Tracing of natural gas migration by light hydrocarbons:A case study of the Dongsheng gas field in the Ordos Basin,NW China

Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.

Local Perception on the Exploitation, the Current State and Taboos Related to Pangolins (Pholidota, Mammalia) by the Communities Living in the Tayna Nature Reserve and Its Surroundings (RNT) North Kivu DRC

Pangolins are currently considered the most endangered mammal species due to their high rank in local and international traffic. This species is protected in DRC and worldwide, unfortunately it is threatened by numerous human actions. The objective of this study is to identify the different reasons for which these animals are exploited, to provide information to determine from the opinions of the respondents the current state of the population from 2015 to today and to identify their hunting techniques by the local populations. We carried out surveys in the households of hunters, farmers and people practicing other professions in 12 villages, located within the RNT and surroundings areas. Two interview techniques were used: the individual interview and the participatory diagnostic technique. 175 people were interviewed individually. Nearly 97% of our respondents are motivated to consume pangolin as bush meat obtaining by hunting. The main reason for eating pangolin meat is 44% preference and 33% habit. The zone does not know the foreign solicitation of the exploitation of pangolins and its derivatives. The opinions of the population regarding the current state of pangolin in the Tayna Nature Reserve indicate that from 2015 to the present day the common pangolin “Manis tricuspis” has been abundant. Hunters use different hunting techniques, dominated by pickup for the Manis tricuspis, digging burrow, fire at the entrance of the burrow for Manis gigantea and the shotgun for the Manis tetradactyla.

Footprint on the Sand： An Analysis of the State of Nature in Robinson Crusoe

Thomas Hobbes(1588-1679)put forward"state of nature",a term of political theory which had completely changed the Western political philosophy. Deeply influenced by this concept, Daniel Defoe(1660-1731) showed us an island of the state of nature in his Robinson Crusoe. A print of man's foot on the sand, which evoked Robinson's fear, had become a symbol of the state of nature for Robinson's life on the island, and finally brought him a"state of war".

Residues of High Concentration Carbendazim on Plants in Natural State

[ Objective] The paper was to explore the residual dynamics and degradation rule of high concentration carbendazim in natural condition. [ Method J The earbendasim solutions with mass fractions of 0.2% （ recommended concentration）, 0.4% （2 times of the recommended concentration） and I. 0% （5 times of the recommended concentration） were sprayed on plant leaves, and the residual amount of earbendazim in natural condition was determined. The dynamic models of carbendazim residues Under 3 concentrations were also studied. [ Result~ The degradation of earbcndazim under recommended concentration was accorded with Kinetic model for degradation, but the degradation Kinetic model for samples under 2 times and 5 times concentration appeared dissimilation. The residue of carben- dazim on plant was affected by absorption capacity of plants and weather conditions. The absorption capacity was affected by application concentration and growth condition of plant, higher concentration application and slow growth stage of p]ant were not conducive to the absorption of carbendazim; weather condition was mainly referred to temperature and humidity, higher temperature and dry weather were not conducive to the degradation of earbendazim. [Condusion ] The paper provided theoretical basis for guiding the application of carbendazim under different growth stages of crops and different weather conditions in agricultural production.

EQUATION OF STATE BASED HYDRATE MODEL FOR NATURAL GAS SYSTEMS CONTAINING BRINE AND POLAR INHIBITOR

A new thermodynamic model for gas hydrates was established by combining the modified Patel-Teja equation of state proposed for aqueous electrolyte systems and the simplified Holder -John multi -shell hydrate model. The new hydrate model is capable of predicting the hydrate formation/dissociation conditions of natural gas systems containing pure water/formation water (brine) and polar inhibitor without using activity coefficient model. Extensive test results indicate very encouraging results.

A New Alpha-function for the Peng-Robinson Equation of State： Application to Natural Gas

Cubic equations of state(EOSs) are simple and easy at calculation. One way of improving the accuracy of a cubic EOS is through the modification of temperature-dependent energy parameter by using alpha-function.The industrial applications of natural gas are very wide and as a result, prediction of thermodynamic properties and phase behavior of natural gas is an important part of design for such processes. In this work we develop a newα-function for the Peng-Robinson(PR) EOS with the parameters optimized especially for natural gas components.The parameters are generalized as a linear function of acentric factor. The results are compared to the predictions from original PR EOS and other α-functions in literature. It is shown that the new α-function presents a good accuracy with the average deviation of 1.42% for natural gas components.

