The CH3D absorption spectrum in the 1.58 μm transparency window of methane: Empirical line lists at 81 K and 294 K and temperature dependence

In spite of its low isotopic abundance in methane (about 5×10⁻⁴), CH₃D contributes greatly to the very weak absorption in the 1.58 μm methane transparency window. This methane window deserves to be characterized in details because it is important for planetary applications in particular for Titan and the giant planets. In this work, we recorded the CH₃D spectrum by high sensitivity differential absorption spectroscopy (α_min≈5×10⁻⁸ cm⁻¹) both at room temperature and at 81 K. A list of more than 9000 lines was constructed from the 81 K spectrum for the 6099–6530 cm⁻¹ region. In order to get the temperature dependence of the line intensities, the low energy values have to be determined. The rovibrational assignments available in the literature provide low energy values for about 380 strong transitions of the region. This is insufficient to characterize the temperature dependence of the CH₃D absorption between 6200 and 6400 cm⁻¹. In this interval, a list of 5500 lines was constructed from the room temperature spectrum. The empirical energy values of the transitions were derived from the ratio of the intensities at 81 K and 294 K. The exact and empirical lower state energies included in the final line lists provided as Supplementary Material, allow for accounting for the temperature dependence of the CH₃D spectrum in the entire 6099–6530 cm⁻¹ region.Our measurements have been compared to the spectroscopic parameters and assignments available in the literature in particular those adopted in the HITRAN database. Improvements and corrections are proposed for the wavenumber calibration and for some lower state energies.     

Control of flexural waves on a beam using distributed vibration neutralisers

This paper is concerned with the use of distributed vibration neutralisers to control the transmission of flexural waves on a beam. Of particular interest is an array of beam-like neutralisers and a continuous plate-like neutraliser. General expressions for wave transmission and reflection metrics either side of the distributed neutralisers are derived. Based on transmission efficiency, the characteristics of multiple neutralisers are investigated in terms of the minimum transmission efficiency, the normalised bandwidth and the shape factor, allowing optimisation of their performance. Analytical results show that the band-stop property of the neutraliser array depends on various factors, including the neutraliser damping, mass, separation distance in the array and the moment arm of each neutraliser. Moreover, it is found that the particular attachment configuration of an uncoupled force-moment-type neutraliser can be used to improve their overall performance. It is also shown that in the limit of many neutralisers in the array, the performance tends to that of a continuous neutraliser.     

胍基化试剂的制备及其应用木

制备了两种胍基化试剂:N-硝基-1-(3,5-二甲基吡唑)脒1,N,N'-二叔丁氧羰基硫脲2,将一系列胺类化合物分别与两种胍基化试剂作用,制得新化合物1a-1J,2a-2j,并对两种胍基化试剂的性能进行了比较.所有新化合物的结构均经IR,1H NMR和元素分析证实.     

Load supporting prefabricated wall reinforced by a frame

This load supporting prefabricated wall consists of a thin plate reinforced along its boundaries by a frame. With the loads acting on the frame, the plate has its boundary conditions defined neither by forces nor by displacements. On the basis of satisfying the biharmonic equation of the stress function for the plate, we make the total strain energy to be minimum to ensure the compatibility of displacements for the two elastic bodies. Thus we get a set of infinite simultaneous equations. The results obtained indicate the method of solution is effective.     

小麦液泡膜H~ -ATPase的Ca~(2 )激活特性

纯化小麦液泡膜H -ATPase,测定了纯化的小麦液泡膜H -ATPase 受Mg2 和Ca2 双重激活的特性及两种激活状态下酶的特性. Mg2 激活时酶水解活性受DCCD的抑制,受磷脂酰丝氨酸(PS)影响明显,ATP水解和泵质子活性相偶联.而在Ca2 激活时酶水解活性不受DCCD抑制,受PS影响微弱,Ca2 激活时ATP水解与泵质子活性解偶联. Mg2 和Ca2 对小麦液泡膜H -ATPase的激活作用不具有叠加效应.     

