基于开关电容能量球的低噪声超声测距仪的研究

本文研制了一种新型的基于开关电容的低噪声超声波测距仪，相比现有的变压器驱动测距仪，它采用一种电容充放电原理的能量球自适应驱动原理，通过能量球内部快速电子开关切换，利用电路谐振原理激励出比储能电容电压高出3～5倍的能量球驱动电压，对超声波探头进行驱动。该能量球具有体积小、噪声低的特点。根据该原理研制的超声波测距仪，在污水厂进行了超声波测距的对比试验。结果表明，该仪表的能量球驱动方式相比变压器驱动方式，量程提高近20％，信噪比提高18．5dB，适用于恶劣工况。

建立“能量球”模型,解决相关问题

当一个物体的能量向各个方向球对称辐射时,它的辐射能量将分布在以它为球心的球面上.我姑且称之为"能量球"(如图所示).解决此类问题的关键是找出单位球面积上的能量.下面试举例说明.

能量缓释拟谷物淀粉微球的构建及食用品质分析

构建一种慢消化淀粉和抗性淀粉含量较高,且具有一定谷物品质特征的淀粉微球,即能量缓释拟谷物淀粉微球。探究不同添加量的海藻酸钠、结冷胶、壳聚糖与马铃薯淀粉,对所构建微球中慢消化淀粉含量的影响,并在此基础上,做响应面优化。结果表明,海藻酸钠浓度0.051 mol/L、结冷胶浓度0.047 mol/L及壳聚糖浓度0.014 mol/L时,制备的微球慢消化淀粉含量57.88%,而抗性淀粉含量较低。用月桂酸改性的马铃薯淀粉制备的微球,在具有高水平慢消化淀粉的同时,抗性淀粉含量大幅提高至31.49%。两种淀粉微球具有良好的吸水性和膨胀性,而微球的汤液pH值较低,汤液干物质量和碘蓝值也明显低于大米和小米。此外,微球具有与小米相似的质构特性,可作为拟谷物食品食用。

低噪声回波测距系统的电路设计与系统分析

描述了超声波脉冲回波测距系统的基本组成,重点研究了超声波测距系统中的低噪声问题,设计了分时和分区的开关隔离式超声波发射和接收电路,彻底切断了发射电路和其他电干扰信号对接收电路的影响.低噪声“能量球”的设计,极大地提高了回波的信噪比,实现了超声波低功率发射条件下的信号稳定接收.同时介绍了软件滤波器在超声波的智能化低噪声处理方面的应用.

Study on Internal Waves Generated by Tidal Flow over Critical Topography

Resonance due to critical slope makes the internal wave generation more effectively than that due to supercritical or subcritical slopes(Zhang et al., 2008). Submarine ridges make a greater contribution to ocean mixing than continental margins in global oceans(Müller, 1977; Bell, 1975; Baines, 1982; Morozov, 1995). In this paper, internal wave generation driven by tidal flow over critical topography is examined in laboratory using Particle Image Velocimetry(PIV) and synthetic schlieren methods in synchrony. Non-tidal baroclinic velocities and vertical isopycnal displacements are observed in three representative regions, i.e., critical, outward-propagating, and reflection regions. Temporal and spatial distributions of internal wave rays are analyzed using the time variations of baroclinic velocities and vertical isopycnal displacement, and the results are consistent with those by the linear internal wave theory. Besides, the width of wave beam changes with the outward propagation of internal waves. Finally, through monitoring the uniformly-spaced 14 vertical profiles in the x-z plane, the internal wave fields of density and velocity fields are constructed. Thus, available potential energy, kinetic energy and energy fluxes are determined quantitatively. The distributions of baroclinic energy and energy fluxes are confined along the internal wave rays. The total depth averaged energy and energy flux of vertical profiles away from a ridge are both larger than those near the ridge.