Quantum Mechanical Nature in Liquid NMR Quantum Computing

The quantum nature of bulk ensemble NMR quantum computing the center of recent heated debate,is addressed. Concepts of the mixed state and entanglement are examined, and the data in a two-qubit liquid NMRquantum computation are analyzed. The main points in this paper are: i) Density matrix describes the "state" of anaverage particle in an ensemble. It does not describe the state of an individual particle in an ensemble; ii) Entanglementis a property of the wave function of a microscopic particle (such as a molecule in a liquid NMR sample), and separabilityof the density matrix cannot be used to measure the entanglement of mixed ensemble; iii) The state evolution in bulk-ensemble NMRquantum computation is quantum-mechanical; iv) The coefficient before the effective pure state densitymatrix, e, is a measure of the simultaneity of the molecules in an ensemble. It reflects the intensity of the NMR signaland has no significance in quantifying the entanglement in the bulk ensemble NMR system. The decomposition of thedensity matrix into product states is only an indication that the ensemble can be prepared by an ensemble with theparticles unentangled. We conclude that effective-pure-state NMR quantum computation is genuine, not just classicalsimulations.

Quantum Mechanical Nature in Liquid NMR Quantum Computing

The quantum nature of bulk ensemble NMR quantum computing — the center of recent heated debate, is addressed. Concepts of the mixed state and entanglement are examined, and the data in a two-qubit liquid NMR quantum computation are analyzed. The main points in this paper are: i) Density matrix describes the 'state' of an average particle in an ensemble. It does not describe the state of an individual particle in an ensemble; ii) Entanglement is a property of the wave function of a microscopic particle (such as a molecule in a liquid NMR sample), and separability of the density matrix cannot be used to measure the entanglement of mixed ensemble; iii) The state evolution in bulk-ensemble NMR quantum computation is quantum-mechanical; iv) The coefficient before the effective pure state density matrix, ?, is a measure of the simultaneity of the molecules in an ensemble. It reflects the intensity of the NMR signal and has no significance in quantifying the entanglement in the bulk ensemble NMR system. The decomposition of the density matrix into product states is only an indication that the ensemble can be prepared by an ensemble with the particles unentangled. We conclude that effective-pure-state NMR quantum computation is genuine, not just classical simulations.

XPS characteristics of sulfur of bio-oxidized arsenic-bearing gold concentrate and changes of surface nature of bio-oxidation residue

During bio-oxidation of sulfides, the chemical state change of sulfur is a complex and key factor. It is not only an indicator of the extent and intensity of the bio-oxidation, but also controls the property of bio-leaching medium and the period of oxidation. The chemical state of sulfur in sulfides oxidized by leaching bacteria was studied with XPS. Sulfide minerals in the arsenic-bearing gold concentrate consist of pyrite, arsenopyrite, chalcopyrite, galena, sphalerite and so on. In order to probe the pattern of the chemical state change of sulfur in the bio-oxidation residue of arsenic-bearing gold concentrate, the structure of the grains, and the surface nature of the residue, XPS test was carried out through different sputtering duration. The study of XPS clearly shows that: sulfides is progressively oxidized from the surface of minerals to the core by leaching bacteria; the chemical valence of sulfur changes from S2- or [S2]2- to [SO4]2-; sulfur in the core is in a reduction state, S2- or [S2]2-, but exists in an oxidation state S6+ on the surface; due to the chemical state change of sulfur, mineral phase of the bio-oxidation residue is also changed（sulfides inside, while sulfates outside）; the layered structure is found in the grains of the bio-oxidation residue.

Prediction of Volumetric Properties(p-v-T)of Natural Gas Mixtures Using Extended Tao-Mason Equation of State

A statistical-mechanical-based equation of state(EOS)for pure substances,the Tao-Mason equation of state,is successfully extended to prediction of the(p-v-T)properties of fourteen natural gas mixtures at temperatures from 225 K to 483 K and pressures up to 60.5 MPa.This work shows that the Tao-Mason equation of state for multicomponent natural gas is predictable with minimal input information,namely critical temperature,critical pressure,and the Pitzer acentric factor.The calculated results agree well with the experimental data.From a total of 963 data of density and 330 data of compressibility factor for natural gases examined in this work,the average absolute deviations(AAD)are 1.704%and 1.344%,respectively.The present EOS is further assessed through the comparisons with Peng-Robinson(PR)equation of state.For the all of mixtures Tao-Mason(TM)EOS outperforms the PR EOS.

