Galileo at Io: results from high-resolution imaging

During late 1999/early 2000, the solid state imaging experiment on the Galileo spacecraft returned more than 100 high-resolution (5 to 500 meters per pixel) images of volcanically active Io. We observed an active lava lake, an active curtain of lava, active lava flows, calderas, mountains, plateaus, and plains. Several of the sulfur dioxide-rich plumes are erupting from distal flows, rather than from the source of silicate lava (caldera or fissure, often with red pyroclastic deposits). Most of the active flows in equatorial regions are being emplaced slowly beneath insulated crust, but rapidly emplaced channelized flows are also found at all latitudes. There is no evidence for high-viscosity lava, but some bright flows may consist of sulfur rather than mafic silicates. The mountains, plateaus, and calderas are strongly influenced by tectonics and gravitational collapse. Sapping channels and scarps suggest that many portions of the upper approximately 1 kilometer are rich in volatiles.     

A Magnetic Signature at Io: Initial Report from the Galileo Magnetometer

During the inbound pass of the Galileo spacecraft, the magnetometer acquired 1 minute averaged measurements of the magnetic field along the trajectory as the spacecraft flew by Io. A field decrease, of nearly 40 percent of the background jovian field at closest approach to Io, was recorded. Plasma sources alone appear incapable of generating perturbations as large as those observed and an induced source for the observed moment implies an amount of free iron in the mantle much greater than expected. On the other hand, an intrinsic magnetic field of amplitude consistent with dynamo action at Io would explain the observations. It seems plausible that Io, like Earth and Mercury, is a magnetized solid planet.     

Thermal Structure of Jupiter's Upper Atmosphere Derived from the Galileo Probe

Temperatures in Jupiter's atmosphere derived from Galileo Probe deceleration data increase from 109 kelvin at the 175-millibar level to 900 ± 40 kelvin at 1 nanobar, consistent with Voyager remote sensing data. Wavelike oscillations are present at all levels. Vertical wavelengths are 10 to 25 kilometers in the deep isothermal layer, which extends from 12 to 0.003 millibars. Above the 0.003-millibar level, only 90- to 270- kilometer vertical wavelengths survive, suggesting dissipation of wave energy as the probable source of upper atmosphere heating.     

农业结构综合评价及农业内部结构相关性分析——以沂蒙山区为例

根据《中国统计年鉴》中的相关数据,对沂蒙山区农业总体结构及农业内部结构现状进行了分析。通过改进的要素综合评价方法对沂蒙山区农业结构及农业内部结构进行综合评价,其综合评价安全系数为2.626 696~4.987 546,不在高安全度区间,因此有其调整的必要性。通过相关性分析研究了沂蒙山区农业内部结构的相互内在联系：沂蒙山区总体农业结构与种植业结构、林业结构呈负相关,而与养殖业结构呈正相关;种植业结构与养殖业结构呈负相关,与林业结构呈正相关;林业结构与养殖业结构呈负相关。     

Structure and Density of FeS at High Pressure and High Temperature and the Internal Structure of Mars

In situ x-ray diffraction measurements revealed that FeS, a possible core material for the terrestrial planets, transforms to a hexagonal NiAs superstructure with axial ratio (c/a) close to the ideal close-packing value of 1.63 at high pressure and high temperature. The high-pressure-temperature phase has shorter Fe-Fe distances than the low-pressure phase. Significant shortening of the Fe-Fe distance would lead to metallization of FeS, resulting in fundamental changes in physical properties of FeS at high pressure and temperature. Calculations using the density of the high-pressure-temperature FeS phase indicate that the martian core-mantle boundary occurs within the silicate perovskite stability field.     

Io: ground-based observations of hot spots

Observations of Io in eclipse demonstrate conclusively that Io emits substantial amounts of radiation at 4.8 and 3.8 micrometers and a measurable amount at 2.2 micrometers. Color temperatures derived from the observations fit blackbody emission at 560 K. The required source area to yield the observed 4.8-micrometer flux is approximately 5 x 10(-5) of the disk of Io and is most likely comprised of small hot spots in the vicinity of the volcanoes.     

Io's thermal emission from the Galileo photopolarimeter-radiometer

Galileo's photopolarimeter-radiometer instrument mapped Io's thermal emission during the I24, I25, and I27 flybys with a spatial resolution of 2.2 to 300 kilometers. Mapping of Loki in I24 shows uniform temperatures for most of Loki Patera and high temperatures in the southwest corner, probably resulting from an eruption that began 1 month before the observation. Most of Loki Patera was resurfaced before I27. Pele's caldera floor has a low temperature of 160 kelvin, whereas flows at Pillan and Zamama have temperatures of up to 200 kelvin. Global maps of nighttime temperatures provide a means for estimating global heat flow.     

Earth-Based Observations of the Galileo Probe Entry Site

Earth-based observations of Jupiter indicate that the Galileo probe probably entered Jupiter's atmosphere just inside a region that has less cloud cover and drier conditions than more than 99 percent of the rest of the planet. The visual appearance of the clouds at the site was generally dark at longer wavelengths. The tropospheric and stratospheric temperature fields have a strong longitudinal wave structure that is expected to manifest itself in the vertical temperature profile.     

