来自新西兰的纯净声音

Hayley Westenra 出生于南岛基督城的海莉一直是新西兰的骄傲．《纯净》专辑是她的第一张专辑。专辑一经发行就保持了4周的销售冠军，而当年这个长相甜美的小姑娘才16岁。海莉不仅取得南半球销售冠军，也成功地打进了美国市场并赢得了全世界歌迷的心。

浅析20世纪初美国联邦《纯净食品与药品法》出台的历史背景

19世纪80年代以来美国食品加工技术的提高和食品市场的扩大使政府对食品市场进行管制成为必要。这种管制最先表现为各州制定了纯净食品法。然而州管制既不足以保护消费者,也不足以保护食品生产者。于是,在科学界的呼吁和媒体的宣传下,觉醒消费者开始大力推动联邦政府对食品市场进行管制,大型食品生产者利益集团在这方面态度也十分积极,最后促成了1906年《纯净食品与药物法》的出台,开始了联邦管制食品市场的新时代。

《纯净脆弱的心》:爱的负罪与重生

很多纯爱电影都愿意设置一个绝症主题,其用意不只是煽情,更是对生命的一种纯粹的敬畏与追问。

“万灵丹”危急时刻的契机

“危机时刻”的出现,有时会使得本来没有成为公共议程一部分的议题,变成当下公共议程的迫切要务;有时它则会成为政治家实现其胸中块垒的助力,从而促成规制变迁的发生。

Effect of refining processes on inclusions and mechanical properties of cast Al-2Li-2Cu-0.2Zr alloy

The effect of different refining processes on inclusions and mechanical properties of cast Al-2Li-2Cu-0.2Zr alloy was investigated, including two-stage hexachloroethane (C2Cl6) refining process, two-stage rotating gas bubbling refining process and two-stage composite refining process. It was found that the two-stage composite refining process, which combined C2Cl6 and rotating gas bubbling, can significantly improve the melt purity and mechanical properties of cast Al-2Li-2Cu-0.2Zr alloy. Compared to the unrefined alloy, the volume fraction of gas porosity defects and slag inclusions decreased from 1.47% to 0.12%, and the yield strength, ultimate tensile strength and elongation of as-quenched alloy increased from 113 MPa,179 MPa and 3.9% to 142 MPa, 293 MPa and 18.1%, respectively. C2Cl6 was first utilized to degas and remove large size slag inclusions before lithium addition, and then the rotating gas bubbling was utilized to do the further degassing and remove the suspended fine inclusions after lithium addition. The two-stage composite refining process can take advantage of two methods and get the remarkable refining effect.

Preparation of Arsenic Oxide and High Purity Ultrafine Antimony Compounds from Flue Dust Containing Arsenic and Antimony

A new hydrometallurgical process of chlorination-distillation at low temperatures about 100 °C was developed for recovery of valuable metal and environmental protection. This process was used to treat flue dust containing arsenic and antimony and satisfactory results were obtained. Over 99% of arsenic and antimony were recovered, and high purity As2O3 and SbCl3 were produced. A metallic alcoholate technique was developed and proved to be of significant to the utilization of antimony resources. Using this technique, a number of antimony oxide powders were prepared, such as high purity and ultrafine Sb2O3, ultrafine Sb2O3-Sb2O5 and Sb2O3-SnO2 composite powders.

CdTe Films Deposited by Closed-space Sublimation

CdTe films are prepared by closed-space sublimation technology. Dependence of film crystalline on substrate materials and substrate temperature is investigated. It is found that films exhibit higher crystallinity at substrate temperature higher than 400 ℃. And the CdTe films deposited on CdS films with higher crystallinity have bigger crystallite and higher uniformity. Treatment with CdCl 2 methanol solution promotes the crystallite growth of CdTe films during annealing.

Viscosities of Pure Water, Acetic Acid ＋ Water, and p-Xylene ＋ Acetic Acid ＋ Water at Different Temperature and Pressure

The viscosities of pure water,the acetic acid+water binary system,and the p-xylene+acetic acid+ water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313.15 to 473.15 K and pressures from 0.10 to 3.20 MPa.The viscosity data were fitted by a correlation equation for the estimation of the mixture viscosities.The average absolute deviations(AAD)of the correlation for binary and ternary systems are 2.48%and 1.77%,respectively.

