Models of CN and C2 comae for comet Tago-Sato-Kosaka and comet bennett

Based on the CN and C₂ comae isophotes for two comets (1961 IX and 1970 16) given by Rahe et al. and the relevant theory of physical chemistry, we have deduced the distributions of the CN and C₂ modecules in the coma, their scale heights and mean lifetimes. The results favour the viewpoint that HCN is the parent of CN, and that C₂H₂ is the parent of C₂.     

Modelling the April 15 spectrum of Supernova 1993 J

We present the modeling of the ultraviolet and optical spectra obtained simultaneously on 1993 April 15 with the HST and at Lick Observatory. A Monte Carlo code is employed in the modeling and a comparison is made between models reported by different groups. With an atmosphere similar to the Sun in chemical composition, the observed spectral lines are well reproduced by a power law density structure of index around 20 except the strong H and HeI λ5876 lines which have peculiar absorption profiles. The photospheric velocity is found to be 9500 km/s and the blackbody temperature of the spectrum is 7990 K. For H and HeI λ5876, we suggest a two-component density structure which has a smoother layer located immediately outside the steeply decreasing inner envelope. The power law indices are most probably 20 and 3, respectively, with the transition point at about 13 000 km/s. In addition, this outer smooth layer serves to flatten the far UV spectrum as observed.     

A THREE-DIMENSIONAL ELASTIC NESTED-GRID MESO-(β-γ)SCALE ATMOSPHERIC MODEL——PARTI:MODEL DESCRIPTION

A three-dimensional elastic nonhydrostatic mesoscale(β-γ)model with nested-grid is presented.It uses a set of fullequations in terrain-following coordinates as its basic dynamic frame,which is solved with a time-splitting algorithmfor acoustic and gravity waves.The model physical parameterization includes a K-theory subgrid eddy mixing for cloudand free atmosphere,a bulk planetary boundary layer parameterization,and three types of sofisticated cloudmicrophysics schemes with double-parameters for hail-bearing clouds,warm clouds and snowing clouds respectively.The model is designed to be used flexibly for simulations of a variety of meso-and small-scale atmospheric processes,and can be improved as a regional and local operational NWP system in future.     

南秦岭十里坪锑矿床成矿时代及成因的初步研究

十里坪锑矿床受赵川陆缘隆_滑构造的主滑脱拆离带的控制。矿体呈脉状赋存于韧_脆性主滑脱带上部的脆性次级断层_节理中,矿石类型主要为萤石石英辉锑矿型。围岩为太古宙_元古宙变质岩系,围岩蚀变弱。成矿流体属H2O_CO2_NaCl体系,流体包裹体盐度w(NaCleq)为3.6%～11.3%,均一温度为109～232℃,形成压力大致为800×105Pa。硫、铅同位素研究表明,矿质主要来源于变火山岩围岩;氢、氧同位素显示,成矿流体以大气降水为主,初步将该矿床定为变质岩源就地式大气降水热液矿床。矿石中萤石Sm_Nd等时线年龄为(392±24)Ma,与南秦岭北部晚古生代拗陷区热水喷流_沉积成矿时代相一致,它们都形成于秦岭微板块泥盆纪非造山裂解阶段。     

四川某矿山边坡失稳机理及稳定性评价

四川某矿山开采边坡迄今已有30余年,随采区规模的逐渐扩大,在矿区南坡构成一典型的顺层开挖边坡,因矿层中夹有不同数量的软弱夹层,在边坡前缘破坏坡角、并加上降雨及爆破振动影响,时常发生颁层滑坡,不仅给矿山人民生命财产带来严重危害,而且也严重制约矿山的正常发展。通过对典型开挖边坡所在部位的工程地质条件凋查,在确定影响边坡稳定的主要控制因素和边界条件的基础上。考虑四种工况条件下的稳定性分析和评价,为矿山下一步施工提出了较为合理的开挖方案。     

