基于时空分配组合的消防设施服务范围计算方法探讨

基于时空分配组合方法,综合考虑服务时间在主干道路和街区内分配的各种情形,探讨了符合实际需求的消防站点服务范围计算方法.提出了基于多个独立指标的评价消防设施布局方案的方法,对消防规划方案进行评价.最后以武汉市武昌区为例对所提出方法进行了实验,实验结果也验证了该方法的可行性和合理性.     

内蒙古桌子山煤田火区特征及灭火方法探讨

内蒙古自治区桌子山煤田赋存着较为稀缺的煤种一焦煤,煤田内存在的火区不仪烧掉了宝贵的焦性煤炭资源,给煤矿生产带来严重的事故隐患,对当地生态环境也造成极大的破坏。经查明区内有26处子火区,分布面积约760万m^2,通过煤田地质特征、煤质特征、地表指示特征、同位素氡气的浓度相对分布特征、物性特征分析了区内煤层发火原因,根据桌子山煤田火区特点,建议采用浅剥、深灌与覆盖相结合的灭火方法,并对火区进行动态监测。     

江西省九岭区地质灾害危险性区划

对九岭区地质灾害发育的基本特征及其地质环境条件进行了概述,并对其形成条件进行了相关性分析;通过对地质灾害发育的基本规律、控制因素、触发因素与地质灾害关系的分析,采用环境地质学原理,建立区域地质灾害空间预测模型,圈定九岭区地质灾害的危险性分区,为实时地质灾害时间预警预报圈定有效的空间靶区。预测单元采用规则的栅格(500m×500m),共14415个单元;评价指标主要包括地形地貌、工程地质岩类、地质构造、破坏地质环境人类工程活动等四大类26个因子;利用GIS技术,提取出相关的数据信息;信息量预测方程:Ii=-1.164X1-0.999X2-0.681X3 …… 0.203X25-0.135X26(其中X1、X2、X3、…X26取1或0,即某单元中存在某种因素时取1、否则取0),据此计算出各单元格的信息量;根据地质灾害危险性分区临界指标,确定单元格的地质灾害危险性等级;合并同类项,并考虑类似的地质、自然环境具有类似的地质灾害问题的原则,进行归并与单元边界线的修改,得出九岭区地质灾害危险性分区。     

Multi-cloud model (MCM) method and its applications to the study on asymmetric spectral profiles

A method of multi-cloud model (MCM) is proposed in this paper in order to research asymmetric profiles of spectral line formed by solar discrete active objects aligned along the line-of-sight difection. Based on the MCM method, under the conditions of certain assumptions and approximations, the line-of-sight velocityV and three other physical parameter approximation values, (i.e. Doppler width _D , source functionS and optical depth at line center ₀) within different clouds may be derived simultaneously by fitting both profiles theoretical and observational. An application example of the method withm=3 shows that MCM method is suitable to measure the velocity fields of multi-object at the same time from their non-Gaussian profiles of complex. TheV and _D derived from the method are reliable,S and ₀ are approximation. An influence of the variations of initial values in the parameter on the solution is given as well.     

Calorimetric study of the coesite-stishovite transformation and calculation of the phase boundary

High temperature drop-solution calorimetry in molten 2 PbO · B₂O₃ at 1044 K for coesite and stishovite polymorphs of silica was carried out to determine the enthalpy of the coesite-stishovite transition. These experiments were performed on high-purity, single-phase samples of coesite and stishovite. Our new value for the enthalpy of the coesitestishovite transition (ΔH ₂₉₈ ⁰ ) is 29.85 ± 0.78 kJ/mol, which is about 35% lower than previously reported by Akaogi and Navrotsky (1984) and Holm et al. (1967), but which compares well with new measurements by Akaogi et al. (1994b). Using these new data, we have calculated the equilibrium phase boundary between coesite and stishovite and obtained a slope, dP/dT=0.0031 (2) GPa/K. This calculated slope is in good agreement with that determined [0.0026 (2) GPa/K] from the in-situ X-ray diffraction study of Zhang et al. (1996).     

Flux determination over a smooth surface under strongly unstable conditions

Careful micrometeorological measurements on an empty parking lot allowed determination of the surface fluxes of sensible heatH and of momentum by applying profile equations derived from Monin-Obukhov similarity theory with two sets of the stability correction function for momentum _m and sensible heat _h . These fluxes were compared with reference values ofH independently determined by means of an eddy correlation technique. In general, better agreement was found betweenH values derived from profiles with the stability functions of Brutsaert (1992) and referenceH values, than when the Businger-Dyer functions were used to deriveH. The disagreement in the latter comparison was especially serious under strongly unstable conditions, with the value ofy=–z/L (wherez is the height andL is the Obukhov length) larger than 10. A closer look at the procedure for calculatingH from the profiles revealed that the large differences between theH values derived with these two different versions of the stability correction functions were caused by the small differences of the _h values, and not by the larger differences of the _m values. This result stems from the strong sensitivity of the resultingH values on the choice of _h .     

