The investigation of the (p,ρ,T) and (ps,ρs,Ts) properties of {(1−x)CH3OH + xLiBr} for the application in absorption refrigeration machines and heat pumps

The (p,ρ,T) and (p_s,ρ_s,T_s) properties of {(1−x)CH₃OH + xLiBr} over a wide range of state parameters are reported for the first time. The experiments were carried out in a constant volume piezometer over a temperature range from 298.15 K to 398.15 K, at 0.08421, 0.13617, 0.19692, 0.23133 and 0.26891 mole fractions and from atmospheric pressure up to 60 MPa. The experimental uncertainties are ΔT=±3 mK for temperature, Δp=±5·10⁻² MPa for high pressure and Δp=±5·10⁻⁴ MPa for atmospheric pressure, Δρ=±3·10⁻² kg · m⁻³ for density. An equation of state was derived for correlation of the experimental data of the solutions.     

Bacteriorhodopsin as an Example of a Light-Driven Proton Pump

Apart from the long known visual pigments, another retinal protein complex exists in nature, viz. bacteriorhodopsin from halobacteria. In contrast to the visual pigments such as the rhodopsins, which act as light sensors in the eye, bacteriorhodopsin actually transforms light energy. This energy conversion is connected with the asymmetric incorporation of bacteriorhodopsin in the lattice structure of the purple membrane which forms patches on the cell surface of halobacteria. Alongside the chlorophyll system, the purple membrane system represents the second light energy conversion principle to be discovered in living nature. Bacteriorhodopsin acts as a light-driven proton pump or as the main component of such a pump system. Absorption of light triggers off a cycle of reactions coupled with the spatially oriented uptake and release of a proton. In the intact cell an electrochemical gradient is thus built up across the cell membrane of the bacterium in which part of the absorbed light energy is stored and which is not dependent upon redox processes as in the case of respiration or photosynthesis. This electrochemical gradient can supply the energy required for ATP synthesis in the cell; a reversible proton-translocating ATPase serves as catalyst system.     

Adsorption Heat Pump Using an Innovative Coupling Refrigeration Cycle

An adsorption heat pump system using a new binary coupling adsorptive cycle is developed and tested. Experimental results show that the COP of the binary coupling cycle is higher than that of a pure zeolite-water system. The system operating pressure is found to be moderate (close to the ambient pressure) when a proper concentration of ammonia is used in the system. The moderate operating pressure of the new coupling cycle results in low leakage to the system, achieving long life and the light design of the system vessels. The use of the new binary adsorption cycle greatly improves the feasibility and reliability of the adsorption heat pumps, providing essential benefits for the industrialisation of adsorption heat pumps.     

变频控制直接膨胀式太阳能热泵的数值模拟

文中通过对变频控制直接膨胀式太阳能热泵的数值模拟,指出PV/T- SAHP系统实现变频控制从而解决太阳能热泵集热器面积与压缩机的容量不匹配的关键问题是找到系统集热/蒸发器的MSS线.为变工况下太阳能热泵系统的研究提供参考.     

Combining selection valve and mixing chamber for nanoflow gradient generation: Toward developing a liquid chromatography cartridge coupled with mass spectrometer for protein and peptide analysis

Toward developing a micro HPLC cartridge, we have recently built a high-pressure electroosmotic pump (EOP). However, we do not recommend people to use this pump to deliver an organic solvent directly, because it often makes the pump rate unstable. We have experimented several approaches to address this issue, but none of them are satisfactory. Here, we develop an innovative approach to address this issue. We first create an abruption (a dead-volume) within a fluid conduit. We then utilize an EOP to withdraw, via a selection valve, a train of eluent solutions having decreasing eluting power into the fluid conduit. When these solutions are further aspirated through the dead-volume, these solutions are partially mixed, smoothening concentration transitions between two adjacent eluent solutions. As these solutions are pushed back, through the dead-volume again, a smooth gradient profile is formed. In this work, we characterize this scheme for gradient formation, and we incorporate this approach with a high-pressure EOP, a nanoliter injection valve, and a capillary column, yielding a micro HPLC system. We then couple this micro HPLC with an electrospray ionization – mass spectrometer for peptide and protein separations and identifications.     

Gated-controlled electron pumping in connected quantum rings

We study the electronic transport across connected quantum rings attached to leads and subjected to time-harmonic side-gate voltages. Using the Floquet formalism, we calculate the net pumped current generated and controlled by the side-gate voltage. The control of the current is achieved by varying the phase shift between the two side-gate voltages as well as the Fermi energy. In particular, the maximum current is reached when the side-gate voltages are in quadrature. This new design based on connected quantum rings controlled without magnetic fields can be easily integrated in standard electronic devices.     

基于微流控技术的蛋白质结晶及其筛选方法的研究进展简

微流控技术以其高通量、低消耗和集成化等优点成为蛋白质结晶微型化研究的重要手段. 本文综述了基于微流控技术的蛋白质结晶技术和方法,主要包括微泵微阀、液滴(Droplet)、滑动芯片(SlipChip)以及液滴实验室(DropLab)等技术. 此外,还针对当前膜蛋白在结构生物学研究中的重要地位,综述了应用于膜蛋白结晶的微流控技术的研究进展.     

基于功率谱包络能量和SVM的舰用发动机故障诊断

发动机是军舰上的重要部件之一,其稳定性对军舰的正常航行具有重要影响。以舰用发动机关键部件(主泵轴承)为具体研究对象,提出了基于功率谱包络能量和支持向量机相结合的故障诊断方法。首先获取了大量可表征舰用发动机主泵轴承健康状态的振动加速度信息,对其进行功率谱分析,获得其功率谱的包络能量;以获取的舰用发动机主泵轴承功率谱的包络能量构建特征向量,并设计基于SVM的舰用发动机主泵轴承故障诊断模型,对主泵轴承的故障进行诊断研究。研究结果表明,采用基于功率谱包络能量和SVM相结合的舰用发动机关键部件故障诊断方法,可以很好实现主泵轴承的故障诊断效能,为舰用发动机主泵轴承故障诊断的工程应用奠定了基础。     

流动控制沉积法制备PMMA叠层光子晶体薄膜及其光学性能研究

采用流动控制沉积法, 通过调控泵速和聚甲基丙烯酸甲酯(PMMA)胶体微球溶液的浓度, 制备出微球排列高度有序且薄膜紧密附着于基底的高质量光子晶体薄膜. 获得了制备高质量PMMA光子晶体薄膜的组装条件范围, 发现在该条件范围内, 当泵速或胶体微球溶液浓度一定时, PMMA光子晶体薄膜的厚度随胶体微球溶液浓度的增加或泵速的降低而增加. 研究了组装条件对PMMA光子晶体薄膜光学性能的影响, 发现光子禁带位置随光子晶体薄膜厚度增加或减少而红移或蓝移. 在此基础上, 控制组装条件得到了不同尺寸微球堆叠而成的叠层光子晶体薄膜, 并研究了其光学性能的变化规律. 结果显示, 叠层光子晶体薄膜的光子禁带峰为各层叠层光子晶体禁带峰的简单叠加, 且峰强度受光入射角方向影响.