Sunspot activity and cosmic ray modulation at 1 a.u. for 1900–2013

The descent of sunspot cycle 23 to an unprecedented minimum of long duration in 2006–2009 led to a prolonged galactic cosmic ray (GCR) recovery to the highest level observed in the instrumental era for a variety of energetic charged particle species on Earth, over a wide range of rigidities. The remarkable GCR increase measured by several ground-based, balloon-borne, and detectors on a satellite is described and discussed. It is accompanied by a decrease in solar wind velocity and interplanetary magnetic field at 1 a.u., reaching the lowest values since measurements of the solar wind began in October 1963; the solar polar field strength (μT) measured at the Wilcox Solar Observatory (WSO) is also significantly reduced compared to prior cycles since the start of the program in 1976, the polar field in the northern hemisphere reversed in June 2012 and again in February 2014, that in the southern hemisphere reversed in July 2013. If updates of WSO data confirm the second reversal in northern solar hemisphere, it would pose a serious challenge to the Dynamo Theory. The long-term change in solar behavior may have begun in 1992, perhaps earlier. The physical underpinnings of these solar changes need to be understood and their effect on GCR modulation processes clarified. The study discusses the recent phenomena in the context of GCR modulation since 1900. These happenings affected our empirical predictions for the key parameters for the next two sunspot cycles (they may be progressively less active than sunspot cycle 24) but it enhanced support for our prediction that solar activity is descending into a Dalton-like grand minimum in the middle of the twentyfirst century, reducing the frequency of the coronal mass ejections; they determine the space weather affecting the quality of life on Earth, radiation dose for hardware and human activities in space as well as the frequency of large Forbush decreases at 1 a.u.     

Fundamental (f) oscillations in a magnetically coupled solar interior-atmosphere system – An analytical approach

Solar fundamental (f) acoustic mode oscillations are investigated analytically in a magnetohydrodynamic (MHD) model. The model consists of three layers in planar geometry, representing the solar interior, the magnetic atmosphere, and a transitional layer sandwiched between them. Since we focus on the fundamental mode here, we assume the plasma is incompressible. A horizontal, canopy-like, magnetic field is introduced to the atmosphere, in which degenerated slow MHD waves can exist. The global (f-mode) oscillations can couple to local atmospheric Alfvén waves, resulting, e.g., in a frequency shift of the oscillations. The dispersion relation of the global oscillation mode is derived, and is solved analytically for the thin-transitional layer approximation and for the weak-field approximation. Analytical formulae are also provided for the frequency shifts due to the presence of a thin transitional layer and a weak atmospheric magnetic field. The analytical results generally indicate that, compared to the fundamental value ($\omega =\sqrt{\mathit{gk}}$), the mode frequency is reduced by the presence of an atmosphere by a few per cent. A thin transitional layer reduces the eigen-frequencies further by about an additional hundred microhertz. Finally, a weak atmospheric magnetic field can slightly, by a few percent, increase the frequency of the eigen-mode. Stronger magnetic fields, however, can increase the f-mode frequency by even up to ten per cent, which cannot be seen in observed data. The presence of a magnetic atmosphere in the three-layer model also introduces non-permitted propagation windows in the frequency spectrum; here, f-mode oscillations cannot exist with certain values of the harmonic degree. The eigen-frequencies can be sensitive to the background physical parameters, such as an atmospheric density scale-height or the rate of the plasma density drop at the photosphere. Such information, if ever observed with high-resolution instrumentation and inverted, could help to gain further insight into solar magnetic structures by means of solar magneto-seismology, and could provide further insight into the role of magnetism in solar oscillations.     

E.T.您好!

今年6月11日是《E.T.外星人》公映20周年,看过这部电影的人一定对其中的外星人记忆犹深,因为至今,它仍是“外星人”的经典形象。 3月19 日,《E.T.外星人》的20周年纪念活动在佛罗里达州的奥克兰大学演播厅中举行,国际空间站上的3名航天员也在大屏幕上凑热闹,他们除了对此片的导演斯皮尔伯格表示敬意外,还参与了学生们的讨论。其中一名中学生问:“人类什么时候可以去拜访E.T.的家?”     