Scattering of elastic waves by a fracture zone containing randomly distributed cracks

We theoretically study the scattering ofP, SV andSH waves by a zonal distribution of cracks, which simulates a fault fracture zone. An investigation is conducted how the geometrical properties of the crack distribution and the frictional characteristics of the crack surface are reflected in the attenuation and dispersion of incident waves, as well as in the amplitudes of the transmitted and reflected waves from the zone. If the crack distribution within the fault zone changes temporally during the preparation process of the expected earthquake, it will be important for earthquake prediction to monitor it, utilizing the scattering-induced wave phenomena.We consider the two-dimensional problem. Aligned cracks with the same length are assumed to be randomly distributed in a zone with a finite width, on which elastic waves are assumed to be incident. The distribution of cracks is assumed to be homogeneous and sparse. The crack surface is assumed to be stress-free, or to undergo viscous friction; the latter case simulates fluid-filled cracks. The opening displacement of the crack is assumed to be negligibly small. The idea of the mean wave formalism is employed in the analysis, and Foldy's approximation is assumed.When the crack surface is stress-free, it is commonly observed for every wave mode (P, SV andSH) that the attenuation coefficientQ ^–1 peaks aroundka1, the phase velocity is almost independent ofk in the rangeka<1 and it increases monotonically withk in the rangeka>1, wherek is the intrinsicS wavenumber anda is the half length of the crack. The effect of the friction is to shift the peak ofQ ^–1 and the corner of the phase velocity curve to the low wavenumber range. The high wavenumber asymptote ofQ ^–1 is proportional tok ^–1 independently of model parameters and the wave modes. If the seismological observation thatQ ^–1 ofS waves has a peak at around 0.5 Hz in the earth's crust is combined with our results, the upper limit of crack size within the crust is estimated about 4 km. The information regarding the transmitted and reflected waves, such as the high wavenumber limit of the amplitude of the transmitted wave etc., allows estimation of the strength of the friction.     

地震前水氡短临异常判别指标及预报三要素的方法探讨

本文分析了中国大陆(重点是南北地震带北段)水氧异常变化,深入研究了有震与无震异常的时空分布特征、异常总频次、起始异常时间差等,发现有震异常往往呈现“同步性”或“群体性”特征,而大部分“零散性”异常则属于非地震异常。根据上述研究,本文还提出了利用水氡异常预报地震的发震时间、地点和震级的初步方法。     

Study on the kinetics of iron oxide leaching by oxalic acid

The presence of iron oxides in clay or silica raw materials is detrimental to the manufacturing of high quality ceramics. Although iron has been traditionally removed by physical mineral processing, acid washing has been tested as it is more effective, especially for extremely low iron (of less than 0.1% w/w). However, inorganic acids such as sulphuric or hydrochloric acids easily contaminate the clay products with SO₄²⁻ and Cl⁻, and therefore should be avoided as much as possible. On the other hand, if oxalic acid is used, any acid left behind will be destroyed during the firing of the ceramic products. The characteristics of dissolution of iron oxides were therefore investigated in this study.The dissolution of iron oxides in oxalic acid was found to be very slow at temperatures within the range 25–60 °C, but its rate increases rapidly above 90 °C. The dissolution rate also increases with increasing oxalate concentration at the constant pH values set within the optimum range of pH2.5–3.0. At this optimum pH, the dissolution of fine pure hematite (Fe₂O₃) (105–140 μm) follows a diffusion-controlled shrinking core model. The rate expression expressed as 1 − (2 / 3)x − (1 − x)^2 / 3 where x is a fraction of iron dissolution was found to be proportional to [oxalate]^1.5.The addition of magnetite to the leach liquor at 10% w/w hematite was found to enhance the dissolution rate dramatically. Such addition of magnetite allows coarser hematite in the range 0.5–1.4 mm to be leached at a reasonable rate.     

藏西北三岔口地区泥瓮系生物礁特征及其意义

在羌塘西部的三岔口一带泥盆系拉竹龙组中发现规模较大的生物礁——台地前缘礁。下层礁体厚7．28m，上层礁体厚40.98m。两个礁体均为叠置礁，礁体由礁基、礁核、礁顶组成。剖面显示发育有礁前垮塌角砾、礁格架、礁间及礁后环境。泥盆纪生物礁的发现为羌塘盆地寻找油气资源提供了新思路。