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。     

高海拔隧道涌突水预测分析——以四川小卡子隧道为例

小卡子隧道是连接九龙县城和石棉县城的一条便利通道,它是连接S215和S211的绿色保障,九龙和石棉之间是海拔高度4 000 m以上,九龙县城周边为高原宽谷丘陵地区,地势起伏较大。九龙至周边沿线不良地质和特殊褶皱构造发育,其中冰雪害几乎每年冬春都发生,且影响线路较长,其它地质灾害也时常暴发,致使交通事故频繁发生,成为制约九龙县发展,因而急需要对线路进行改造,拟建连接九龙县至石棉县小卡子隧道即为公路改建工程。     

基于解析信号振幅识别磁源体边界的分析解释方法

解析信号本质上是一种全通滤波器,由于其不受人为因素干扰,能够较好地反映原始信号包含的信息特征。该方法不仅是对非平稳信号进行分析的有效方法,也是检测信号局部特征的有力工具。本文通过对实信号的解析信号处理得到复信号,由该复信号的振幅,能清晰地刻画信号能量空间分布特征。模型试验表明,解析信号振幅方法减小了常规化极方法在勘探程度较低的地区引起假异常的问题,使地下磁性体与振幅中心位置对应。尤其在低纬度或地形切割较大的地区,该方法更具优势。将该方法应用于老挝爬立山铁矿区实测磁异常的分析,由此圈定了磁铁矿分布位置,并由区内56个钻孔证实该推断的可靠性。     

Restudy of conodont biostratigraphy of the Permian–Triassic boundary section in Zhongzhai,southwestern Guizhou Province,South China

New conodont samples have been systematically collected at high stratigraphic resolution from the upper part of the Longtan Formation through to the lower part of the Yelang Formation at the Zhongzhai section, southwestern Guizhou Province, South China, in an effort to verify the first local occurrence of Hindeodus parvus in relation to the Permian–Triassic boundary at this section. The resampled conodont fauna from the Permian–Triassic boundary interval comprises five identified species and two undetermined species in Hindeodus and Clarkina. Most importantly, the first local occurrence of Hindeodus parvus is found for the first time from the bottom of Bed 28a, 18 cm lower than the previously reported first local occurrence of this species at this section. Considering the previously accepted PTB at the Zhongzhai section, well calibrated by conodont biostratigraphy, geochronology and carbon isotope chemostratigraphy, this lower (earlier) occurrence of H. parvus suggests that this critical species could occur below the Permian–Triassic boundary. As such, this paper provides evidence that (1) the first local occurrences of H. parvus are diachronous in different sections with respect to the PTB defined by the First Appearance Datum (FAD) of this species at its GSSP section in Meishan, China and that (2) the lower stratigraphic range of H. parvus should now be extended to latest Permian.     

“平、剖面三维联动编辑”的实现途径

基于对平、剖面三维联动编辑的概念、动因的探讨及相关研究成果的认识,提出了平、剖面三维联动编辑的几何原理与实现途径,如:地质曲面的表达、基于等高线的曲面构建、剖面图的构建、以及平面图与剖面图的联动修改方法。并对三维地质建模的需求、矿产资源勘探应提交的三维地质模型、三维地质建模的数据标准以及广义的三维联动编辑等问题进行了延伸讨论。认为平、剖面三维联动编辑可能成为三维建模软件推广应用中的"杀手级应用"。     

Discrete modeling of strain accumulation in granular soils under low amplitude cyclic loading

An advanced understanding of the strain accumulation phenomenon in granular soils subjected to low amplitude cyclic loading with relatively high frequency is needed to enhance the ability to predict the settlement of granular soils induced by vibrations. In the current study, the discrete element method is used to study this phenomenon. A loose and a medium dense sample composed of a relatively large number of spheres are considered. A series of stress controlled cyclic triaxial tests with different excitation amplitudes and frequencies is performed on these samples at different static stress states. The response of these samples at the macroscopic and microscopic scales is analyzed. The sample density, the cyclic stress amplitude and the static stress state importantly affect strain accumulation. However, the cyclic excitation frequency has a small effect on strain accumulation. At the microscopic scale, frictional sliding occurring at a few contacts continuously dissipates energy and the fraction of these contacts varies periodically during cyclic loading. The coordination number of these samples increases slightly as strain accumulates. However, the anisotropy remains almost constant during low amplitude cyclic excitation. A qualitatively good agreement between numerical and experimental results is found.     

