Case Study on the γ-algorithm:Possible Tests from the Luminosity versus Displacement Correlation of High Mass X-Ray Binaries

Using the apparent correlation of luminosity(Lx)versus displacement(R)of high mass X-ray binaries(HMXBs),we aim to constrain the common envelope(CE)mechanism,wh...     

Shaking table test on the seismic failure characteristics of a subway station structure on liquefiable ground

In order to investigate the seismic failure characteristics of a structure on the liquefiable ground, a series of shaking table tests were conducted based on a plaster model of a three‐story and three‐span subway station. The dynamic responses of the structure and ground soil under main shock and aftershock ground motions were studied. The sand boils and waterspouts phenomena, ground surface cracks, and earthquake‐induced ground surface settlements were observed in the testing. For the structure, the upward movement, local damage and member cracking were obtained. Under the main shock, there appeared longer liquefaction duration for the ground soil while the pore pressure dissipated slowly. The acceleration amplification effect of the liquefied soil was weakened, and the soil showed a remarkable shock absorption and concentration effect with low frequency component of ground motion. However, under the aftershock, the dissipation of pore pressure in the ground soil became obvious. The peak acceleration of the structure reduced with the buried depth. Dynamic soil pressure on the side wall was smaller in the middle and larger at both ends. The interior column of the model structure was the weakest member. The peak strain and damage degree for both sides of the interior column exhibited an ‘S’ type distribution along the height. Moreover, the seismic response of both ground soil and subway station structure exhibited a remarkable spatial effect. The seismic damage development process and failure mechanism of the structure illustrated in this study can provide references for the engineers and researcher. Copyright © 2013 John Wiley & Sons, Ltd.     

1979-2012年北极海冰运动学特征初步分析

利用美国冰雪数据中心(NSIDC)发布的海冰速度和范围数据,本文分析了1979—2012年间北极海冰的运动学特征,以及北极海冰运动与分布范围演变之间的关系。结合欧洲中期天气预报中心(ECMWF)发布的2007和2012年高分辨率的气压场、风场数据,探讨了北极风场和气压场与海冰运动、辐散辐合和海冰面积的关系。结果表明,在1979-2012年间北极海冰平均运动速度呈显著增强的趋势,冬季海冰平均运动速度增加趋势明显强于夏季;北极、波弗特-楚科奇海域和弗拉姆海峡的冬、夏季海冰平均运动速度的增加率分别为2.1%/a和1.7%/a、2.0%/a和1.6%/a以及4.9%/a和2.2%/a。1979-2012年北极海冰平均运动速度和范围的相关性为-0.77,二者存在显著的负相关关系。北极冬季和夏季风场的长期变化趋势与海冰平均运动速度的变化趋势一致,冬季和夏季的相关系数分别为0.50和0.48。风场和气压场对海冰的运动、辐散及重新分布发挥着重要作用。2007年夏季,第234~273天波弗特海域一直被高压系统控制,波弗特涡旋加强,使得波弗特海域海冰聚集在北极中央区;顺时针的风场促使海冰向格陵兰岛和加拿大北极群岛以北聚合。2012年,白令海峡和楚科奇海域处于低压和高压系统的交界处,盛行偏北风,海冰从北极东部往西部输运,加拿大海盆的多年海冰因离岸运动而辐散,向楚科奇海域的海冰输运增加,受太平洋入流暖水影响,移入此区域的海冰加速融化,从而加剧海冰的减少。     

Design of measuring instrument with whole direct method for bed shear stress under two-dimensional water-flow co-action

The present study aims at the design and making of measuring instrument of whole direct method for bed shear stress under two-dimensional water-flow co-action. The instrument combines the traditional strain gauge with a precise pressure gauge, and adopts the method directly measuring the difference between the lateral hydrodynamic pressure and different head pressures on both sides of the force plate. As a result, such an instrument solves a technical puzzle of the past strain gauge, i.e. the difficulty to set apart shear stress and lateral force. Static force test and sink test both prove that the instrument is precise, stable and applicable to the measurement of rough beds with different shear stresses.     

依兰盆地达连河油页岩成矿控制因素研究

达连河油页岩含矿区位于黑龙江省依兰地区,该区是一个半地堑式断陷盆地。油页岩形成受到多重因素制约,构造上在靠近断裂F₂的煤和油页岩厚度较厚,随着湖盆沉积范围的扩大,表现了一种从湖平面逐渐向岸上上超的过程;高水位体系域浅湖-半深湖相和水进体系域湖泊-沼泽相形成不同成因类型油页岩;孢粉分析结果可知油页岩形成的气候总体呈现出气候温和、 温度下降的发展趋势;而气候的波动影响了古生物的发育,降低了有机质生产能力,进而造成油页岩含油率低。     

Soil microbial community response to seawater intrusion into coastal aquifer of Donghai Island,South China

