On retroactive occurrence and twin events in quantum mechanics

Bohr's well-known claim that only a registered phenomenon is a true phenomenon is further elaborated into occurrence in the past: If ideal occurrence of an eventP ((1–P)) is a state at a timet _i makes another eventQ ((1–Q))certain at a later timet _f, and, finallyU is the evolution operator fromt _i tot _f, then, it is proved that the final collapsed stateQ(U U ⁺)Q/TrQU U ⁺, which comes about in ideal occurrence ofQ att _f,equals the initial collapsed stateU(P P/TrP)U ⁺, which evolves from the state resulting from the ideal occurrence ofP in att _i. Utilizing the latter state is called theretroactive apparent ideal occurrence (RAIO) ofP in. A number of consequences, including the general notion of twin events (the case whent _f=t _i, andU=1) is derived. It is pointed out that RAIO is relevant in second-kind quantum measurement, in Wheeler's delayed-choice experiments in second-kind (or conditional) quantum preparators.     

Measurement: It ain't over till it's over

Elby (1993) has raised certain problems that appear to be devastating for modal interpretations of quantum mechanics, but do not arise for Bohm's pilot wave theory. Here I show that the features Elby identifies as objectionable in my version of the modal interpretation have their counterpart in Bohm's theory. To the extent that Bohm's theory works as a no collapse solution to the measurement problem - and I think it does - so does my modal interpretation.     

A Systematic Evaluation of Polyurethane as a Conformal Coating for the Inhibition of Corrosion on Electronic Components

The corrosion of printed circuit boards can be effectively prevented with a polyurethane conformal coating. In this study, the protective performance of PU coating was investigated systematically through electrochemical measurements and simulated exposure/immersion tests. Some fungi tests were also included. All experimental results show that a polyurethane coating effectively inhibits corrosion on printed circuit boards. The optimal thickness of the coating film should be about 60 μm. Long-term exposure tests showed that this coating material could preserve the reliability of the investigated printed circuit boards for more than 400 days in a 90% relative humidity environment at 25°C.     

Uncertainty of the Thermal Conductivity Measurement Using the Transient Hot Wire Method

This work deals with uncertainty analysis of the thermal conductivity measurement using the transient hot wire method. The characterization is made from a sample of low-density, polyethylene BRALEN SA 200-22. The utilized experimental data are obtained from the test measurements performed on the air at room temperature. The sources of measurement errors are analyzed and the uncertainty of the measured value of the thermal conductivity is evaluated. The analysis shows that in the present case the uncertainty of the thermal conductivity measurement is about ±3.3% for 68% confidence level.This revised version was published online in November 2005 with corrections to the Cover Date.     

New far infrared laser lines obtained by optically pumping13CD3OD

We have obtained laser action on 34 far infrared lines for the first time in fully deuterated methyl alcohol with the¹³C isotope (¹³CD₃OD), and we have measured the frequency of 13 lines. The molecule was pumped by a cw CO₂ laser. We have measured the wavelength, the relative polarization, the relative intensity of most lines, the frequency, and the CO₂ pump frequency offset of the strongest lines. The new lines are distributed in the wavelength region from 75.27 m to 464.7 m.Supported in part by a joint grant with the U.S. National Science Foundation grant # INT 80-19014 and the Brazilian Conselho Nacional de Pesquisas (CNPq).     

采用Seemann－Bohlin准聚焦X射线衍射仪测量薄膜厚度的误差理论分析

本文从理论上分析了衍射强度比偏差Δ（Ｉ／Ｉ∞）和衍射峰位偏差Δ２θ对Ｓｅｅｍａｎｎ－Ｂｏｈｌｉｎ准聚焦Ｘ射线衍射仪测量表面单层薄膜厚度误差的影响。分析结果表明，降低Δ（Ｉ／Ｉ∞）可提高膜厚的测量精度，在Δ（Ｉ／Ｉ∞）－定的情况下，按μρｔ［Ｓｉｎ（－１）γ＋Ｓｉｎ（－１）（２θ－γ）］＝１选择靶辐射和衍射晶面可使由Δ（Ｉ／Ｉ∞）导致的膜厚测量误差具有极小值；选择高角度衍射线有助于减小试样离焦引起的衍射峰位偏差，亦可降低因衍射角测量偏差导致的膜厚测量误差，当衍射线处于薄膜的法向２θ＝γ＋π／２时，角度项误差（Δｔ／ｔ）（２θ）完全消除。     

气相色谱质谱法快速测定人血浆中克仑特罗

血浆样品经0.01mol·L-1盐酸和无水乙醇浸取,在碱性条件下用氯仿萃取,GG-MS-选择离子测量法测定,外标法定量。在选定的色谱条件下,盐酸克仑特罗的检出限为0.05ng,线性范围为0.1-100ng,方法的平均回收率为95.6％,RSD小于6.82％(n=6)。该法毋需衍生化,基质无干扰,简便可靠,适用于生物材料中克仑特罗的快速分析。     

一种新的库仑微水滴定仪的设计方法

在传统微库仑滴定仪原理的基础上，利用８７５１单片机和微机，采用对电解电流时间调制的方法以及测量精度为准则判断滴定终点，从而大大地提高了仪器的测量精度和重复性。