freedom(DOF)and the creation of complex bio-mimicking body motions.A kinematic model for the motion’s characteristics is developed,to achieve accurate position feedback with the use of strain *** measurements validate the complex deformation of the body and deliver the basis for the calibration of the kinematic ***,it can be shown,that the calibrated model presented allows the tracking of the deformation of the entire body with an accuracy of 0.1 mm.

摘要：The melting and solidification process of sodium nitrate, which is used as energy storage material, is studied in a vertical arranged energy storage device with two different bimetal finned tube designs （with and without additional lateral fins） for enhancing the heat transfer. The finned tube design consists of a plain steel tube while the material for the longitudinal （axial） fins is aluminum. The investigation analyses the influence of the lateral fins on the charging and discharging process. Three-dimensional transient numerical simulations are performed using the ANSYS Fluent 14.5 software. The results show that, every obstruction given by lateral fins reduces the melting and solidification velocity in direction to the outer shell.

摘要：A new superstructure model of heat exchanger networks (HEN) with streamsplits based on rangers of streams supply temperatures and heat capacity flow rates is *** simultaneous optimal mathematical model of flexible HEN synthesis is established too. Firstly,the streams with rangers of supply temperatures and/or the streams with the rangers of heat capacityflow rates are pretreated; Secondly, several rules are proposed to establish the superstructuremodel of HEN with splits and the simultaneous optimal mathematical model of flexible HEN; Thirdly,the improving genetic algorithm is applied to solve the mathematical model established at the secondstep effectively, and the original optimal structure of HEN based on the maximum operation limitingcondition can be obtained easily; Finally, the rules of heat exchange unit merged and the heat loadof heat exchanger relaxed are presented, the flexible configuration of HEN satisfied the operationcondition between the upper and down bounds of supply temperature and heat capacity flow rates canbe obtained based on the original optimal structure of HEN by means of these rules. A case studydemonstrates the method presented in this paper is effective

摘要：The measurement of droplet velocities in Diesel sprays close to the nozzle is important because of the complexity of in-nozzle flow, spray break-up and evaporation. However, the measurement of droplet velocities in the dense region of Diesel sprays is very difficult or impossible by means of widely used laser diagnostic techniques, in particular under engine-like high-pressure and high-temperature conditions. The limitations of phase Doppler anemometry （PDA） and particle image velocimetry （PIV） prevent the application to the ultra-dense region of the spray. It was demonstrated that these problems can be greatly reduced by the laser flow tagging （LFT） technique. It was also demonstrated recently that LFT measurements can be conducted in clustered Diesel jets with improved spatial resolution and increased number of simultaneous measurements in the near-nozzle region. In the present work, the nozzle design, the temperature and pressure of the ambient air, and the fuel rail pressure are varied, in order to investigate the influence on the near-nozzle jet velocity and the underlying physical mechanisms.

摘要：所有的换热器网络(HENs)都是在给定的运行工况下进行设计的.但有时它们并非在设计工况下运行,即某些过程流体进口参数与其设计值存在着偏差,因而其他过程流体进口参数需要进行调节以维持过程流体的出口参数设计值.换热器网络在非设计工况下的运行问题可以分为3种情况:调节参数的个数大于、等于或小于出口目标参数的个数,如果进口参数偏差处于换热器网络的可行域内,那么将可能分别存在一种、多种调节方案,或者不存在调节方案.对于存在多种调节方案的情形,最优的方案需要确定.

摘要：Ionic liquids combined with supercriticalfluid technology hold great promise as working solvents for developing compact *** liquids,which are organic molten salts,typically have extremely low volatility and high functionality,but possess high viscos-ities,surface tensions and low diffusion coefficients,which can limit their ***_(2),on the other hand,especially in its supercritical state,is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass *** solubility of CO_(2) in the ionic liquid is key to estimating the important physical properties that include partition coefficients,viscosities,densities,interfacial tensions,thermal conductivities and heat capacities needed in contactor *** this work,we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO_(2)-ionic liquid solubility data and report new correlations for CO_(2)-ionic liquid systems with equations of state that have some industrial applications including:(1)general,(2)fuel desulfurization,(3)CO_(2) capture,and(4)chiral *** measurements of solubility data for the CO_(2) and 1-butyl-3-methylimidazolium octyl sulfate,[bmim][OcSO4]system are reported and *** the correlation of the CO_(2) ionic liquid phase behavior,the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are *** is shown that excellent correlation of CO_(2) solubility can be obtained with either equation and they share some common characteristics regarding inter-action *** the Sanchez-Lacombe equation,parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO_(2)-ionic liquid solubility data.