微动探测技术在工程地质中的应用与研究

与浅层地震、高密度电法和电磁法等相比,微动探测技术在工程地质勘察应用上具有受环境影响更小的特点,尤其在城区复杂地质条件中。文章通过详细介绍微动技术在堤坝隐患(管涌渗水点)、油气管道定向穿越、溶洞探测及尾砂库渗漏检测等方面的应用,结果表明:微动探测技术对管涌渗水点具有明显的勘探效果,明显的中低速异常形态反映管涌渗漏点的埋深及大小;地层破碎表现为较低速度异常,为油气管道施工中山体定向穿越提供超前预报;溶洞表现为低速异常,为后期开发工程提供基础资料。     

矿山酸性污水土石坝渗漏探测及诱因分析

物探方法以其轻便、快捷的特点广泛应用于堤防及坝体的隐患勘查中。通过采用高密度电法和探地雷达等两种方法对某矿山污水坝灾害隐患进行勘探,结合相关地质情况和坝体结构特征,推断出隐患的性质、产状和埋深等情况,证明综合物探方法在堤坝隐患探测中是可行的和有效的。对隐患部位进行分析得出:矿山酸性污水的腐蚀作用是导致大坝渗漏的主要原因。     

尾矿库技术改造措施

1.概述 1986年8月,冶山铁矿尾矿坝第一期子坝顶部(91m)标高南端出现管涌后,由冶金部建筑研究总院、武汉勘察研究设计院提供该库的险情调查报告及地质勘探资料,经过专家们综合分析,结论如下: 1.1 尾矿堆积坝稳定性不足坝体各土层的成层规律不强,从地质分     

汶川地震触发陕西省境内地质灾害灾险情特征

在实地调查、汶川地震震后次生地质灾害隐患排查成果的基础上,结合县市地质灾害调查数据,从灾情和险情两个方面,对汶川地震触发地质灾害灾险情的致灾灾险情、灾种、类型等特征进行了较系统的分析对比.进一步比较了陕西在汶川地震触发地质灾害受灾省份中的情况,并对地质灾害趋势做了初步预测.研究表明,灾险情集中分布在龙门山构造带向陕西境内的延伸部分,险情比灾情分布范围广.灾险情的灾种都以崩塌为主,其次为滑坡,地震对地质体的震动触发作用明显.机关学校是汶川地震触发陕西境内地质灾害的主要受灾对象.陕西受汶川地震触发地质灾害的灾险情轻于四川、甘肃,三省地质灾害震前均较为严重,地震触发地质灾害的影响具有长期性,未来陕西境内地质灾害发生的频率可能增大.     

EH4电磁成像系统在水库大坝勘查渗漏的应用

介绍了EH4电磁成像系统的原理、特点。通过辽宁省白山水库和龙湾水库坝体实际应用，探测结果与地勘结果相吻合，表明该系统对探测水库坝体渗漏情况是一种有效的方法。     

EH-4在堤坝渗漏探测中的应用

EH-4连续电导率成像系统是新一代数字化的电磁法仪器。分析了EH-4观测信号经离散傅里叶变换后,不同频率时长的傅立叶变换不可避免地产生信号频谱泄露。在分析和理解窗口函数特点及其作用的基础上,结合堤坝渗漏探测中对信号的分析与处理,确定了堤坝渗漏的空间位置,为帷幕灌浆提供了科学依据。     

电学渗漏检测在防渗土工膜施工质量保证中的应用

探讨垃圾填埋场防渗土工膜施工破坏的各种情况以及施工保证措施,着重介绍了电学渗漏位置探测的原理及其在施工质量保证中的作用。     

电学渗漏检测在防渗土工膜施工质量保证中的应用

探讨垃圾填埋场防渗土工膜施工破坏的各种情况以及施工保证措施,着重介绍了电学渗漏位置探测的原理及其在施工质量保证中的作用.     

电学渗漏检测在防渗土工膜施工质量保证中的应用

探讨垃圾填埋场防渗土工膜施工破坏的各种情况以及施工保证措施，着重介绍了电学渗漏位置探测的原理及其在施工质量保证中的作用。     

云中液态水含量在人工影响天气中的应用

针对云中液态水含量的重要意义、不同方法探测云中液态水含量的优点和不足进行了详细地阐述,并提出了云中液态水含量在人工影响天气中的应用前景.     