Liouville—Ttype Theorems for Conformal Gaussian Curvature Equations in R^2

In this paper,we derive an elementary identity for smooth solutions of the following equation:△u(x) K(x)e^2u(x)=0 in R^2 and use it to get some global properties of the solutions.     

Lp (?m × ?n) boundedness for the Marcinkiewicz integral on product spaces

L^p(R^m × Rⁿ) boundedness is considered for the multiple Marcinkiewicz integral. Some size conditions implying the L^p(R^m × Rⁿ) boundedness of the multiple Marcinkiewicz integral for some fixed 1 > p > ∞ are obtained.     

Using stochastic optimization to determine threshold values for the control of unreliable manufacturing systems

A manufacturing system with two tandem machines producing one part type is considered in this work. The machines are unreliable, each having two states, up and down. Both surplus controls and Kanban systems are considered. Algorithms for approximating the optimal threshold values are developed. First, perturbation analysis techniques are employed to obtain consistent gradient estimates based on a single simulation run. Then, iterative algorithms of the stochastic optimization type are constructed. It is shown that the algorithms converge to the optimal threshold values in an appropriate sense. Numerical examples are provided to demonstrate the performance of the algorithms.The research of these authors was supported in part by grants from URIF, MRCO, National Science Foundation, and Wayne State University. The authors would like to thank Dr. X. R. Cao, Digital Equipment Corporation, for the valuable initial discussion and Dr. X. Y. Zhou, University of Toronto, for his helpful comments.     

Study on the Interaction Between Water-Soluble CdTe Quantum Dots and Ovalbumin by Optical Spectroscopy

ABSTRACT

CdTe quantum dots (QDs) modified by 2-mercaptoethylamine hydrochloride (CA) and thioglycolic acid (TGA), respectively, were synthesized in aqueous medium. The interaction of CdTe QDs with ovalbumin has been investigated in depth by Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption, fluorescence-quenching spectrometry, and resonance Rayleigh scattering spectroscopy (RRS). Fluorescence data show that the quenching type of ovalbumin by CA-CdTe QDs is static quenching with the binding constant being 10^?4 M^?1, and the number of binding sites being one. The calculated thermodynamic parameters demonstrate that the main binding forces are hydrophobic interaction and electrostatic attraction. In contrast, the quenching style of ovalbumin by TGA-CdTe QDs is verified to be dynamic quenching. Under suitable acidity conditions, the interaction of CA-CdTe QDs or TGA-CdTe QDs with ovalbumin leads to the remarkable enhancement of RRS, and the increments are found to be proportional to the concentration of ovalbumin in a certain range. A simple and highly sensitive RRS approach for determining ovalbumin is developed. In addition, the causes for the enhancement of RRS and the quenching of fluorescence are investigated to shed light on the quenching mechanism.     

Design and Performances of a Carbon Monoxide Sensor Using Mid-Infrared Absorption Spectroscopy Technique at 4.6 µm

Based on infrared absorption spectroscopy technique, a carbon monoxide sensor was developed using the fundamental absorption band of carbon monoxide molecule at the wavelength around 4.6 µm. The developed sensor consists of pulse-modulated wideband incandescence, open ellipsoid light-collector gas-cell, dual-channel detector, and control and signal-processing module. With the prepared standard carbon monoxide gas sample, sensing characteristics on carbon monoxide were investigated using the sensor. Experimental results reveal that the limit of detection is about 10 ppm, the relative error at the limit of detection point is less than 14%, and that is less than 7.8% within the low concentration range of 20～180 ppm. The maximum absolute errors of 50 min long-term measurement on the 0 and 14 ppm CO gas samples are about 3 and 3.17 ppm, respectively, and the standard deviations are as small as 0.18 and 1.25 ppm, respectively. Compared with the reported carbon monoxide detection systems utilizing quantum cascaded lasers and distributed feedback lasers, the proposed sensor shows potential applications in carbon monoxide detection under the circumstances of coal-mine and environmental protection, by virtue of high performance, low cost, simple optical structure, and so on.