农业产业内部结构与农民收入结构协调性研究

结合我国1978—2013年农业产业和农民收入的数据分析二者的协调性关系,使用设计统计指标的定量研究方法发现,农业产业内部结构与农民收入结构的变异系数值波动较大,结构偏离度呈差异化分布,农业内部各部门的人均收入率存在着很大的差异,弹性系数值较小等现象。可以看出,我国农业的产业内部结构、农民收入结构在不断调整,但是农业产业内部结构与农民收入结构的协调性较差,农业产业内部结构与农民收入结构还没有形成良性的互动机制。这既限制了农业产业内部结构自身的优化调整,又限制了农民收入结构的调整。     

Io: longitudinal distribution of sulfur dioxide frost

Twenty spectra of Io (0.26 to 0.33 micrometer), acquired with the International Ultraviolet Explorer spacecraft, have been studied. There is a strong ultraviolet absorption shortward of 0.33 micrometer that is consistent with earlier ground-based spectrophotometry; its strength is strongly dependent on Io's rotational phase angle at the time of observation. This spectral feature and its variation are interpreted as indicative of a longitudinal variation in the distribution of sulfur dioxide frost on Io. The frost is most abundant at orbital longitudes 72 degrees to 137 degrees and least abundant at longitudes 250 degrees to 323 degrees . Variations in spectral reflectivity between 0.4 and 0.5 micrometer, reported in earlier ground-based spectral studies, correlate inversely with variations in reflectivity between 0.26 and 0.33 micrometer. It is concluded that this is because the Io surface component with the highest visible reflectivity (sulfur dioxide frost) has the lowest ultraviolet reflectivity. At least one other component is present and may be sulfur allotropes or alkali sulfides. This model is consistent with ground-based ultraviolet, visible, and infrared spectrophotometry. Comparison with Voyager color photographs indicates that the sulfur dioxide frost is in greatest concentration in the "white" areas on Io and the other sulfurous components are in greatest concentration in the "red" areas.     

论大学内部治理结构的完善与优化

完善大学内部治理结构是构建现代大学制度的基石。结合当前高校内部治理结构中存在权力配置不均衡、章程缺失、缺乏职业化管理等问题进行分析,提出进一步落实高校办学自主权、加强大学章程建设、管理重心下移、管理者职业化等完善大学内部治理结构的措施。     

基于引力模型的城市圈地价空间结构模型研究

当前城市地价空间结构的研究方法有多种,主要是基于单个城市的地价空间分布的定级估价理论和多个城市的土地地域差异的城市土地分等理论,这两种方法都没能充分满足城市圈地价空间结构研究。引力模型是强调城市间要素的相互联系性,它测度了城市圈各城市的质量、城市间距离、城市综合潜力等因素,将该模型应用到城市圈地价空间结构的研究中,并实践该模型在城市圈地价空闻结构中的应用。     

高校内控体系建设与完善治理结构研究

当前大多数高校的内控体系建设均有待加强,且治理结构亦有待进一步完善。对此,各高校均当积极基于自身当前与内部控制体系及治理结构方面的问题,结合COSO的企业内部控制体系原理来建立一套完善且符合高校发展规律的内部控制体系,由此方能在强化对学校内部的环境控制同时尽可能地降低学校的财务、管理等各方面风险,继而维护学校的健康发展。     

水泥浆凝结硬化时内部结构与超声频谱的变化

论述了超声脉冲穿过硬化过程中的水泥浆时超声频谱的变化，并分析了声速，频率幅值与水泥浆期龄之间的关系。实验证明超声频率是观察硬化水泥浆早期结构的变化及测定水泥凝结时间的有效方法。     

梁柱刚度对结构计算模型和内力的影响

 钢筋混凝土框架结构体系是常用的结构体系。现阶段均可采用计算机求得精确解,但一些近似计算的手算方法由于概念清楚,计算简便,在结构方案设计中能快速手算出结构的近似内力,从而得出合理结构方案。本文以内框架房屋为例,详细分析了不同刚度的梁支承于柱,分别按铰支座、框架两种不同模型并考虑活荷载的不利布置,计算并比较梁端的控制截面内力,通过对控制内力的分析,找出不同梁柱线刚下类似结构合理简洁的计算方法,对工程设计有较强的指导意义。     

Galileo, planetary atmospheres, and prograde revolution

Early in March 1610 Galileo was preoccupied with curious brightness variations of the newly discovered satellites of Jupiter. In formulating an incorrect explanation he advanced important generalizations about the existence of planetary atmospheres and counterclockwise circulation within the solar system.     

Galileo multispectral imaging of the north polar and eastern limb regions of the moon

Multispectral images obtained during the Galileo probe's second encounter with the moon reveal the compositional nature of the north polar regions and the northeastern limb. Mare deposits in these regions are found to be primarily low to medium titanium lavas and, as on the western limb, show only slight spectral heterogeneity. The northern light plains are found to have the spectral characteristics of highlands materials, show little evidence for the presence of cryptomaria, and were most likely emplaced by impact processes regardless of their age.     

Origin of mountains on Io by thrust faulting and large-scale mass movements

Voyager stereoimages of Euboea Montes, Io, indicate that this mountain formed when a large crustal block was uplifted 10.5 kilometers and tilted by approximately 6 degrees. Uplift triggered a massive slope failure on the northwest flank, forming one of the largest debris aprons in the solar system. This slope failure probably involved relatively unconsolidated layers totaling approximately 2 kilometers in thickness, overlying a rigid crust (or lithosphere) at least 11 kilometers thick. Mountain formation on Io may involve localized deep-rooted thrust faulting and block rotation, due to compression at depth induced during vertical recycling of Io's crust.     

Earth-Based Radio Tracking of the Galileo Probe for Jupiter Wind Estimation

Although the Galileo probe was designed to communicate only to the orbiter, the probe radio signal was detected at two Earth-based radio observatories where the signal was a billion times weaker. The measured signal frequency was used to derive a vertical profile of the jovian zonal wind speed. Due to the mission geometry, the Earth-based wind estimates are less sensitive to descent trajectory errors than estimates based on probe-orbiter Doppler measurements. The two estimates of wind profiles agree qualitatively; both show high wind speeds at all depths sampled.