Document Type Profiles in Nature, Science, and PNAS： Journal and Country Level

Purpose： In this contribution, we want to detect the document type profiles of the three prestigious journals Nature, Science, and Proceedings of the National Academy of Sciences of the United States （PNAS） with regard to two levels： journal and country. Design/methodology/approach： Using relative values based on fractional counting, we investigate the distribution of publications across document types at both the journal and country level, and we use （cosine） document type profile similarity values to compare pairs of publication years within countries. Findings： Nature and Science mainly publish Editorial Material, Article, News Item and Letter, whereas the publications of PNAS are heavily concentrated on Article. The shares of Article for Nature and Science are decreasing slightly from 1999 to 2014, while the corresponding shares of Editorial Material are increasing. Most studied countries focus on Article and Letter in Nature, but on Letter in Science and PNAS. The document type profiles of some of the studied countries change to a relatively large extent over publication years. Research limitations： The main limitation of this research concerns the Web of Science classification of publications into document types. Since the analysis of the paper is based on document types of Web of Science, the classification in question is not free from errors, and the accuracy of the analysis might be affected.Practical implications： Results show that Nature and Science are quite diversified with regard to document types. In bibliometric assessments, where publications in Nature and Science play a role, other document types than Article and Review might therefore be taken into account. Originality/value： Results highlight the importance of other document types than Article and Review in Nature and Science. Large differences are also found when comparing the country document type profiles of the three journals with the corresponding profiles in all Web of Science journals.

The Natural Law of Transition of a Charged Particle into a Compound State under the Action of an Electroscalar Field

This article is the continuation of article [1] where the experimental facts of observation of the electroscalar radiation in the spectrum of the Sun have been presented [2]. This radiation comes into the world having a long wavelength, being longitudinal and extraordinarily penetrating. In accordance with the principle of least action, the Lagrangian of the electroscalar field and the tensor of energy-moment are determined using the variation the potential and coordinates. The equation of motion the charged particle in electroscalar field is determined and the energy of particle has the negative sign with respect to the mechanical energy of particle and the energy of electromagnetic field. So, this is decreasing the electrical potential of particle during the propagation. The electroscalar energy of charged particle and field’s force acting on the particle during their motion change the particle’s electrical status which, in its turn, may trigger the transition of the particle into a compound state during interaction with any object. Due to the continuity this process can lead the particle to the state which enters into a compound state with a negative energy for a different particle’s velocity. This state is the physical vacuum’s state. Analysis of the solar spectrum demonstrates that scattering and absorption of electroscalar wave go on the cavities of solids. The spreading out of electroscalar field obeys to the law of plane wave and the transfer the energy and information can occur in vacuum and any medium.

鄂尔多斯盆地大牛地气田上古生界致密气轻烃地球化学特征

大牛地气田是鄂尔多斯盆地典型致密砂岩大气田之一。为了更深入了解该区天然气的成因和来源,揭示天然气运移相态,对大牛地气田上古生界致密气开展了轻烃地球化学特征分析。研究表明,该区上古生界致密气C5-7轻烃组成具有异构烷烃优势分布,C6-7轻烃组成中芳烃含量整体偏低(<10%),甚至未检出芳烃,C7轻烃组成具有甲基环己烷优势分布特征,甲基环己烷相对含量均超过50%。上二叠统下石盒子组天然气K_(1)值、K_(2)值均与二叠系山西组和石炭系太原组天然气一致,而δ^(13)C_(1)值则与山西组天然气一致,与太原组天然气有明显不同。与山西组天然气相比,下石盒子组天然气整体具有偏低的苯/正己烷、苯/环己烷和甲苯/正庚烷比值,以及明显偏高的正庚烷/甲基环己烷比值。轻烃地球化学特征及烷烃气碳氢同位素组成综合表明,大牛地气田上古生界天然气为典型煤成气,其中山西组和太原组天然气均为原地自生自储,而下石盒子组天然气为下伏山西组烃源岩生成的天然气经历了游离相垂向运移聚集形成,太原组烃源岩不具有显著贡献。受天然气运移和水溶等作用影响,庚烷值、异庚烷值、苯/正己烷比值等轻烃指标直接用于判识大牛地气田致密气成熟度会存在偏差。

