Evaluating the information content of a measure of plant output: An application to high-technology manufacturing

Commonly used measures of plant output have been criticized for their inability to provide information required to manage the dynamic operations of high-technology manufacturing plants. In this paper, we propose tests to evaluate the information content of a measure of plant output that is specifically directed at these issues. These tests are based on recent developments in DATA Envelopment Analysis (DEA), namely the Cone Ratio Envelopments. In this new application of DEA models, we shift the focus from Decision Making Units (DMUs) being evaluated to the DMUs that are being used to effect evaluations. The proposed tests are applied to evaluate the information contnet of a complexity adjusted measure of plant output, which we refer to as Total Net Die Equivalent (TNDE). Developed recently in the context of a high-technology manufacturing plant—a wafer fabrication plant of a merchant semiconductor manufacturing company-TNDE reflects the ongoing changes in product and process technologies, process flow characteristics, and volume of production. Evaluating the information content on joint criteria of recency and efficiency, the results of our tests, conducted over a 28-month period in the wafer fabrication plant,show that TNDE as a single aggregate (scalar) measure of plant output outperforms the two outputs from which it is synthesized. Thus, TNDE as a single measure of output can be used to provide an improved basis for planning a plant's future operations. En route to the development and application of the proposed tests, we illustrate how DEA concepts and models provide a rigorous and systematic basis for conducting ex post technology evaluation to guide continuous improvements in a plant's current operations.     

Synthesis of fluorescent dendritic 8-hydroxyquinoline ligands and investigation on their coordinated Zn(II) complexes

A series of luminescent PAMAM dendrons emanating from 8-hydroxyquinoline have been synthesized and their coordination with Zn(II) was investigated for the first time. The obtained dendritic Zn(II) complexes were soluble in common organic solvents. It was found that the luminescence intensity of G2 dendron 6 was higher than that of G1 dendron 4. Furthermore, when they were coordinated with Zn(II), red-shift was observed and the intensities of the coordinated Zn(II) complexes were higher than that of the corresponding ligands.     

Three-dimensional mesoporous titanosilicates prepared by modified sol-gel method: Ideal gold catalyst supports for enhanced propene epoxidation

Mesoporous titanosilicates with 1-12 mol % Ti content and with three-dimensional wormhole-like mesoporosity are prepared by a modified sol-gel technique. Sorption analysis shows that there is little change in the surface properties with increasing Ti concentration in the samples, implying that Ti atoms either are well-dispersed on the walls of the silica matrix or are present inside the framework with no pore blocking effect. Spectroscopic analysis shows that the Ti atoms are atomically dispersed in the silica matrix even at very high Ti concentration and there is no observable Ti aggregate (anatase) present in the samples. These titanosilicate samples after Au deposition followed by trimethylsilylation (for enhanced hydrophobicity) are highly efficient catalysts for vapor-phase propene epoxidation using O2 and H2. It was possible to achieve commercially desirable performance with about 7% propene conversion, >90% propene oxide selectivity, and about 40% hydrogen efficiency.     

Reactions of Diethyl [(3-Bromomethyl-2-Thienyl)-Methylene]Propanedioate with Hydrazines: Syntheses of Dihydropyridazines,Pyridazines and O-Dimethylaminomethylarenecarbonitriles

Facile syntheses of dihydropyridazines, pyridazines, and o-dimethylaminomethylarenecarbonitriles have been achieved by the retro-malonate addition reaction. Bromoalkylidenemalonates 1,7, and 10 were treated with hydrazine to give dihydropyridazines 4, 8, and 11 in quantitative yields. DDQ or air oxidation of 4, 8, and 11 gave pyridazines 5, 9, and 12, Alternatively, treatment of 1, 7, and 10 with 1,1-dimethylhydrazine afforded o-dimethylaminomethylarenecarbonitriles 6,13, and 14 in good yields.     

Preparation and spectroscopic properties of 2-benzothiazolyl araldehyde hydrazones

Notwithstanding its tendency toward air oxidation in solution, 2-hydrazinobenzothiazole I reacted with aromatic aldehydes in ethanol to give the corresponding hydrazones III-XV in high yields and analytical purity. In related examples, acylation took place under similar conditions to produce hydrazides XVI-XX . The near-infrared bands of the absorption spectra of the araldehyde hydrazones have been associated with charge transfer and appeared to correlate with structural elements of the compounds in a way suggesting that the charge transfer was intermolecular.     

Equilibrium theory of two-dimensional simple liquids

Using the Wigner-Kirkwood expansion and bare Lennard-Jones (LJ) (12-6) potential, an effectiveLJ potential is derived, which includes the quantum effects through the expressions of the effective diameter∂(T, λ) and well-depth (T, λ). We use theWCA perturbation theory to calculate the free energy and pressure for theLJ and effectiveLJ potentials. Simple analytic expressions are given for the reference system and the first order correction calculated. The results are quite good at high density. The quantum effects on the free energy and pressure are also discussed.     

钇对2618合金组织及性能的影响

采用X射线，光学显微镜及扫描电镜等手段研究了2618合金中的组织与相结构，并研究了元素钆在2618合金中的存在形式及其对合金力学性能的影响。结果表明，微量钆元素在铝合金中是以化合物形式存在的；钆对合金中的铸态组织及Al9FeNi仃形态没有影响。由于微量钆的加入，降低了铜与镁在2618合金中的固溶量，减少了时效析出相A2CuMg数量，从而降低2618合金的室温强度帮在250℃的高温瞬时强度；但由于微量钆减少了铜与镁在2618合金中的扩散速度，延缓了时效机的粗化，并由于第二相数量的增多，因此提高了2618合金在250℃经100h高温热暴露后的高温瞬时强度。     

Chemistry of azoimidazoles. Synthesis,spectral characterization and redox studies of N(1)-benzyl-2-(arylazo)imidazolepalladium(II)chloride

Arylazoimidazoles (2) are N,N-chelating ligands. The polymerization trend of the azolate system is restricted via N(1)-benzylation. The parent molecules (2), N(1)-benzylated products (3) and palladium complexes (4) were made by standard methods. The ligands (3) and complexes (4) are new. They have been characterized by elemental analysis, i.r., u.v.-vis. and high resolution 1H-n.m.r. spectral data. Redox studies were carried out by cyclic voltammetry. On complexation, azo reduction is shifted anodically.     

Two new sesquiterpene lactones with the sulfonic acid group from Saussurea lappa

Two new sesquiterpene lactones with the unusual sulfonic acid group, 13-sulfo-dihydrosantamarine (1) and 13-sulfo-dihydroreynosin (2), have been isolated from the roots of Saussurea lappa C. Their structures, including the absolute configurations, were elucidated by spectroscopic methods.