水库水气界面温室气体通量监测方法综述

水库水体中的有机碳,经过水中微生物代谢分解,生成甲烷、二氧化碳等温室气体,通过扩散、气泡等方式,经由水气界面排向大气.目前国外对水库水气界面的温室气体通量监测已经发展了静态箱法、梯度法、倒置漏斗法、TDLAS法以及涡度相关法等.综述了以上监测方法的原理、应用、优缺点及适用范围,从水体、陆地和气候环境方面分析了影响水气界...     

Search for class I methanol maser emission in various types of objects in the interstellar medium

Observations of various types of objects in the northern sky were obtained at 44 GHz in the 7₀-6₁ A ⁺ methanol line on the 20-m Onsala radio telescope (Sweden), in order to search for Class I methanol maser emission in the interstellar medium: regions of formation of high-mass stars, dust rings around HII regions, and protostellar candidates associated with powerful molecular outflows and Galactic HII regions. Seven new Class Imethanolmasers have been discovered toward regions of formation of highmass stars, and the existence of two previously observed masers confirmed. The following conclusions are drawn: (1) neither the association of a bipolar outflow manifest in the wings of CO lines with a highmass protostellar object (HMPO) nor the presence of thermal emission in lines of complex molecules are sufficient conditions for the detection of Class I methanol emission; no association with HMPOs radiating at 44 GHz was found for EGOs (a new class of object tracing bipolar outflows); (2) the existence of H₂O masers and Class II methanol masers in the region of aHMPOenhances the probability of detecting Class I methanol emission toward the HMPO; Class II methanol masers with stronger line fluxes are associated with Class I methanol masers.     

Chemical composition of gas and grains in dense interstellar clouds

This paper is a short review of the present knowledge on the composition of dense clouds where stars form, with extensions to the less dense interstellar medium and to the most likely sites of grain formation. The problem is complex and intricate, and it is still difficult to answer such fundamental questions as the lifetime of the dense clouds or the lifetime of the interstellar grains.     

The influence of variations of elemental composition on the thermal properties of interstellar gas

The mixing of metals and redistribution of the relative abundances of chemical elements in the interstellar medium often takes place on a timescale that exceeds the characteristic timescales for many other processes, such as ionization and the establishment of thermal equilibrium. Under these conditions, different regions of interstellar gas can have different thermal, chemical, and spectral properties. The paper considers the ionization kinetics and thermal regime of interstellar gas with variations in the relative elemental abundances. The thermal properties and observational (spectral) characteristics are most sensitive to variations of the relative abundance of carbon, oxygen, neon, and iron. The dynamic consequences of such variations are considered.     

Stability of the parameters of the Stellar black-hole mass distribution estimated using nonparametric methods

Individual probability-density distributions for the masses of compact objects in 20 X-ray binary systems have been constructed. The mass distributions were modeled using Monte-Carlo simulations. The closeness of the components in systems with massive optical stars was taken into account using K corrections. The parameters of the resulting black-hole mass distributions were obtained using nonparametric statistical methods. The presence of a statistically significant mass gap in the range 3–5M _⊙ is confirmed. The currently observed probability-density distributions of the compact-object masses are stable against small amounts of data contamination.     

测定非饱和土水力参数的一步流动方法研究

详细介绍了改进的常流速联合测试系统,该系统增加了气泡冲刷和量测装置,能够冲刷试验过程中溢出陶土板的气泡并测量气泡的体积,进而对溢出水量进行修正,使测量值更加接近于真值。使用该系统对试样进行一步脱湿、吸湿流动试验,得出溢出水量随时间变化的关系曲线,利用HYDRUS-1D水分运移模型对该曲线进行拟合并得出相关参数。根据这些参数,反算得出试样脱湿段和吸湿段的土-水特征曲线和渗透函数并和实测数据进行对比。结果表明,该方法能很好的拟合实测溢出水量随时间变化的关系曲线,通过模型得出的土-水特征曲线和实测值比较接近,证实了该方法的可靠性。并且,与传统的测试方法相比,该方法能够节约大量的时间。因此,通过一步流动试验测定非饱和土-水力学参数的方法是可行的。     

地下结构对渗流场阻隔问题的解析~半解析法

针对当前地下空间开发引起的地下水渗流场变化量化评价需要,本文就渗流场受地下结构阻隔后的稳定流状态下的流量及各部位(上游段、阻隔段和下游段)的水位计算公式进行了探讨,分别导出了上、下阻隔两种情况下的承压水问题的解析解和潜水问题的半解析解,并利用数值试验直观解释了一些阻隔现象,以及获得了小水力梯度条件下潜水问题半解析解可以用同条件下的承压水问题解析解来近似的结论。     

Analytical comparison of two methods of assay weighting using vein assays from Butte,Montana

