威特DI2002测距仪性能及其与ME—3000反射镜匹配研究

本文通过对威特ＤＩ２００２测距仪性能的测试，发现影响测距精度的主要因素是ＧＲＴ１０－ＧＰＨ１Ａ的反射镜系统。威特ＤＩ２００２测距仪匹配ＭＥ－３０００反射镜后，需加两项改正，但观测精度显著提高，实测表明达到与ＭＥ－３０００测距仪相同的精度。     

DI2002测距仪在高原的测量实验

分析DI2002测距仪在川西高原虾拉沱基线场地对基线AB边和AC边进行短距测量实验所得数据,检验DI2002测距仪在气候独特的高原环境中是否满足距离测量限差精度要求,并将其测量结果与同期基线测量数据资料进行比较.得出DI2002测距仪能适用于气候瞬息多变的川西高原.     

长基线法和短基线法在LCR-G型重力仪格值因子标定中的应用

介绍了LCR-G型重力仪长、短基线标定格值因子的方法和过程,并对标定结果进行比较。统计了两台重力仪2008—2017年在灵山基线场标定的格值因子,分析了时序变化规律,总结了该种仪器长、短基线标定的优点、不足和适用范围。     

用甚长基线干涉测量数据检测冰期后地壳回弹

本文利用甚长基线干涉测量（VLBI）技术提供的实测站速度和地球物理模型ICE_4G提供的数据,采用实测站速度法和基线长度变化率法分别检测了冰期后地壳回弹的垂直运动和水平运动.对用空间技术求解的实测值和用ICE_4G模型求解的估计值进行线性拟合和相关分析,两者的相关系数达到0.8～0.9,表明空间技术已经能够检测1～10mm/a的冰后回弹运动;在方向上两者基本一致,在量级上,实测结果的绝对值比模型估计值系统性的偏大约20%,表明当前冰期后的地壳回弹运动比地质时期要猛烈.     

雷达干涉PS网络的基线识别与解算方法

时序雷达干涉图中的永久散射体(PS)可看作“天然GPS点”, 以构成网络用于监测长期的地表形变. 本文提出采用邻接矩阵拓扑模型对基于Delaunay剖分算法生成的PS网络进行基线识别, 并采用时序相干最大化算法求解PS基线的线性形变速度增量和高程误差增量. 该数据模型和计算方法被应用于探测香港地区2006~2007年间的区域地表沉降. 实验研究采用由Envisat卫星ASAR传感器对该地区成像所获取的时序SAR影像作为数据源, 并联合该地区12个GPS连续运行参考站的观测数据予以大气修正和地面控制. 实验结果表明, 该模型和方法应用于地表形变测量是有效的和可靠的, PS网络方法探测地面沉降的精度约为±2.0 mm/a.     

拉萨地磁台磁偏角(D)基线值计算方法的讨论

通过对拉萨地磁台磁偏角基线值计算方法进行讨论,得到了有益的结果。(1)目前拉萨台的D 值以偏西为主,有时出现偏东现象,为了整理资料的方便,将偏东值统一到偏西时的基线值系统,计算公式为:D_(B(W))=-(D_(E)+SN)W,含意为偏西负;(2)若该台的 D 绝对值过渡到偏东为主时,有时出现偏西情形,计算式为 D_(B(E))=-D_(W)+SN,即将偏西磁偏角归算到偏东基线值系列;(3)用微机计算地磁观测报告时,须注意基线值前的负号。     

以昆仑山口西地震为例研究GPS基线长度与方向对地震的敏感性

应用中国地壳观测网络GPS基准站连续观测资料, 研究了昆仑山口西地震前后基线长度及方向的变化特征; 根据昆仑山口西地震破裂方向, 讨论了不同方位基线变化特征的差异性; 从理论上探讨了基线长度与基线方向变化对地震的灵敏性问题。 研究结果表明: ① 当基线方向与地震破裂方向近于一致时, 基线长度的灵敏性要高于基线方向的灵敏性; ② 当基线方向与地震破裂方向近于垂直时, 基线方向的灵敏性要高于基线长度的灵敏性; ③ 当基线方向与地震破裂方向近似于45°时, 基线长度和基线方向对地震都有一定程度的反映, 同时在震前有可能出现明显的变化。     