Suitability of Dynamic Modeling for Flood Forecasting during Ice Jam Release Surge Events

Ice jam release surges present a unique challenge to the flood forecaster, since the surge released when an ice jam fails is highly dynamic in nature and, therefore, traditional hydrologic flood routing techniques are inapplicable. The problem is analogous to the classic dam break scenario and should be amenable to analysis by hydraulic flood routing techniques. However, previous investigations suggest that the influence of ice on the wave propagation and attenuation must also be considered to achieve accurate results. This study explores the applicability of dynamic hydraulic flow modeling techniques to the ice jam surge propagation problem, presenting the results of numerical simulations of the ice jam release event which occurred on the Saint John River upstream of Grand Falls, N.B., in April 1993. The surge propagation analysis was conducted using a one-dimensional finite element implementation of the Saint Venant equations adapted for natural channel geometries. Even neglecting ice effects, the resulting model is successful in terms of reproducing the observed peak stage and the surge propagation speed. Based on these results, it is concluded that accurate channel geometry is a key factor in effectively modeling ice jam release surge events.     

汛期采金船的缆绳牵拉

本文介绍了采金船渡汛时的停泊方向及采金船在洪水中可能产生拖曳力的估算方法，为了防止采金船汛期发生溜船事故，建议采用缆绳牵拉固船的措施，以保障采金船的汛期安全。     

HSPF Simulation of Runoff and Sediment Loads in the Upper Changjiang River Basin, China

To evaluate the performance of a computer model simulating runoff and sediment load in the upper region of the Changjiang (Yangtze River) basin over a relatively short time interval, including examining the applicability of the input precipitation data generated from global circulation models and satellite data, we used a spatially distributed model, HSPF with the International Satellite Land Surface Climatology Project (ISLSCP) precipitation data for 1987 and 1988 as input data. The Nash–Sutcliffe coefficient (R2) for 5-day average streamflow was 0.94 in the calibration period and 0.95 in the verification period for the whole upper region. Moreover, the model simulated the 5-day average streamflow well in each main tributary, as shown by R2 values of 0.46–0.96, except that it underestimated the peak flow rates during the flood season over 2 years by up to 71% in Tuojiang and 61% in Jialingjiang. The model simulated the 5-day concentrations of suspended solids (SS) fairly well in the headwaters and upper regions of the Jinshajiang, Yalongjiang, and Minjiang watersheds, as shown by R2 values of 0.31–0.65. In the other regions, however, the model underestimated the SS load by up to 72%, and rarely simulated the fluctuation of SS concentration in each river channel during the flood season. These errors led to the underestimation of sediment runoff volume from the whole upper region during the flood season, as shown by the ratio of the simulated sediment load to the observed data at Yichang: 0.69 in the calibration period and 0.68 in the verification period. The ISLSCP precipitation tended to be more frequent and less intense than the measured precipitation. This was probably the main reason why the HSPF did not perform well in all regions at all times.     

Evidence that the mediobasal hypothalamus is the primary site of action of estradiol in inducing the preovulatory gonadotropin releasing hormone surge in the ewe

Although a neural site of action for estradiol in inducing a LH surge via a surge of GnRH is now well established in sheep, the precise target(s) for estrogen within the brain is unknown. To address this issue, two experiments were conducted during the breeding season using an artificial model of the follicular phase. In the first experiment, bilateral 17beta-estradiol microimplants were positioned in either the medial preoptic area (MPOA) or the mediobasal hypothalamus (MBH), and LH secretion was monitored. An initial negative feedback inhibition of LH secretion was observed in ewes that had estradiol microimplants located in the MPOA (6 of 6 ewes) or caudal MBH in the vicinity of the arcuate nucleus (4 of 4). In contrast, a normal LH surge was only found in animals bearing estradiol microimplants in the MBH (5 of 10). Detailed analysis of estradiol microimplant location with respect to the estrogen receptor-alpha-immunoreactive cells of the hypothalamus revealed that 4 of the 5 ewes exhibiting a LH surge had microimplants located bilaterally within or adjacent to the area of estrogen receptor-expressing cells of the ventromedial nucleus. Two of these ewes exhibited a LH surge without showing any form of estrogen negative feedback. In the second experiment, we used the technique of hypophyseal portal blood collection to monitor GnRH secretion directly at the time of the LH surge induced by estradiol delivered either centrally or peripherally. Central estradiol implants induced the GnRH surge. The duration and mean plasma concentration of GnRH during the surge were not different between animals given peripheral or central MBH estradiol implants. Cholesterol-filled MBH microimplants did not evoke a GnRH surge. We conclude that the ventromedial nucleus is the primary site of action for estradiol in stimulating the preovulatory GnRH surge of the ewe, whereas the MPOA and possibly the caudal MBH are sites at which estrogen can act to inhibit LH secretion. These data provide evidence for the sites within the ovine hypothalamus responsible for mediating the bimodal influence of estradiol on GnRH secretion and suggest that different, and possibly independent, neuronal cell populations are responsible for the negative and positive feedback actions of estradiol.     

