Encounter with venus: an update

This report is an introduction to the accompanying collection of early results from the Pioneer Venus orbiter and multiprobe missions, which encountered Venus on 4 December and 9 December 1978, respectively. Initial results for the multiprobe mission and for the first 30 days of the orbiter mission were reported in the 23 February issue of Science. Additional mission features and updated mission parameters based on refined tracking data and trajectory computations are presented here. New scientific results for both missions are given in the subsequent reports which cover the first 130 days (or orbits) of the nominal 243-day orbiter mission.     

社会企业的交叉补贴定价及福利效应分析——基于三级价格歧视的视角

社会企业是社会创业的重要载体，是致力于解决社会问题的兼具社会和经济属性的创新组织，在服务于欠缺支付能力的弱势群体方面发挥着重要作用。通过与商业企业的比较,以区别于商业企业定价目标的社会使命收益最大化为出发点，借鉴三级价格歧视理论，研究社会企业的交叉补贴定价策略及福利效应，并以印度Aravind眼科医院为例分析，发现社会企业采取的交叉补贴定价是可行的，且在某种程度上实现了帕累托改进。     

Undergraduate research, graduate mentoring, and the university's mission

Undergraduate research and graduate mentoring have received a great deal of attention in recent times. What do these activities have in common? They both speak to the primary mission of the research university, which is not merely carrying out research but training students to do research. The knowledge-based global economy, with its wealth of information and opportunities, has increased undergraduate students' need for research skills as well as graduate students' desire for personal guidance. As the research university matures, the boundaries between graduate and undergraduate education are blurring. Indeed, if we focus on the learning process, we find not two but five levels of learning at the research university: lower division, upper division, master's, doctoral, and postdoctoral. All five levels form a continuum, a series of gradual steps. The mission of the university is to introduce students to research, to inspire in them a passion for discovery at each of these levels.     

新农村建设思路下的农民工群体贡献研究

“三农”问题是现代化建设中的关键性问题,它反应了一个复杂的矛盾领域。社会主义新农村建设是“三农”问题中一个阶段性的历史任务,在这一历史任务的完成过程中,农民工群体起着十分重要的作用,尤其是返乡创业的农民工,直接促进了社会主义新农村建设。在新农村建设的新思路下,对农民工群体的贡献进行了探讨。     

Atmospheric physics and Earth observations: atmospheric spectral imaging

An array of imaging spectrometers flown on the Spacelab 1 mission was capable of providing spectra of the atmospheric emissions over a broad wavelength range from 300 to 12,700 angstroms and acquiring each complete spectrum nearly simultaneously. The instrument was used to make observations on the day side and night side of the earth, looking down in the nadir direction, radially away from the earth, and in various limb-scanning modes. Observations were made looking at various angles to the vehicle velocity vector and during thruster firings and water dumps as well as at times when such events were inhibited. As a result of the mission a data base has been acquired that is valuable for studies of both the upper atmosphere and the shuttle-Spacelab vehicle environment.     

PLANETARY SCIENCE: Asteroids Come of Age

Since the discovery of the first asteroid almost 200 years ago, these celestial bodies have advanced from nuisances hampering stellar studies to the focus of geological studies aimed at understanding the early solar system. Binzel describes the history of their study, which has now culminated in NASA's NEAR mission to the asteroid Eros. Four papers report first results from this first rendezvous mission with an asteroid.     

高校院（系）决策机制研究——院（系）决策机制层次结构数学模型构建及运用

根据《影响高校院（系）决策机制的要素分析》的结果,和院（系）的职能以及决策任务与决策机构特点,采用层次分析法构建高校院（系）决策系统科学决策方案层次结构模型,并进行决策任务重要性评价、决策任务与决策机构相关性分析,在此基础上进行决策机构的设置与分工,建立决策权、执行权、监督权等既相互制约又相互协调的权力结构和运行机制。     

Mars surface diversity as revealed by the OMEGA/Mars Express observations

The Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) investigation, on board the European Space Agency Mars Express mission, is mapping the surface composition of Mars at a 0.3- to 5-kilometer resolution by means of visible-near-infrared hyperspectral reflectance imagery. The data acquired during the first 9 months of the mission already reveal a diverse and complex surface mineralogy, offering key insights into the evolution of Mars. OMEGA has identified and mapped mafic iron-bearing silicates of both the northern and southern crust, localized concentrations of hydrated phyllosilicates and sulfates but no carbonates, and ices and frosts with a water-ice composition of the north polar perennial cap, as for the south cap, covered by a thin carbon dioxide-ice veneer.     

新时代基层党校工作的形势、困境和对策——以十堰市基层党校的工作为例

实现伟大梦想,必须推进伟大事业,党员干部则是新时代党和国家事业的引路人和开拓者。建设一批精干高效、群众拥护的基层干部队伍,不仅能提升基层党组织的执政能力和领导水平,也能确保党的路线方针政策在基层顺利推进。当前,我们党面临着实现中华民族伟大复兴的新时代历史使命,党的使命也是党校的使命。基层党校必须在深入学习贯彻习近平新时代中国特色社会主义思想的指导下,正确认识当前基层党校工作存在的不足和短板,全面掌握基层干部的思想动态和教育需求,方能在新时代描绘基层党校的宏伟蓝图。     

信息革命还能持续多久?