The Maximum Ice Age Glaciation between the Karakorum Main Ridge (K_2) and the Tarim Basin and its Influence on Global Energy Balance

A modern research approach and working techniques in hitherto unexamined areas, produced the following results: 1). The tongues of deca- kilometre long Karakorum glaciers belong to temperate ice-streams with an annual meltwater output. The short Aghil glaciers on the contrary are continental, arid and cold. 2). The present-day oscillations of the Karakorum glaciers are related to their own mass, and are contrary to and independent of the actual climate. Only the short glaciers, with steep tongue fronts, show a present-day positive balance. 3). C- dated Late Glacial moraines indicate14 a 400~800 m thick valley glacier at the former confluence point of the K2-, Sarpo Laggo- and Skamri glaciers. 4). From the evidence of transfluence passes with roches moutonnées, striae and the limits of glacial polishing, as well as moraines and erratics, a High Glacial at least 1200 m thick ice-stream network between the Karakorums and the Kuen Lun north slopes was reconstructed. The Shaksgam and Yarkand valleys were occupied by glaciers coming from west Tibet. The lowest-lying moraines are to be found in the foreland down to 2000 m, indicating a depression of the High Glacial (LGM) snowline (ELA) by 1300 m. 5). The approximately 10,000 measurements of the radiation balance at up to heights of 5500 m on K2 indicate that with incoming energy near the solar constant the reflection from snow- covered ice is up to 70% greater than from rock and rock waste surfaces. 6).These results confirm for the very dry western margins of Tibet an almost complete ice sheet cover in an area with subtropical energy balance, conforming with the Ice Age hypothesis of the author which is based upon the presence of a 2.4 million km2 Tibetan inland ice sheet. This inland ice developed for the first time when Tibet was uplifted over the snowline during the early Pleistocene. As the measured subtropical radiation balance shows, it was able to trigger the Quaternary Ice Ages.

Quantum Tunneling Radiation of Reissner-Nordstrom de Sitter Black Hole with a Global Monopole

Applying Parikh＇s quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal.

Systematic review of health-related quality of life after esophagectomy for esophageal cancer

This study is aimed to assess the long-term healthrelated quality of life （HRQL） of patients after esophagectomy for esophageal cancer in comparison with established norms, and to evaluate changes in HRQL during the different stages of follow-up after esophageal resection. A systematic review was performed by searching medical databases （Medline, Embase and the Cochrane Library） for potentially relevant studies that appeared between January 1975 and March 2011. Studies were included if they addressed the question of HRQL after esophageal resection for esophageal cancer. Two researchers independently performed the study selection, data extraction and analysis processes. Twenty-one observational studies were included with a total of 1282 （12-355） patients. Five studies were performed with short form-36 （SF-36） and 16 with European Organization for Research and Treatment of Cancer （EORTC） QLQ c30 （14 of them also utilized the disease-specific OESI8 or its previous version OES24）.The analysis of long-term generic HRQL with SF-36 showed pooled scores for physical, role and social function after esophagectomy similar to United States norms, but lower pooled scores for physical function, vitality and general health perception. The analysis of HRQL conducted using the Global EORTC C30 global scale during a 6-mo follow-up showed that global scale and physical function were better at the baseline. The symptom scales indicated worsened fatigue, dyspnea and diarrhea 6 mo after esophagectomy. In contrast, however, emotional function had significantly improved after 6 mo. In conclusion, short- and long-term HRQL is deeply affected after esophagectomy for cancer. The impairment of physical function may be a long-term consequence of esophagectomy involving either the respiratory system or the alimentary tract. The short- and long-term improvement in the emotional function of patients who have undergone successful operations may be attributed to the impression that they have survived a near-death experience.

Spectrum and Binding Energy of an Off-Center Hydrogenic Donor in a Spherical Quantum Dot

Off-center impurity effects in a spherical quantum dot are theoretically studied by degenerate perturbationmethod in strong confinement.The energy levels and binding energies are computed for the typical GaAs material asfunction of the donor position.The numerical results show the quantum size effect.We note that the energy levels andbinding energies are not only related to the position of donor and the strength of confinement,but also related to thefold of degenerate states.We can see obviously that gaps will appear among the degenerate states and the splitting ofenergy levels and binding energies will appear as the position of the impurity is shifted away off the center.