Weighting of vein assays is desirable where assays represent variable vein widths and variable distances along the vein. The method of weighting used is important in ore-reserve calculations and other investigations. Two possible methods are considered here. The first method, commonly applied in mining, assumes in effect linear variation of assay-width products between assay points. The second method, developed in this paper, assumes linear variation of assays and widths separately. The weighted average assay in an interval dby the second method (a_{w1, 2})is given by the expression $$a_{w1,2} = V/[(w_1 + w_2 )/2]$$ where $$\begin{gathered} v = (1/3)(\Delta a)(\Delta w)d + (1/2)(\Delta a)w_1 d + (1/2)(\Delta w)a_1 d + a_1 w_1 d \hfill \\ \Delta a = a_2 - a_1 {\text{,}}\Delta w = w_2 - w_1 \hfill \\ \end{gathered} $$ a₁, w₁ are assay and width at point 1, a₂, w₂ are assay and width at point 2,and dis the distance between points 1and 2.Statistical testing of the two methods, using 8,913 pairs of copper assay-width data from the Belmont mine area at Butte, suggests the following: within major veins or within veins which show near-linear width variations, the second method may be used with the expectation that the average grade calculated will more closely represent the actual average grade than if the first method were used.     

低渗致密气井分类评价方法研究 ——以子洲气田为例

由于子洲气田低渗致密气储层地质情况复杂,储层物性差异大,造成子洲气田各井的产量、压力等生产特征不同。为了更好地指导低渗致密气井高效合理的开发,需要基于各井的静态特征和动态规律,对其进行合理的分类。采用储能系数和地层系数两个储层物性参数,作为静态评价指标;采用稳产期累产气量、稳产期日均产气量、平均日产气和单位压降产气量四个动态参数,作为动态评价指标。创造性地提出依据各评价指标频率分布直方图的特征,对气井进行各指标分级。基于正交矩阵的思路,建立了动静结合的低渗致密气井分类评价方法,最终形成了静-动结合的气井分类结果：子洲气田152口低渗致密气井中I类井（储层物性好,实际产量高）占11.2%、II类井（储层物性较差,实际产量高）占8.5%、III类井（储层物性好,实际产量低）占30.3%、IV类井（储层物性差,实际产量低）占50.0%。其中,III类井是今后生产开发的研究重点,明确III类井的范围,可为将来措施提产指明方向。建立的动静结合低渗致密气井分类评价方法,可为类似区块低渗致密气井的分类提供借鉴。     

高铁路基粗颗粒土水力学参数测试方法研究

高铁路基粗颗粒土的水力学特性对路基内部水分运移及路基的长期累积变形有重要影响。而对这种高压实度的粗颗粒土,常规非饱和土试验仪器存在试样尺寸小、制样难度大的缺点,难以应用。介绍了一种用于测试高压实度路基粗颗粒土-水力学参数的试验装置,利用张力计和时域反射计量器,分别测量路基粗颗粒土在浸湿、干燥阶段不同高度处土体基质吸力、介电常数的变化情况,获得高压实度下高铁路基粗颗粒土土-水特征曲线;并通过瞬态剖面法获得路基粗颗粒土非饱和渗透系数与基质吸力的关系。试验结果表明,该套装置能够适用于最大粒径为20 mm的粗颗粒土,试样压实度最大可达到0.95。通过对一组试验结果分析,并结合Ekblad等试验结果,发现随着填料细颗粒含量增大,?（与进气值有关的参数）值逐渐减小,土体进气值增加;粒径越大,细颗粒含量越低,土体储水能力越低,对应n（与排水程度有关的参数）值越大。为路基粗颗粒土-水力学参数的测定提供了方法。     

Influencing factors for catalytic oxidation of mine gas to methanol in liquid phase

The influencing factors for liquid phase catalytic oxidation of mine gas to methanol （in form of CHaCOOCH3） are studied using the self-established experimental apparatus. The results show that CH3COOCH3 （target product） is obtained by using CH3COOH as reaction solvent, and the yield of target product increases with the increasing of reaction temperature, gas pressure and reaction time. In the mine gas-Pd（OAc）2-CHaCOOH system, the yield of CHaCOOCH3 increases with the increasing of addition of Pd（OAc）2 which is redox catalyst for mine gas conversion. The yield of CH3COOCH3 will be greatly improved by composite additional oxidant which is obtained by equimolar mix of p-benzoquinone with NO2.     

页岩气勘探中的地球物理方法综述及展望

地球物理方法是页岩气勘探中最有效、最准确的预测方法之一.在调研国内外利用地球物理方法勘探页岩气研究成果的基础上,分析总结了页岩气勘探中最有效的地震和测井法对页岩气的响应特征,讨论了常规油气勘探中已获得成功的电磁法、重磁勘探以及综合地球物理方法在页岩气勘探中的应用;对我国页岩气勘探技术的发展进行了展望,为我国页岩气勘探与开发提供参考.     

Analytical methods to estimate the hydraulic conductivity of jointed rocks

Hydrogeology Journal - The hydraulic conductivity of jointed rocks is one of the main input parameters to predict water inflow to engineering structures that are located in the jointed rocks....     

