Homing in the ant Cataglyphis bicolor

Cataglyphis bicolor, an ant widely distributed in North Africa and the Near East, orient to the sun as well as to visual patterns of the environment. These two mechanisms can be separated. Foraging ants (hunters) orient to terrestrial cues as long as possible, and only after these have become ineffective do they switch over to the menotactical sun orientation. In the digging individuals, however, the visual knowledge of locality is significantly inferior to that of the hunters. Diggers vary considerably in size, but hunters belong to the largest size group. In addition, the largest and smallest individuals orient differently toward black and white areas and stripe patterns.     

Honey bee orientation: a backup system for cloudy days

On cloudy days, honey bees are known to navigate to familiar food sources and orient their dances accurately. This capacity could be based on a magnetic compass sense, an ability to perceive the sun or patterns of polarized light through the clouds, or on the bees' memory of the diurnal course of the sun with respect to local landmarks. Experiments pitting these alternatives against one another demonstrate that the navigational backup system of bees is based on memory.     

太阳系天体相对地球某点的波动式螺线运动(Ⅰ)——太阳、月球相对地球某点螺线运动方程推导及模拟分析

为研究太阳系天体相对地球某点的运动规律,首先建立了地心黄道坐标系,并将太阳绕地球的圆周运动转换为太阳绕地心的余弦波动,同时将此余弦波动作为标准余弦曲线.将太阳绕地球的运动分解为波动和"自转",并分双波动坐标轴和波动-螺面坐标轴分析,推导出太阳对地球赤道某点的波动式螺线运动轨迹方程,同时进行计算机模拟与分析,得到了太阳对地球某纬度某点的波动式螺线运动轨迹方程.以此类推,推导出月球对地球某点的波动式螺线运动轨迹方程,并分别进行计算机模拟与分析.结果表明,太阳、月球相对于地球某点的运动轨迹为与幅值与角度相关的波     

两种鲭科以及其他鱼类松果体窗形态结构的比较

为了解鲭科鱼类颅顶松果体窗的结构和其与生活习性、鱼类系统进化的关系、利用光镜、X射线同步辐射技术以及组织石蜡切片技术观察了黄鳍金枪鱼（Thunnus albacares）和日本鲐鱼渊（Pneumatophorus japonicus）松果体窗的组织学结构。此外,通过随机取样分属9目17科的20种鱼类标本,检测松果体窗形态结构,分析松果体窗与鱼类进化发育的关系,并探讨其在鱼体可能发挥的生理功能。研究结果表明,具松果体窗的鱼类大都居于近海或淡水水域的底层,松果体窗的产生与它们的生存环境有一定关系,这种特殊的生理结构可以使鱼类在弱光环境中尽可能多地接受光线,让光线到达大脑并调节生理功能。同时,具有洄游特性的海洋鱼类也具有松果体窗结构,这种结构有利于鱼类通过感知光线的变换来确定洄游路线。     

Heliotropism in modern stromatolites

Modern microbial mats and stromatolites exhibiting a preferred orientation toward specular sunlight were found at two sites. In Hamelin Pool of Shark Bay, Western Australia, subtidal decimeter-sized columns and intertidal centimeter-sized tufts were found pointing north. In thermal spring effluents and pools of Yellowstone National Park, mats were found with columnar and conical centimeter-sized structures inclined to the south. These examples of heliotropism in modern stromatolites are each built by a different community of photosynthetic microbes under markedly different environmental conditions. These new observations support the proposal that stromatolites can orient themselves toward the sun.     

Migrating songbirds recalibrate their magnetic compass daily from twilight cues

Night migratory songbirds can use stars, sun, geomagnetic field, and polarized light for orientation when tested in captivity. We studied the interaction of magnetic, stellar, and twilight orientation cues in free-flying songbirds. We exposed Catharus thrushes to eastward-turned magnetic fields during the twilight period before takeoff and then followed them for up to 1100 kilometers. Instead of heading north, experimental birds flew westward. On subsequent nights, the same individuals migrated northward again. We suggest that birds orient with a magnetic compass calibrated daily from twilight cues. This could explain how birds cross the magnetic equator and deal with declination.     

