热阻和回热损失对铁电斯特林制冷机的(火用)经济优化性能的影响

应用有限时间Yong分析法，研究热阻及回热损失对铁电斯特林制冷机Yong经济优化性能的影响。利用铁电晶体的热力学特性，考虑传热规律服从牛顿定律，得到铁电斯特林制冷机的基本优化关系。以利润率为目标，导得最大利润率情况时的制冷系数及其他性能参数，所得结论可为铁电斯特林制冷机的研制和设计提供指导。     

量子卡诺制冷机的优化性能

研究了量子卡诺制冷机的最优性能，得到了制冷机的最佳制冷率与制冷系数间的优化关系，所得结果为制冷机的工况预选提供了一个可行方案。     

1／2自旋量子卡诺制冷机的最优性能

研究了１／２自旋量子卡诺制冷机的最优性能，得到了量子制冷机制冷率与制冷系数间的优化关系以及其它最佳特性参数。所得结果为制冷机的工况预选提供了一个最佳的可行方案。     

脉管型斯特林制冷机的实验研究

对脉管型斯特林制冷机用于普冷的可行性进行了分析研究。用实验的方法对脉管到斯特林制冷机和单纯的斯特林制冷机的性能进行了对比，得出了在２４５Ｋ以上温区脉管型斯特林制冷机的性能优于单纯的斯特林制冷机的重要结论．对小孔和脉管长度变化对脉管型斯特林制冷机性能的影响进行了讨论．     

斯特林制冷机的最佳火用输出率

研究导热和回热损失对斯特林制冷机火用优化性能的影响，导出制冷机的最佳火用输出率与制冷系数以及与制冷率间的关系。由此揭示了斯特林制冷机火用优化性能的主要特征，并与制冷率优化性能作了比较，获得一些对实际制冷机有指导意义的新结论。     

量子卡诺制冷机制冷率与熵产率的协调优化性能

研究了内可逆谐振子量子卡诺制冷机的整体最优性能。得到了协调优化目标函数Ｅ最大时量子制冷机的制冷系数以及最佳制冷率和熵产率。     

斯特林制冷机的分析及其计算

本文作者分析了斯特林制冷机的循环,讨论了单级、双级及多级斯特林制冷机的相互关系。并推导建立了斯特林制冷机的计算通式,对实际制冷量、耗功和制冷系数的计算方法也进行了探讨。图5、表1．、参考文献5。     

脉管型斯特林制冷机的能量方程推导及性能分析

通过对脉管型斯特林制冷机的分析和讨论，提出了此类制冷机的物理模型，对能量方程进行了推导，并编制了程序。计算结果显示，脉管斯特林制冷机在较高的制冷温区比单纯的斯特林制冷机有更大的制冷系数和更高的制冷量。     

气动型斯特林制冷机气动腔气体热力迟滞行为特性的理论分析

近年来，气体驱动斯特林制冷机在此重量、可靠性，振动和噪声等方面得到提高，在红外技术和超导电子学等领域具有诱人的应用前景，其研究工作一直是低温领域的一个热点，首先简要描述了气动型斯特林制冷机气动腔内气体热力迟滞行为特性，其次主要理论推导该部分气体热力迟滞行为特性造成的损失，并且给出了一个计算机仿真结果说明该项损失对制冷机性能的影响。本文对更为逼真地仿真微型气动斯特林制冷机的热动力特性行为提供了有力支撑。     

经典极限下量子卡诺制冷机有限时间热力学性能界限和优化准则

研究了量子卡诺制冷机的最优性能和有限时间热力学优化准则，得到了量子制冷机制冷率与致冷系数之间的优化关系以及制冷的有限时间热力学性能界限。     

普适定常流内可逆热泵循环模型的有限时间火用经济性能优化

用有限时间热力学理论分析了由一个定热容吸热过程、两个定热容放热过程和两个绝热过程组成的一类普适内可逆热泵循环模型的火用经济性能,导出了循环利润率、供热系数与温度比的关系式,由数值计算得到了利润率和供热系数的特性关系。所得结果包含了内可逆Carnot循环、Otto循环、Diesel循环、Dual循环、Atkinson循环和Brayton循环的有限时间火用经济性能。     

普适定常流内可逆制冷机循环模型的炯经济性能优化

用有限时间热力学方法分析工作在恒温热源TH、TL之间内可逆普适制冷机循环模型的炯经济性能，导出循环利润率与工质温比、制冷系数与工质温比的关系式，和利润率与制冷系数的特性关系。所得结果包含了内可逆Carnot、Diesel、Otto、Atkinson和Brayton制冷循环的有限时间炯经济性能。     

不可逆四热源吸收式制冷机炯经济优化性能

应用有限时间热力学理论，基于利润率为目标函数，对牛顿传热规律下四热源吸收式制冷机进行优化分析，导出制冷机的[火用]经济优化性能，揭示了其与生态学优化性能的内在联系。所得结论可为四热源制冷机的优化设计和最佳工况选择等提供些新理论依据。     

不可逆四热源吸收式制冷机(火用)经济优化性能

应用有限时间热力学理论,基于利润率为目标函数,对牛顿传热规律下四热源吸收式制冷机进行优化分析,导出制冷机的(火用)经济优化性能,揭示了其与生态学优化性能的内在联系.所得结论可为四热源制冷机的优化设计和最佳工况选择等提供些新理论依据.     

