On the Disappearance of Kilohertz Quasi-periodic Oscillations at a High Mass Accretion Rate in Low-Mass X-Ray Binaries

We here investigate the possibility that the ultra-high-energy cosmic-ray (UHECR) events observed above the Greisen-Zatsepin-Kuzmin (GZK) limit are mostly protons accelerated in reconnection sites just above the magnetosphere of newborn millisecond pulsars that are originated by accretion-induced collapse (AIC). We formulate the requirements for the acceleration mechanism and show that AIC pulsars with surface magnetic fields 1012 G/=10(20) eV. Because the expected rate of AIC sources in our Galaxy is very small ( approximately 10(-5) yr(-1)), the corresponding contribution to the flux of UHECRs is negligible and the total flux is given by the integrated contribution from AIC sources produced by the distribution of galaxies located within the distance that is unaffected by the GZK cutoff ( approximately 50 Mpc). We find that reconnection should convert a fraction xi greater, similar0.1 of magnetic energy into UHECRs in order to reproduce the observed flux.     

虚拟天文台数据访问系统(VO-DAS)任务调度设计与实现

为解决异地、异构、海量天文数据无缝透明地统一访问,中国虚拟天文台(China-VO)研究小组自主设计并开发了一套解决方案——虚拟天文台数据访问系统(VO-DAS)。着重从执行流程、设计模式、Session机制、生命周期、资源销毁、异常处理等模块详细阐述了该系统的任务调度设计。为了验证该系统的可行性和性能,最后描述了多个天文科学范例。     

“数字地球”科学工程

“数字地球”是集科学、技术和工程于一体的一项宏伟的科学体系。“数字地球”由基础研究、技术支撑和科学工程三部分组成,其中科学工程是“数字地球”的核心和目标。文章在我国“数字地球”科学工程现状分析的基础上,结合国情,对我国“数字地球”科学工程的发展提出了建议。     

Sedimentary macro-structures and forming mechanism of debris flow

IIWr~IOWThesedimentarycharacteristicsofdebrisflowcanreflectthecompoSition,fluidtypeandsedimentaryprocess.ThescholarswhostudymoderndebrisfloWinChinagenerallyclassifydebrisflowbythemethodofviscositywithfloWpattern.SeveraltypicalschemesareshowninTable1,inwhichthemethodofunitweight(fluiddensityinunitvolumet/m3)isusedandfluidunitweightisthoughttobethedirectproPOSitiontotheviscosityofdebrisflow(Wu,1990).Ithasbeenprovedbyhydrcrmechacsthatnon-cohesivedebrisf1OwfollowsBagnoldgranular'flowmedel(B…     

Recruitment of postlarval prawns,Penaeus Orientalis,to a tidal estuary of Jiaozhou Bay,China

PostlarvalPenaeus orientalis kishinouye were simultaneously sampled at three fixed stations near the mouth of the Dagu River estuary in northwestern Jiaozhou Bay, China, at hourly intervals over a 49-h period in mid-June, 1984. The purpose of this sampling was to investigate the prawn’s recruitment into estuaries from coastal areas. The abundance of the postlarvae varied considerably between stations and time, but they tended to concentrate at the surface. Maximum entropy spectral analysis was first applied in the study of prawn recruitment and it revealed that variations in abundance involved a pronounced 12.4 hr cycle. It was concluded that natural tidal cycles had a strong influence on the changes of postlarval abundance, in contrast with the minor effects of diet and other environmental cycles. A tidally varying cross-river gradient of postlarval density was found. During flood tides the postlarvae were more abundant in the axis of the channel than over the banks. The opposite held true during ebb tides. Mechanisms of the postlarval recruitment are discussed in terms of alternating movements of the postlarvae between the banks and the channels in response to tidal cycles. Contribution No. 1485 from the Institute of Oceanology, Academia Sinica     

本溪地区太古宙岩石中黑云母击象的发现及其地质意义

作者在辽宁省本溪地区大范围内发现黑云母击象,这在该区尚属首次。黑云母击象以及存在的地质环境表明,在地质演变史上,本溪地区曾存在至少一期影响普遍的快速构造变形—岩浆活动事件,它很可能代表一次古断裂地震活动。     

COMBINATION OF ECMWF REANALYZED DAILY RAINFALL AND PENTAD CMAP IN CHINA

In this study, 16 combinations of the ECMWF (European Centre for Medium-Range Weather Forecast) reanalyzed daily rainfall and the pentad CMAP in China for the period 1980- 1993( 1May - 31 Dec. ) were calculated. Correlation analysis was used to roughly evaluate daily rainfall for the whole of China and a combination of RPC (rotated principal component) and wavelet analyses was applied to data on observed and combined daily rainfall to obtain a detailed evaluation of the quality of these combined datasets in 6 selected major rainfall regions of eastern China. The results showed that except for intraweekly fluctuation, the best combination was roughly similar to or accorded well with observation in the aspects of space variation patterns and long period rainfall fluctuations related to monsoon onset and serious meteorologic disasters, indicating that this combination yielded better values of long term daily mean and standard deviation through the pentad CMAP ( CPC Merged Analysis of Precipitation), and can also represent rainfall fluctuations through the reanalyzed daily rainfall.     

Case history of the disastrous debris flows of Tianmo Watershed in Bomi County,Tibet, China: Some mitigation suggestions

Debris flows and landslides, extensively developing and frequently occurring along Parlung Zangbo, seriously damage the Highway from Sichuan to Tiebt(G318) at Bomi County. The disastrous debris flows of the Tianmo Watershed on Sept. 4, 2007, July 25, 2010 and Sept. 4, 2010, blocked Parlung Zangbo River and produced dammed lakes, whose outburst flow made 50 m high terrace collapse at the opposite bank due to intense scouring on the foot of the terrace. As a result, the traffic was interrupted for 16 days in 2010 because that 900 m highway base was destructed and 430 m ruined. These debris flows were initiated by the glacial melting which was induced by continuous higher temperature and the following intensive rainfall, and expanded by moraines along channels and then blocked Parlung Zangbo. At the outlet of watershed,the density, velocity and peak discharge of debris flow was 2.06 t/m3, 12.7 m/s and 3334 m3/s, respectively. When the discharge at the outlet and the deposition volume into river exceeds 2125 m3/s and 126×103 m3, respectively, debris flow will completely blocked Parlung Zangbo. Moreover,if the shear stress of river flow on the foot of terrace and the inclination angel of terrace overruns 0. 377 N/m2 and 26°, respectively, the unconsolidated terrace will be eroded by outburst flow and collapse. It was strongly recommended for mitigation that identify and evade disastrous debris flows, reduce the junction angel of channels between river and watershed, build protecting wall for highway base and keep appropriate distance between highway and the edge of unconsolidated terrace.     

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Damming of large river by debris flow: Dynamic process and particle composition

The frequency and extent of debris flows have increased tremendously due to the extreme weather and the Wenchuan earthquake on May 12, 2008. Previous studies focused on the debris flow from gullies damming the mountain streams. In this paper, an equation for the run-out distance of debris flow in the main river is proposed based on the dynamic equation of debris flow at different slopes given by Takahashi. By undertaking field investigations and flume experiments, a new calculation method of the volume of debris flow damming large river is obtained. Using the percolation theory and the renormalization group theory it was deduced that the large particles should comprise more than 50% for forming a stable debris flow dam. Hence, the criteria of damming large river by debris flow is presented in terms of run-out distance and grain composition which was then validated through the event of damming river by debris flow at Gaojia gully, the upper reaches of the Minjiang River, Sichuan, China, on July 3, 2011.