贵州剑河寒武系黔东统杷榔组沉积环境 及生物地层再研究 ——以剑河交榜剖面为例

贵州剑河交榜剖面杷榔组顶底完整,三叶虫序列完整,产出掘头虫类三叶虫5属7种。其中Arthricocephalus chauveaui Bergeron,1899,Changaspis elongata Lee in Chien,1961,Arthricocephalites jishouensis(Zhou in Zhou et al.),1977,3个种也出现在北美格陵兰的Henson Glatsche组,提供了三叶虫全球对比的重要信息。其中A.chauveaui在交榜剖面杷榔组底部4 m首现,延伸至近顶部278 m。交榜剖面杷榔组岩石地层、生物地层和年代地层研究信息表明该剖面更适合作杷榔组岩石地层标准剖面,该剖面应是A.chauveaui首现点位定义的都匀阶界线层型剖面。可能是全球寒武系第4阶具有竟争潜力的界线层型剖面。     

云南省祥云县存得村矿区冷风箐矿段与相邻矿区的类比分析

存得村矿区冷风箐矿段位于马厂箐杂岩体南接触带,其产出的铜钼多金属矿总体受宝兴厂-铜厂向斜南翼斑岩脉（体）与围岩接触带附近的挤压破碎带控制,该挤压破碎带（碎裂岩带）为该矿段矿液的运移、矿体的赋存提供了良好的通道和赋存空间,并严格控制了铜、钼矿脉（体）的空间就位。但由于多期构造活动及多期次侵入岩体的影响使得该区地质情况复杂,加之工作年限短,地质工作程度低等因素使得如何取得找矿突破成为该区的首要目标。本文参照宝兴厂-铜厂铜钼矿、乱硐山铜钼矿的找矿成果及经验,同冷风箐矿段进行类比,结合2011工作成果进行综合分析,为下步地质工作提供了参考。     

川西采气厂首口地质导向水平井钻井技术

广金6-2 HF井是川西采气厂在蓬莱镇组气藏首次应用随钻地质导向钻井技术完成的一口长水平段水平井。该井利用随钻地质导向技术及综合录井技术,优选钻具组合,精确控制井眼轨迹,准确卡住目的层砂顶以及A靶垂深,实现A靶精确着陆。单弯双扶钻具组合在蓬莱镇气藏具有良好的稳斜效果,该井水平段进尺为980.84 m,其中滑动钻进进尺为21.5 m,复合钻进进尺为959.34 m,复合钻进比例为97.8％,大大提高了钻井效率。岩屑录井显示,水平段钻遇泥岩4 m,泥质粉砂岩8 m,细粒岩屑砂岩968.84 m,储层钻遇率为98.8％。该井完钻后没有测井,利用地质导向资料及录井资料确定射孔位置,从而缩短了钻井周期,降低钻井成本。     

吹填砂场地强夯振动特性研究及安全评估

针对曹妃甸工业园区液化天然气储罐地基加固过程中所引起的地面振动进行了深入研究,通过对现场强夯振动观测记录进行统计分析、频域分析以及规律拟合,给出了吹填砂场地上强夯所引起的地面振动衰减规律、振幅（振速）随夯击次数的变化规律以及强夯振动的主频变化规律,并就场地周围已存的海堤工程和天然气储罐工程进行了振动安全评估,为现场强夯施工参数的选取提供了理论支撑,同时也弥补了国内对于类似场地振动特性研究不足的局面。