天然气运移轻烃地球化学示踪--以鄂尔多斯盆地东胜气田为例

基于天然气中轻烃化合物组成分析和区域性对比,结合组分和甲烷碳同位素组成特征,揭示轻烃地球化学特征对鄂尔多斯盆地东胜气田上古生界天然气运移和水溶及逸散等示踪作用,探讨运移作用对特定轻烃指标的关联效应。研究表明:①东胜气田二叠系下石盒子组天然气C5−7异构烷烃含量高于正构烷烃,C6−7轻烃组成呈链烷烃优势分布且芳香烃含量明显偏低(小于4.0%),C7轻烃主体呈甲基环己烷优势分布,整体表现出煤成气特征且受到了水溶等作用影响;②东胜气田天然气经历了自南向北的游离相运移,并在充注后发生不同程度的水溶作用,其中泊尔江海子断裂以北什股壕地区天然气在聚集后具有明显的散失;③长距离的游离相运移导致天然气C7轻烃中甲基环己烷相对含量和甲苯/正庚烷值降低、正庚烷/甲基环己烷值和庚烷值增大,水溶作用导致轻烃异庚烷值增大,天然气散失导致什股壕地区天然气中C5−7正构烷烃相对异构烷烃含量增加。

异质资本持股、内外部治理与国有企业股价崩盘风险

防范系统性金融风险是经济健康发展的重要保障。鉴于股价崩盘风险与系统性金融风险的关联性,以2014~2020年国有企业为样本,实证检验不同性质的非国有资本参股对国有企业股价崩盘风险的影响,并进一步考察企业内外部治理对非国有资本参股与国有企业股价崩盘风险之间关系的调节效应。研究结果表明,民营资本参股降低了股价崩盘风险,机构投资者参股增加了股价崩盘风险,而外资参股不存在显著影响。在进行一系列稳健性检验之后,结果仍然成立。就内外部治理而言,内部治理水平仅对民营资本持股比例与股价崩盘风险之间的关系有显著的正向调节作用,外部治理环境仅对机构投资者持股比例与股价崩盘风险之间的关系有显著的负向调节作用。

基于可靠性方法的大口径天然气管段壁厚设计

我国陆上天然气管道规模庞大,管道路由地形、地貌和气候特征复杂多样。面对管道及管道所处环境的复杂性,提高油气管道的本质安全水平是行业和民众的共同需求,保证陆上天然气管道安全和可靠运行也越来越成为行业关注的焦点。为达到这个目标,可以采用从源头上对陆上天然气管道的设计方法进行改进的办法。目前天然气管道设计大多普遍利用传统的基于应力的设计方法,该方法由于采用单一的安全系数导致油气管道的安全裕度难以考量,针对此问题,基于可靠性的油气管道设计和评估方法(Reliability Based Design and Assessment,简称RBDA)正成为现代陆上天然气管道设计的趋向,该方法可量化管道全生命周期中的风险,避免采用不合理或过于保守的设计标准。故本研究综合CSAZ662《油气管道系统》标准规范的油气管道可靠性设计方法,并结合国内部分机构根据我国国情而修正的可靠性研究,利用RBDA方法流程,根据某段实际天然气管道确定该管道失效的主要原因(以腐蚀和第三方破坏为主),设计了管道在其生命周期内的极限状态,根据极限状态选择对应的极限状态方程类型,并利用多种数据统计分析方法和软件确定方程中所涉及各个随机变量参数的分布类型,之后利用蒙特卡洛法(Monte-Carlo法)计算设计壁厚条件下得到天然气管道失效概率,统筹考虑其他失效原因的权重,进而得到该管道的可靠度,将该可靠度数据与国内外标准规范确定的目标可靠度进行对比,检验是否满足可靠度目标。由此,对大口径天然气管段完成壁厚设计,实现了使用RBDA方法对1016 mm大口径天然气管道设计的整体流程。

