山东省矿产资源开发利用现状与保护对策探讨     

郑福华  吕昶  柴永昌 《山东国土资源》1999,(2)

山东是矿业大省,矿产资源的开发程度较高,但也存在着不容忽视的问题。针对产生这些问题的原因,提出了实现矿产资源可持续开发利用的六项建议,强调应从增强矿产资源的忧患意识、保护生态环境、加强矿产勘查、强化政府管理职能及依靠科技进步等方面加大工作力度。  相似文献   

冰雹天气过程的综合分析   总被引：6，自引：2，他引：4  

宋晓辉  柴东红  蔡守新  张功文  王海峰 《气象科技》2007,35(3):330-334

选取发生在邯郸辖区内的5次冰雹天气过程,应用常规观测资料并结合雷达回波资料,从天气形势、物理量场和雷达回波演变特征等几方面进行了综合分析。结果表明:冰雹天气出现在对流性不稳定层结条件下,中高层干冷低层暖湿,地面有中尺度辐合切变线配合,0℃层、-20℃层和强垂直风切变的高度适宜。多普勒雷达能很好地监测中尺度天气系统的发展演变过程,回波强度和回波顶高度的变化、速度对和逆风区的出现、1 h降水累积值和垂直积分液态水含量的急剧增加等都对冰雹的出现具有指示意义。  相似文献   

Multi-level temporal autoregressive modelling of daily activity satisfaction using GPS-integrated activity diary data     

Guanpeng Dong  Mei-Po Kwan  Yiming Wang  Yanwei Chai 《International journal of geographical information science》2018,32(11):2189-2208

In this research, we match web-based activity diary data with daily mobility information recorded by GPS trackers for a sample of 709 residents in a 7-day survey in Beijing in 2012 to investigate activity satisfaction. Given the complications arising from the irregular time intervals of GPS-integrated diary data and the associated complex dependency structure, a direct application of standard (spatial) panel data econometric approaches is inappropriate. This study develops a multi-level temporal autoregressive modelling approach to analyse such data, which conceptualises time as continuous and examines sequential correlations via a time or space-time weights matrix. Moreover, we manage to simultaneously model individual heterogeneity through the inclusion of individual random effects, which can be treated flexibly either as independent or dependent. Bayesian Markov chain Monte Carlo (MCMC) algorithms are developed for model implementation. Positive sequential correlations and individual heterogeneity effects are both found to be statistically significant. Geographical contextual characteristics of sites where activities take place are significantly associated with daily activity satisfaction, controlling for a range of situational characteristics and individual socio-demographic attributes. Apart from the conceivable urban planning and development implications of our study, we demonstrate a novel statistical methodology for analysing semantic GPS trajectory data in general.  相似文献   

Proof of homothally of Pheopolykrikos hartmannii and details of cyst germination process     

Chai  Zhaoyang  Hu  Zhangxi  Liu  Yuyang  Tang  Yingzhong 《中国海洋湖沼学报》2020,38(1):114-123

Resting cysts play crucial roles in the ecology of dino?agellates, especially in wintering or surviving unfavorable conditions, seeding harmful algal blooms(HABs), and facilitating the geographic expansion. Encystment of dino?agellates is tightly coupled with sexual reproduction in most cases, which can occur either through homothallism(self-fertilization) or heterothallism(intercrossing of +/-strains). The types of sexual reproduction have important ecological implications. The toxic and HAB-forming dino?agellate, Pheopolykrikoides hartmannii has been previously reported to be heterothallic. Here, we provide visual con?rmation of homothally of P. hartmannii and the ?rst detailed visual recording of cyst germination based on the observations of a clonal isolate from Jiaozhou Bay, China. To document the homothallism, we ?rst observed cell pairs in sexual mating, planozygotes with two longitudinal ?agella, and cysts with typical morphology as described previously from the clonal culture. We then germinated a single cyst, established a new clonal culture from one of the two daughter cells after the ?rst cell division of the germling(i.e. from the diploid germling to two haploid cells), and produced cysts again from the newly established clonal culture. For the observation of the germination time-series, we took micrographs and videos to show all germination processes, particularly with an interesting observation of the short amoeboid stage of the germling releasing from the archeopyle(～15 s), which was a landmark of the germination process and has not been reported elsewhere. This de?nitive evidence of homothallic sexuality and cyst production in P. hartmannii provides a new insight into the biology and ecology of the species, particularly a mechanism that may partly account for the population dynamics and ubiquitous distribution of the species.  相似文献   

