Ion acceleration and Alfvén wave generation at the Earth’s bow shock

The processes of ion acceleration and Alfvén wave generation by accelerated particles at the Earth’s bow shock are studied within a quasi-linear approach. Steady-state ion and wave spectra are shown to be established in a time of 0.3–4 h, depending on the background level of Alfvénic turbulence in the solar wind. The Alfvén waves produced by accelerated ions are confined within the frequency range 10^?2–1 Hz and their spectral peak with a wave amplitude βB ～ B comparable to the interplanetary magnetic field strength B corresponds to the frequency v = (2–3) × 10^?2 Hz. The high-frequency part of the wave spectrum (v > 0.2 Hz) undergoes damping by thermal ions. The calculated spectra of the accelerated ions and the Alfvén waves generated by them reproduce the main features observed in experiments.     

松辽盆地深层断陷沙河子组烃源岩分布预测与生气潜力

松辽盆地下白垩统沙河子组是深层断陷的主要烃源岩发育层系,目前钻井揭示其厚度大（＞700 m）,埋藏深（＞3500 m）,但钻井大都分布于深层断陷的边部,断陷内部烃源岩层揭示少。根据断陷结构样式及地震反射特征,总结出单断箕状断陷和双断地堑式断陷两种沙河子组烃源岩发育模式,并确定深层烃源岩主要有五种存在形式。断陷中部席状平行结构、成层性、连续性好的地震反射特征的烃源岩最为落实,主要为深湖-半深湖相,暗色泥岩厚度大,暗地比高（45％～70％）。深层沙河子组烃源岩总生气量约148.38×1012 m3,天然气资源潜力巨大。     

特征约束六面体网格生成的改进栅格法

目前,针对地学对象的非结构化六面体网格生成问题仍未得到很好的解决。为满足相关地学研究对六面体网格的需求,促进地学模拟及传统GIS空间分析的进一步发展,本文对传统栅格法进行扩展,提出了一种面向地学研究的六面体网格生成的改进栅格法。通过提取实体模型表面的几何特征,考虑内部孔、洞约束生成骨干网格,在此基础上构建一套特征约束模板来处理复杂的特征约束,使之既能保持地学研究对象的几何形态特征,又能实现加密区域与非加密区域的平滑过渡,从而满足地学分析与模拟的需求。     

一种程控宽频带多波形信号发生器的研制

针对目前专门的函数信号发生器IC功能简单、精度不高、调节方式不灵活等缺点和DDS芯片外围电路设计复杂、成本较高等问题,设计研制了一种程控宽频带多波形信号发生器。该信号发生器采用单片机STC89C52控制专用函数发生器MAX038实现,通过键盘设置输出波形类型、频率、占空比和幅度等各种参数,采用闭环控制方法对输出频率自动反馈控制以提高频率精度,并由八位LED显示器实时显示状态信息。实际运行结果表明:该系统可以产生频率范围在1Hz~20MHz、幅度在2~10V(VPP)连续可调、占空比在10%~90%变化的三角波、锯齿波、方波、正弦波和PWM波,输出频率精度小于0.01%。该仪器具有电路结构简单、性能优良、成本低廉、功能多样、使用方便等优点,在生产实践和科技研究领域中具有广泛的应用前景。     

Electricity generation and cooling water use: UK pathways to 2050

Thermoelectric generation contributes to 80% of global electricity production. Cooling of thermoelectric plants is often achieved by water abstractions from the natural environment. In England and Wales, the electricity sector is responsible for approximately half of all water abstractions and 40% of non-tidal surface water abstractions. We present a model that quantifies current water use of the UK electricity sector and use it to test six decarbonisation pathways to 2050. The pathways consist of a variety of generation technologies, with associated cooling methods, water use factors and cooling water sources. We find that up to 2030, water use across the six pathways is fairly consistent and all achieve significant reductions in both carbon and water intensity, based upon a transition to closed loop and hybrid cooling systems. From 2030 to 2050 our results diverge. Pathways with high levels of carbon capture and storage result in freshwater consumption that exceeds current levels (37–107%), and a consumptive intensity that is 30–69% higher. Risks to the aquatic environment will be intensified if generation with carbon capture and storage is clustered. Pathways of high nuclear capacity result in tidal and coastal abstraction that exceed current levels by 148–399%. Whilst reducing freshwater abstractions, the marine environment will be impacted if a shortage of coastal sites leads to clustering of nuclear reactors and concentration of heated water discharges. The pathway with the highest level of renewables has both lowest abstraction and consumption of water. Freshwater consumption can also be minimised through use of hybrid cooling, which despite marginally higher costs and emissions, would reduce dependence on scarce water resources thus increase security of supply.     