Binding Energy of an Off-Center D^-in a Spherical Quantum Dot

Using the method of matrix diagonalization, we investigate an off-center D^- in a spherical quantum dot （QD） subjected to a parabolic potential confinement. We discuss the effect of the position of an impurity in the QD on the binding energy of the D system, Eurthermore, we compare a negatively charged donor D^- with a neutral donor DO confined by a spherical QD with a parabolic potentiM. The results have clearly demonstrate the so-called quantum size effect. The binding energy is dependent on the confining potential hw0 and the impurity ion distance D.

Improved sweat gland function during active heating in tennis athletes

Background：Relatively few studies on the peripheral sweating mechanisms of trained tennis athletes have been conducted.The purpose of this study was to compare the sweating capacities of tennis athletes against untrained subjects（controls）.Methods：Thirty-fi e healthy male volunteers participated including 15 untrained subjects and 20 trained tennis athletes（nationally ranked）.Active heat generation was performed for 30 min（running at 60%VO2max） in a climate chamber（temperature,25.0°C ± 0.5°C;relative humidity,60% ± 3%,termed active heating）.Sweating data（local sweat onset time,local sweat volume,activated sweat glands,sweat output per gland,whole body sweat loss volume） were measured by the capacitance hygrometer-ventilated capsule method and starch-iodide paper.Mean body temperature was calculated from tympanic and skin temperatures.Results：Local sweat onset time was shorter for tennis athletes（p〈0.001）.Local sweat volume,activated sweat glands of the torso and limbs,sweat output per gland,and whole body sweat loss volume were significant y higher for tennis athletes than control subjects after active heating（p〈0.001）.Tympanic and mean body temperatures were lower among tennis athletes than controls（p〈0.05）.Conclusion：These results indicate that tennis athletes had increased regulatory capacity of their sweat gland function.

Simultaneous Effects of Hydrostatic Pressure and Conduction Band Non-parabolicity on Binding Energies and Diamagnetic Susceptibility of a Hydrogenic Impurity in Spherical Quantum Dots

Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical GaAs/Alx- Ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.

Reducing Heat-Load in Buildings through the Use of Solar Screens： Case Study of Bookshop House, Lagos

Technology advancement has ensured a better means of livelihood essentially in certain parts of West Africa, specifically Nigeria, where the climate is predominantly hot in most parts throughout the year. Air-conditioning has reduced the harshness of indoor discomforts to the barest minimum. It is no more uncommon to find it regularly in use in most homes and offices. Currently, the economy has the centrality of its power supply hinged on generator plants. The enigma of the current situation is how this alternative problem has catastrophic after effects on the environment. This and many more add up to the greatest of all the threats now evading our environment and the world -- Global warming. The threat of Global warming is real and the need to find less environmentally destructive sources of energy cannot be overemphasized. This paper is a contribution towards energy saving in buildings through the reduction of solar radiation incident on buildings. Sustainable Building calls for an integrated planning approach for operating buildings economically, substantially reducing their impact on the environment by reducing energy/power consumption, amongst others, and enhancing the well-being of their inhabitants. Only buildings that reconcile all of the above factors are fit for the future. A case study of the CMS （Catholic Mission School） Book Shop house in Lagos was carried out. The methodology involved the use of a solar chart and shadow angle protractor to determine the overheated periods represented by the shading masks and data collected. From this analysis, it was decided to accept the use of external sun shading and preliminary designs and specifications were prepared by the architects. The use of external solar screens made a saving of up to 75% of the energy input which would otherwise have been required by air-conditioning.

Progress in Research of Gas Hydrate

It is of great significance to study gas hydrate because of following reasons. （1） Most organic carbon in the earth reserves in the form of natural gas hydrate, which is considered as a potential energy resource for the survival of human being in the future. （2） A series of novel technologies are based on gas hydrate. （3） Gas hydrate may lead to many hazards including plugging of oil/gas pipelines, accelerating global warming up, etc. In this paper, the latest progresses in exploration and exploitation of natural gas hydrate, the development of hydrate-based technologies including gas separation, gas storage, CO2 sequestration via forming hydrate, as well as the prevention of hydrate hazards are reviewed. Additionally, the progresses in the fundamental study of gas hydrate, including the thermodynamics and kinetics are also reviewed. A prospect to the future of gas hydrate research and application is given.

