基于树轮宽度重建川西南137年秋冬季平均气温变化

在全球气候变暖背景下,青藏高原东南缘的川滇横断山高海拔地区秋冬季温度变化已经成为区域气候变化研究热点。为了更好地了解长时间尺度下秋冬季平均气温变化对树木生长的影响,本文运用泸沽湖地区丽江云杉（Picea likiangensis）树轮宽度资料,建立了标准年表。并基于气温与树轮宽度指数的关系,重建了过去137年来川西南地区的秋冬季平均气温波动历史。重建序列存在2个暖期（1911~1927 A.D.,1992~2015 A.D.）、1个冷期（1939~1991 A.D.）。与其他树轮序列、沉积记录及历史记录的比较和空间相关分析,显示重建结果可靠,且具有区域代表性。集合经验模态（EEMD）分解得到2 a、19 a和54 a的周期控制序列冷暖波动。厄尔尼诺-南方涛动（ENSO）,太阳黑子,太平洋年代际涛动（PDO）和北大西洋涛动（NAO）可能是以上周期的驱动因子

     

Accurate U-Pb Age and Trace Element Determinations of Zircon by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry

Various zircons of Proterozoic to Oligocene ages (1060-31 Ma) were analysed by laser ablation-inductively coupled plasma-mass spectrometry. Calibration was performed using Harvard reference zircon 91500 or Australian National University reference zircon TEMORA 1 as external calibrant. The results agree with those obtained by SIMS within 2s error. Twenty-four trace and rare earth elements (P, Ti, Cr, Y, Nb, fourteen REE, Hf, Ta, Pb, Th and U) were analysed on four fragments of zircon 91500. NIST SRM 610 was used as the reference material and ²⁹Si was used as internal calibrant. Based on determinations of four fragments, this zircon shows significant intra-and inter-fragment variations in the range from 10% to 85% on a scale of 120 μm, with the variation of REE concentrations up to 38.7%, although the chondrite-normalised REE distributions are very similar. In contrast, the determined age values for zircon 91500 agree with TIMS data and are homogeneous within 8.7 Ma (2 s ). A two-stage ablation strategy was developed for optimising U-Pb age determinations with satisfactory trace element and REE results. The first cycle of ablation was used to collect data for age determination only, which was followed by continuous ablation on the same spot to determine REE and trace element concentrations. Based on this procedure, it was possible to measure zircon ages as low as 30.37 0.39 Ma (MSWD = 1.4; 2 s ). Other examples for older zircons are also given.     

压裂液在煤层中的运移模拟研究

为给山西省临县三交区块的地下水环境保护提供科学依据,运用地下水数值模拟技术对压裂液在煤层中的运移进行了预测。在分析研究区地质结构的基础上,建立了水文地质概念模型,将山西组3^#煤层概化为一个承压含水层,其上覆二叠系砂岩、泥岩作为隔水层,下伏的泥岩、砂岩互层作为隔水层,并确定了地下水系统的边界条件。运用地下水模型软件(Feflow)对研究区内的压裂液在煤层中的运移进行了模拟和预测,预测结果表明,压裂液在煤层中的的运移范围在煤层压裂影响范围以内,即压裂井周围300 m范围内。     

鲈鱼苗烂鳃、烂尾病病原菌的研究

１９９７年４～５月,对花鲈（Ｌａｔｅｏｌａｂｒａｘｊａｐｏｎｉｃｕｓ）鱼苗期细菌性烂鳃和烂尾病的病原菌进行了研究。从具有明显症状的病鱼的病灶组织分离到２株致病菌Ｃ－１和Ｗ－１,经人工感染及从人工感染发病鱼体再分离的Ｗ－４和Ｗ－５菌株的再感染试验结果表明,所分离的细菌为鲈鱼苗烂尾,烂鳃病的致病菌。经６４项生物学特性,生理生化特征测试结果表明,这４株菌可归为一类,同属于鳗弧菌（Ｖｉｂｒｉｏａｎｇｕｉｌａｒｕｍ）。药敏试验结果表明,痢特灵、ＣＩＮ１００、ＭＥＬ２５、呋喃妥因、氯霉素、磺胺药＋ＴＭＰ和美洛西林等７种药物对病原菌有显著的抑制作用。     

Distinguishing streamflow trends caused by changes in climate,forest cover,and permafrost in a large watershed in northeastern China

Understanding how rivers respond to changes in land cover, climate, and subsurface conditions is critical for sustainably managing water resources and ecosystems. In this study, long‐term hydrologic, climate, and satellite data (1973–2012) from the Upper Tahe River watershed (2359 km²) in the Da Hinggan Mountains of northeast China were analysed to quantify the relative hydrologic effects of climate variability (system input) and the combined influences of forest cover change and permafrost thaw (system characteristics) on average annual streamflow (system response) using 2 methods: the sensitivity‐based method and the Kendall–Theil robust line method. The study period was subdivided into a forest harvesting period (1973–1987), a forest stability period (1988–2001), and a forest recovery period (2002–2012). The results indicated that the combined effects of forest harvesting and permafrost thaw on streamflow (+ 47.0 mm) from the forest harvesting period to the forest stability period was approximately twice as large as the effect associated with climate variability (+20.2 mm). Similarly, from the forest stability period to the forest recovery period, the decrease in average annual streamflow attributed to the combined effects of forest recovery and permafrost thaw (?38.0 mm) was much greater than the decrease due to climate variability (?22.2 mm). A simple method was used to separate the distinct impacts of forest cover change and permafrost thaw, but distinguishing these influences is difficult due to changes in surface and subsurface hydrologic connectivity associated with permafrost thaw. The results highlight the need to consider multiple streamflow drivers in future watershed and aquatic ecosystem management. Due to the ecological and hydrological susceptibility to disturbances in the Da Hinggan Mountains, forest harvesting will likely negatively impact ecohydrological processes in this region, and the effects of forest species transition in the forest recovery process should be further investigated.     