A search for ultra-narrowband signals of extraterrestrial origin

Nearly 200 nearby stars similar to the sun were observed at the 21-centimeter neutral hydrogen wavelength (in the heliocentric frame) with a bandwidth of 1 kilohertz and a resolution of 0.015 hertz, using the Arecibo 305-meter antenna. At this resolution the effects of terrestrial interference are so slight that the detection limit of 4 x 10(-27) watt per square meter was set by receiver noise alone. No evidence of artificial signals was found.     

遮阴对大头茶、薄果猴欢喜幼苗生长的影响

对２ａ生大头茶（Ｇｏｒｄｏｎｉａａｃｕｍｅｎａｔａ）和薄果猴欢喜（Ｓｌｏａｎｅａｌｅｐｔｏｃａｒｐａ）幼苗进行遮阴实验，结果表明，大头茶幼苗的叶面积、茎长、枝长年变化曲线和总生量为：全光照＞部分光照＞部分阴暗＞阴暗；而薄果猴欢喜为：部分阴暗＞阴暗＞部分光照或全光照，这体现了阳性树种（大头茶幼苗）和阴性树种（薄果猴欢喜幼苗）的不同特点。从全光照到阴暗，大头茶、薄果猴欢喜幼苗的平均叶面积重（ＳＬＷ）和根／冠比均下降，而叶面积率（ＬＡＲ）均增加，并且，平均叶面积在部分阴暗下最高，全光照下最低。可见，大头茶、薄果猴欢喜幼苗对其相应光环境具有一定的适应能力     

The Sun Again Intrudes on Earth's Decadal Climate Change

Researchers have long doubted that solar cycles affect terrestrial climate, because no one has yet come up with a convincing mechanism to explain how tiny changes on the sun might change climate on Earth. Now, however, two such correlations--a 22-year climate cycle recorded in glacial sediments and the tracing of an 11-year cycle from the stratosphere into the lower atmosphere--may be robust enough to give the sun-climate link a touch more respectability.     

Orientation by pigeons: is the sun necessary?

Although most recent hypotheses of pigeon homing have assigned an essential role to the sun, there has been some evidence suggesting that the sun is not essential. Two series of releases were designed to examine the question more carefully. Birds whose internal clocks had been shifted 6 hours were used in the critical tests. Under sun, the vanishing bearings of the clock-shifted birds were deflected in the direction predicted by a hypothesis of use of the sun as a simple compass. By contrast, under total overcast the bearings of both the clock-shifted and the control birds were homeward oriented and there was no difference between them, even at a release site the birds could never have seen previously. Therefore it is concluded that the sun is used as a compass when it is available, but that the pigeon navigation system contains sufficient redundancy to make accurate orientation possible in the absence of both the sun and familiar landmarks; the orientational cues used under such conditions do not require time compensation. This conclusion is in complete disagreement with the Matthews sun-arc hypothesis of pigeon navigation, and it makes necessary a major reformulation (at the very least) of the other principal hypothesis, that of Kramer.     

太湖地区桔小实蝇的生活习性

[目的]为开展桔小实蝇检疫防控技术研究提供技术基础。[方法]利用养虫室、养虫笼等设施,采用人工饲养和果实培养等方法建立和维持桔小实蝇种群并进行持续的室内生物学观察;在太湖东山地区建立隔离网室,配备温湿度记录装置,栽种各类寄主植物,每天观察桔小实蝇的生活习性。[结果]通过实验室饲养观察,掌握了桔小实蝇成虫、幼虫、蛹和卵的生活习性;通过土壤深度对蛹羽化率影响的试验可知将土层深度加大到40cm仍有成虫出现,且羽化率为80%;通过室内趋向性试验,发现桔小实蝇对苏州地产水果的选择性从高到低排序为柑橘、枣、石榴、桃、橙、梨、柿子。而野外调查表明,果树品种根据桔小实蝇为害率从高到低排序为柑橘、枣、石榴、梨、柿子。在本地柑橘品种中,其为害率从高到低排序为洞庭蜜橘、早橘、温柑、黄皮、早红、料红。[结论]建立了桔小实蝇人工饲养设施,为开展桔小实蝇生物学特性观察和生物学试验奠定了基础。     