Inconsistence of Non-Singular Spherically Symmetric Solution and a Satisfactory Energy-Momentum Complex

Two spherically symmetric non-singular black hole solutions in Moiler tetrad theory of gravitation have been obtained. Although the two solutions have the same form of metric （spherically symmetric nonsingular black hole）, their energy contents are different. We use another method given by Gibbons and Hawking to calculate the energy content of these solutions. We also obtained different value of energy. Study the requirements of a satisfactory energymomentum complex given by Moiler we find that the second solution, which behaves as 1/√r, is not transformed as a four-vector under Lorentz transformation.

Existence of Tensor Glueball ξ（2230） and Its Mass, Spin, and Decay Width

In order to solve the current experimental controversy on the existence of the tensor glueball ξ(2230), we examine whether the conclusion from Seth's experimental measurement, which rejects existence of ξ(2230), is reliable.We claim that the non-observation of the resonance structure by Seth is not a sound ground for rejecting the existence of ξ(2230) but it may just indicate that ξ(2230) has a broad width. We also study the tensor glueball properties: the mass, spin, and decay width. Our theoretical predictions of the mass and the spin of the ξ(2230) using QCD sum rule are about 2.23 GeV and J = 2, respectively. Our theoretical results also evidently show that the ξ(2230) must have a total decay width of about 100 MeV, which is much broader than the reported 20 MeV but a small partial decay width of 2 MeV into pp decay channel.

Quantifying Environmental Sustainability of Buildings through Its Carbon Foot-Print： An Analytical Approach

It is known that the building sector consumes about 40% of earth＇s resources in their process of commissioning, erection and subsequent operation. As a consequence there is significant amount of CO2 emission to the atmosphere. Assessment of environmental performances of buildings has assumed immense significance in such backdrop and calls for assessing the ＂Carbon Footprint＂ of building systems for estimating their environmental compatibility. The present paper discusses a case specific environmental evaluation exercise by estimating the Carbon Footprint of a conventionally constructed tourist accommodation by tracking its resource consumption pattern during both the execution and operational phases in the hot and humid climatic zone of Indian sea-side. The result of the analysis is compared against the average carrying capacity of Earth to develop a method of measuring and quantifying the building＇s environmental performance with respect to Earth＇s reported threshold of tolerance and check the extent of failure or success, as the case may be. This process also leads to a tool named ＇Sustainability Quotient＇. The method of quantification is simple and can be adopted for environmental assessment of both new and old buildings.

Linear and Nonlinear Optical Properties in Spherical Quantum Dots

We calculate the energy eigenvalues and the sate functions of one-electron Quantum Dot （QD） by using a combination of Quantum Genetic Algorithm （QGA） and Hartre-Fock-Roothaan （HFR） method. The linear and the third-order nonlinear optical absorption coefficients for the 1s-1p, 1p-1d, and 1d-1f transitions are examined as a function of the incident photon energy for three different values of the stoichiometric ratio. The results show that the stoichiometric ratio, impurity, relaxation time, and dot size have great influence on the optical absorption coefficients of QDs.

Power Supply and Programmable Controller for Multishot Pellet Injector

MPI（multishot pellet injector） was imported from Russia about ten years ago. During the year＇s operation in HL-1M, most electrical equipments were repaired. Since the components are non-standard, so it is difficult to maintain. To fueling experiment meet the requirement of in HL-2A. The power supplies of fast valve and a programmable controller for shooting pellets were developed.

On the Mystery of the Interpulse Shift in the Crab Pulsar

A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation emitted by positrons moving towards the surface of the neutron star along inclined magnetic field and reflected from the surface. Such radiation interferes with transition radiation emitted from the neutron star when positrons hit the surface. Proposed mechanism explains the mystery of the interpulse shift in the Crab pulsar at high frequencies discovered by Moffett and Hankins twenty years ago. We have found also reflected energy flux and spectrum, discussed coherence and disappearance of interpulse shift with increase of frequency.