Due to the sea level rise and the excessive exploitation of freshwater, seawater intrusion is becoming a critical issue. To clarify the degree of seawater intrusion in Donghai Island and the microbial community structure and functional response to seawater intrusion, groundwater samples and sediment samples were collected at profiles A, B; the profiles were along the direction of groundwater flow, perpendicular to the coastline, a hydrogeochemical survey and soil microbial community analysis were also performed. The hydrogeochemistry analysis showed that the chemical type of groundwater was Na–Cl, brackish water was dominant in the area, and coastal groundwater was strongly affected by seawater intrusion. The effect of seawater intrusion on structural and functional diversity of soil microbes was analyzed from soil samples of the study area, by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). The results of DGGE patterns and phylogenetic tree show that the extent of seawater intrusion has directly influenced soil microbial community structure. The changes of microbial community structure might be related to the major elements’ concentrations in groundwater. Phylogenetic affiliation indicated that γ-proteobacteria were dominated in the profile A, while β-proteobacteria were mainly appeared in the profile B. The Flavobacteriaceae was only appeared at the shrimp ponds nearby.     

黄河口邻近海域浮游幼虫群落结构季节变化

基于2019-2020年4个季节的6个航次海上生态调查,研究黄河口邻近海域的浮游幼虫群落结构及其与环境因子的关系,旨在为海域生物多样性保护与重要生物资源养护提供科学基础.结果显示:在黄河口邻近海域,共鉴定出浮游幼虫16类,阶段性浮游幼虫是主要组成类群.浮游幼虫月均丰度以11月最高、1月最低.浮游幼虫香农-威纳多样性指数...     

City size distribution and its spatiotemporal evolution in China

Based on the National Land Use/Cover Database of China(NLUD-C) in the end of the 1980s(the 1980s,hereafter), 1995, 2000, 2005, and 2010, 665 cities were selected to study the size distribution and its changes of urban lands in China. In this study, the spatiotemporal evolutions of urban land size distribution as well as the influence of administrative-level on these cities were explored by combining urban spatial positions and administrative-levels. Results indicate that: 1) City size distribution using urban lands was more practical and reasonable than using non-agricultural population. 2) In the 1980s, cities with ascending urban land rank were centralized in Eastern China, specially the Changjiang(Yangtze) River Delta, the Zhujiang(Pearl) River Delta, and Beijing-Tianjin-Hebei region. Cities in Central, Western, and Northeast China mainly indicated descending urban land rank. 3) The transfer of national development focus resulted in cities with ascending urban land rank becoming evenly distributed nationwide; however, this trend was slightly centralized around Chengdu, Chongqing, and Wuhan in different periods. 4) During the 1980s to 2010, the proportion of cities with ascending urban land rank in provincial capitals, municipalities, and special administrative regions(high-level cities, hereafter) was consistently higher than those in prefecture- and county-level cities except for 2005–2010. The ranks of the majority of the prefecture- and county-level cities were mainly descending, supported by ascending; the proportion of cities with unchanged rank is small. This study breaks through the bottleneck of traditional research in the area of city size distribution by examining urban land replacing the non-agricultural population. The current study also provides scientific explanation for the healthy and reasonable development of urban land as well as the coordinated development of population urbanization and land urbanization.     

闽江下游黄岐屿遗址的光释光测年

为了更好地理解闽江下游的连江县黄岐屿遗址的环境背景和考古年代,在已有AMS¹⁴C年代学研究的基础上,选择黄岐屿遗址的T2剖面进行年代学样品采样,在室内运用中颗粒石英的单片再生剂量法进行光释光年代学研究。结果表明：黄岐屿遗址地层的OSL埋藏年龄范围为8.5±0.5－4.4±0.2 ka,属于早－中全新世阶段的沉积/文化地层。其中2019118样品的年龄为4.4±0.2 ka,属于昙石山文化,与AMS¹⁴C年龄相当;2019117样品年龄为5.7±0.3 ka,可能存在年龄的高估;2019119样品的年龄为8.5±0.5 ka,受采样环境的影响,该地层的OSL埋藏年龄可能指示遗址底界的最大年龄。对比黄岐屿遗址所在的福州盆地地貌和环境演化过程以及区域史前人类活动发现,该遗址对应6 500－4 000 a B P的大暖期气候和相对高海面时期,该时期福州盆地发育了众多的同时期的史前遗存,区域内产生了繁荣的昙石山文化和昙石山下层文化。新石器时代末期4.2－4.0 ka气候突变的冷事件、4 000－3 000 a B P太平洋两岸热带－亚热带地区的气候环境的急剧变化以及北方吴越文化的侵入可能是造成该遗址缺失后续文化遗存的原因。     

情理整合视角下旅游者环境责任行为与 意愿悖离研究——基于Logistic-ISM模型

基于对岳麓山景区447位旅游者的实地调研,运用拓展的计划行为理论并结合Logistic回归模型,分析影响两者发生悖离的因素,并进一步利用ISM解释结构模型分析各因素之间的逻辑关系.从Logistic回归结果看,旅游者的行为态度、感知行为控制等相关理性认知越好,发生悖离的可能性越低;旅游者积极环境情感和消极环境情感对悖离...