稀土元素Ce对雨生红球藻生长及虾青素积累影响的研究

采用反相高效液相色谱分析法（RP-HPLC）研究了稀土元素铈（Ce^3＋）对雨生红球藻（Haematococcus pluvialis）生长及虾青素积累的影响。结果表明,低质量浓度的Ce^3＋对微藻生长和虾青素积累均具有明显的促进作用,当Ce^3＋的质量浓度为0．1mgm时,对藻生长的促进效果最佳,细胞密度较对照组提高34％;当Ce^3＋的质量浓度为1mg/L时,虾青素质量分数可达到细胞干质量的3．2％,较对照组提高167％。此外,高质量浓度Ce^3＋的对雨生红球藻有抑制作用,当Ce^3＋的质量浓度高于40mgm时,红球藻的生长完全被抑制,虾青素质量分数也明显降低。     

Historic changes in flux of matter and nutrient budgets in the Bohai Sea

Over the past four periods （ 1959--1960, 1982--1983, 1992--1993, and 1998--1999）, the ecosystem of the Bohai Sea changed due to both a significant decrease of river water discharge from the Huanghe River and a reduction of precipitation. The shifts in nutrient chemistry could result in changes in the phytoplankton composition with an increased potential for non-diatom algal blooms. Simple box model was used to estimate the water - mass balance and nutrient budgets for the Bohai Sea. Water budgets indicate that the residual flow changed from out of the Bohai Sea before 1993, but became inflow to the Bohai Sea after then. The nutrient budgets developed indicate that the Bohai Sea was a sink for nutrients except for phosphate in 1959--1960 and 1982-- 1983 and for silicate in 1982--1983. Net water flow transports nutrients out of the Bohai Sea in 1959--1960, 1982--1983 and 1992--1993, but into the sea in 1998--1999 due to climate changes, such as precipitation and subsequent freshwater discharge. The residual fluxes of nutrients are minor relative to atmospheric deposition and riverine inputs. Conversions of phosphate values to carbon by stoichiometric ratios were used to predict that the system was net heterotrophic before 1982--1983 and net autotrophic after then. Nutrient budgets can explain the change of nutrient concentrations in the Bohai Sea except nitrates, which should include the surface runoff.     

中国南方含油气区构造-沉积类型及其勘探潜力

南方含油气的复杂构造区根据构造—沉积类型的不同,可将其分为四种类型。通过对不同类型典型含油气区的生烃量及非构造运动天然气散失量的化学动力学计算,认为这四种类型含油气区的油气聚集潜力从好到坏依次为:喜马拉雅运动抬升暴露型、燕山运动抬升暴露型、反复抬升—沉降型和海西—印支运动抬升暴露—后期浅埋型。主要构造运动发生越晚,对油气保存越有利。     

有限区域大气-海浪耦合模式的建立及海表粗糙度参数化试验

利用LINUX操作系统下的进程通讯(IPC)技术将中尺度大气模式MM5(V3)与第三代海浪模式WW3进行双向耦合,建立考虑大气-海浪相互作用的风浪耦合模式,在耦合模式中引入3种海表粗糙度参数化方案,通过对一次热带气旋过程的模拟,研究大气-海浪相互作用对热带气旋系统的影响及耦合模式对海表粗糙度参数化方案的敏感性。结果表明:LINUX系统下的进程通讯技术可以方便有效地实现大气和海浪模式的双向耦合,模式运行稳定;耦合模式能够较好的模拟热带气旋的发展和演变过程及其影响下海浪场的分布和演变,模拟结果对海表粗糙度参数化方案较敏感;海浪的反馈作用同时影响了海气间的动力和热力作用过程,不同的海表粗糙度参数化方案下,海浪对两种作用过程不同的影响程度决定了其对气旋系统强度的影响。     

Construction and Application of a Climate Risk Index for China

In the context of global warming, China is facing with increasing climate risks. It is imperative to develop quantitative indices to reflect the climate risks caused by extreme weather/climate events and adverse climatic conditions in association with different industries. Based on the observations at 2288 meteorological stations in China and the meteorological disasters data, a set of indices are developed to measure climate risks due to water-logging, drought, high temperature, cryogenic freezing, and typhoon. A statistical method is then used to construct an overall climate risk index (CRI) for China from these individual indices. There is a good correspondence between these indices and historical climatic conditions. The CRI, the index of water-logging by rain, and the high temperature index increase at a rate of 0.28, 0.37, and 0.65 per decade, respectively, from 1961 to 2016. The cryogenic freezing index is closely related to changes in the consumer price index for food. The high temperature index is correlated with the consumption of energy and electricity. The correlation between the yearly growth in claims on household property insurance and the sum of the water-logging index and the typhoon index in the same year is as high as 0.70. Both the growth rate of claims on agricultural insurance and the annual growth rate of hospital inpatients are positively correlated with the CRI. The year-on-year growth in the number of domestic tourists is significantly negatively correlated with the CRI in the same year. More efforts are needed to develop regional CRIs.     

