隧道围岩断面轮廓分维数的小波分析算法及应用

隧道的超欠挖对衬砌结构稳定性影响较大,研究其规律,对于掌握围岩受力,确保施工安全,具有深远意义。隧道断面轮廓超欠挖序列具有统计自相似性,根据小波分析的多分辨率的特点,本文给出了利用小波理论估计分维数的方法。选定恰当的小波函数和分解层数,对隧道围岩断面的整体轮廓、拱顶和边墙的超欠挖序列分别进分形维数的小波分析估算,结果安全可靠。根据计算结果,分析了设计围岩类别与断面轮廓曲线分形维数估计值之间的关系,并结合现场实际情况,简明分析了断面轮廓分形维数与围岩稳定性之间的关系。     

iCAP 6300电感耦合等离子体发射光谱仪的常规维护方法

电感耦合等离子体发射光谱仪在使用过程中,由于控制气体流量的电磁阀出现机械性移位,致使工作气流量过于偏大或偏小,对进样系统及分析数据产生不利影响;长期频繁使用条件下,由于控制光学系统的机械定位装置的磨损,致使谱峰坐标偏离而影响仪器灵敏度;很长时间不能"引燃"等离子体,检查进样系统和氩气纯度并没有发现异常,需要验证RF发生器有无功率输出时有一定的困难;在等离子体工作时产生的高温尾气的长期作用下,难免造成点火头末端铜丝的锈蚀,致使点火头放电微弱,不能"引燃"等离子体。因此,为保证仪器的正常运行,提高工作效率,确保检测数据的准确度,实验室应建立健全电感耦合等离子体发射光谱仪维护保养方案,解决上述问题。本文结合实际工作经验,以iCAP 6300电感耦合等离子体发射光谱仪为例,提出可以借助"Manufacturing and Service.exe"程序校正工作气流量,验证RF发生器是否输出功率;利用C 193.091 nm谱线为基准校正谱线修正CID检测器的谱峰坐标系统;另外,对点火头、分析软件数据库及主机灰尘的清理也进行了详细的维护说明,这些措施有益于保障仪器的性能及提高设备的利用率。     

云南玉溪抗旱找水定井典型实例分析

西南大旱百年不遇,山东找水专家组紧急驰援云南抗旱。通过对云南抗旱找水成功定井实例的分析,总结了高原岩溶水和＂红层＂基岩裂隙水的找水勘察工作,并联系云南、四川、山东等贫水区找水定井实践,阐述了贫水区找水定井思路与方法。     

Effects of the geometry of two‐dimensional fractures on their hydraulic aperture and on the validity of the local cubic law

Flow through rough fractures is investigated numerically in order to assess the validity of the local cubic law for different fracture geometries. Two‐dimensional channels with sinusoidal walls having different geometrical properties defined by the aperture, the amplitude, and the wavelength of the walls' corrugations, the corrugations asymmetry, and the phase shift between the two walls are considered to represent different fracture geometries. First, it is analytically shown that the hydraulic aperture clearly deviates from the mean aperture when the walls' roughness, the phase shift, and/or the asymmetry between the fracture walls are relatively high. The continuity and the Navier–Stokes equations are then solved by means of the finite element method and the numerical solutions compared to the theoretical predictions of the local cubic law. Reynolds numbers ranging from 0.066 to 66.66 are investigated so as to focus more particularly on the effect of flow inertial effects on the validity of the local cubic law. For low Reynolds number, typically less than 15, the local cubic law properly describes the fracture flow, especially when the fracture walls have small corrugation amplitudes. For Reynolds numbers higher than 15, the local cubic law is valid under the conditions that the fracture presents a low aspect ratio, small corrugation amplitudes, and a moderate phase lag between its walls.     

关于西沙海槽正磁异常带的地球物理认识

南海北部西沙海槽存在东西向正磁异常带,长约350 km,前人推测为基性或超基性物质反磁化的反映.通过对西沙海槽大比例尺高精度航磁资料分带化极处理和反演拟合,发现西沙海槽正磁异常带由海槽北缘隐伏强磁性体斜磁化引起.磁性体埋深超过9 km,推测是残留洋壳（蛇绿岩）,为海南岛昌江—琼海断裂带或海南岛九所—陵水断裂带所代表的缝合带在南海北部的延伸段.     

