随机控制与输出反馈控制的最优协调性合成

应用双控制器的最优协调性合成设计方法，在离散时间域内研究了随机控制作用和输出反馈控制作用的合成设计问题，构造了一个数值迭代计算方案来求解相应的控制规律，然后，通过设计实例验证了设计方法的有效性，并进行了有意义的对比分析。     

试论政府转换经济职能的着眼点

政府转换经济职能的含义,主要是处理好政府与企业、管理与服务、直接管理方式与间接管理方式,以及政府机构调整四个方面的关系,中心是解决政府为企业服务的问题,因此,转换政府经济职能应当紧紧抓住服务,认真做好(1)更新观念、确立起企业在经济活动中的主体地位;(2)制订经济计划、行业规划以及完善各项法规条例;(3)以“小政府、大服务”的原则调整政府机构;(4)政府经济职能法制化等方面的工作。     

Biosphere 2 Test Module: a ground-based sunlight-driven prototype of a closed ecological life support system.

Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments. It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters. It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR). The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber ("lung") permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward. Several series of closed ecological system investigations have been carried out in this facility. One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions. Another series of experiments included one human in the closed system for three, five and twenty-one days. During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system. Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases. Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.     

组合发动机多种燃料和多种氧化剂的当量比计算法

提出了两种计算燃料和氧化剂当量比的方法。方法之一是“混合气法”;假方法之二是“当量油气比法”。燃烧过程中使用的燃料种类数及氧化剂种类数均没有限制。还假设了一个组合发动机作为例题。它包括火箭发动机、冲压发动机、涡喷发动机及加力燃烧室。使用的燃料为液氢、甲烷、丙烷和航空煤油。氧化剂为液氧和空气。     

Optical design and testing of a fast,large aperture,infrared space telescope

An optical design study for a next generation infrared space telescope has been performed. The concept is that of a passively cooled telescope of minium aperture 2.5 metre with an F/1.2 primary and wavelength coverage from = 2 to at least 40 m, and possibly to 100 m. Compactness, low thermal emission from the optics and structure, diffraction limited imaging at = 2 m, and sensitivity to misalignment aberrations and manufacturing errors were the main considerations for this study. Ray tracing results are presented showing the characteristics of the various designs considered. A preliminary investigation of stray light properties is also given. Special emphasis has been placed on the testing of such a fast primary, and optical systems using a lateral shearing interferometer are described for testing both the primary and the primary/secondary combination.     

Galileo Photopolarimeter/Radiometer experiment

The Photopolarimeter/Radiometer (PPR) is a remote sensing instrument on the Galileo Orbiter designed to measure the degree of linear polarization and the intensity of reflected sunlight in ten spectral channels between 410 and 945 nm to determine the physical properties of Jovian clouds and aerosols, and to characterize the texture and microstructure of satellite surfaces. The PPR also measures thermal radiation in five spectral bands between 15 and 100 m to sense the upper tropospheric temperature structure. Two additional channels which measure spectrally integrated solar and solar plus thermal radiation are used to determine the planetary radiation budget components. The PPR photopolarimetric measurements utilize previously flown technology for high-precision polarimetry using a calcite Wollaston prism and two silicon photodiodes to enable simultaneous detection of the two orthogonal polarization components. The PPR radiometry measurements are made with a lithium tantalate pyroelectric detector utilizing a unique arrangement of radiometric stops and a scene/space chopper blade to enable a warm instrument to sense accurately the much colder scene temperatures.     

The plasma instrumentation for the Galileo Mission

The plasma instrumentation (PLS) for the Galileo Mission comprises a nested set of four spherical-plate electrostatic analyzers and three miniature, magnetic mass spectrometers. The three-dimensional velocity distributions of positive ions and electrons, separately, are determined for the energy-per-unit charge (E/Q) range of 0.9 V to 52 kV. A large fraction of the 4-steradian solid angle for charged particle velocity vectors is sampled by means of the fan-shaped field-of-view of 160°, multiple sensors, and the rotation of the spacecraft spinning section. The fields-of-view of the three mass spectrometers are respectively directed perpendicular and nearly parallel and anti-parallel to the spin axis of the spacecraft. These mass spectrometers are used to identify the composition of the positive ion plasmas, e.g., H⁺, O⁺, Na⁺, and S⁺, in the Jovian magnetosphere. The energy range of these three mass spectrometers is dependent upon the species. The maximum temporal resolutions of the instrument for determining the energy (E/Q) spectra of charged particles and mass (M/Q) composition of positive ion plasmas are 0.5 s. Three-dimensional velocity distributions of electrons and positive ions require a minimum sampling time of 20 s, which is slightly longer than the spacecraft rotation period. The two instrument microprocessors provide the capability of inflight implementation of operational modes by ground-command that are tailored for specific plasma regimes, e.g., magnetosheath, plasma sheet, cold and hot tori, and satellite wakes, and that can be improved upon as acquired knowledge increases during the tour of the Jovian magnetosphere. Because the instrument is specifically designed for measurements in the environs of Jupiter with the advantages of previous surveys with the Voyager spacecraft, first determinations of many plasma phenomena can be expected. These observational objectives include field-aligned currents, three-dimensional ion bulk flows, pickup ions from the Galilean satellites, the spatial distribution of plasmas throughout most of the magnetosphere and including the magnetotail, and ion and electron flows to and from the Jovian ionosphere.     

The Lightning And Radio Emission Detector (LRD) instrument

The Lightning and Radio Emission Detector (LRD) instrument will be carried by the Galileo Probe into Jupiter's atmosphere. The LRD will verify the existence of lightning in the atmosphere and will determine the details of many of its basic characteristics. The instrument, operated in its magnetospheric mode at distances of about 5, 4, 3, and 2 planetary radii from Jupiter's center, will also measure the radio frequency (RF) noise spectrum in Jupiter's magnetosphere. The LRD instrument is composed of a ferritecore radio frequency antenna ( 100 Hz to 100 kHz) and two photodiodes mounted behind individual fisheye lenses. The output of the RF antenna is analyzed both separately and in coincidence with the optical signals from the photodiodes. The RF antenna provides data both in the frequency domain (with three narrow-band channels, primarily for deducing the physical properties of distant lightning) and in the time domain with a priority scheme (primarily for determining from individual RF waveforms the physical properties of closeby-lightning).     

Simple solutions for hyperbolic and related position fixes

Navigation fixed from range differences to three stations and an additional piece of information are investigated. It is shown that if the additional information is the navigator altitude, or the range difference to a fourth station, the computation of the navigation fix is reduced to finding the roots of a quadratic. If the additional information is the range to another station, or that the navigator is on the Earth ellipsoid, the fix can be obtained by solving a quartic. By emphasizing the underlying geometric interpretations, these fixes and their simple solutions are made clear. The derivations also show that the same solution algorithms are applicable if the basic navigation measurements are range sums instead of range differences     

小振幅振荡圆柱域内部的定常整流旋涡流动

对充满静止不可压缩粘性流体的圆柱形，当柱壁沿垂直于柱轴方向作小振幅简谐振荡时的内部流动进行了实验研究，发现柱壁振荡在圆柱域内也诱导形成旋涡形态的定常整流流动。流动图谱随不同的振荡参数组合呈现四涡形态、双涡形态以及足印状双涡和蝶状四涡的过渡形态，并初步给出了不同整流图谱随数变化的演化规律。