关于B.V.A.石英谐振器的进一步发展

在1976年和1977年两届频率控制年会的论文集中,曾介绍过一种新型压电谐振器的设计。本文介绍有关5兆赫谐振器的幅频效应和老化与激励电平和石英材料相比较的最新结果。尤其要指出的是,可以使用极高的激励电平(一直到30毫瓦),而且激励电平的增加并不影响老化性能。此外,在给定的激励电平上能够得到“零老化率”。所渭“零老化激励电平”,就是老化率是在给定的功率损散时过零的。最后,将讨论BVA器件在工业生产方面的问题     

美物理学博士R.F.C.Vessot在京作学术报告

美国史密松宁天文台(SAO)物理学博士R.F.C.Vessut应中国燕山科学技术公司的邀请于1982年9月13日至16日在北京就氢原子频率标准的现状及其在空间技术中的应用作了学术报告。一、氢原子频率标准的现状     

Host–parasite interactions in closed and open microbial cultivation system

The study addresses interaction of bacteria and phages in the host–parasite system in batch and continuous cultures. The study system consists of the auxotrophic strain of Brevibacterium – Brevibacterium sp. 22L – and the bacteriophage of Brevibacterium sp., isolated from the soil by the enrichment method.

1.

Closed system. In the investigation of the relationship between the time of bacterial lysis and multiplicity of phage infection it has been found that at a lower phage amount per cell it takes a longer time for the lysis of the culture to become discernible. Another important factor determining cytolysis in liquid medium is the physiological state of bacterial population. Specific growth rate of bacteria at the moment of phage infection has been chosen as an indicator of the physiological state of bacteria. It has been shown that the shortest latent period and the largest output of the phage are observed during the logarithmic growth phase of bacteria grown under favorable nutrient conditions. In the stationary phase, bacterial cells become “a bad host” for the phage, whose reproduction rate decreases, and the lysis either slows down significantly or does not occur at all.     

Earth–Moon low energy trajectory optimization in the real system

The problem of the Earth–Moon low energy trajectory optimization in the real system (the model defined by the JPL ephemeris DE405) is considered in this paper. First, this problem is investigated in the model of circular restricted three-body problem, since the fuel consumption is closely related to the Jacobi integral of the transfer trajectory, a method based on Jacobi integral is proposed and eight optimal trajectories are obtained. These optimal trajectories provide initial information (the flight time and the braking velocity impulse) to search the optimal low energy trajectories in the real system through optimization techniques. Considering the merit and drawback of particle swarm optimization and differential evolution algorithm in solving the space trajectory problem, an improved cooperative evolutionary algorithm is put forward. Result shows that the low energy trajectories in the real system are more fuel-efficient than the corresponding ones under the circular restricted three-body problem.     

向量迭代正余弦函数的计算原理及其在数字P.P.I.中的应用

本文所讨论的正余弦函数的计算方法,是从物理向量开始,用严密的数学方法推导,配合计算机的状态程序,使数的值逐步形成。这是一种新的设想,是一种既快又省的方法。 其计算功能甚多。本文只讨论其中正余弦函数的计算部分及其应用于雷达数字P.P.I.分解器的情况。它使P.P.I.具有极强的通用性,适合于各种天线角度码盘。     

意大利“E.T.”事件始末（二）

卡博尼开始了解更多与怪物有关的知识，比如外星人、心灵感应等，寻思着也许下次相见可以明白它的动作的含义。或者接收到它的心灵感应。1993年6月的某夜。卡博尼和朋友卡罗等一起在村子俱乐部看完电视后回家。突然．卡罗发现大门方向有动静，传来一声低沉的叫声。     

最先进的攻击型核潜艇技术发展美国V.S.俄罗斯

攻击型核潜艇是建立强大海军不可或缺的重要武器装备，也是冷战时期美苏相互比拼的重要筹码。随着冷战结束，美，俄两个超级大国的海军所承担的战略任务发生了很大改变．即从重视海洋作战转移到局部战争的近海作战．但攻击型核潜艇的地位和作用并来降低。伊拉克战争中，美英联军共向战区派遣了12艘攻击型核潜艇．发射了约300枚“战斧”巡航导弹．对加速战争的进程起到了重要的作用。为了应对新型威胁，新型攻击核潜艇在设计思想上强调以多功能．多用途为主．除继续强调反潜、反舰功能外．还要求具有较强的对陆攻击．监视，情报收集，特种部队输送、局部海上控制能力等。[编者按]     