吸力基础抗拔与拔出机理的研究进展

黄土是第四纪以来形成的具有多孔隙弱胶结的特殊沉积物,受自然环境及人类工程活动影响,黄土体内分布大量不连续面,统称为黄土界面。黄土界面是黄土灾变的本底控制因素。依据界面灾害效应,黄土界面划分为巨观、宏观、细观和微观界面。黄土细观界面是指分割黄土块体的不连续面。本文通过野外调查,归纳出细观界面具有圆形状、对钩状、尖灭状及V形状的几何形态特征,组合特征表现为发散型的爪状、阶梯状、羽列状以及闭合型网格状。按成因分类为物理力学成因、生物活动成因、水土耦合成因、风化成因以及异相成因。黄土细观界面的发育演化是一个动态循环再生过程,具有时空特性、辐射特性,对土体具有分离、松动和软化渗透的灾变效应。本文针对黄土细观界面的初步探讨,旨在完善黄土界面灾变理论体系的科学基础,以期为黄土灾变机理研究提供科学参考依据。     

Unraveling reservoir compaction parameters through the inversion of surface subsidence observations

In an attempt to derive more information on the parameters driving compaction, this paper explores the feasibility of a method utilizing data on compaction-induced subsidence. We commence by using a Bayesian inversion scheme to infer the reservoir compaction from subsidence observations. The method’s strength is that it incorporates all the spatial and temporal correlations imposed by the geology and reservoir data. Subsequently, the contributions of the driving parameters are unravelled. We apply the approach to a synthetic model of an upscaled gas field in the northern Netherlands. We find that the inversion procedure leads to coupling between the driving parameters, as it does not discriminate between the individual contributions to the compaction. The provisional assessment of the parameter values shows that, in order to identify adequate estimate ranges for the driving parameters, a proper parameter estimation procedure (Markov Chain Monte Carlo, data assimilation) is necessary.     

海域非成岩天然气水合物储层改造方法分析

天然气水合物是未来重要的战略开采资源,受到了世界各国的广泛关注,因此对海底天然气水合物进行大规模开采成为必然。目前,海底天然气水合物开采还处于试采阶段,到目前为止还未形成成熟的开采方式。本文从人们所担心的海域天然气水合物开采过程中因储层非成岩可能出现的海底水合物大规模气化、破坏海洋生态环境、产生海底地质灾害等问题出发,对海域天然气水合物开采的安全性进行了分析。同时调研了当前世界各国海域天然气水合物试采现状,指出了进行储层改造是海域天然气水合物未来进行大规模开采的必由之路。探讨分析了采用水力喷射微小井眼技术边钻进水平井边喷射改进发泡水泥浆以进行储层改造的可行性,可为我国水合物商业化开采提供借鉴。     

页岩气解析测试中的几个问题——以柴达木盆地柴页1井为例

岩石含气量是页岩气资源量评价及勘探开发的关键性技术指标,其测试技术与方法尚处于发展与完善过程中。利用恒温解析-氢火焰离子检测法对柴达木盆地柴页1井侏罗系大煤沟组不同岩性的岩心进行了页岩气解析测试,通过对解析曲线和含气量数据分析研究发现:①页岩气解析测试的气体释放过程包括一系列的复杂解析过程,而非简单的解吸附过程,具有多级性,其解析速率曲线表现出多峰性;②岩石中吸附气的解吸量在早期恒温解析阶段遵循USBM直线规律,这一时间段的解析数据适合于计算损失气量;③岩石中的残余气是被岩石的物理构造所限滞的气体部分,应该在将岩石粉碎后测定;④将含页岩气岩心短期封存对于解析气测定结果的影响不大,在30天内完成测试即可。这些认识对于页岩气解析测试技术方法的改进、完善与规范具有重要参考价值。     

页岩气解析测试中的几个问题——以柴达木盆地柴页1井为例

岩石含气量是页岩气资源量评价及勘探开发的关键性技术指标,其测试技术与方法尚处于发展与完善过程中。利用恒温解析-氢火焰离子检测法对柴达木盆地柴页1井侏罗系大煤沟组不同岩性的岩心进行了页岩气解析测试,通过对解析曲线和含气量数据分析研究发现：①页岩气解析测试的气体释放过程包括一系列的复杂解析过程,而非简单的解吸附过程,具有多级性,其解析速率曲线表现出多峰性;②岩石中吸附气的解吸量在早期恒温解析阶段遵循USBM直线规律,这一时间段的解析数据适合于计算损失气量;③岩石中的残余气是被岩石的物理构造所限滞的气体部分,应该在将岩石粉碎后测定;④将含页岩气岩心短期封存对于解析气测定结果的影响不大,在30天内完成测试即可。这些认识对于页岩气解析测试技术方法的改进、完善与规范具有重要参考价值。     

煤层气储层参数多信息综合定量预测方法

提出了以地震属性和钻孔测井参数为基础, 以数学地质为桥梁, 实现煤层气储层参数定量预测的科学方法。薄煤层厚与反射波振幅之间为单调增减关系公式; 孔隙度与地震反射瞬时频率成正比关系, 可采含气量与地震反射瞬时振幅成反比关系, 且相关程度高。最后应用该成果对山西沁水煤层气地震勘探工程实际预测, 对储层厚度、孔隙度、含气量做出定量预测。该成果有利于提高煤矿采煤安全性和降低煤层气开采的风险性, 同时也将开拓地震勘探技术新的应用领域。