矿物纤维粉尘的表面特性及对生物活性的影响

通过对矿物纤维粉尘对人体的危害性及对环境影响的研究，提出了一些矿物产生毒理作用过程的假说和因素判定；研究了矿物与生物体之间的相互作用时应重视矿物表面－细胞物理化学作用，并依据初步试验提出表面特征是矿物纤维表征生物活性的关键因子（如表面活性域、催化作用等），而纤维性只是矿物表面特性的表征因素之一。     

Performance of multiple tuned mass dampers for attenuating undesirable oscillations of structures under the ground acceleration

Multiple tuned mass dampers (MTMDs) consisting of many tuned mass dampers (TMDs) with a uniform distribution of natural frequencies are considered for attenuating undesirable vibration of a structure. The MTMD is manufactured by keeping the stiffness and damping constant and varying the mass. The structure is represented by its mode‐generalized system in the specific vibration mode being controlled using the mode reduced‐order method. The optimum parameters of the MTMD are investigated to delineate the influence of the important parameters on the effectiveness and robustness of the MTMD by conducting a numerical searching technique in two directions. The parameters include: the frequency spacing, average damping ratio, mass ratio and total number. The criterion selected for the optimization is the minimization of the maximum value of the dynamic magnification factor (DMF) of the structure with MTMD (i.e. Min.Max.DMF). In this paper, for the sake of comparison, the MTMD(II), which is made by keeping the mass constant and varying the stiffness and damping coefficient, and a single TMD are also taken into account. It is demonstrated that the optimum frequency spacing of the MTMD is the same as that of the MTMD(II) and the optimum average damping ratio of the MTMD is a little larger than that of the MTMD(II). It is also found that the optimum MTMD is more effective than the optimum MTMD(II) and the optimum single TMD with equal mass. Copyright © 2000 John Wiley & Sons, Ltd.     

Laboratory study on cement admixed marine silt bricks

For the purpose of efficient utilization of sediments dredged from harbor, a new method was proposed in this study. Marine silt bricks were made by mixing sediments with cement and gypsum, placing it in a cubic mold with 240 mm in length, 115 mm in width, and 53 mm in height, and curing for certain days. To investigate the effects of cement and initial water content of soil on the mechanical behavior of marine silt bricks, unconfined compressive and flexural strength tests were carried out. Given the same curing time and cement content, the higher the initial water content, the lower the compressive and flexural strength. After 60 days of curing, the compressive strength of marine silt bricks with cement content = 20% and water content = LL (liquid limit) reached approximately 5 MPa. The flexural strength was relatively low. The flexural strength of marine silt bricks with 20% cement and water content = LL was around 1.5 MPa. The compressive and flexural strength decreased with the increase of water/cement ratio. As for the curing time, longer curing time had a positive impact on the compressive strength. The ratio of flexural to compressive strength varied slightly in the range of 0.4–0.5.     

地面核磁共振技术勘查西北干旱浅层地下水效果浅析

地面核磁共振技术勘查地下水是一种新的应用领域,该技术是目前国际上唯一的能直接进行地下水勘查的技术.我所自一九九九年引进法国Numis仪器以来,先后在陕西黄土区、宁南黄土区等地开展寻找不同类型浅层地下水的试验工作,取得了一定的野外成果.本文是在分析总结这些成果的基础上,针对存在的问题如强干扰背景下勘查结果的可靠性,同一测点"8”字型与"正方形”发射线框二者勘查结果比较等方面进行探讨分析.     

一种用于海底类型聚类的新方法

By using sonar imaging, this paper presents a new algorithm for the clustering of seabed types based on the self-organizing feature maps （SOFM） neural network. The theory as well as data processing is studied in detail. Some valuable conclusions and suggestions are given     

A Directed-Line-Segment-Based Photogrammetry Method to Survey the Tunneling Working Surface of Mine Roadway

Absolute orientation is a basic technical work in digital image geologic logging of underground coal mine. Traditional control-point-based absolute orientation method requires setting object space control points of the known three-dimensional coordinates, which may lead to low efficiency. Therefore, this paper proposed a point-free close-range photogrammetry absolute orientation algorithm, which utilized direction line segments including plumb line segments and line segments with known directions and lengths to identify the dimensional orientation of a stereoscopic model. Experiment results show that the precision of the orientation results is favorable. σ _X and σ _Y are as high as 0.5 mm, and σ _Z is 0.3 mm. Finally, this paper introduced the application of the proposed algorithm in rapid geological logging of coal mine roadway, which was fast and reliable, convenient and feasible.     

贺兰山群变质杂岩主期变质作用的温压环境研究

分布于贺兰山脉北部的贺兰山群变质杂岩的主期变质作用达角闪麻粒岩相,其矿物组合特征与低压相系麻粒岩相似、利用共生矿物组合和矿物对的温度计、压力计估算主期变质温度740—764(?),压力460—501MPa。温度压力条件与低压相系的地热梯度线较接近,变质作用强度具面型分布的特征,与东部密云、冀东等地的麻粒岩相区相似,但变质压力明显低,压力类型也不同,应属不同构造背景下的变质产物。     

白龙江中上游地区金矿控矿因素及成矿模式探讨

白龙江中上游地区微细浸染型金矿,是受地层和构造双重控制的金矿床。在阐述矿床空间分布规律、控矿因素、区域矿化和地球化学特征等基础上,初步建立了地质地球化学成矿模式。     

我国贫困山区可持续发展的因素与目标研究--以黔江地区为例

以黔江地区为例,分析了我国贫困山区可持续发展面临的主要问题和具备的有利条件,在此基础上把区域看作一个完整的系统,运用系统论的观点建立了区域可持续发展的目的体系,并采用灰色系统等定量分析技术与定性分析相结合的方法,探讨了区域可持续发展目标的制定方法。