Etude du fonctionnement d’un mélangeur à jonction métal-isolant-métal dans I’infrarouge lointain

Annals of Telecommunications - L’effet tunnel entre deux métaux permet de représenter la non-linéarité d’une diode mim (métal-isolantmétal). Le schéma...     

Do the opportunities for learning and personal development lead to happiness? It depends on work-family conciliation.

The study shows how the perceptions of opportunities for learning and personal development predict five dimensions of affective well-being (AWB: pleasure, comfort, placidity, enthusiasm, and vigor), and how this relationship is moderated by the perceptions of work-family conciliation. A sample comprising 404 individuals was collected. The findings show the following: (1) both the perceptions of opportunities for learning and personal development and perceptions of work-family conciliation predict AWB, the happier individuals being those who have high perceptions on both variables; (2) both variables interact in predicting AWB, in such a way that perceptions of high opportunities for learning and personal development may not lead to higher AWB if work-family conciliation is low. Post hoc analysis also suggests that the relationship between the perceptions of opportunities for learning and personal development and AWB tends to be nonlinear for individuals with perceptions of low work-family conciliation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Building test cases and oracles to automate the testing of web database applications

Many organizations rely on web applications that use back-end databases to store important data. Testing such applications requires significant effort. Manual testing alone is often impractical, so testers also rely on automated testing techniques. However, current automated testing techniques may produce false positives (or false negatives) even in a perfectly working system because the outcome of a test case depends on the state of the database which changes over time as data is inserted and deleted. The Automatic Database Tester (AutoDBT) generates functional test cases that account for database updates. AutoDBT takes as input a model of the application and a set of testing criteria. The model consists of a state transition diagram that shows how users navigate pages, a data specification that captures how data flows, and an update specification that shows how the database is updated. AutoDBT generates guard queries to determine whether the database is in a state conducive to performing and evaluating tests. AutoDBT also generates partial oracles to help validate whether a back-end database is updated correctly during testing. This paper describes the design of AutoDBT, a prototype implementation, several experiments with the prototype, and four case studies.     

内建电场调控光生电荷分离效率的研究进展

光催化技术是解决现今环境污染和能源危机的重要手段之一,然而大部分催化剂的光催化效率较低,提高光生电荷的分离是提高光催化效率的一种有效方法.首先对催化剂的光催化原理进行了概述;结合近年来国内外在提高光生电荷分离效率方面取得的最新成果及进展,从内建电场的产生机理入手,综述了半导体p-n结、异相结、极化表面和铁电材料极化对光...     

Performance of High Explosives in Underwater Applications. Part 1: CHNO explosives

The change in postdetonation free energy, rather than the often used change in detonation enthalpy, is suggested as a measure of the underwater performance of high explosives. Results of a correlation analysis of data from 11 explosives are presented. It is suggested that the detonation pressure is also a significant factor for the energy available for mechanical work, but this can not be verified by the present data. However, in the partition of energy between shock wave and bubble the detonation pressure is the dominant factor.     

Label-Free Study of the Global Cell Behavior during Exposure to Environmental Radiofrequency Fields in the Presence or Absence of Pro-Apoptotic or Pro-Autophagic Treatments

It remains controversial whether exposure to environmental radiofrequency signals (RF) impacts cell status or response to cellular stress such as apoptosis or autophagy. We used two label-free techniques, cellular impedancemetry and Digital Holographic Microscopy (DHM), to assess the overall cellular response during RF exposure alone, or during co-exposure to RF and chemical treatments known to induce either apoptosis or autophagy. Two human cell lines (SH-SY5Y and HCT116) and two cultures of primary rat cortex cells (astrocytes and co-culture of neurons and glial cells) were exposed to RF using an 1800 MHz carrier wave modulated with various environmental signals (GSM: Global System for Mobile Communications, 2G signal), UMTS (Universal Mobile Telecommunications System, 3G signal), LTE (Long-Term Evolution, 4G signal, and Wi-Fi) or unmodulated RF (continuous wave, CW). The specific absorption rates (S.A.R.) used were 1.5 and 6 W/kg during DHM experiments and ranged from 5 to 24 W/kg during the recording of cellular impedance. Cells were continuously exposed for three to five consecutive days while the temporal phenotypic signature of cells behavior was recorded at constant temperature. Statistical analysis of the results does not indicate that RF-EMF exposure impacted the global behavior of healthy, apoptotic, or autophagic cells, even at S.A.R. levels higher than the guidelines, provided that the temperature was kept constant.     

靖边气田地层压力评价方法适用性研究

地层压力是气田开发过程中动态分析必不可少的参数,目前地层压力不仅反映气藏的剩余能量,还体现了气藏的开发效果和开发能力。针对靖边气田特殊的储层性质,分析了几种地层压力评价方法,并优选出计算单井目前地层压力的方法,进而确定区块以至整个气田的地层压力,对未来的开发方向具有一定的指导意义。     

DeepHP: A New Gastric Mucosa Histopathology Dataset for Helicobacter pylori Infection Diagnosis

Emerging deep learning-based applications in precision medicine include computational histopathological analysis. However, there is a lack of the required training image datasets to generate classification and detection models. This phenomenon occurs mainly due to human factors that make it difficult to obtain well-annotated data. The present study provides a curated public collection of histopathological images (DeepHP) and a convolutional neural network model for diagnosing gastritis. Images from gastric biopsy histopathological exams were used to investigate the performance of the proposed model in detecting gastric mucosa with Helicobacter pylori infection. The DeepHP database comprises 394,926 histopathological images, of which 111 K were labeled as Helicobacter pylori positive and 283 K were Helicobacter pylori negative. We investigated the classification performance of three Convolutional Neural Network architectures. The models were tested and validated with two distinct image sets of 15% (59K patches) chosen randomly. The VGG16 architecture showed the best results with an Area Under the Curve of 0.998%. The results showed that CNN could be used to classify histopathological images from gastric mucosa with marked precision. Our model evidenced high potential and application in the computational pathology field.     

Aminolysis of Aziridines Catalyzed by Samarium Iodides

Abstract  

Samarium diiodide is an efficient catalyst for the aminolysis of either activated or non activated aziridines with aromatic amines. A variety of N-diprotected β-diamines has been prepared including new products. The comparison of the N-protecting groups of aziridines in reactions catalyzed by samarium diiodide or by samarium iodobinaphtholate indicates that N-Boc protection leads to the best results.     

Synthesis and reactivity of 4-chloro-3,3,4-trifluoro-methoxycarbonyl cyclobutene (CTMC)

An improved synthesis of CTMC is described. This cyclobutene is thermally stable towards electrocyclic ring opening. Its reactivity is explored and a number of radical adducts are described. A more complicated picture is observed with various nucleophiles. The strong dienophilic character of CTMC is illustrated by numerous examples. CTMC reacts well as a dipolarophile with diphenylnitrone, diphenylnitrilimine and diazoalkanes. The high reactivity of this cyclobutene is due to its inherent polarity and strain.