Epidemiological studies regarding the "summer infertility syndrome" of sows in confinement housing

In confined pig herds, located in Northwest-Germany and affiliated to a hybrid breeding organisation, 3 retrospective observational studies were performed to study the effects of "meteorological seasons" on sow fertility. A subsequent field trial was performed to study the effects of photoperiod and of temperature on sow fertility separately. Associations of economically important fertility disorders and season resp. climate categories were determined by adjusted Relative Risks in stratified analysis (observational studies), or by Odds Ratios in the Multiple Logistic Regression Analysis (field trial). Due to nonconsistent seasonal findings in the observational studies and a lack of temperature or photoperiod effects in the field trial we conclude that season and its main contributing climatic factors had no substantial effects on sow fertility in the well-managed herds of our climate zone. Nonclimatic risk factors for the so-called "Summer Infertility Syndrome" are discussed.     

The "pinch off" syndrome: a complication of implantable catheter systems in the subclavian vein

We report the case of a 63-year-old male patient who received a subcutaneous Port-a-cath system in the right subclavian vein for administration of chemotherapy. Five weeks after successful use, flushing with NaCl 0.9% caused a painless subcutaneous swelling. Fluoroscopy confirmed a leakage below the right clavicle. The catheter was explanted and replaced by a new catheter via Seldinger technique. Two weeks later another leakage occurred and the catheter was removed definitively. Defective equipment was ruled out by the catheter producing company. The "pinch off" syndrome, a rare phenomenon of catheter compression and consecutive catheter fracture, is described, together with the diagnostic signs, the incidence and preventive measures suggested in the literature.     

尾矿库危险有害因素及安全管理对策和措施

通过对尾矿库潜在的危险有害因素进行分析,指出了尾矿库安全管理中应该重点防范的危险因素有:尾矿堆积坝边坡过陡,浸润线逸出,裂缝,渗漏,滑坡,坝外坡裸露拉沟,排洪构筑物排洪能力不足,排洪构筑物堵塞,排洪构筑物错动、断裂、垮塌,干滩长度不够,安全超高不足,抗震能力不足,库区渗漏、崩岸和泥石流,地震,淹溺,雷击等;有害因素有:废水超标排放,坝面扬尘,尾矿输送管道破裂泄漏等。同时,对尾矿库的安全管理提出了建议,提出了相应的安全管理和技术管理对策和措施。     

玲珑金矿地质灾害防治及环境保护

玲珑金矿地质灾害的主要表现形式为采空塌陷区、渣石流、地表裂缝、洪水倒灌、矿坑突发性涌水、深部采空区剩余实体承重部分地压加大等。其中,采空塌陷区、地表裂缝、洪水倒灌等地质灾害相互联系、相互伴生、相互诱发,具有隐蔽性和突发性强、破坏性和危险性大等特点,对人身安全、地表建筑、采矿实施、道路、农田、电力设施等都有较大的危害。近些年,玲珑金矿一直注重生态环境保护和加强地质灾害防治,已取得了一定成效,并将这项工作作为矿山长期任务来抓。     

山东蓬莱矿业选矿厂尾矿堆放及排水方式探讨

为了解决蓬莱矿业选矿厂的尾矿堆存与排水问题,通过对比各种堆存方式的优缺点,结合当前选矿厂的生产工艺和地形特点,因地制宜地采用尾矿坝前堆放和涵洞方式排水,成功解决了尾矿堆放、回水及雨季泄洪问题。该种尾矿堆存及排水方式的成功运用,为小型-山谷型尾矿库的使用与维护提供了宝贵经验,具有较好的经济社会效益。