中加矿业与地学研讨会在京举行

经国务院批准,应国土资源部邀请,加拿大自然资源部拉尔夫.古德尔部长于2000年1月22～30日率领90多人的代表团访问我国.1月24日,国土资源部与加拿大自然资源部在北京中国大饭店共同举办"中加矿业和地学研讨会"及商贸洽谈,出席研讨会的中方人员有国土资源部有关领导和部分省(区)地矿、有色、冶金行业代表,加方人员有加拿大自然资源部官员、数十家矿业公司及矿业咨询公司代表.     

煤市或迎新一轮降价潮

正1月8日公布的2014年度第一期环渤海动力煤价格指数显示:发热值为5500大卡动力煤在之前神华、中煤两大集团下调动力煤价格的带动下,不出意料地"大幅跳水",下跌了21元/吨。据了解,该指数从去年10月中旬以来,连涨11周后达到631元/吨,逼近去年首期价格指数的633元/吨之后,在今年初就掉头向下,大跌21元/吨,至610元/吨。汾渭能源咨询公司煤炭市场分析师王旭峰表示,从神华、中煤今年下调1月份动力煤价格     

更具创造性的经济或从机构改革开始

据《华尔街日报》报道,咨询公司Solidian编制的亚洲最具创造性的城市排行榜出炉,新加坡高居榜首,上海远远落后. 这份排行榜希望挑出商业环境理想、生活质量高,本土或外来的艺术家、学者和发明家都希望定居的城市.最后,新加坡因政治稳定、政府管制少和全球品牌饱和度高而获得高分.悉尼、墨尔本和奥克兰位居前列. 但在16个上榜城市中,上海表现较差,位列第14.报告作者称,上海被模仿重于创新的文化拖了后腿.     

煤市或迎新一轮降价潮

<正>1月8日公布的2014年度第一期环渤海动力煤价格指数显示:发热值为5500大卡动力煤在之前神华、中煤两大集团下调动力煤价格的带动下,不出意料地"大幅跳水",下跌了21元/吨。据了解,该指数从去年10月中旬以来,连涨11周后达到631元/吨,逼近去年首期价格指数的633元/吨之后,在今年初就掉头向下,大跌21元/吨,至610元/吨。汾渭能源咨询公司煤炭市场分析师王旭峰表示,从神华、中煤今年下调1月份动力煤价格     

Impacts of land use change on landscape patterns in mountain human settlement: The case study of Hantai District(Shaanxi,China)

Mountain area is an important geographical unit of land,and its ecology is sensitive and fragile.Over the past few decades,human activities have caused dramatic changes in land use in mountainous areas,which caused changes in landscape patterns and impacts on the ecological environment.It is unknown how the mechanism of land use affects the landscape pattern at different scales.The Hantai District,a typical human settlement in the mountain area in Shaanxi,China,was chosen as the study area.Based on the remote sensing images,the mathematical models and landscape indexes were adopted to evaluate the impact of land use change from 1998 to 2017 on the landscape pattern at different scales,and its main driving forces were analyzed.The results showed that the urbanized land expanded largest from 15.39%to 24.30%,and cultivated land experienced the largest decline from 43.54%to 35.35%.Changes in land use have made the patch morphology of most land types developed from a natural random to a sawtooth shape,and its spatial pattern evolved from a ruleset to a fragmented expansion.This reflects the continuous strengthening of human intervention in the process of regional development.Under the jurisdiction of Hantai District,the biggest change in landscape pattern is in Hanzhong City and Qili Town.The improved economy and increasing population and urbanization rate were the main factors that cause these changes.This research could provide necessary information for understanding the evolution mechanism of land resources in mountainous human settlements for mountainous areas with significant geomorphic differentiation.     