Functional characterization of a novel microbial esterase identified from the Indian Ocean and its use in the stereoselective preparation of(R)-methyl mandelate

Genomic mining has identifi ed a novel microbial alkaline esterase from the Indian Ocean. This esterase was overexpressed in E. coli BL21（DE3） and further functionally characterized. Under optimal conditions（10 mmol/L substrate, p H 6.0, 2 h at 40 ℃）, this esterase can hydrolyze racemic methyl mandelate to（ R）-methyl mandelate with very high optical purity（e. e. 〉99%） and yield（nearly 90%）. Interestingly, the stereoselectivity of this esterase is opposite to that of two previously reported lipases that can generate（ S）-methyl mandelate through the hydrolysis of racemic methyl mandelate. No organic solvents or other additives were required to optimize the optical purity and production of the fi nal chiral product（R）-methyl mandelate, which can potentially simplify the production procedure of（ R）-methyl mandelate catalyzed by esterase.

Generation of Entanglement Between Two Noninteracting Qubits via Interaction with Nonclassical Radiation Field

We study the interaction between a single-mode quantized field and a quantum system composed of two qubits. We suppose that two qubits initially be prepared in the mixed and separable state, and study how entanglement between two qubits arises in the course of evolution according to the Jaynes-Cummings type interaction with nonclassical radiation field. We also investigate the relation between entanglement and purity of qubit subsystem. We show that different photon statistics have different effects on the dynamical behavior of the qubit subsystem. When the qubits are initially prepared in the maximally mixed and separable state, for coherent state field we cannot find entanglement between two qubits; for squeezed state field entanglement between two qubits exists in several short period of time; for even and odd coherent state fields of large photon number, the dynamical behavior of the entanglement between two qubits shows collapse and revival phenomenon. For odd coherent state field of small photon number, the entanglement with both qubits initially prepared in maximally mixed state can be stronger than that with both qubits initially prepared in pure states. For fields of small photon number, the entanglement strongly depends on the states they are initially prepared in. For coherent state field, and odd and even coherent state fields of large photon number, the entanglement only depends on the purity of the initial state of qubit subsystem. We also show that during the evolution the unentangled state may be purer than the entangled state, and the maximum degree of entanglement may not occur at the time when the qubit subsystem is in the purist state.

Knotted Picture of a Quantum Network of Two Nodes

This article discusses the variation of the knotted picture of the quantum pure state with the variation of the complex coefficients α and β. It is shown that there are three kinds of link that correspond to three different ranks of the matrix of covariance correlation tensor, i.e., the zero rank corresponds to trivial link, the rank one corresponds to the two-component link with two crossings, and the rank three corresponds to the two-component link with four crossings.

唐敏散文散论

现代散文的定义是新文化运动的产物,包含了太多的非文学成份。散文无非是一种感情的语言艺术,唐敏的散文就是以心情支配情节和叙述的典范,且具有很强的女性化特征。如果你已经厌倦了几千年来男人散文的所谓“闲知”,所谓“小题大做”,所谓“一粒沙里见世界,半瓣花上说人情”,那么,不妨读一下唐敏的《纯净的落叶》。

Heat Transfer Performance of a Multi-heat Pipe Using Graphene Oxide/Water Nanofluid

A multi-heat pipe is a device for heat transmission. It is composed of a heating section, a cooling section and an adiabatic section. The heating and cooling sections are the same and both are connected by four circular parallel tubes. This experimental study is performed to investigate heat transfer performance of a multi-heat pipe in the vertical orientation using pure water and GO （graphene oxide）/water nanofluid. GO/water nanofluids were synthesized by the modified Hummers method with 0.05%, 0.1%, 0.15%, and 0.2% volume concentrations. The thermal performance has been investigated with varying heat flux in the range of 10-30 W and 100% fill charge ratio. Wall temperature, thermal resistance, and heat transfer coefficient of the heat pipe are measured and compared with those for the heat pipe using pure water. The experimental results show that the evaporator wall temperature with GO nanofluid is lower than that of the base fluid. Also, the heat pipe that charged with nanofluids showed lower thermal resistance compared with pure water. Heat transfer enhancement is caused by suspended nanoparticles and is pronounced with the increase in particle volume fraction.