论生态环境损害赔偿制度的法理基础与规范构造

理解生态环境损害赔偿制度,须从环境治理体系和治理能力现代化的整体视域展开,同时,还要厘清生态环境与自然资源、生态环境损害与损害赔偿、赔偿请求权与赔偿诉权等核心概念。既有理论将自然资源国家所有权作为生态环境损害赔偿中的实体权利基础,然而,不论是公权说、私权说,还是二阶结构说、三层结构说,都不周延。因为生态环境损害赔偿制度存在二元构造,即赔偿请求权区别于赔偿诉权,赔偿请求权中基于自然资源所有权的物上请求权区别于侵害生态环境的侵权之债请求权,赔偿诉权中程序意义上的提起生态环境损害赔偿诉讼区别于实体意义上的救济自然资源所有权。这种二元构造客观上源于生态环境中单体自然资源的结构面向与整体生态功能的功能面向存在区分,其学理基础在于承继和发展了传统所有权的解释范式,其核心内容是对生态环境类的损害进行类型化。为此,该制度可从两个方面予以展开。长期而言,须仰仗制定中的生态环境法典规定生态环境损害赔偿的系列内容;当务之急,则是借助司法解释促进这些内容的适度法制化。

再论汉代人的国家意识

汉代人的国家意识在带有“公”属性的同时,其一家一姓“皇帝专属”的“私”属性十分浓厚。虽然总体来看,汉代人的强国与爱国意识得到了空前强化,但汉代人的国家意识也具有多层次性、差异性和可变性。理性看待汉代人的国家意识,可为现今中国真正有效、稳固、积极、健康的群体爱国意识的形成及爱国行为的产生提供有价值的历史启示。

可充电动物遥测系统在自然状态小鼠心电监测中的应用

目的探讨可充电动物遥测系统在自然状态小鼠心电监测中的应用,并提供自然清醒状态小鼠的心电参数。方法20只C57小鼠(雌雄各半)安装植入式电极,连续记录小鼠全天24 h心电活动并分析其心电参数。结果20只C57小鼠均完成24 h监测。C57小鼠全天平均心率为(493.55±73.29)次/分。雌鼠全天平均心率为(522.83±63.70)次/分,最大心率673.60次/分,最小心率385.90次/分。雄鼠全天平均心率为(464.27±70.55)次/分,最大心率641.60次/分,最小心率321.50次/分。雌性小鼠的全天平均心率快于雄性小鼠,差异有统计学意义(P<0.05);雄性小鼠夜间平均心率较白天平均心率增快,差异有统计学意义(P<0.05)。白天07∶00-19∶00,夜间19∶00-次日07∶00小鼠相关心率变化指标结果显示,雌性小鼠白天平均心率较夜间平均心率增快,雄性小鼠白天平均心率较夜间平均心率减慢,差异有统计学意义(P<0.05)。麻醉状态下小鼠的心电指标结果显示,雌、雄小鼠P波振幅、P波时限以及RR间期差异具有统计学意义(P<0.05);雄性小鼠的QRS时限较雌性小鼠延长,差异有统计学意义(P<0.05);雌、雄小鼠QRS振幅以及QT间期差异无统计学意义(P>0.05)。结论可充电动物遥测系统可安全、微损伤地对自由活动状态的小鼠进行24小时心电参数记录,其记录的信号清晰、稳定,可用于正常及急慢性模型小鼠自然状态下心率及心律的监测。

掺氢天然气管网数值仿真轻量化算法

目前针对管网数值仿真算法的优化主要集中在代数方程组的求解上。针对管网流动数值仿真算法提升计算效率方案中缺少针对封闭关系与状态方程的优化,分析了目前优化方案各模块的耗时情况,发现了仿真程序中耗时模块为封闭关系与状态方程求解。最后,结合计算机库函数的缺点以及现代CPU中SIMD (Single Instruction Multiple Data)模型的特点,提出了针对封闭关系与状态方程的轻量化算法,并验证了算法的高效性。研究结果表明:(1)封闭关系与状态方程模型中的耗时原因为直接调用库函数的次幂运算、指数运算、对数运算以及除法运算;(2)由于次幂运算效率远低于其他运算,通过变换消除了模型中几乎所有的次幂运算;(3)利用SIMD指令来计算指数运算与对数运算,实现了在单核CPU上同时计算多个数据的指数与对数,最后通过数学变换将所有除法转换为乘法;(4)轻量化算法加速效果显著,其整体加速比为18,而在状态方程求解模块的加速比更是高达70以上。结论认为,该轻量化算法在不影响计算精度的条件下提高了计算速度,对于提高掺氢天然气管网在线仿真与智能管网的建设具有重要的理论价值和技术支撑。