松辽盆地深层断陷沙河子组烃源岩分布预测与生气潜力

松辽盆地下白垩统沙河子组是深层断陷的主要烃源岩发育层系,目前钻井揭示其厚度大(700 m),埋藏深(3 500 m),但钻井大都分布于深层断陷的边部,断陷内部烃源岩层揭示少。根据断陷结构样式及地震反射特征,总结出单断箕状断陷和双断地堑式断陷两种沙河子组烃源岩发育模式,并确定深层烃源岩主要有五种存在形式。断陷中部席状平行结构、成层性、连续性好的地震反射特征的烃源岩最为落实,主要为深湖--半深湖相,暗色泥岩厚度大,暗地比高(45%~70%)。深层沙河子组烃源岩总生气量约148.38×1012m3,天然气资源潜力巨大。     

冀中坳陷东北部石炭-二叠系烃源岩热史及成熟史模拟

石炭-二叠系煤成气藏是冀中坳陷东北部亟待突破的勘探领域。文中基于大量的钻井、测井、地球化学和古地温资
料,分别模拟构建了大城凸起、文安斜坡和武清凹陷的埋藏史和考虑岩浆热液侵入作用的热演化史。研究结果表明冀中坳
陷东北部石炭-二叠系地层总体上经历了“三沉两抬”的构造演化过程,在印支运动前全区具有近似的演化历史,印支
期、燕山期区内构造演化开始分异,至新生代形成总体“东隆西坳”的构造格局。区内烃源岩热演化包括一次生烃和二次
生烃,并可细分为长期隆升型、后期强烈沉降深成变质型和岩浆热变质型三种类型。一次成烃主要发生在三叠系末期,二
次成烃分别在新近纪和古近纪岩浆侵入期。区内斜坡浅部和隆起区一次成烃,斜坡和凹陷深部为后期强烈沉降深成变质二
次成烃、斜坡和凸起岩浆热液侵入区发生岩浆热变质二次成烃。一次成烃期Ro 值在0.7%左右,不具成藏潜力,二次成烃
期烃源岩可达高熟、过熟阶段,成藏配置条件好,成藏潜力巨大。     

塔里木盆地石炭系烃源岩成熟演化研究

尽管塔里木盆地石炭系富含有机质且已发现其生成的原油,但关于石炭系烃源岩热演化研究却很薄弱。根据基础地质资料、古地温梯度和实测镜质体反射率数据,本文定量模拟了塔里木盆地6口典型井的石炭系烃源岩热演化史和这套烃源岩底界、顶界在二叠纪末期、三叠纪末期、白垩纪末期及现今成熟度的平面分布规律。塔北隆起南部、塔西南坳陷和阿瓦提凹陷在石炭-二叠纪作为沉降中心接受了巨厚的沉积物,造成这些地区石炭系烃源岩底界成熟度在二叠纪末期达到0.9%～1.3%（中-高成熟）,顶界为0.5%～0.9%（低-中成熟）,成为有利生油区。中生代时期,塔里木盆地中、东部长期处于沉降状态,石炭系烃源岩处于成熟演化阶段。白垩纪末期,塔中低凸起和满加尔凹陷的石炭系底界成熟度为0.7%～0.9%（中成熟）,顶界为0.5%～0.7%（低成熟）,而塘古孜巴斯坳陷底界成熟度为0.9%～1.1%（中-高成熟）,顶界为0.7%～0.9%（中成熟）。受羌塘地体、拉萨地体、印度板块分别与欧亚板块南缘碰撞远程效应的影响,塔西南坳陷和巴楚隆起在中生代一直处于隆升剥蚀状态,烃源岩热演化进入停滞状态。新生代以来,塔西南坳陷和阿瓦提凹陷演化为前陆盆地,再次接受了巨厚沉积物,致使石炭系烃源岩快速成熟演化,底-顶界成熟度现今已超过2.0%,进入干气阶段。满加尔凹陷石炭系烃源岩自石炭纪至今一直处于成熟演化阶段,现今达到最大,为0.8%～1.0%。另外,热史研究表明塔西南坳陷和阿瓦提凹陷石炭系烃源岩具有二次生烃潜力。本研究不仅丰富了塔里木盆地石炭系烃源岩热史研究成果,而且对油气勘探与开发具有重要的指导意义。     

Thermal simulation of basic volcanic fluid influence on different source rocks

Based on thermal simulation experiment, interactions between volcanic fluids and source rocks were studied. Gas generations in the dry system and fluid system under different temperatures were analyzed. The results showed that the various types of source rocks are similar in composition, containing gaseous C1-C5 hydrocarbons, H2 and CO2 whose gas yields increase with increasing temperature. The gas yield of source rocks of type I is the high- est, followed by type II, and that of source rocks of type III is the lowest, indicating that the yield of hydrocarbon gases is related to their hydrocarbon generating potential. Although the generating potential of type III is the lowest, it can still be regarded as a useful gas source when it is buried deeply enough. The basic volcanic fluid restrains the generation of gaseous hydrocarbons in different types of source rocks, but promotes the generation of inorganic gases.     

氢化物发生-原子荧光光谱法测定砷等元素分析探讨

本文分析探讨氢化物发生—原子荧光光谱法测定土壤中低质量浓度的砷、锑、铋的方法实验。