Unified Model of Purification Units in Hydrogen Networks

Purification processes are widely used in hydrogen networks of refineries to increase hydrogen reuse. In refineries, hydrogen purification techniques include hydrocarbon, hydrogen sulfide and CO removal units. In addition, light hydrocarbon recovery from the hydrogen source streams can also result in hydrogen purification. In order to simplify the superstructure and mathematical model of hydrogen network integration, the models of different purification processes are unified in this paper, including mass balance and the expressions for hydrogen recovery and impurity removal ratios, which are given for all the purification units in refineries. Based on the proposed unified model, a superstructure of hydrogen networks with purification processes is constructed.

A unified graphical method for integration of hydrogen networks with purification reuse

Introducing purifiers into hydrogen network can enhance the recovery and reuse of hydrogen in refineries, further reducing the consumption of fresh hydrogen. Based on previous graphical methods, this work proposes a simple and unified graphical method for integration of hydrogen networks with purification processes. Scenarios with different hydrogen concentrations of purified product can be analyzed by the unified procedure. As a result, the maximum hydrogen saved by purification reuse can he identified and the corresponding purification process can be optimized, The proposed method is easy and non-iterative, and it is valid to purification processes with any feed concentration. A conventional hydrogen network is analyzed to test the effectiveness of the proposed method.

A novel purification process for dodecanedioic acid by molecular distillation

A novel purification process is involved to obtain the high purity[>99%(by mass)]dodecanedioic acid(DC_(12)).It involves a re-crystallization followed by molecular distillation from the crude product.The objective of this study is to investigate general conditions,feed rate,distilling temperature and vacuum,necessary for centrifugal distillation of DC_(12).Under the optimum conditions,distilling temperature 180℃,pressure 30 Pa and feed flow rate700 ml·h^(-1),the purity of DC_(12) in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography.Multiple-pass distillation made a considerable contribution by improving the purity to99.22%.Additionally,the effect of pretreatment(re-crystallization) on distillation process was revealed through a series of comparative experiments.

业界利益与公共福利双赢：美国医学会与药品管理的联邦化(1891-1912)

1891年,以参议院讨论的第一道纯净食品和药品综合议案为契机,美国医学会开始介入政府的药品管理。1901年的"机制性"改组是重要的分水岭,美国医学会逐步发展为强大的"医学政治组织"。它通过内部动员,借助《美国医学会杂志》制造社会舆论,外联妇女组织、"黑幕揭发者"以及官僚机构,以多种方式敦促国会颁布了《纯净食品和药品法》和《谢利修正案》,管理国内药品的掺假和贴假商标,规制专利药品制造及贸易。美国医学会与联邦政府的互动、合作优化了转型年代国家与社会的关系,美国医学会也藉对公共卫生事务的参与最终实现了业界利益与公共福利的双赢。

Investigations on Heat Transfer Enhancement in Pool Boiling with Water-CuO Nano-Fluids

The main focus of the present work is to investigate Critical Heat Flux (CHF) enhancement using CuO nanofluid relative to CHF of pure water. To estimate the effect of nanoparticles on the CHF, pool boiling CHF values were measured for various volume concentrations of CuO nanofluid and compared with pure water. CHF enhancement of 130% was recorded at 0.2 % by volume of CuO nano-fluids. Surface roughness of the heater surface exposed to three measured heating cycles indicated surface modifications at different volume concentrations of nanofluid. SEM image of the heater surface revealed porous layer build up, which is thought to be the reason for CHF enhancement.

Metallic nanoparticles analysis for the blood flow in tapered stenosed arteries： Application in nanomedicines

Blood flow model is recycled to study the influence of magnetic field and nanoparticles in tapered stenosed arteries. The metallic nanoparticles for the blood flow with water as base fluid are not explored so far. The representation for the blood flow is through an axially non-symmetrical but radially symmetric stenosis. Symmetry of the distribution of the wall shearing stress and resistive impedance and their growth with the deve- loping stenosis is another important feature of our analysis. Exact solutions have been evaluated for velocity, resistance impedance, wall shear stress and shearing stress at the stenosis throat. The graphical results of different types of tapered arteries （i.e. conver- ging tapering, diverging tapering, non-tapered artery） have been examined for different parameters of interest for pure water and Copper water （Cu-water）.