边城廿八都

浙西南的江山市廿八都镇,地处浙闽赣三省交界。四面群山拱卫,仙霞古道穿镇而过,自古有“东南锁钥,入闽咽喉”之称。小镇类似文学家沈从文笔下的边城,当时“也有商人落脚的客店,坐镇不动的理发馆。此外,饭店、杂货铺、油行、盐栈、花衣庄,莫不各有一种地位,装点这条小河街。”而唐宋古道驿站遗址和明清古桥民居至今尚存。     

"一户一宅"的思考

《土地管理法》第六十二条规定,农村村民一户只能拥有一处宅基地。这对于节约集约用地,强化农村宅基地管理具有十分重要的指导意义。长期以来,农村旧的宅基地管理模式造成农村村民住房严重超标,一户多宅以及空心村的现象普遍存在,农村宅基地极度浪费。“一户一宅”制从当前全国农村的实际出发,对农村宅基地使用作出了科学合理的界定。但是,在执行“一户一宅”过程中,也出现一些新情况新问题,在市场经济条件下,这些新情况新问题必须在立法和实践中加以解决,并不断完善现有的制度,以达到科学合理地利用农村土地。     

房地产宏观政策期待加大执行力

4月27日,中国社会科学院城市发展与环境研究中心和社会科学文献出版社联合主办的2007年中国房地产高峰论坛暨《 房地产蓝皮书》2007年版出版发布会在北京举行.来自中国社会科学院、国土资源部、建设部、国家统计局、中国房地产协会等部门的专家、学者和官员出席了会议.     

Influence of the roots of mixed-planting species on the shear strength of saline loess soil

In order to improve our knowledge of the mechanical effect of the roots of mixed-plantings on soil reinforcement and slope protection,the influence of roots of a mixed-planting with four herb species(Medicago sativa L.,Elymus nutans Griseb.,Puccinellia distanx(L.),and Poa pratensis L.)and one shrub species(Caragana korshinskii Kom.)were investigated on the shear strength characteristics of saline loess soil.The root distribution characteristics were assessed via a survey when the plants grew for one year.The effects of the root biomass density,the root mass ratio(RMR)of the fine roots to the coarse roots,the moisture content,and the salt content on the shear strength index of the rooted soil were analyzed via a triaxial compression test,and the mechanism of these effects was discussed.The results indicate that the biomass density decreased linearly with increasing depth.The RMR initially decreased with depth and then increased,exhibiting in a quadratic relationship.The cohesion of the rooted soil increased linearly as the biomass density increased.The cohesion of the rooted soil initially increased with increasing RMR and salt content,and then it decreased.The turning point of the cohesion occurred when the RMR was 0.6 and the salt content was 1.18%.The internal friction angle of the rooted soil initially increased with biomass density and then decreased,and the turning point of the internal friction angle occurred when the biomass density was 0.015 g/cm3.The relationships between the internal friction angle of the rooted soil and the RMR and salt content were exponential incremental and linear subtractive relationship,respectively.Both the cohesion and the internal friction angle of the rooted soil linearly decreased with increasing moisture content.     

Combined Bearing Capacity of Spudcans on a Double Layer Deposit of Strong-Over-Weak Clays

An extreme sea storm process can lead to a jack-up rig under the combined loading condition of vertical load(V), horizontal load(H), and moment(M) to have stability problems. This paper presents the analysis of combined bearing capacities of a circular spudcan on layered clays with a strong layer overlying a comparatively weaker layer. Numerical models combined with displacement-based load tests, swipe tests, and constant ratio displacement probe tests are adopted to calculate the uniaxial bearing capacities, failure envelopes in combined V-H, V-M planes, and failure envelopes in a combined V-H-M load space, respectively. A parametric study on the effects of vertical load level V, the layer strength ratio s_u,t/s_u,b, and the hard layer thickness t_1 on the bearing capacities is then performed. Results show that the vertical load level is a key factor that influences the values of H and M and the size of the H-M failure envelope. The existence of the underlying weak clay decreases the bearing capacities in all directions, and the vertical capacity Vult is affected more than the horizontal(H_ult) and moment(M_ult) capacities based on a single uniform deposit. The influence of the underlying weak clay on H-M failure envelope is mainly shown where H and M are coupled in the same direction. In contrast, little difference is observed when H and M are coupled in opposite directions.