多源地理空间矢量数据关联分析

针对多源地理空间矢量数据多来源、难以集成综合利用这一现状,本文提出了多源地理空间矢量数据关联方法,并以此为基础构建了多源地理空间矢量数据关联的可视与计算查询系统。首先,对多源地理空间矢量数据关联的概念及分类进行了定义。然后,以此为基础,提出了关联关系构建技术：自适应四叉树编码技术、扫描线技术、几何匹配及语义匹配技术。最后,为实现关联关系的直观展示,设计了原型系统。关联技术的提出可建立起多源地理空间矢量数据之间的关联关系,原型系统的构建也为用户综合利用多源地理空间矢量数据提供了平台,提高了数据的利用率及数据查询的效能。     

Two-step method for the determination of the differential code biases of COMPASS satellites

The differential code bias (DCB) in satellites of the Global Navigation Satellite Systems (GNSS) should be precisely corrected when designing certain applications, such as ionospheric remote sensing, precise point positioning, and time transfer. In the case of COMPASS system, the data used for estimating DCB are currently only available from a very limited number of global monitoring stations. However, the current GPS/GLONASS satellite DCB estimation methods generally require a large amount of geographically well-distributed data for modeling the global ionospheric vertical total electron content (TEC) and are not particularly suitable for current COMPASS use. Moreover, some satellites with unstable DCB (i.e., relatively large scatter) may affect other satellite DCB estimates through the zero-mean reference that is currently imposed on all satellites. In order to overcome the inadequacy of data sources and to reduce the impact of unstable DCB, a new approach, designated IGGDCB, is developed for COMPASS satellite DCB determination. IGG stands for the Institute of Geodesy and Geophysics, which is located in Wuhan, China. In IGGDCB, the ionospheric vertical TEC of each individual station is independently modeled by a generalized triangular series function, and the satellite DCB reference is selected using an iterative DCB elimination process. By comparing GPS satellite DCB estimates calculated by the IGGDCB approach based on only a handful (e.g., seven) of tracking stations against that calculated by the currently existing methods based on hundreds of tracking stations, we are able to demonstrate that the accuracies of the IGGDCB-based DCB estimates perform at the level of about 0.13 and 0.10?ns during periods of high (2001) and low (2009) solar activity, respectively. The iterative method for DCB reference selection is verified by statistical tests that take into account the day-to-day scatter and the duration that the satellites have spent in orbit. The results show that the impact of satellites with unstable DCB can be considerably reduced using the IGGDCB method. It is also confirmed that IGGDCB is not only specifically valid for COMPASS but also for all other GNSS.     

互联网+社区地震应急桌面演练的设计与实施——以青海省海西州为例

地震灾害应对实践表明,社区作为社会治理的基本单元,在抢救生命、安置群众生活等方面发挥着重要作用。应急演练是有效提升民众防灾减灾意识和社区应对灾害能力的重要途径。近年来,社区开展了不同程度的地震应急演练,但在专业性和实效性方面仍存在很大提升空间。本文基于互联网+应急演练理念,提出基于互联网云服务的分布式、多社区、不限人数、同步或异步开展的应急桌面演练新模式,并在青海省海西蒙古族藏族自治州进行了试点应用。实践表明,互联网+社区地震应急桌面演练融合了传统桌面演练与实战演练的优势,可针对社区管理层开展地震灾害全过程桌面推演,能有效促进社区管理层应急组织协调能力的提升。     

Improvement of the semi-Lagrangian advection scheme in the GRAPES model: Theoretical analysis and idealized tests

ABSTRACT The Global/Regional Assimilation and PrEdiction System （GRAPES） is the newgeneration numerical weather predic- tion （NWP） system developed by the China Meteorological Administration. It is a fully compressible non-hydrostatical global/regional unified model that uses a traditional semi-Lagrangian advection scheme with cubic Lagrangian interpola tion （referred to as the SL_CL scheme）. The SL_CL scheme has been used in many operational NWP models, but there are still some deficiencies, such as the damping effects due to the interpolation and the relatively low accuracy. Based on Reich＇s semi-Lagrangian advection scheme （referred to as the R2007 scheme）, the Re_R2007 scheme that uses the low- and high-order B-spline function for interpolation at the departure point, is developed in this paper. One- and two-dimensional idealized tests in the rectangular coordinate system with uniform grid cells were conducted to compare the Re..R2007 scheme and the SL_CL scheme. The numerical results showed that： （1） the damping effects were remarkably reduced with the Re_R2007 scheme; and （2） the normalized errors of the Re_R2007 scheme were about 7.5 and 3 times smaller than those of the SL_CL scheme in one- and two-dimensional tests, respectively, indicating the higher accuracy of the Re..R2007 scheme. Furthermore, two solid-body rotation tests were conducted in the latitude-longitude spherical coordinate system with non uniform grid cells, which also verified the Re_R2007 scheme＇s advantages. Finally, in comparison with other global advection schemes, the Re_R2007 scheme was competitive in terms of accuracy and flow independence. An encouraging possibility for the application of the Re_R2007 scheme to the GRAPES model is provided.     

哀牢山过山气流的气候效应

本文研讨哀牢山脉北段西南季风与东北季风的过山气候效应。