定点观测气候序列的均一性研究

文章分析了气候资料产生非均一性的原因，介绍了近年来国内、外气候资料均一性研究的方法以及一些国家利用这些研究方法对本国或区域气候序列均一性问题的研究成果。对我国气象观测站观测站址、仪器变化等因素进行了总结，并介绍了我国气象资料均一性检验的一些结论，讨论了与气象资料均一性研究相关的一些问题。     

The accurate location of the injection-induced microearthquakes in German Continental Deep Drilling Program

Introduction The scientific drilling belongs to the International Lithosphere Program and is one of the four lithospheres explorations. So far there are more than ten countries, which have taken the scientific drilling. The German Continental Deep Drilling Program was later than the others and is the sec-ond deep drilling, but is the most significant scientific super deep drilling in the world. The Ger-man Continental Deep Drilling Program (Kontinentales Tiefbohrprogram der Bundesrepub…     

新疆天山金矿可持续发展建议

新疆天山成矿带是我国重要的金成矿带,主要发育韧性剪切带型、火山型和穆龙套型3种类型金矿床。随着社会经济的快速发展,黄金的需求量在逐年增大,这就要求新疆对金矿的勘查开发要加大力度。本文通过研究新疆天山金矿的特征并就可持续发展提出建议。     

单片机控制交流稳压器

阐述了以89C2051单片机为核心的交流稳压器的设计原理,介绍了一种高精度的电网电压测量电路。     

压力注浆液地下作用机理

介绍了压力注浆液的性能和要求;根据不同地质条件下注浆工艺的不同,建立了各自的数学模型;并在实践中得到应用和验证。      

地基GNSS遥感探测气象应用

全球导航卫星系统（GNSS）给定位、导航和授时服务带来了革命性变化,同时其L波段（1160～1610MHz）微波信号可用于全球覆盖、高时间分辨率的大气、海洋和陆表参数遥感探测。基于信号类型,GNSS遥感可分为折射信号遥感和反射信号遥感两大类;基于探测平台,GNSS遥感可分为地基GNSS遥感、空基GNSS遥感和天基GNSS遥感三大类。随着我国自主建设的北斗卫星导航系统全面建成,GNSS遥感将迎来新的发展机遇和挑战。本文回顾近20年地基GNSS遥感探测在气象领域的应用进展,展望其在气象领域下一步可能的应用。     

Application of the radial basis function neural network to the short term prediction of the Earth’s polar motion

By a number of test cases using different sample numbers and sample lengths, we obtain a Radial Basis Function Neural Network (RBFNN) model that is suitable for the short-term forecast of polar motion, especially for the ultra-short-term forecast. By using the same data sample of Earth’s polar motion, this RBFNN model can achieve better short-term prediction accuracy than the least-squares+autoregressive (LS+AR) method, and better ultra-short-term prediction accuracy than the LS+AR+Kalman method. Using this model to forecast the polar motion data from January 1, 2002 to December 30, 2007 and from January 1, 2010 to December 30, 2016, respectively, experimental results show that the ultra-short-term forecast accuracy of this RBFNN model is within a precision of 3.15 and 3.08 milliseconds of arc (mas) in polar motion x direction, 2.02 and 2.04 mas in polar motion y direction; the short-term forecast accuracy of RBFNN model is within a precision of 8.83 and 8.69 mas in polar motion x direction, and 5.59 and 5.85 mas in polar motion y direction. As is stated above, this RBFNN model is well capable of forecasting the short-term of polar motion, especially the ultra-short-term.     

Total organic carbon fluxes of the Red River system (Vietnam)

Riverine transport of organic carbon from terrestrial ecosystems to the oceans plays an important role in the global carbon cycle. The Red River is located in Southeast Asia where river discharge, sediment loads and fluxes of elements (carbon, nitrogen and phosphorus) associated with suspended solids have been dramatically altered over past decades as a result of reservoir impoundment and land use, population, and climate change. Dissolved organic carbon (DOC) and particulate organic carbon (POC) concentrations were measured monthly at four stations of the Red River system from January 2008 to December 2010. The results reveal that POC changed synchronically with total suspended solids (TSS) concentration and with the river discharge, whereas no clear trend was observed for DOC concentration. The mean value of total organic carbon (TOC = DOC + POC) flux in the delta of the Red River was 31.5 × 10¹³ ± 4.0 × 10¹³ MgC.yr^?1 (range 27.9–35.8 × 10¹³ MgC.yr^?1 which leads to a specific TOC flux of 2012 ± 255 kgC.km^?2.yr^?1 during this 2008–2010 period. About 80% of the TOC flux was transferred to the estuary during the rainy season as a consequence of the higher river water discharge. The high mean value of the POC:Chl‐a ratio (1585 ± 870 mgC.mgChl‐a^?1) and the moderate C:N ratio (7.3 ± 0.1) in the water column system suggest that organic carbon in the Red River system is mainly derived from erosion and soil leaching in the basin. The effect of two new dam impoundments in the Red River was also observable with lower TOC fluxes in 2010 compared with 2008. Copyright © 2017 John Wiley & Sons, Ltd.     

Basin-scale seawater lead isotopic character and its geological evolution indicated by Fe-Mn deposits in the SCS

Abstract

The geochemical characteristics and Pb isotope variations in Fe-Mn deposits collected from the South China Sea (SCS) were studied in this paper. The mineralogical and chemical composition data indicate that the deposits are almost all hydrogenetic in origin. Compared with the Fe-Mn deposits in other oceans, the SCS Fe-Mn deposits have a significantly higher Pb content because of higher material supply in addition to a lower growth rate of the deposits. Pb isotope ratios in the surface of the SCS Fe-Mn deposits are relatively uniform, with a characteristic of relatively lower ²⁰⁶Pb/²⁰⁴Pb ratio. The Pb isotopic compositions of the SCS Fe-Mn deposits are controlled by the Pacific Deep Water and local inputs, which include eolian dust from the Asian continent and weathering products from Taiwan, Luzon and SCS submarine volcanic rocks. The continuously increasing ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb ratios along the transect of nodule D581 over the past 3.5?Ma are affected by the stepwise closure of the Luzon Strait that reduced volcanic material supply and the deep current strengthen at the same time.     

A simple and direct method to analyse the influences of sampling fractions on modelling intra-city human mobility

Sampling fraction is crucial to sampling-related studies and applications, especially in the big data era when most data are neither originally designed nor controllable in the data collection process. A common concern among researchers is ‘what’s the modelling accuracy when using a sample?’. Taking intra-city human mobility as the study objective, this study utilizes a simple and direct method to analyse the influences of various sampling fractions on modelling accuracy. Five common intra-city human mobility indicators (travel distance, travel time, travel frequency, radius of gyration and movement entropy) are evaluated considering mean value, median and probability distribution. Experimental results demonstrate that the representativeness of each considered indicator converges to 1 in its own unique rate and variances. The minimum required sampling fractions to satisfy specific accuracies differ for various indicators and evaluation measures. To further investigate how related factors influence the modelling accuracy of sampling fractions, additional experiments are conducted considering multiple sampling methods, study scopes, and data sources. Several interesting general findings are observed. This study provides a reference for other sampling-based applications.