基于实测波浪的单桩式海上风电基础波浪力计算研究

基于实测波面的波浪力获取作为结构动力响应分析以及数字孪生模型建立的必备环节,对海上风电数字化运维至关重要。为了满足更大的装机容量需求,单桩式海上风电基础趋于大型化,其尺度因子D/L也随之增大;并且实际海域均为非规则波,以尺度因子划分波浪力计算理论的方法对非规则波的适用性尚不明确。通过建立数值水槽,依据实际工况对不规则波与桩基的作用进行数值模拟,得到入射波浪场与桩基所受波浪力,在此基础上,基于入射波浪场分别采用Morison方程以及绕射理论求解波浪力并将之与数值模拟结果进行对比,分析了不同波浪力计算理论关于尺度因子的适用性,同时探究了波浪要素对计算精度的影响。结果表明：Morison方程在波高较大时精度下降;相对于Morison方程,绕射理论在该尺度下的精度更高。最后,通过分析实测数据进一步探讨了典型工况下的波浪力特征,以期通过实测波面计算波浪力的方法为实际服役风机波浪力计算提供技术支持。     

On the exact solutions and invariant rays of the phase plane in Brans-Dicke theory

On the basis of the model properties of the expansive nondecelerative universe, present temperature of cosmic microwave background and specific entropy in the era of matter, the present parameters of our Universe may be exactly determined.     

铜陵新桥层状菱铁矿成因的矿物学证据及成矿意义

安徽铜陵新桥矿区二叠系栖霞组底部和石炭系黄龙组—船山组之间产出层状、似层状菱铁矿矿层。开展菱铁矿矿层成因研究对于深入剖析区域层控矽卡岩型铜铁矿床成矿机制具有重要意义。本文利用粉晶X射线衍射（XRD）、扫描电镜（SEM）对菱铁矿矿石进行矿物学研究,结果发现菱铁矿矿石主要由菱铁矿、石英、伊利石和有机质等组成,菱铁矿颗粒粒径较小,表面具有成岩自生的自形石英硬模的微结构,SEM原位微区成分分析显示菱铁矿中除了主量元素铁,还含有大量的锰、锌和钙。矿石中存在两种微结构和不同成因的石英：表面具菱铁矿硬模和次生加大结构的碎屑石英;具六方双锥、单锥以及生物成因球形的自生石英。菱铁矿矿石的组成和矿物表面微结构表明其为沉积成因,非岩浆热液起源。富有机质和亚铁的沉积菱铁矿层和沉积胶状黄铁矿层协同作用,可能是铜陵地区乃至长江中下游成矿带层状铜铁矿床层控性重要制约因素,以及可能作为燕山期中酸岩浆演化的氧化性含铜成矿流体卸载成矿的地球化学还原障。

     

Site effect on vulnerability of high-rise shear wall buildings under near and far field earthquakes

Worldwide experience repeatedly shows that damages in structures caused by earthquakes are highly dependent on site condition and epicentral distance. In this paper, a 21-storey shear wall-structure built in the 1960s in Hong Kong is selected as an example to investigate these two effects. Under various design earthquake intensities and for various site conditions, the fragility curves or damage probability matrix of such building is quantified in terms of the ductility factor, which is estimated from the ratio of storey yield shear to the inter-storey seismic shear. For high-rise buildings, a higher probability of damage is obtained for a softer site condition, and damage is more severe for far field earthquakes than for near field earthquakes. For earthquake intensity of VIII, the probability of complete collapse (P) increases from 1 to 24% for near field earthquakes and from 1 to 41% for far field earthquakes if the building is moved form a rock site to a site consisting a 80 m thick soft clay. For intensity IX, P increases from 6 to 69% for near field earthquake and from 14 to 79% for far field earthquake if the building is again moved form rock site to soft soil site. Therefore, site effect is very important and not to be neglected. Similar site and epicentral effects should also be expected for other types of high-rise structures.     

Comparison of debris-flow volume and activity under different formation conditions

Debris flows frequently occurred in Wenchuan earthquake region from 2008 to 2010, resulting in great damage to localities and being a prolonged threat to reconstruction. Forty three events' data including debris-flow volume, sediment volume and watershed area are analyzed and compared with other debris-flow events in Eastern Italian Alps, burned areas in USA and in Taiwan. The analysis reveals that there is a strong empirical relationship between debris-flow volume and loose materials volume in the earthquake region. In addition, the relationship between debris-flow volume and watershed area in the earthquake region has a wider variation range than that in other three regions while the debris volume also appears to be larger than that in the other three regions, which implies the volume of debris flows with strong influence of earthquakes is larger than that with no such influence and it is hard to predict the post-quake volume only by the watershed area. The comparison of the maximal debris-flow erosion modulus in the Wenchuan region and in Taiwan indicates that debris flows will be very active in a short time after strong earthquake.