Evolutionary shape control during colloidal quantum-dot growth

Size-dependent optical properties of semiconductor nanocrystals are of great interest because of the myriad of phenomena stemming from them. The preparation of more complex colloidal shapes will facilitate the systematic study of shape-dependent phenomena. It is shown that a strategy to obtain systematically more complex nanocrystal structures is to exert a sequence of shape-directing steps during the colloidal growth. Using experiments based on multiple reagent injections we show how changes in the type of surfactant introduced during growth of CdSe nanocrystals promotes shape evolution. On this basis, we propose a means to achieve a further generation of shape design in nanometer-sized colloids by using a series of growth steps, each one building from the previous conditions of shape as well as surface-specific reactivity. To understand the shape formation and stability in nanocrystalline colloids, and particularly the importance of surface ligands, we introduce an analogy with the thermodynamics of droplets.     

Fabrication of quantum-dot devices in graphene

Abstract

We describe our recent experimental results on the fabrication of quantum-dot devices in a graphene-based two-dimensional system. Graphene samples were prepared by micromechanical cleavage of graphite crystals on a SiO₂/Si substrate. We performed micro-Raman spectroscopy measurements to determine the number of layers of graphene flakes during the device fabrication process. By applying a nanofabrication process to the identified graphene flakes, we prepared a double-quantum-dot device structure comprising two lateral quantum dots coupled in series. Measurements of low-temperature electrical transport show the device to be a series-coupled double-dot system with varied interdot tunnel coupling, the strength of which changes continuously and non-monotonically as a function of gate voltage.     

混合制冷工质充注装置设计与分析计算

设计了一套混合制冷工质充注装置,该装置采用定容积储气罐,通过测量其温度和压力变化,根据工程热力学原理可以得到所充制冷工质的质量。针对充注过程进行了分析,对装置的结构和原理进行了讨论。运用两种方法计算本装置在环境温度下充注制冷工质的质量,并对两种计算结果进行了对比分析。     

Quantum Dot-Siloxane Anchoring on Colloidal Quantum Dot Film for Flexible Photovoltaic Cell

Lead sulfide (PbS) colloidal quantum dots (CQDs) are promising materials for next-generation flexible solar cells because of near-infrared absorption, facile bandgap tunability, and superior air stability. However, CQD devices still lack enough flexibility to be applied to wearable devices owing to the poor mechanical properties of CQD films. In this study, a facile approach is proposed to improve the mechanical stability of CQDs solar cells without compromising the high power conversion efficiency (PCE) of the devices. (3-aminopropyl)triethoxysilane (APTS) is introduced on CQD films to strengthen the dot-to-dot bonding via QD-siloxane anchoring, and as a result, crack pattern analysis reveals that the treated devices become robust to mechanical stress. The device maintains 88% of the initial PCE under 12 000 cycles at a bending radius of 8.3 mm. In addition, APTS forms a dipole layer on CQD films, which improves the open circuit voltage (V_OC) of the device, achieving a PCE of 11.04%, one of the highest PCEs in flexible PbS CQD solar cells.     

Effect of heat transfer on the performance of thermoelectric generator-driven thermoelectric refrigerator system

A model of thermoelectric generator-driven thermoelectric refrigerator with external heat transfer is proposed. The performance of the combined thermoelectric refrigerator device obeying Newton’s heat transfer law is analyzed using the combination of finite time thermodynamics and non-equilibrium thermodynamics. Two analytical formulae for cooling load vs. working electrical current, and the coefficient of performance (COP) vs. working electrical current, are derived. For a fixed total heat transfer surface area of four heat exchangers, the allocations of the heat transfer surface area among the four heat exchangers are optimized for maximizing the cooling load and the coefficient of performance (COP) of the combined thermoelectric refrigerator device. For a fixed total number of thermoelectric elements, the ratio of number of thermoelectric elements of the generator to the total number of thermoelectric elements is also optimized for maximizing both the cooling load and the COP of the combined thermoelectric refrigerator device. The influences of thermoelectric element allocation and heat transfer area allocation are analyzed by detailed numerical examples. Optimum working electrical current for maximum cooling load and COP at different total number of thermoelectric elements and different total heat transfer area are obtained, respectively.