新疆阿尔泰南缘阿巴宫铁矿区康布铁堡组变质火山岩年龄及地质意义   总被引：15，自引：1，他引：14  

柴凤梅 《地质学报》2008,82(11):1592-1601

阿尔泰南缘古生代康布铁堡组火山岩系是许多铁矿、铜锌矿以及铅锌矿的赋矿围岩。但赋矿地层目前还缺乏精确的同位素年代学资料。本研究应用SHRIMP锆石U-Pb定年法,获得阿尔泰南缘克朗盆地内阿巴宫铁矿区康布铁堡组地层中变质流纹岩的形成年龄为412±3.5Ma（MSWD=1.4）,证明了阿尔泰南缘克朗盆地内泥盆纪早期存在着强烈的火山活动,与区内广泛发育的火山岩属于同一事件的产物,可能与同时代的花岗岩有相同的动力学背景。本项结果为研究阿尔泰南缘古生代构造演化及阿巴宫铁矿床成因提供了重要的依据。  相似文献   

西宁城市居民家内外活动时间分配及影响因素——基于结构方程模型的分析     

张雪  柴彦威 《地域研究与开发》2017,36(5)

为深入挖掘居民不同类型活动的出行需求,进而制定更加精细化的交通政策,从活动分析法的视角出发,基于结构方程模型分析西宁城市居民家内外活动时间分配的机理及影响因素。结果表明:工作日,居民的通勤出行仍然是城市交通需要重点解决的问题。休息日,工作和通勤时间长的居民更倾向于在家内进行维持活动;而休息日不工作的居民更容易产生进行家外维持活动的出行需求。不同社会经济属性的居民对于家内外时间分配具有差异化特征。单位大院职住接近的特征对于减少居民通勤出行时间仍然具有积极作用,但维持性活动时间分配与其他类型社区居民已经没有显著差异。  相似文献   

太平洋几种海面要素的升降趋势及其对海平面上升的影响     

马继瑞  田素珍  张冬生  柴新敏 《热带海洋学报》1995,(4)

对ＣＯＡＤＳ资料中１９５０－１９９２年太平洋４°×８°方区的海水表层温度及海面气温、气压、风速序列数据，进行了时间序列分析。分析结果表明：太平洋海表气温和水温年上升率分别为０．００６３℃·ａ（－１）和０．００２６℃·ａ（－１）。两者的变化趋势在赤道太平洋都有一个年上升率高值区；而在东海以北的西北太平洋广大海区，都有一个年下降率的低值区。西太平洋海面气压呈上升趋势，东太平洋则相反。气温和水温的升降区域分布特征与风速分量增强和减弱的变化趋势有关。文章还指出，中国和日本沿岸今后几十年海平面变化趋势的预测模式，应以太平洋或全球海平面上升趋势的预测为基础，加上本海区海平面的局地变化订正。  相似文献   

The buckling of GRP hemi-ellipsoidal dome shells under external hydrostatic pressure     

C. T. F. Ross  Bak Hock Huat  Tay Boon Chei  Chai Min Chong  M. D. A. Mackney 《Ocean Engineering》2003,30(5):691-705

The paper reports on a theoretical and an experimental investigation into six GRP hemi-ellipsoidal dome shells, which were tested to destruction under external hydrostatic pressure. All six domes were of oblate shape and of three different aspect ratios. Each aspect ratio consisted of two dome shells, one made from two layers of glass fibre and one made from three layers of glass fibre. The theoretical analysis was via the finite element method where a non-linear theory was used which allowed for both geometrical and material non-linearity. Comparison between theory and experiment was good.  相似文献   

Size-fractionated phytoplankton standing stock and primary production in the Bohai Sea during late spring     

Ning Xiuren  Cai Yuming  Liu Zilin  Chai Fei 《海洋学报(英文版)》2002,21(3):423-435

During June 1997 cruise by R/V Science No.l, observations on temporal and spatialvariations of the size-fractionated phytoplankton standing stock and primary production were carried out in the Bohai Sea. The size-fractionated chlorophyll a (Chl a) and primary production, photosynthet-ically available radiation (PAR), as well as the related physico-oceanographic and zooplanktonic parameters were measured at five time-series observation stations representing sub-areas of the sea. Results obtained show that there were the marked features of spatial zonation of Chl a and primary production in the Bohai Sea. The values in the Laizhou Bay, the Liaodong Gulf and the Bohai Gulf were high and showed close relation with tidal fluctuations, i.e. high Chl a concentration occurred during high tide in the Laizhou Bay, and during low tide in the Liaodong Gulf and the Bohai Gulf. In the strait and the central region of the Bohai Sea, the values were relatively low and no relationship with tidal fluctuation could be foun  相似文献   

海洋沉积物可溶铁样品保存条件的试验研究     

王维法  陈荣星 《海洋地质与第四纪地质》1995,15(2):105-112

沉积物可溶性Ｆｅ＾３＋、Ｆｅ＾２＋含量变化，是反映氧化还原环境的重要指标之一，海洋沉积物Ｆｅ＾３＋／Ｆｅ＾２＋比值已被应用于海洋地质及油气化探上。可溶性亚铁很容易被氧化，为此我们进行了海洋沉积物可溶铁样保存条件的试验研究。试验结果表明，在１０℃以下温度条件保存的海洋沉积物样品其可溶铁Ｆｅ＾３＋／Ｆｅ＾２＋比值在９０天内变化甚微。  相似文献