基于加权水平精度因子的伪卫星基站选择方法

提出一种以加权水平精度因子为依据的基站选择方法,该方法根据基站和用户的相对位置给予每个基站不同的权值,降低测量误差较大的基站被选中参与定位的可能性。通过对伪距测量误差数学模型的分析,推导伪卫星定位系统加权矩阵,并设计了基于基站对WHDOP贡献的基站选择方法。仿真结果表明,该方法能更加高效、准确地实现伪卫星基站的选择,降低接收机的计算量,提高系统的定位精度。     

Distribution Patterns of Major and Trace Elements and Provenance of Surface Sediments on the Continental Shelf off Western Guangdong Province and Northeastern Hainan Island

A coupled approach based on grain size and geochemical elements is used to trace the provenance of surface sediments and to confirm the distribution patterns of grain size and elements on the continental shelf off western Guangdong Province and northeastern Hainan Island. The mean grain size ranges from 0.05 φ to 7.28 φ with a mean value of 5.60 φ. The average concentrations of major elements descend in the order of SiO_2Al_2O_3CaOFe_2O_3K_2OMgONa_2OTiO_2 P_2O_5 MnO, while those of trace elements exhibit a descending order of Sr Rb Zn V Cr Pb Ni Cu As Cd. On the basis of the distribution patterns of elements and results of statistical analysis, the study area is classified into three zones. Zone I locates on the continental shelf off western Guangdong Province, and the sediments are mainly from Pearl River, Taiwanese rivers, and small rivers nearby. Zone II locates in the eastern exit of Qiongzhou Strait and the coastal area off Leizhou Peninsula, and the sediments are mainly from the erosion products of Qiongzhou Strait and Hainan Island. Zone III locates off the eastern Hainan Island and the continental shelf deeper than-50 m isobaths, and the sediments are mainly from Hainan Island and coral reef. The influence from open water should also be considered. Results indicate that the grain size is the main controlling factor for major and trace element contents and that anthropogenic impact and biological activity also play an important role in the distribution of these elements.     

Formation of an anticyclonic eddy and the mechanism involved: a case study using cruise data from the northern South China Sea

Data from satellite altimetry and in situ observations together with the Hybrid Coordinate Ocean Model(HYCOM)reanalysis data were used to investigate the mechanism and formation of an anticyclonic eddy in the northeastern South China Sea(SCS).Analysis of water mass using cruise data indicated that the water captured in the eddy differs from those in the SCS,the Kuroshio intrusion,and the eddy-forming region.Data from sea surface height(SSH)and sea level anomaly(SLA)indicate that the eddy formed due both to the Kuroshio intrusion and the local circulation in the SCS.The Kuroshio intrusion is present at the start of the eddy growth(March 5-9)before Kuroshio leaps the Luzon Strait.The eddy then becomes larger and stronger in the absence of the Kuroshio intrusion.From the eddy budget of the HYCOM reanalysis data,the formation of the eddy goes in three steps.By the third step,the eddy had become affected by variations of local SCS circulation,which is more strongly than in the first step in which it is affected more by the Kuroshio intrusion.The variability of the temperature and salinity inside the eddy provide a support to this conclusion.The water in the SCS intruded into the eddy from the southeast,which decrease the salinity gradually in the southern part of the eddy during the growth period.     

The Light Regime Effect on Triacylglycerol Accumulation of Isochrysis zhangjiangensis

Stress state of microalgal cells is caused under unfavorable conditions such as disordered light regime and depleted nitrogen. The stress state can impair photosynthetic efficiency, inhibit cell growth and result in the accumulation of triacylglycerol(TAG) from protective mechanisms. Continuous light or nitrogen starvation was applied on microalgae and performed effectively on inducing TAG production. To evaluate the light regime effect on inducing TAG production, the effect of different light regimes on nitrogen-starved Isochrysis zhangjiangensis was investigated in this work. The continuous light and nitrogen starvation elevated TAG content of biomass by 73% and 193%, respectively. Furthermore, the TAG accumulation of I. zhangjiangensis cell under nitrogen starvation decreased under aggravated stress from continuous illumination. Our results demonstrated that culturing the cells with 14 L: 10 D light regime under nitrogen starvation is the optimal mode to achieve maximal accumulation of TAG. A recovery in light regime was necessary for I. zhangjiangensis cultivation.     

遥感技术在泰山区域矿山环境治理修复工程的监测应用

区域矿山环境治理修复是国土空间修复的主要形式和内容,是生态文明建设的重要组成部分。遥感技术是获取生态修复治理信息和效果的主要途径之一。该文以泰山区域矿山环境治理修复工程为研究区域,提出一种利用遥感技术方法为主,结合往年资料提取矿山地质环境变化信息,对修复过程进行监测,对修复效果进行分析的方法。     

