中国氢氟碳化物、全氟化碳和六氟化硫排放源初步估算

通过调研大量资料和统计分析,初步估算出1995年中国氢氟碳化物（HFCs）、全氟化碳（PFCs）和六氟化硫（SF6）这6种温室气体的排放量,分别为2244、2581.2和215t,分别占当年全球排放总量的0.9%、6.45%和3.7%。     

应用近景摄影法研究沙纹的移动

近景摄影能够在无干扰的条件下,精确地测定正在发育阶段的风成沙纹,以波动方式整体移动的平均移动速度V_R(cm·min^-1),和相应的沙纹波长L(cm)波高Δh(mm)及其平均值。同时,求得沙纹移动速度V_R与局地风速V_L之间的实验关系式为V_R=158×(V_L-5.5)^0.67,沙纹移动是缓慢的,其数量级变化于10^-1~10¹cm·min^-1之间。沙纹波长与波高与直接测定值相当吻合。     

赣东北地区不同时代硅质岩的地球化学特征及其地质意义

赣东北地区硅质岩各时代均有不同程度的发育,各时代硅质岩的SiO2含量变化范围为74．90％～97．19％,Si／Al为10．84～93．21,与Al2O3呈较好的负相关关系,表明它们含有较高比例的陆源泥质沉积物,硅质岩样品的Al2O3／(Al2O3+F2O3)=0．60～0．99,Ce／Ce=0．99～1．22,(La／Ce)N=0．91～1．83,V／Y<5．78,Ti／V>17。上述特征表明本区硅质岩形成于大陆边缘构造环境,而与大洋盆地及洋中脊构造环境无关。自古生代以来,该地区没有出现深海大洋盆地环境。     

利用FFT技术计算大地水准面高若干问题研究

本文首先从普通二维 FFT算法的基本定义和要求出发 ,深入分析和比较了大地水准面二维平面和二维球面 FFT算法的特点和差异 ,找出了影响二维球面 FFT计算精度的主要误差源 ,并给出了二维球面 FFT计算公式的改进形式。在此基础上 ,本文详细分析讨论了参考场选取、积分球冠半径确定以及核函数改化对大地水准面计算结果的作用和影响。最后 ,本文利用全国 5′× 5′实测重力异常对我国海陆大地水准面进行了试算 ,并将计算结果分别同陆上GPS水准和海上卫星测高观测值作了比较。     

壳-幔演化和板块俯冲作用过程中的硼同位素示踪

硼同位素是近年来发展起来的一门新兴的稳定同位素地球化学方法。硼有两个稳定同位素 :10 B和11B。硼同位素组成自然界变化十分大 ,δ11B值为 - 37‰～ +58‰。对地幔岩石的硼同位素研究表明 ,原始地幔的δ11B值为 - 10‰± 2‰ ,B的质量分数估算为 (0 2 5± 0 1)×10 -6。相对而言 ,地壳岩石的B含量和δ11B值均较高。由于壳、幔岩石具有不同的B含量和δ11B值 ,硼同位素已被广泛应用于研究壳幔演化和板块俯冲作用过程 ,用于示踪俯冲板块中大洋沉积物和蚀变洋壳在地幔中的循环。     

基于多种GPS数据研究福建及其邻近海域1994-1997年地壳水平运动

为研究中国大陆东南部的边缘海动力学,基于中国大陆和福建区域的ＧＰＳ观测网 以及环绕中国大陆的ＩＧＳ（Ｉｎｔｅｒｎａｔｉｏｎａｌ ＧＰＳ Ｓｅｒｖｉｃｅ）跟踪站在１９９４—１９９７年间的测量数据, 建立块体运动和块内变形两种力学模型,研究了福建及其邻近海域现今地壳水平运动速度场 和应变率场．结果表明：无论在中国大陆还是在中国大陆周边框架内,或相对于台湾而言,福 建及其邻近海域均整体地向着东南或东偏南方向,即指向海洋的方向作水平运动．运动平均 速率为１１．２±３．０ｍｍ／ａ（福建网）或１４．０±４．０ｍｍ／ａ（全国网）．然而在福建区域内还存在着 一种由海洋指向大陆内部的北西向运动,其运动平均速率为 ３．０± ２．６ｍｍ／ ａ．区域应变率场 主压应变方位为ＮＷ（ＮＷＷ）－ＳＥ（ＳＥＥ）．印度板块对欧亚板块的碰撞通过中国大陆内部各 块体间的侧向传递和菲律宾海板块对台湾（欧亚大陆东南沿）的仰冲与挤压,同时作用到福建 及其邻近海域。此种联合作用现今仍在继续进行中,前者的影响比后者更强烈,但前者形成的 速率场均匀,而后者不均匀。     

