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111.
A new computational fluid dynamics (CFD) method for the simulation of fast-axial-flow CO2 laser is developed.The model which is solved by CFD software uses a set of dynamic differential equations to describe the dynamic process in one discharge tube.The velocity,temperature,pressure and turbulence energy distributions in discharge passage are presented.There is a good agreement between the theoretical prediction and the experimental results.This result indicates that the parameters of the laser have significant effect on the flow distribution in the discharge passage.It is helpful to optimize the output of high power CO2 laser by mastering its kinetic characteristics.  相似文献   
112.
A new charge measurement method, time over threshold (TOT), has been used in some gas detectors lately. Here TOT is studied for TOF system, made of plastic scintillator counter, which can simplify the electronics of the system. The signal characteristics are measured and analyzed with a high quality oscilloscope, including noise, pedestal, signal amplitude, total charge, rise time and the correlation between them. The TOT and charge are related and can be fitted by some empirical formula. The charge measurement resolution by TOT is given and this will help the design of TOF electronics.  相似文献   
113.
We compute the Euler characteristics of the individual connectedcomponents of the intersection of two opposed big cells in thereal flag variety of type G2, verifying a conjecture of Rietsch[6]. 2000 Mathematical Subject Classification: primary 14M15; secondary20G20.  相似文献   
114.
The electronic processes in disordered organic solids were analyzed, classified, and summarized. They include the photogeneration of charge pairs, electron transport, geminal and bimolecular recombination, and the capture of charge carriers in local electronic states. General criteria were formulated for the targeted search for and the creation of new prospective polymers and their compositions with organic pigments and related compounds having specific photoelectric characteristics for electrographic and holographic media, photoelectric converters, and electroluminescent and photorefractive devices.  相似文献   
115.
In the paper calculation of the moments of inertia for nuclei from the region 87 ≤ Z ≤ 100 and 130 ≤ N ≤ 156 was made in dependence on the angular momentum of their rotational states. The experimental values of the moments of inertia were calculated for rotational energy of the classic rotor in its quantum form, with the use of a simple formula. The moment of inertia term appearing in the formula was treated as a variable. The calculations were carried out on the basis of experimental data for the energies of the rotational levels for 51 bands built on ground states for even-even nuclei and for nuclei with odd mass number A. In addition, 30 rotational bands built on excited states were also analysed in the investigated region in case of even-even nuclei. For many bands and nuclei the considered dependence of the moment of inertia on angular momentum has been found in the analytical form by fitting polynomials to the experimental data. It turned out that obtained results for the moments of inertia made it possible to describe the energies of rotational levels with a relative deviation not greater or only slightly greater than 1%. In general, in the case of 12 bands of ground level the maximum relative deviation of obtained level energies is smaller than 1%.   相似文献   
116.
The aims of this study were to analyze 1) whether there was the relationship between the neonatal behavioral characteristics and amount of crying in premature infants at term age, and 2) what kind of difference between infants with high levels of crying and cry less on neonatal behavioral characteristics using the Neonatal Behavioral Assessment Scale (NBAS). The study participants consisted of 69 healthy low birth-weight infants who were admitted to the NICU at the Nagasaki University Hospital, Nagasaki, Japan. This study analyzed the relationship between NBAS scores measured neonatal behavioral performance and crying at term age. This study results indicate that there was significant statistical negative correlation between the amount of total daily crying and Habituation, Range of state, Regulation of state, and Autonomic stability cluster scores and some individual items scores (Response decrement to light, Response decrement to tactile of foot, Alert responsiveness, Examiner persistence, Motor maturity, Irritability, General irritability, Cuddliness, Consolability, Self-quieting activity, and State regulation). The high levels crying group also showed higher responsivity than less crying group in the items of Peak of excitement, Rapidity of build-up, Irritability and General irritability. In conclusion, neonatal behavioral characteristics such as poor inhibit discrete stimuli while asleep, hyper-responsivity and poor state regulation abilities were risk factors of high levels of crying.  相似文献   
117.
用自行组装的直流辉光放电原子发射光谱(dc G D A E S)仪器对分析铜合金的某些基本特性进行了研究 探讨了光源放电室结构、放电气体压力、放电电压等操作参数以及试样尺寸大小对放电性能及元素谱线强度的影响,并进行了优化 考察了在不同放电气压条件下样品的溅射率和优化条件下辉光放电的稳定性最后,分析了铜合金标准样品中的 Al和 Mn,结果较满意  相似文献   
118.
In this note we present a new proof of the quintuple product identity which is based on our study of order theta functions with characteristics and the identities they satisfy. In this context the quintuple product identity is another example of an identity which when phrased in terms of theta functions, rather than infinite products and sums, has a simpler form and is much less mysterious.

  相似文献   

119.
Nozzle profiles capable of generating constant extensional strain rates are termed hyperbolic dies. When used in polymer extrusion, they exhibit greater potential in inducing and retaining polymer molecular orientation than conventional capillary dies. Most mathematical expressions found in the literature involve several processing variables in describing and designing such nozzle profiles. This report reveals that a hyperbolic die profile, although rather complicated, can be expressed with equations in terms of two ordinary geometrical parameters—the exit diameter and the hyperbolic length. This finding greatly simplifies the design procedure of hyperbolic dies. The extensional strain rate of a hyperbolic die can be related to the length-to-diameter ratio for any given exit diameter. Examples of various types of die profiles are presented and their constant extensional strain-rate characteristics are discussed.  相似文献   
120.
在光合作用原初过程中,太阳能转化成电能的关键步骤为:在光引发下,电子从一个叶绿素给体 D 转移到泛醌受体 A,从而产生D~ 和 A~-。光合作用原初过程及其人工模拟是受到世界各国普遍重视的一个研究领域。特别是近年来。卟啉(D)-醌(A)类化合物引起了人们的广泛兴趣,其中三块板式化合物是目前最接近  相似文献   
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