信息技术有三大历史使命。第一大历史使命是普及,掀起一场产业革命;第二大历史使命是扩散,掀起一场社会革命;第三大历史使命是提升人类智慧,掀起一场大脑革命,并最终催生以生物技术为代表的新的产业革命。     

The autonomous viking

The two Viking spacecraft launched to Mars in 1975 were designed for 90 days of intense observations followed by an extended mission phase to end in 1978. Because the spacecraft were still operating so well in 1978, three more mission phases were added and the project was not officially terminated until 1980. During these last three mission phases delays in controlling the orbiters from the earth increased. The spacecraft were kept functional and the length of the Viking mission was extended because the ground crew, over a period of 2 years, gradually made the orbiters autonomous.     

Temperature and Thermal Emissivity of the Surface of Neptune's Satellite Triton

Analysis of the preliminary results from the Voyager mission to the Neptune system has provided the scientific community with several methods by which the temperature of Neptune's satellite Triton may be determined. If the 37.5 K surface temperature reported by several Voyager investigations is correct, then the photometry reported by the imaging experiment on Voyager requires that Triton's surface have a remarkably low emissivity. Such a low emissivity is not required in order to explain the photometry from the photopolarimeter experiment on Voyager. A low emissivity would be inconsistent with Triton having a rough surface at the approximately 100-microm scale as might be expected given the active renewal processes which appear to dominate Triton's surface.     

The yohkoh mission for high-energy solar physics

The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission.     

Near-optimal coverage trajectories for image mosaicing using a mini quad-rotor over irregular-shaped fields

Aerial images are useful tools for farmers who practise precision agriculture. The difficulty in taking geo-referenced high-resolution aerial images in a narrow time window considering weather restrictions and the high cost of commercial services are the main drawbacks of these techniques. In this paper, a useful tool to obtain aerial images by using low cost unmanned aerial vehicles (UAV) is presented. The proposed system allows farmers to easily define and execute an aerial image coverage mission by using geographic information system tools in order to obtain mosaics made of high-resolution images. The system computes a complete path for the UAV by taking into account the on-board camera features once the image requirements and area to be covered are defined. This work introduces a full four-step procedure: mission definition, automatic path planning, mission execution and mosaic generation.     

A sublimation model for martian south polar ice features

In their pioneering work, Leighton and Murray argued that the Mars atmosphere, which at present is 95% carbon dioxide, is controlled by vapor equilibrium with a much larger polar reservoir of solid carbon dioxide. Here we argue that the polar reservoir is small and cannot function as a long-term buffer to the more massive atmosphere. Our work is based on modeling of the circular depressions commonly found on the south polar cap. We argue that a carbon dioxide ice layer about 8 meters thick is being etched away to reveal water ice underneath. This is consistent with thermal infrared data from the Mars Odyssey mission.     

任务型语言教学的意义及实施途径

任务型语言教学是基于任务的一种教学方法,其核心是在实施教学过程中培养学生综合运用语言的能力。任务型语言教学有一个任务链,即任务前、任务中和任务后三个主要阶段,其中,分组学习不可少。     

基于无线传感器网络的节水灌溉智能监测系统设计

针对农田灌区范围广、数据量大、实时传输难的特点,提出一种基于无线传感器网络的农田自动节水灌溉系统,综合运用无线传感器智能信息处理技术、无线数据通信技术,全面提升系统的自动化与监测水平。该系统以单片机为控制核心,由无线传感器网络实时采集及处理数据,将其发送到接收端,在接收端对数据进行存储和显示,实时监测土壤温湿度变化,实现节水灌溉的自动化控制及水资源的高效利用。试验证明,该系统稳定性好,数据传输可靠性高,使用灵活,适合不便直接连线的一般监测场合应用。     

农业院校图书馆为社会主义新农村服务的思考

建设社会主义新农村是我国现代化建设进程中重大任务之一.作为农业高校图书馆,为建设社会主义新农村提供优质服务是时代赋予的历史重任.文章重点论述农业院校图书馆为建设社会主义新农村服务的意义、内客及途径.     

Exposed water ice deposits on the surface of comet 9P/Tempel 1

We report the direct detection of solid water ice deposits exposed on the surface of comet 9P/Tempel 1, as observed by the Deep Impact mission. Three anomalously colored areas are shown to include water ice on the basis of their near-infrared spectra, which include diagnostic water ice absorptions at wavelengths of 1.5 and 2.0 micrometers. These absorptions are well modeled as a mixture of nearby non-ice regions and 3 to 6% water ice particles 10 to 50 micrometers in diameter. These particle sizes are larger than those ejected during the impact experiment, which suggests that the surface deposits are loose aggregates. The total area of exposed water ice is substantially less than that required to support the observed ambient outgassing from the comet, which likely has additional source regions below the surface.     

Gravity: first measurement on the lunar surface

The gravity at the landing site of the first lunar-landing mission has been determined to be 162,821.680 milligals from data telemetered to earth by the lunar module on the lunar surface. The gravity was measured with a pulsed integrating pendulous accelerometer. These measurements were used to compute the gravity anomaly and radius at the landing site.