波纹开缝翅片管换热器传热与流动性的数值模拟

提出一种波纹开缝翅片管换热器,对其传热与流动特性进行三维数值模拟,选择Re范围在1 000到5 000时与平板开缝翅片的模拟相比较。结果表明,在Re小于2 752时,平板开缝比波纹开缝的换热效果好,而Re大于2 752时,波纹开缝比平板开缝换热效果更好,并且波纹开缝翅片管换热器的流动阻力小于平板开缝,因此,Re大于2 752时波纹开缝比平板开缝综合效果更好。     

Application on drilling parameter monitor in drilling engineering monitoring

The drilling parameter monitor is an important tool in drilling engineering applied to monitoring drilling process, carrying out scientific analysis and decision-making. Based on discussing the present development situation of the domestic and foreign drilling machine parameter monitors, the metering scheme for vehicle-loaded drilling parameter monitor was designed. By using detection system for MSP430 single-chip microcomputer (SCM) in combination with peripheral circuit such as sensors, the drilling-rig control system was obtained to detect, and for every parameter in real-time display in order to keep operating the drilling rig status. The experiment shows that the drilling parameter monitor reaches design requirements and can be applied to drilling engineering monitoring, which has characters such as simple structure, high credibility and low cost.     

The Impact of Climatic and Environmental Factors on n-Alkanes Indices in Southwestern Tibetan Plateau

n-Alkanes are widely used in paleoenvironmental reconstructions.However,our understanding of changes in the distribution of n-alkanes with climatic and environmental factors remains unclear in arid/semi-arid regions.We sampled 26 surface sediments from three climatic zones across the southwestern Tibetan Plateau to evaluate the sensitivity of chain length distributions of n-alkanes to climatic and environmental parameters.Our observations demonstrate that average chain length (ACL), proportion of aquatic macrophyte (Paq),carbon preference index (CPI) and ratio of the contents of nC27 and nC31 (nC27/nC31) are all sensitive to hydroclimatic conditions.In contrast to commonly-adopted assumptions,the correlations between these indices and hydrological parameters are not always good,which indicates that the interpretation of n-alkane indices is special on the southwestern Tibetan Plateau.These might be related to the vegetation characteristics and seasonality of biological activity,and need to be considered in paleoclimatic reconstruction.The impact of seasonal precipitation on n-alkanes indices was also evaluated.     

Revisiting the Relationship Between Urbanization and Economic Development in China Since the Reform and Opening-up

The relationship between urbanization and economic development has become a hot topic in the scientific community due to its great practical significance,and economic and social value.However,this relationship continues to change dynamically.In the new stage of urbanization,it is urgent to reveal the causal relationship quantitatively and diagnose the future direction systematically.Based on this,this paper calculates the contribution rate of China’s urbanization to economic development from 1978 to 2019 and uses the panel data cointegration test method to explore the causal relationship between urbanization and economic development in China.The study has three principal results.First,the contribution rate of urbanization to economic growth has maintained the overall growth trend from1978 to 2019,but the growth rate of urbanization’s contribution to economic growth has been relatively low since 2012.It is an important reason that the real estate sector has moved into a new stage of transformation.Second,the cointegration test shows that economic development is a significant factor in advancing urbanization and the urbanization is the product of economic development.Urbanization has a positive feedback effect on economic development,but this effect does not pass the 5%significance level test.The impulse response function shows that the impact of urbanization on economic development is relatively small and stable,indicating that it is limited that the boost of economic development by land-centered urbanization.Third,China’s urbanization and economic development have both shown rapid growth for some time,but their relationship is still the low level of coordination,which has also led to a downward trend in the contribution of new-type,people-oriented urbanization to economic growth in recent years.In the future,China’s urbanization and economy need to maintain relatively medium-low speed growth in the medium-long term,and we should boost the coordinated development of urbanization and economy from low level to high level.