基于机器视觉金鱼游动方向监测算法的研究

针对金鱼游动方向自动监测,提出了一种基于机器视觉金鱼游动方向的监测算法。金鱼图像首先通过阈值分割得到分割图像,然后通过分割图像或者腐蚀后的分割图像提取金鱼的像素点,再分别使用最小二乘法拟合一次、二次曲线从而得到金鱼的游动方向。15幅金鱼图像的实验表明在室内单条金鱼监测中通过分割图像提取像素后一次曲线拟合得到的结果最好,仅6.67%的误差。     

Morphology and ionization of the interstellar cloud surrounding the solar system

The first encounter between the sun and the surrounding interstellar cloud appears to have occurred 2000 to 8000 years ago. The sun and cloud space motions are nearly perpendicular, an indication that the sun is skimming the cloud surface. The electron density derived for the surrounding cloud from the carbon component of the anomalous cosmic ray population in the solar system and from the interstellar ratio of Mg(+) to Mg degrees toward Sirius support an equilibrium model for cloud ionization (an electron density of 0.22 to 0.44 per cubic centimeter). The upwind magnetic field direction is nearly parallel to the cloud surface. The relative sun-cloud motion indicates that the solar system has a bow shock.     

Ultraviolet spectroscopy and the composition of cometary ice

Our current knowledge of the composition of the cormetary nucleus is largely inferred from observations of the gas and dust comae that are produced by sublimation of cometary ice when a comet is near the sun. During the past decade, far-ultraviolet spectroscopy from above the terrestrial atmosphere has shed new light on the physics and chemistry of the gaseous component of the coma. The advent of interplanetary missions to Halley's comet in 1986 and the development of a new generation of earth-orbiting observatories promise further insights into the nature of these frozen remnants of the primordial solar system.     

四方井水库建设主要生态环境影响及其保护措施

以拟建的四方井水库为例,从水库蓄水与淹没、大坝阻隔及上下游河道径流变化等方面,分析水库建设和运行对陆生动植物、水生生物及鱼类资源产生的影响;针对主要生态影响,结合工程布置、区域特点和景观要求,提出可行的对重点保护动植物、古树名木、鱼类资源、生态流量的保护措施,以期最大限度地降低不利生态环境影响,使工程经济效益、生态效益和社会效益得到协调发展。     

Terrestrial microclimate: amelioration at high latitudes

At latitudes north of the Arctic Circle the diel range of sun altitude declines progressively, reducing the frequency of temperature inversions over level, unshaded ground in summer and extending the frost-free season. North of about 70 degrees north, the potential number of inversion-free days increases rapidly with latitude; this ameliorates the microclimate close to the ground-the zone to which terrestrial organisms are increasingly restricted in higher latitudes. The relation between screen and ground-surface temperatures differs north and south of about 70 degrees north; north of that latitude there are progressively more frost-free days than would be inferred from screen temperatures, were no allowance made for this latitude-dependent change.     

Orientation of homing pigeons altered by a change in the direction of an applied magnetic field

Homing pigeons were equipped with a pair of small coils around their heads. Birds with an induced field of 0.6 gauss and the south magnetic pole up, oriented toward home normally under both sun and overcast. Birds with the polarity reversed oriented toward home when the sun was visible but often flew away from home under overcast.     

3年生苦楝生长量与坡向、坡位关系的研究

采用随机区组调查法对寿宁县3年生苦楝与不同坡向、坡位的生长量关系进行研究,通过对比分析,结果表明：不同坡向、与坡位的生长量存在极显著差异,阳坡能显著促进苦楝生长,苦楝造林最好选择阳坡下部山地、农地。     

Aerial vision: unique adaptation in an intertidal fish

Mnierpes macrocephalus, a clinid fish of rocky shores of the eastern tropical Pacific, makes frequent terrestrial sojourns. The normal fish eye is myopic in air because of curvature of the cornea. This is overcome in Mnierpes by the presence of two flattened corneal surfaces.