《地理学报》80年载文分析

本文回顾并且评述了过去80年《地理学报》的载文历史,发现它刻画了中国地理学经历了4个发展阶段,即：1934-1948年的艰难探索的近现代地理学的形成阶段,1949-1966年的地理学发展中的科学化和应用化兴起阶段,1978-2000年的地理学繁荣的百花齐放阶段,2000年后的地理学自主创新突出的大发展阶段。《地理学报》当前的载文反映,中国地理学日益国际化,今后的发展是不仅需要融入世界地理学的发展,而且应该成为具有中国文化引导国际地理学发展的期刊。     

我国气象科技期刊发展与作用

在对历史资料研究的基础上,对气象科技期刊的发展历程与作用进行了回顾及评述,并对目前气象科技期刊的现状及存在的问题做了简要分析。     

单层工业厂房-TMD减震控制系统研究

提出了采用质量调谐减震控制技术对厂房结构进行减震控制的方法。利用屋盖系统作为附加质量,屋盖支座采用夹层橡胶隔震垫,建立了厂房-TMD系统模型,并用非线性时程分析法对其进行了多种地震动激励下的计算分析,探讨了厂房-TMD减震体系减震效果的参数影响及减震机理。结果表明,采用质量调谐减震技术对单层工业厂房进行减震是一种有效的方法。     

A study on the seismic behavior of a retrofitted building based on nonlinear static and dynamic analyses

This study describes the seismic performance of an existing five storey reinforced concrete building which represents the typical properties of low-rise non-ductile buildings in Turkey. The effectiveness of shear walls and the steel bracings in retrofitting the building was examined through nonlinear static and dynamic analyses. By using the nonlinear static analysis, retrofitted buildings seismic performances under lateral seismic load were compared with each other. Moreover, the performance points and response levels of the existing and retrofitting cases were determined by way of the capacity-spectrum method described in ATC-40 (1996). For the nonlinear dynamic analysis the records were selected torepresent wide ranges of duration and frequency content. Considering the change in the stiffness and the energy dissipation capacities, the performance of the existing and retrofitted buildings were evaluated in terms of story drifts and damage states. It was found that each earthquake record exhibited its own peculiarities, dictated by frequency content, duration, sequence of peaks and their amplitude. The seismic performance of retrofitted buildings resulted in lower displacements and higher energy dissipation capacity depending mainly on the properties of the ground motions and the retrofitting strategies. Moreover, severe structural damage (irreparable or collapse) was observed for the existing building. However, buildings with retrofit alternatives exhibited lower damage levels changing from no damage to irreparable damage states.     

Tectonic Evolution of the Middle Frontal Area of the Longmen Mountain Thrust Belt, Western Sichuan Basin, China

By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt,China,we concluded that it had experienced five tectonic stages:(1)the formation stage (T3x) of the miniature of Longmen Mountain, early Indosinian movement, and Anxian tectonic movement created the Longmen Mountain;(2)the stable tectonic stage(J1)where weaker tectonic movement resulted in the Longmen Mountain thrust belt being slightly uplifted and slightly subsiding the foreland basin;(3)the intense tectonic stage(J2-3),namely the early Yanshan movement;(4) continuous tectonic movement(K-E),namely the late Yaushan movement and early Himalayan movement;and(5)the formation of Longrnen Mountain(N-Q),namely the late Himalayan movement. During those tectonic deformation stages, the Anxian movement and Himalayan movement played important roles in the Longmen Mountain'S formation.The Himalayan movement affected Longmen Mountain the most;the strata thrust intensively and were eroded severely.There are some klippes in the middle part of the Longmen Mountain thrust belt because a few nappes were pushed southeastward in later tectonic deformation.     

A simplified methd of evaluating the seismic performance of buildings

This paper presents a simplified method of evaluating the seismic performance of buildings. The proposed method is based on the transformation of a multiple degree of freedom (MDOF) system to an equivalent single degree of freedom (SDOF) system using a simple and intuitive process. The proposed method is intended for evaluating the seismic performance of the buildings at the intermediate stages in design, while a rigorous method would be applied to the final design. The performance of the method is evaluated using a series of buildings which are assumed to be located in Victoria in western Canada, and designed based on the upcoming version of the National Building Code of Canada which is due to be published in 2005. To resist lateral loads, some of these buildings contain reinforced concrete moment resisting frames,while others contain reinforced concrete shear walls. Each building model has been subjected to a set of site-specific seismic spectrum compatible ground motion records, and the response has been determined using the proposed method and the general method for MDOF systems. The results from the study indicate that the proposed method can serve as a useful tool for evaluation of seismic performance of buildings, and carrying out performance based design.     

