Seasonal Variations in the Sea off Sanriku Coast, Japan

The temperature and salinity data obtained by the Iwate Fisheries Technology Center for the 25-year period from 1971 to 1995 were analyzed to clarify the seasonal variations in the sea off Sanriku, Japan. The variations of three typical waters found in this region, the Tsugaru Current water, the Oyashio water, and the Kuroshio water are discussed in terms, of a T-S scatter diagram referring to the water mass classification proposed by Hanawa and Mitsudera (1986). The mean temperature and salinity fields averaged for each month show clear seasonal variation. Distributions of the Tsugaru Current water and the Oyashio water can barely be distinguished in the fields deeper than 200 m since the Tsugaru Current has a shallow structure; however, the fields at 100 m depth indicate remarkable seasonal variation in the area of the Tsugaru Current. At 100 m depth, the temperature and salinity fronts between the Tsugaru Current water and the Oyashio water gradually disappear in January through April, appear again in May, then become clearest in September. This revised version was published online in July 2006 with corrections to the Cover Date.     

用塑料薄膜袋进行一级藻种培养的研究

本文主要介绍用塑料薄膜袋代替1—2×1O~4mL细口瓶来进行饵料一级藻种培养,此法保证了扇贝育苗所需大量饵料的优质藻种,简单易行。 Ⅰ.材料与方法 Ⅰ.1.制袋的材料和方法 采用直径30cm,长度120cm的聚乙烯透明     

第一届全国地层会议与全国地层委员会的成立

六十年前召开的第一届全国地层会议对我国的地层学、古生物学发展起了非常大的推动作用,带来了我国地层古生物学科发展的第一个黄金时期,为改革开放之后我国地层古生物学的辉煌发展打下了坚实的基础。这次会议上成立的全国地层委员会作为全国地层工作的组织、协调单位至今仍然在发挥着重要而且积极的作用。     

Navigating the tensions in collaborative watershed governance: Water governance and Indigenous communities in British Columbia,Canada

First Nations in British Columbia (BC), Canada, have historically been—and largely continue to be—excluded from colonial governments’ decision-making and management frameworks for fresh water. However, in light of recent legal and legislative changes, and also changes in water governance and policy, there is growing emphasis in scholarship and among legal, policy and advocacy communities on shifting water governance away from a centralized single authority towards an approach that is watershed-based, collaborative, and involves First Nations as central to decision-making processes. Drawing on community-based research, interviews with First Nations natural resource staff and community members, and document review, the paper analyzes the tensions in collaborative water governance, by identifying First Nations’ concerns within the current water governance system and exploring how a move towards collaborative watershed governance may serve to either address, or further entrench, these concerns. This paper concludes with recommendations for collaborative water governance frameworks which are specifically focused on British Columbia, but which have relevance to broader debates over Indigenous water governance.     

Acoustic radiation from shear deformable ring-stiffened laminated composite cylindrical shell submerged in flowing fluid

Acoustic radiation from a point driven, infinite, periodically ring-stiffened, laminated composite cylindrical shell submerged in flowing fluid is investigated theoretically. Both the effects of in-plane and out-of-plane vibrations of the ring-stiffeners and the effects of fluid convection on far field acoustic radiation behaviors are concerned. The equations of motion of the laminated composite cylindrical shell is presented on the basis of the first order shear deformation theory. Fourier transform and Poisson summation formula are used to transform the equations into a set of infinite algebraic equations expressed in the wavenumber domain. After truncation, the response of the laminated composite cylindrical shell is solved, and the stationary phase approximate is employed to find the expression for the far field sound pressure. Convergence analysis of the numerical solutions is conducted. The theoretical model and numerical method proposed in this paper are validated by comparison with those presented in available literature. Finally, numerical results are presented to demonstrate the effects of various parameters such as the size and spacing of the ring-stiffener, the thickness and the radius of the cylindrical shell, the lamination angle and the lamination scheme of the composite materials as well as the Mach number on the far field sound pressure.     

异步时序设计亚稳态的消除方法

提出一种基于异步比较法产生空满标志位，并利用锁存器实现标志位与时钟同步的FIFO，同时还给出了相应的Verilog HDL代码。该方法能提高时钟频率,节约版图面积。     

一个FUZZY聚类分析的快速算法

Fuzzy聚类分析,是近年来在气象预报等很多科学领域中广泛应用的一种客观分析技术。本文根图的可迁闭包性质,探讨从模糊相似矩阵R中节点的可达性问题着手,生成相应的深度优先生成树(DFT)来完成聚类,从而得到一个时间复杂性为O(n~2)的快速Fuzzy聚类算法。     

Tree-ring dates on two pre-Little Ice Age advances in Glacier Bay National Park and Preserve, Alaska, USA

Two interstadial tree ring-width chronologies from Geikie Inlet, Glacier Bay Southeast, Alaska were built from 40 logs. One of these chronologies has been calendar dated to AD 224–999 (775 yr) crossdating with a living ring-width chronology from Prince William Sound, Alaska. Trees in this chronology were likely killed through inundation by sediments and meltwater from the advancing Geikie Glacier and its tributaries ca. AD 850. The earlier tree-ring chronology spans 545 yr and is a floating ring-width series tied to radiocarbon ages of about 3000 cal yr BP. This tree-ring work indicates two intervals of glacial expansion by the Geikie Glacier system toward the main trunk glacier in Glacier Bay between 3400 and 3000 cal yr BP and again about AD 850. The timing of both expansions is consistent with patterns of ice advance at tidewater glaciers in other parts of Alaska and British Columbia about the same time, and with a relative sea-level history from just outside Glacier Bay in Icy Strait. This emerging tree-ring dated history builds on previous radiocarbon-based glacial histories and is the first study to use tree-ring dating to assign calendar dates to glacial activity for Glacier Bay.