水文学研究进展与展望

水文学是研究地球上水的起源、存在、分布、循环运动等变化规律,并运用这些规律为人类服务的知识体系。水文学研究经历了由经验到理论、由简单过程到复杂系统、由定性描述到定量模拟的发展历程,其学科体系演进与科学技术进步及社会发展需求紧密联系,并由此衍生出诸如生态水文学、气象水文学、冰冻圈水文学、遥感水文学、同位素水文学、城市水文学、社会水文学等多种交叉研究领域与分支学科。当今水文学研究在水文多尺度观测、陆面—水文—社会耦合模拟及多源观测—模型同化技术等领域取得显著进展,水文学研究的广度和深度不断拓展。未来水文学研究将面向陆地水文循环的变化规律及其效应,重点关注水文循环变化特征和机理、水文循环变化趋势预估及水文循环变化的自然和社会影响等前沿课题;从原有就水论水研究思路转向在自然地理综合分析框架下以水循环为纽带开展的多尺度、多过程集成研究。     

Quantifying multi-modal public transit accessibility for large metropolitan areas: a time-dependent reliability modeling approach

The temporal dimensions of public transit accessibility have recently garnered an increasing amount of interest. However, the existing literature on transit accessibility is heavily based on oversimplified assumptions that transit services operate at deterministic speeds using predetermined timetables. These measurements may overestimate transit accessibility, especially for large metropolitan areas where inter- and intra-modal transfers are frequent. To handle travel time uncertainty, a multi-modal transit accessibility modeling approach is proposed to account for realistic variations in travel time and service reliability. The proposed approach is applied to the mapping of transit accessibility in Shenzhen (China), where transit services exhibit significant travel time variations over space and time. Compared to traditional transit accessibility measures, our method has been demonstrated to better capture intrinsic spatial and temporal accessibility variations with complex multi-modal transit networks. Normal distribution of inter-stop travel times and constant travel speed between GPS sampling points are assumed to simply the computation, which we consider to adjust in future studies to better quantify the dynamics of transit accessibility across space and time.     

贺兰山深部构造及其对浅部构造的响应过程

根椐实测贺兰山地区二叠系、三叠系和侏罗系含煤地层热解数据及石英脉中包裹体测温发现贺兰山地区热演化程度整体水平较高,相对邻区而言,明显具有异常地热场的特征。在分析航磁ΔT化极图、重力上延5km、10km等值线图后认为该区并不存在磁力高,前人设想贺兰山下2~5km处发育中酸性巨型岩基造成该区地热异常的说法缺乏足够证据。并且在贺兰山地区重力上延3km、5km等值线图上存在明显的重力高,剩余重力异常、莫霍面深度和地温梯度图也显示贺兰山地区为一热异常的幔隆区,它明显有别于其他造山带区。因此,贺兰山地区的高热演化特征应是莫霍面的上隆引起的地温梯度升高所致。最后结合研究区玄武岩地质地球化学特征认为贺兰山及周邻地区莫霍面上隆是造成早中侏罗世以来的热事件的原因。     

室内定轨移动测量系统组合定位技术精度分析

移动三维激光扫描系统应用到室内的一个重大技术问题,便是对惯性导航系统实时的进行位置改正。但是众所周知,在室内应用卫星定位精度不能达到足够的定位精度。因此本文主要针对室内移动三维激光扫描系统的定位定姿问题作了细致深入的调查研究,文中通过对比分析选择UWB室内定位方案与惯性导航系统组合,对惯性导航系统进行实时的位置改正,并对该系统的原理以及精度等问题进行研究分析。     

FFT在变形监测中的应用与分析

在变形监测中获取的观测数据可以看作是时间与空间上的一组变形信号,一般该信号都会呈现趋势性,隐藏其中的周期性不易被发现;利用FFT对其拟合后的残差和小波分解后的高频信号进行变换与分析,通过时间序列分析对其分析结果建模得到短期的预测、预报,效果比较理想。