Horizon synthesis for archaeo‐astronomical purposes

In this paper I describe a simple numerical procedure to compute synthetic horizon altitude profiles for any given site. The method makes use of a simplified model of local Earth's curvature, and it is based on the availability of digital elevation models describing the topography of the area surrounding the site under study. Examples constructed using the Shuttle Radar Topographic Mission (SRTM) data (with 90 m horizontal resolution) are illustrated, and compared to direct theodolite measurements. The proposed method appears to be reliable and applicable in all cases when the distance to the local horizon is larger than ∼10 km, yielding a rms accuracy of ∼0.1 degrees (both in azimuth and elevation). Higher accuracies can be achieved with higher resolution digital elevation models, like those produced by many modern national geodetic surveys (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Phylogeography of the shrimp Palaemon floridanus (Crustacea: Caridea: Palaemonidae): a partial test of meta‐population genetic structure in the wider Caribbean

Marine organisms with a pelagic stage are often assumed to display minor population structure given their extended larval development and subsequent high long‐distance dispersal ability. Nonetheless, considerable population structure might still occur in species with high dispersal ability due to current oceanographic and/or historical processes. Specifically, for the wider Caribbean and Gulf of Mexico, theoretical and empirical considerations suggest that populations inhabiting each of the following areas should be genetically distinct: Panama, Belize, Southwest Florida (Tampa), and Southeast Florida (Fort Pierce). This study tests the hypothesis of significant genetic differentiation in Palaemon floridanus populations across the wider Caribbean and Gulf of Mexico. Population level comparisons were conducted using sequences of the mtDNA COI. In agreement with predictions, AMOVA and pairwise F_ST values demonstrated population differentiation among most pairs of the studied populations. Only Panama and East Florida populations were genetically similar. An isolation‐with‐migration population divergence model (implemented in IMA2) indicated that population divergence with incomplete lineage sorting can be invoked as the single mechanism explaining genetic dissimilarity between populations from the east and west coast of Florida. Historical demographic analyses indicated demographic expansion of P. floridanus in some localities [recent in Panama and ancient in East Florida and the wider Caribbean (entire dataset)] but constant population in other localities (in Belize and West Florida). This study rejects the idea of panmixia in marine species with high long‐distance dispersal ability. Contemporary and historical processes might interact in a complex manner to determine current phylogeographic patterns.     

Incorporating uncertainty into the estimation of biological reference points for a spiny lobster (Panulirus penicillatus) fishery

The status of a fishery is often defined as the probability of fishing mortality rate exceeding a perilous level for long‐term sustainability. Lobster stock assessments are often subject to large uncertainty in input data and high levels of natural variability in lobster life history processes, which calls for incorporating uncertainty associated with both indicator and management reference points in an evaluation of biological risk of overfishing. Using a Monte Carlo simulation approach, we evaluated the impacts of uncertainty in modelling on the determination of the status of the Taitung spiny lobster (Panulirus penicillatus) fishery (Taiwan), which has not been quantitatively determined despite its commercial importance. The commonly used biological reference points derived from the per recruit model (F _0.1 the fishing mortality rate where the slope of the curve of yield‐per‐recruit model is 10% of the maximum slope and F _4Q%, the fishing mortality rate that reduces the expected egg production for a cohort of female lobsters to 40% of that produced in the absence of a fishery of the egg‐per‐recruit model) were influenced by uncertainties associated with lobster life history and fishery parameters. A large uncertainty in the current fishing mortality rate (F _cnr) and estimates of biological reference points (F _BRPs) increased the uncertainty in determining the risk of overexploitation throughout the confidence levels of the stochastic decision‐making framework. This simulation study suggests that the target reference point of F _40% is less sensitive to the input parameters’ uncertainty than F _0.1 We suggest a further evaluation of other F‐based references points and development of biomass‐based reference points before final selection and implementation for the management of the Taitung lobster fishery.     

Comparison and history of Polydora websteri and P. haswelli (Polychaeta: Spionidae) as mud-blister worms in New Zealand shellfish

Shells of commercially valued bivalves in New Zealand, Crassostrea gigas, Perna canaliculus and Pecten novaezelandiae, are damaged by blister-causing Polydora polychaete species known to be close in morphology to the widely recorded oyster pest Polydora websteri Hartman. Recent New Zealand occurrences are here confirmed to relate to two species, P. websteri, and a second similar species, Polydora haswelli Blake & Kudenov, a new record for New Zealand, previously known only from Australia; the two species are described and compared. The worms have limited distributions, with P. websteri confirmed only for Pacific oysters (C. gigas) in northern New Zealand, although prior reports indicate it may also occur on scallops and have reached the northern South Island. Polydora haswelli has been found only in northern New Zealand, occurring on subtidal mussels and scallops and native oysters (Perna canaliculus, Pecten novaezelandiae, Ostrea chilensis), as well as co-existing with intertidal P. websteri on Pacific oysters. The worms are not present in Foveaux Strait O. chilensis beds, a major source of past oyster exports to Australia. The history of mud-blister worm outbreaks in Australasia is examined. While trans-Tasman exports of live oysters from New Zealand were commonplace during the nineteenth century, there is no evidence that mud-blister worms were present in New Zealand then. The earliest reports only date from the early 1970s and only from northern New Zealand, whereas a century earlier in the 1870s at least one of these pest worms had become widespread along eastern Australian coasts.