形形色色的E.T

一个名叫乔·尼克尔的美国民俗学专家对有关遭遇外星人的传闻报道进行了归类整理和“登记注册”，并将他的研究结果发表在《不明现象调查》杂志上。该杂志是一个专门研究神秘物体和超自然现象的委员会的机关刊物。该委员会则是一批担心引起轰动效应的伪科学广泛扩散的科学...     

Two-manoeuvres transfers between LEOs and Lissajous orbits in the Earth–Moon system

The purpose of this work is to compute transfer trajectories from a given Low Earth Orbit (LEO) to a nominal Lissajous quasi-periodic orbit either around the point L₁ or the point L₂ in the Earth–Moon system. This is achieved by adopting the Circular Restricted Three-Body Problem (CR3BP) as force model and applying the tools of Dynamical Systems Theory.     

Future U.S. ocean color missions—OCI,MODIS and HIRIS

The Coastal Zone Color Scanner (CZCS) launched by the National Aeronautics and Space Administration (NASA) on the Nimbus-7 Satellite in 1978 has provided exceptionally valuable data for studies of the productivity of the ocean, fisheries, the detection of oceanic fronts and currents, and the optical properties of the ocean. NASA has been working with the scientific community, the National Oceanographic and Atmospheric Administration (NOAA), France's Centre National d'Etudes Spatiales (CNES), and industry to develop an Ocean Color Imager (OCI), a follow-on instrument which would provide the near real-time and global data necessary to fill these needs in the 1990's. The Earth Observing Satellite Company (EOSAT) is considering flying an ocean and land wide-field color instrument which would meet these needs on Landsat 6 or 7 planned for launch in 1989 and 1991, respectively. It would provide eight ocean color channels for improved atmospheric correction and in-water algorithms, global coverage and near real-time data for operational uses. In the mid 1990's NASA is planning to fly a Moderate Resolution Imaging Spectrometer (MODIS) and a High Resolution Imaging Spectrometer (HIRIS) as part of the Earth Observing System (Eos) on the Polar Platform of the Space Station. These instruments are array spectrometers which would provide full spectral resolution in the visible and infrared. This opens the possibility of separating different groups of phytoplankton, suspended sediments and other substances in the water. Also, HIRIS would have across track pointing ability which will allow high resolution rapid sampling of dynamic coastal areas and estuaries.     

庆国庆,迎中秋E.T.网有礼了!

一:订刊优惠!1.订购《飞碟探索》任意6期,原价:30元,现价:仅需25元,同时需要消费您的2U晶。2.订购《飞碟探索》任意12期,原价:60元,现价:仅需48元,同时需要消费您的4U晶。     

Orbital computations by means of the “Potsdam-5” program system and applications

The POTSDAM-5 program system is based on the numerical integration of the perturbation equations. As a quasi-intertial system the mean astronomical system for the reference epoch J 2000.0 is chosen. The realization of the reference system and the force model is provided for the cm-level. Especially, the latest theories of nutation and tides are implemented for station positioning and orbit dynamics. On the basis of the highly accurate orbit calculations station coordinates, earth-rotation parameters, bias parameters, and some geodynamic parameters can be determined by means of photographical, laser, positional, doppler, and satellite-interferometric measurements. Applications are mainly related to satellite laser ranging data of LAGEOS. Precise station coordinates and earth-rotation parameters were derived using the data of the MERIT Campaign.     

形形色色的外星人E.T

在20世纪四五十年代，种种有关UFO原型及其乘员的说法搅在一起，形成一片混乱的局面。世界各地的目击报告中相继提到在UFO附近或内部目击到酷似人类的生物。但令研究者困惑的是，若从常识上来考虑，这些类人生物的形态、大小、外观及行动是无法理解的。