绝对观测时段对地磁基线值观测质量影响的分析研究

基线值的观测质量是综合评价地磁台观测资料质量的一个重要指标。根据肇庆地磁台2007年9月18日进行的连续46组绝对观测数据．分析研究了相应时段基线值的稳定性及精度。研究结果表明,在磁静日的不同时段进行的绝对观测对基线值的稳定性影响较小,基线值观测精度较高。     

对地磁观测基线值滑动现象的再研究

通过对天水地磁台1991～1995年间H分量磁变仪的基线值的详细分析，结合数值模拟，阐明了以下观点:滑动不是长期存在的现象．对于正常运行多年的仪器，滑动的影响趋于零；基线值随温度的变化在特定的低温段可逆，在高温段不可逆，在高温段的不可逆，是导致基线值随时间的变化在形态上单调下降的主要原因．以往把这种现象归因于滑动是错误的．对于天水台来讲，目前H分量基线值的测量已经不存在滑动的影响．由此提出了分段处理基线值随温度变化关系的方法．      

CT和检验指标对浸润倾向肺腺癌的诊断模型建立

目的:根据多排螺旋CT肺部亚实性结节(SSN)三维重建的定量参数、血液肿瘤标志物和血常规指标,建立用于判断有浸润倾向肺腺癌的多参数诊断模型.材料与方法:回顾性纳入107例接受薄层CT扫描,术后行组织学检查,并做了血液肿瘤标志物和血常规检查的患者.评估指标包括患者年龄、性别;SSN在CT三维重建中的最大径、总体积、实性成...     

中国大陆内部GPS连续观测站基线分析

根据中国地壳运动观测网络基准站1999年初至2010年4月的资料,对中国大陆内部80条GPS基线时间序列进行了分析,讨论了这些基线在正常情况下的趋势性运动特征,总结了2001年昆仑山口西MS8.1和2008年汶川MS8.0两次大震前GPS基线时间序列的异常变化情况,并在此基础上分析了GPS基线近期变化情况。     

Laboratory populations for long-term toxicity tests

International standardization of toxicity tests demands ‘standard’ animals. These are not to be found in nature, and transferring organisms from their natural habitat to the laboratory may add to the stress on them and interfere with the tests. Laboratory cultured animals may help reduce this problem.     

Evaluation of an Ultrafiltration Method for Surfactant Recovery and Reuse During In Situ Washing of Contaminated Sites: Laboratory and Field Studies

Feasibility studies were conducted on the use of ultrafillration to recover surfactant from aqueous waste streams generated from the in situ surfactant washing of a site contaminated with poly-chlorinated biphenyls (PCBs) and oils. A Romicon Model HF-Lab-5 ultrafiltration unit and three types of ultrafillration membranes (PM500, XM50, and CM50) were evaluated for their permeability to a nonionic surfactant previously selected for the in situ washing. Results from laboratory studies using the XM50 membrane cartridge showed that 78 percent of the surfactant passed through the membrane surface (permeate) and was recovered.
Two field-pilot tests of the ultrafiltralion system were conducted using leachate containing a mixture of water, oils, PCBs, and surfactant that was collected from an in situ surfactant-washing demonstration test. Forty-six percent of the surfactant (mass) was recovered during the first field test using the XM50 membrane. The membrane retained 94 percent of the PCBs and 89 percent of the oils. The second field test showed that the PM500 membrane recovered 67 percent of the surfactant in the permeate and retained more than 90 percent and 83 percent of the PCBs and oils, respectively. This study indicates that a significant volume of a nonionic surfactant can be recovered from leachatc mixture containing PCBs and oils by ultrafillration. The recovered surfactant could be reused to improve the economic viability of in situ surfactant washing of contaminated sites.     

