Permanently disentangled states of atom–field system via spontaneously generated coherence

Abstract

The effect of spontaneously generated coherence on evolution of the entanglement between a driven four-level Y-type atom and its spontaneous emission field is studied. We have shown that the atom will be entangled to its spontaneous emission field due to spontaneously generated coherence and coherent population trapping at the steady state. It is found that the degree of entanglement strongly depends on the initial atomic state. So, it can be controlled by the pumping laser pulses used for preparing an initial atomic system. More interestingly, the atom–field system can be found in a permanently disentangled state for a properly prepared atom.     

Engineering-Driven Statistical Adjustment and Calibration

Engineering model development involves several simplifying assumptions for the purpose of mathematical tractability, which are often not realistic in practice. This leads to discrepancies in the model predictions. A commonly used statistical approach to overcome this problem is to build a statistical model for the discrepancies between the engineering model and observed data. In contrast, an engineering approach would be to find the causes of discrepancy and fix the engineering model using first principles. However, the engineering approach is time consuming, whereas the statistical approach is fast. The drawback of the statistical approach is that it treats the engineering model as a black box and therefore, the statistically adjusted models lack physical interpretability. This article proposes a new framework for model calibration and statistical adjustment. It tries to open up the black box using simple main effects analysis and graphical plots and introduces statistical models inside the engineering model. This approach leads to simpler adjustment models that are physically more interpretable. The approach is illustrated using a model for predicting the cutting forces in a laser-assisted mechanical micro-machining process. This article has supplementary material online.     

利用基因工程赋予纤维新的性能

综述了基因工程在纺织领域的应用.现在世界范围内都在研究用基因工程的方法生产新纺织纤维.生物技术在纺织领域的应用包括:对现有棉、毛、亚麻、黄麻、丝之类天然纤维进行基因改性,开发新的纤维或生物聚合物如聚乳酸、生物纤维素等.     

三元乙丙池塘衬垫系统在工程中的应用

介绍了凡士通三元乙丙池塘衬垫系统的特点和系统应用前需考虑的问题，并对该系统主材三元乙丙卷材的安装做了详细阐述．同时简要介绍了该系统在两个实际工程中的应用。     

Patient adherence to cancer control regimens: Scale development and initial validation.

Describes the development of a 38-item self-report Adherence Determinants Questionnaire (ADQ) to assess 7 elements of patients' adherence to medical treatment and prevention: (1) perceptions of interpersonal care, (2) beliefs about susceptibility to disease, (3) beliefs about severity of disease, (4) assessments of perceived utility of adhering (efficacy and benefits vs costs of adhering), (5) perceptions of subjective social norms for adhering, (6) intentions to adhere, and (7) perceptions of supports available for and absence of barriers to adherence. Past adherence and health value were also assessed. In 4 diverse field settings, intentions to adhere were most highly correlated with the perceived utility of adhering. Adherence (self-reported and objectively measured) was related most strongly to the presence of supports for and the absence of barriers to adherence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rod-like oligomers incorporating 2,6-dialkylamino core-substituted naphthalene diimide as acceptors for organic photovoltaic

Core-substituted naphthalene diimides (core-substituted NDIs) were incorporated into rod-like molecules and oligomers through reaction at the imide nitrogen positions. N,N′-Di(4-bromophenyl)-2,6-di(N-alkylamino)-1,4,5,8-naphthalenetetracarboxydiimide was synthesized in only three steps, and used as a versatile platform to prepare extended structures by reaction with thiophene substrates using Suzuki-coupling conditions. The optoelectronic properties of the new compounds were examined by UV/vis absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry and theoretical calculations. The imide substituents had little effect on the optical and electrochemical properties of core-substituted NDIs in solution. A bathochromic shift of the absorption was observed upon film formation, accompanied by quenching of fluorescence. These observations are consistent with increased inter-molecular interactions between core-substituted NDI moieties in the solid state. All compounds were tested in organic solar cells by blending with poly(3-hexylthiophene), and several showed a photovoltaic effect, demonstrating their potential as electron acceptors in organic solar cell. The best solar cell was observed for core-substituted NDI with 4-(thiophen-2-yl)phenyl imide substituents (5a), showing a power conversion efficiency of 0.57% and a large open circuit voltage of 0.87 V. This approach allows new structure–property relationship studies of non-fullerene acceptors in organic solar cells, where one can vary the imide substituent to optimize photovoltaic parameters while keeping the optical and electrochemical properties constant.     

Structure, mechanical properties, and hydrogen permeability of Pd-Cu and Pd-Ru membrane foils prepared by magnetron sputtering

Magnetron sputtering is used to prepare thin (down to 7 μm) Pd-Cu and Pd-Ru membrane foils deposited on the surface of a SiO₂/Si heterostructure at 300 and 700 K. Condensed foils (CFs) of an ordered Pd-Cu solid solution (β phase with a CsCl-type structure) and a Pd-Ru solid solution (fcc lattice) are synthesized for the first time. The foils of both alloys are characterized by a gradient granular structure due to selective development of 〈110〉 and 〈112〉 textures and a 〈111〉 texture in the Pd-Cu and Pd-Ru foils during their deposition, respectively. The hardness of the free surface of both foils removed from the substrate is determined by nanoindentation. The hardness is 3.0–3.6 GPa and is 20–50% lower than that of the contact surface (at the interface with the substrate) owing to the gradient structure. The hydrogen permeability of the Pd-Cu CF (β phase) is higher than that of the Pd CF by almost an order of magnitude (effect of a less dense crystal lattice) and is 5–7 times higher than those of the Pd-Ru CF and the Pd-Cu foil prepared by rolling.     

An Expedient Route to 9-Arylmethylanthracene Derivatives via Tandem Ni-Catalyzed Alkene Dicarbofunctionalization and Acid-Promoted Cyclization-Aromatization

We report a nickel-catalyzed one pot synthesis of 9-arylmethylanthracene motifs, which find applications in medicinal and material chemistry. In this synthesis, we apply three component alkene dicarbofunctionalization of 2-vinylaldimines with aryl iodides and arylzinc reagent to generate a 1,1,2-diarylethyl scaffold, which then undergoes an acid-promoted cyclization followed by aromatization to furnish 9-arylmethylanthracene cores. With the new method, a number of differently-substituted 9-arylmethylanthracene derivatives can be synthesized in good yields.     

Review on transesterification in polycarbonate–poly(butylene terephthalate) blend

Various polycarbonate - poly(butylene terephthalate) polyester (PC-PBT) blend prepared by reactive melt blending primarily in extruder with range of temperature and time are discussed in this review article. In the melt blended PC-PBT blend system, transesterification plays a major role in formation of PC-PBT blend. Transesterification reactions between these two polymers have been analyzed by proper polymer sample, end-capped or having reactive chain end group. The kinetics of mechanism is a function of temperature and PC-PBT ratio. Trace catalyst residue present in PBT catalyzes the transesterification reaction. As the extent of transesterification is increased, it forms various composition of copolymer. Inhibition in the transesterification reaction of PC-PBT blend has been observed when different type of alkyl, aryl, and alkyl-aryl group of phosphite are introduced into it, otherwise there has been collateral change in the morphology, thermal, and mechanical property of blend. Therefore, this PC-PBT blend has been an interesting topic of research in academia and industries.