Multifractal Analysis of Element Distribution in Skarn-type Deposits in the Shizishan Orefield, Tongling Area, Anhui Province, China

A series of element concentrations sampled from four drill cores with a length about 1000 m into different skarn-type deposits were selected from the Shizishan orefield, central Tongling, southeastern part of Anhui Province. Using the multifractal method, the distribution and migration characteristics of the major and trace elements are analyzed. The multifractal spectrum of the major elements is left-skewed, whereas the spectrum of the trace elements is right-skewed, which shows that in the process of skarn formation, the trace elements were enriched only locally, and major elements transported within a much larger range. The correlation coefficients of the multifractal parameters Aa （width of the multifractal spectrum） of the four drill cores are relatively low, but the correlation coefficients of the multifractal parameters R （spectrum symmetry parameter） and Af are relatively higher, indicating that although the non-homogeneous intensity of the distribution of elements is inconsistent, their spatial accumulation patterns are almost the same during the ore-forming process. The statistics of the mnltifractal parameters of various elements in the different locations show that the ore-forming processes and element migration pattern in the Shizishan orefield are consistent, and that the migrations of trace elements and major elements exhibit some differences.     

北京市服务业碳排放增长的分解分析

The output as well as carbon dioxide emissions of tertiary industry have increased continuously in Beijing. Therefore, the tertiary industry has become a new field that needs to be explored for energy saving and emission reduction. This paper calculates the direct and indirect carbon dioxide emissions of tertiary industry in Beijing from 2005 to 2012 using the input-output analysis method. The results indicate that both the direct and indirect carbon dioxide emissions increased continuously and the latter grew more quickly than the former. The growth of the direct and indirect carbon dioxide emissions of tertiary industry was decomposed, which showed that four factors influence the growth of carbon emission of the tertiary industry, including the changes of industrial scale, industrial structure, energy consumption intensity and carbon coefficient. The results show that the industrial scale advancement and the direct energy carbon coefficient change promote the increase of direct carbon dioxide emissions, while the shift of industrial structure and the change of direct energy consumption intensity have the restrain on it. The industrial scale enlargement, industrial structure shift and the indirect energy carbon emission coefficient change promote the growth of indirect carbon dioxide emissions, while the indirect energy consumption intensity change has a restrain.     

东南沿海地区古近纪大陆岩石圈地幔特征及成因

东南沿海地区新生代玄武岩中的橄榄岩包体来自岩石圈地幔 ,上地幔橄榄岩包体的岩石学及地球化学特征都记录了地幔演化的历史。普宁橄榄岩包体斜方辉石含量与太古宙克拉通地幔类似 ,但在矿物学、REE、痕量元素和Sr Nd同位素上又与太古宙岩石圈地幔不同。橄榄岩包体的岩相学、矿物学、REE、痕量元素特征都提供了含H2 O富Si流体交代橄榄岩的证据 ,这种流体可能主要是洋壳物质局部熔融而成。流体交代使橄榄岩富Si,同时富Sr、Pb和强不相容元素等大洋岩石圈物质。这表明普宁大陆岩石圈地幔既保留太古宙岩石圈地幔的特征 ,又具有大洋俯冲地幔的特征 ,它是古老岩石圈地幔向大洋岩石圈地幔转换的一部分 ,这种转换可能是大洋岩石圈与大陆岩石圈地幔相互作用的结果。     

全球气候模式对未来中国风速变化预估

利用世界气候研究计划之第三次耦合模式比较计划 (WCRP/CMIP3) 提供的, 参加IPCC AR4的19个气候模式和国家气候中心为IPCC第五次报告研发的新一代气候模式 (BCC_CSM1.0.1) 及模式集成, 考虑高排放 (A2)、 中等排放 (A1B) 和低排放 (B1) 三种人类排放情景, 预估21世纪中国近地层 (离地10 m) 风速变化。预估结果表明: (1) 21世纪全国平均的年平均风速呈微弱的减小趋势, 且随着预估情景人类排放的增加, 中国年平均风速减小趋势越显著。 (2) 冬季 (夏季) 全国平均风速呈减小 (增大) 趋势, 人类排放量越多, 冬季 (夏季) 风速减小 (增加) 程度越大。21世纪我国风速夏季 (冬季) 增大 (减小) 与全球变暖的背景下未来亚洲夏季风 (冬季风) 增强 (减弱) 有一定关系。 (3) 与20世纪末期 (1980～1999年) 相比, 21世纪初期 (2011～2030年) 中国区域年平均风速A2情景下略偏小, A1B和B1情景下年平均风速无明显变化; 21世纪中期 (2046～2065年) 和后期 (2080～2099年), 三种排放情景下中国年平均风速均比20世纪末期风速小。 (4) 21世纪初期、 中期和后期均表现为冬季 (夏季) 平均风速比20世纪末期冬季 (夏季) 平均小 (大)。 (5) 夏季中国中北部和东北地区风速偏大, 其余地区风速无明显变化或略偏小; 冬季除了东北北部和西藏东南部外, 中国大部地区风速偏小。绝大部分地区超过50%模式一致地预估上述风速变化形式, 具有一定的可信度。     

青海地区钻孔应变干扰及异常分析

简要叙述了青海地区6个钻孔应变台站的观测概况,通过分析,认为主要存在观测技术系统和观测环境变化这两类干扰。在排除各类干扰后,发现只有乐都台和湟源台在汶川地震前出现了前兆异常。