Coliform Bacteria in New Jersey Domestic Wells: Influence of Geology,Laboratory, and Method

Following passage of the New Jersey Private Well Testing Act, 50,800 domestic wells were tested between 2002 and 2007 for the presence of total coliform (TC) bacteria. Wells containing TC bacteria were further tested for either fecal coliform or Escherichia coli (FC/E. coli) bacteria. Analysis of the data, generated by 39 laboratories, revealed that the rate of coliform detections in groundwater (GW) was influenced by the laboratory and the method used, and also by geology. Based on one sample per well, TC and FC/E. coli were detected in wells located in bedrock 3 and 3.7 times more frequently, respectively, than in wells located in the unconsolidated strata of the Coastal Plain. In bedrock, detection rates were higher in sedimentary rock than in igneous or metamorphic rock. Ice‐age glaciers also influenced detection rates, most likely by removing material in some areas and depositing thick layers of unconsolidated material in other areas. In bedrock, coliform bacteria were detected more often in wells with a pH of 3 to 6 than in wells with a pH of 7 to 10 whereas the reverse was true in the Coastal Plain. TC and FC/E. coli bacteria were detected in 33 and 9.5%, respectively, of sedimentary rock wells with pH 3 to 6. Conversely, for Coastal Plain wells with pH 3 to 6, detection rates were 4.4% for TC and 0.6% for FC/E. coli.     

Longer term effects of biological control on tamarisk evapotranspiration and carbon dioxide exchange

Biological control of Tamarix spp. (tamarisk) with Diorhabda spp. (tamarisk beetle) was initiated in several states in the Western United States in 2001. We analysed 12 years of evapotranspiration (ET), net ecosystem production (NEP), and beetle abundance data from a tamarisk-invaded site in Western Nevada along the Truckee River. Diorhabda carinulata (northern tamarisk beetle) appeared at the site in 2007. Large beetle outbreaks and associated defoliation of the tamarisk occurred in 2008 and 2009, then the beetle population was highly variable from year to year. Since 2016, the beetle population declined. Growing season ET noticeably declined from direct beetle herbivory in 2008, 2009, and 2010, but the decline in ET was seasonally transient as trees regrew leaves. In 2012 and 2013, total growing season ET was low, likely due to the combined effects of drought and beetle herbivory pressure. Total seasonal ET losses and NEP were primarily driven by annual precipitation with higher values in wetter years and reduced values when precipitation fell below 100 mm. In the last 2 years of the study, 2017–2018, there were few to no beetles observed at the site, and we measured increased tamarisk leaf area index, ET, and NEP. Since 2010 at the study site, no further releases of the beetles have occurred due to wildlife concerns, and subsequent declines in beetle populations where such that the “outbreak” conditions apparently required to impair tamarisk physiological function and significantly reduce ET have not occurred. ET and photosynthesis were highly correlated (r² ≥ .91) to the Landsat-satellite normalized difference vegetation index (NDVI). Using a relationship between growing season ET and NDVI, we estimated ET for five additional tamarisk sites along several southwestern U.S. rivers. In the 2005 to 2018 analysis period, NDVI-estimated ET declined at all sites after beetle arrival with three sites showing a recovery in pre-beetle ET rates in subsequent years. At the other three sites, ET rates have not recovered to pre-beetle levels.     

Strategies for Successful ANAMMOX Enrichment at Laboratory Scale

Studies on anaerobic ammonium oxidation (ANAMMOX) have been increasing due to its advantages over traditional nitrification–denitrification systems. However, long and difficult start‐up periods of ANAMMOX reactors may sometimes be frustrating for researchers dealing with them first time in the lab. Therefore, a guide for starting up ANAMMOX reactors will greatly help them and enhance the use of this technology. Three trials, each has three reactors, have been carried out to reach successful start up in this study. An expected ANAMMOX enrichment could not be achieved in the first and second trials. Under the light of the experiences gained from the unsuccessful ones, the third trial resulted in >95% ammonium removals within 20–50 days. It is possible to startup or to enrich ANAMMOX reactors within 50 days by presented strategy guide.