κ-卡拉胶对马氏珠母贝肌肉水溶性蛋白稳定性的影响

【目的】探究Kappa-卡拉胶对马氏珠母贝肌肉水溶性蛋白稳定性的影响,为进一步开发利用马氏珠母贝肉以及改善水产肌肉蛋白加工特性提供数据参考。【方法】以马氏珠母贝肌肉水溶性蛋白(WSP)为研究对象,采用浊度法、聚丙烯酰胺凝胶电泳(SDS-PAGE)分析不同pH值条件下,热处理前后kappa-卡拉胶对WSP稳定性的影响,同时利用凝胶过滤层析对WSP进行了初步的分离及分子质量分布分析。【结果】热处理前后,在酸性条件下(pH<4.0)添加了kappa-卡拉胶的胶体蛋白混合体系(K-WSP)透光率均下降;热处理前,pH4.0～5.0范围内,与WSP对照,K-WSP混合体系透光率上升,而pH> 5.0条件下,kappa-卡拉胶对WSP体系透光率无显著性影响;热处理后,pH 4.0～7.5范围内,与WSP对照,K-WSP混合体系透光率上升,而pH>8.0条件下,kappa-卡拉胶对WSP体系透光率无显著性影响。SDS-PAGE结果显示:热处理前,酸性pH条件下与未添加WSP相比较,K-WSP在35 ku附近条带较多。热处理后,WSP和K-WSP的大分子蛋白组分(200、116 ku)均基本发生了热变性。WSP分离纯化曲线显示出两个组分,分子质量分别分布于200～35 ku和35～14.4 ku。【结论】pH值4.0～5.0条件下,kappa-卡拉胶对WSP的热稳定性有一定促进作用。     

海峡西岸经济区城市网络特征分析——基于功能网络与创新网络的视角

全球化和信息化促进了城市网络的复杂化,城际关系不断重构,且往往需要通过多方面要素才能较完整地表现出来,但以往城市网络特征的研究往往聚焦于单一视角下的城市网络结构分析,且较少考虑联系的方向,对其复杂性的揭示上存在一定不足。以城际人员流动数据与共同专利数据为基础,从功能网络与创新网络的视角,利用社会网络分析等方法,研究了海峡西岸经济区的城市网络特征,结果表明：① 区域多级发展的网络格局已经形成,省会城市与副省级城市（福州、厦门）构成了中心性第一梯队,重要地级市（泉州、温州、赣州）构成了中心性第二梯队,一般节点城市（漳州、汕头等）构成了中心性第三梯队。② 强中心性城市中,厦门、福州及温州存在对其他城市较显著的溢出效应,区域中小城市成了辐射的主要受益者。③ 城市在两类网络中的地位整体一致,局部如赣州、龙岩一致性较差。④ 城际创新合作关系整体上较薄弱且较不均衡,而区域功能网络表现为“整体均衡,局部不均衡”态势。     

城市特性与政府网站营销内容的关联性——基于中国28个世界城市的分析

随着全球化的发展和网络社会的崛起,越来越多的城市政府通过政府网站吸引人才、资本、技术等资源的流入,实现经济的快速增长,城市政府网站如何选择营销内容成为城市营销学者关注的热点。研究发现,不同城市的网站营销内容存在显著差异。进一步对造成城市网站营销内容差异背后的机制进行研究,发现城市特性可能与政府网站营销内容的选择存在关联性。城市特性包括经济、政治、社会、文化等多个维度,然而已有研究大多忽视了不同类型的城市特性与城市政府网站营销内容关联性的强弱差异。因此,论文以中国大陆28个世界城市作为研究对象,采用聚类分析、因子分析、多重比较检验等方法,识别中国世界城市政府网站营销内容的主要类型,探究与政府网站营销内容关联性显著的城市特性。研究发现：①就营销内容而言,中国世界城市政府网站可分为政治文化型、政务信息型、生活服务型、景观形象型4种类型;②中国世界城市的网站营销内容与城市自身的经济全球化水平、第三产业化水平、失业人口与政治地位、经济增长速度的关联性较强;③生活质量和旅游业、经济总量和财政预算、客运量和人均年收入、人口增长和土地面积等特性与网站营销内容的关联性不显著,说明并非所有城市特性均与城市政府网站的营销内容存在显著联系,不同类型的城市特性与营销内容的关联性存在差异。     

大菱鲆卵子排放后在卵巢腔内老化特征初探

为了探明大菱鲆(Scophthalmus maximus)卵子在卵巢腔内老化的原因及特征,采用连续跟踪采卵的方式,通过荧光染色、生理生化指标测定,对不同采卵时间(0, 3, 6, 9, 12 h)的卵子活性氧和脂质过氧化情况(氧化产物丙二醛MDA)、抗氧化系统(超氧化物歧化酶SOD,还原型谷胱甘肽GSH)、卵巢液pH值及受精率和孵化率进行对比研究。结果表明,随着卵子在体内老化时间的延长,其活性氧含量及脂质过氧化程度逐渐升高,活性氧含量及过氧化程度与排卵后卵子老化呈正相关;SOD酶活力,GSH酶活力均显著下降,MDA含量显著提高;受精率和孵化率均显著下降。排卵后6h,孵化率降到2.87%～10.60%,此时的卵质已经极度恶化,不能再继续用于后续的生产中。综上,在卵巢腔中,卵子排放后,随着时间的延长,活性氧含量显著升高,抗氧化能力逐渐下降,受精率和孵化率显著降低,老化逐渐加剧。