云南元江金矿矿床模型及矿产经济   总被引：6，自引：2，他引：6  

秦德先  刘春学  燕永锋  李麦兑 《矿物学报》2001,21(4):609-612

随着湿法冶金技术的发展，过去圈定氧化矿的工业指标在当前技术经济 条件下过高，已将大量矿石划为废石，既浪费了资源,又污染了环境。通过建立矿床模型，优化工业指标，重新圈定矿体和计算储量，增加金储量10t，为提高矿山生产的经济效益，充分合理利用矿产资源提供了科学依据。  相似文献   

试论严格依法做好西宁市建筑物抗震设防工作     

许勤  丁平 《高原地震》2001,13(3):40-44

从城市区划、地震安评和城市建设的监管机制等几个方面讨论市建筑物抗震设防工作中存在的问题及相应对策。  相似文献   

Soil quality and sustainable land use in urban-rural marginal area: a case study of Kaifeng   总被引：1，自引：0，他引：1  

QIN Ming-zhou  ZHAO Jie 《地理学报(英文版)》2001,11(3):356-365

Soil quality is closely related to the sustainability of environment and development[1], hence people have paid more and more attention to soil quality research in recent years, and have made a thorough inquiry of the definition of soil quality as well as the method and theory of its expression[2-4]. As a zone devoting to most intensive modern agricultural land use, urban-rural marginal area has become a region where intensity of soil quality change is most remarkable. Moreover, with the devel…  相似文献   

地震动态空区法与中、强震预报     

秦保燕 《地震研究》1995,(2)

本文在组合模式和立交模式的基础上提出了预报中、强地震的动态空区法，应用该法对我国大震进行了回顾性检验。结果表明，这一方法比单空区确定地震危险区有重要改进。文中还讨论了由动态空区出现的频次增多、地震共轭条带以及中小地震活动性加剧等判定震源断层的致锁和解锁时间，由此预测未来主震的震级和发震时间。  相似文献   

利用EOF作相空间拓展与有限区域大气系统混沌吸引子维数的确定     

朱育峰  彭永清等 《南京气象学院学报》1995,18(1):52-56

提出用自然正交函数分解的方法来开拓相空间，从而研究有限区域上大气系统的混沌性质。与利用时间滞后作漂移来开拓相空间方法相比较，前者充分保证了相空间各基矢量的正交性，弥补了后者只能对单点资料进行计算的不足。文中利用欧洲中期数值天气预报中心1980－1986年北半球亚洲地区的500hPa位势高度场逐日格点资料进行了EOF分解并计算得到了该地区大气系统的分维数为D＝6．2，从而表明，为支撑该地区大气系统的混沌吸引子至少应取7维系统或以7个变量才能作出描述。  相似文献   

X－CT检查与X线摄影的区别     

朱事芳  叶琴  高艳 《CT理论与应用研究》1995,(3)

本文列出ＣＴ检查与Ｘ线摄影的成像原理，及各自优缺点，提示临床正确应用ＣＴ检查与Ｘ线摄影，使得诊断更加正确有效，并节省患者的的检查费。  相似文献   

NUMERICAL STUDY OF OROGRAPHIC INFLUENCE ON LOW FREQUENCY OSCILLATION     

张勤  朱育峰  倪允琪  林武银 《热带气象学报(英文版)》1995,1(1):67-74

Orographic effects on monthly-and seasonal-scale low frequency oscillation are investiged in terms of a five-level global spectral model with a triangle truncation at wavenumber 10 that contains relatively full physical parameterization, followed by analysis and comparison of the lowpass filtered data separately obtained from models with and without orography. Results show that remarkable seasonal characteristics are displayed in the orographic forcing-generated low frequency wavetrain on monthly and seasonal scales. It is found that the Northern Hemisphere summer orography-produced tropical heating acts as source of the low-frequency wavetrain for both hemispheres. Besides, the simulations indicate that the orographic wavetrain perturbation can give rise to the anomaly in the equatorial zonal flow, whose transient forcing will cause a new wavetrain in the Southern Hemisphere, thus completing the cross-equatorial propagation of the northern wave in interhemispheric action.  相似文献   

NUMERICAL STUDY ON NONLINEAR INTERACTION BETWEEN TROPICAL CYCLONE AND SEA^*          下载免费PDF全文

Qin Zenghao  Zhu Jianrong 《Acta Meteorologica Sinica》1995,9(1):13-25

Given time-independent monthly mean sea temperature,numerical simulation was done of the path of the tropicalcy clone Forrest and its related physical quantity field in terms of the improved version of the σ-coordinate 10-level primitive equation model for tropical cyclones developed by the Guangzhou Institute of Marine Meteorology.Result ssuggest the similarity between the simulated and observed physical quantity fields except that the simulated path was to the right of the observed,with the deviation increasing with time.Sea and tropical cyclone,in effect,interact mutually.In an attempt to compare the results from coupling and uncoupling experiments,an oceanic mixed layer model was formulated based on experiments with sea response to cyclone and integrated in synchronous coupling with the aforementioned version of tropical cyclones,the computational domain covering the western North Pacific with the coastal configuration involved.The coupling experiment shows that the negative feedback of the interaction between sea and mature cyclone leads to weaker sea response as compared to the uncoupling case.Except for the location of the divergence core of oceanic current,the mixed layer depth and inhomogeneous distribution of sea surface temperature (SST) caused by the cyclone-core position and intensity,the values of the maximum oceanic current,departure of the mixed layer depth and SST drop were smaller in the coupling than in the uncoupling case,and so was the maximum wind near the cyclone core.The path from the coupling run is to the left of the course in the uncoupling experiment but closer to the observed one though remaining somewhat leftward.Even on a scale of less than 3 days,the effects of sea and sea-cyclone interaction on the cyclone were by no means negli-gible.  相似文献   

QBO Features of Tropical Pacific wind Stress Field with the Relation to El Nino     

Zhang Qin  Zhu Yufeng  Ni Yunqi 《大气科学进展》1995,12(1):87-94

Analysis has been implemented of 1970-1992 tropical Pacific wind stress anomaly and sea surface temperature anomaly (SSTA) datasets, indicating that quasi-biennial oscillation (QBO) of the tropical Pacific WS and SSTA is featured both by a standing and a progressive form, the former emerging in the most intense centers of action and the latter travelling east- or west-ward out of the SSTA sources. Results show that the SSTA is in the warm (cold) phase as zonal component of euqatorial wind stress anomaly gets weakened (reinforced) and the QBO of wind stress anomaly is well related to the El Nino cycle.  相似文献   

DETERMINATION OF AERODYNAMIC PARAMETERS OF CROP CANOPIES WITH A CENTER-OF-PRESSURE METHOD          下载免费PDF全文

Qin Wenhan 《Acta Meteorologica Sinica》1995,9(1):78-86

Using data on leaf area density and wind profiles above and within canopies of wheat,rice,soybean and corn,thecenter-of-pressure method (CPM),originally proposed by Thom (1971),is first validated in the field.Aphysically-based model for directly calculating zero-displacement height (d) is derived.The comparison between thefriction velocity (u_*) estimated with CPM and that with eddy correlation technique shows that CPM not only works wellin the field,but also produces more steady and accurate estimates of aerodynamic parameters (which are hardly affectedby atmospheric thermal stability),than those with the widely-used log-profile fitting method in diabatic atmosphere.The results presented in this paper also demonstrate that the ratios of d,z_0 to crop height h usually vary with canopy ar-chitecture,atmospheric stratification and turbulent exchange intensity,and are not just constants as commonly assumedor used.d/h raises with an increase of relative height of the maximum foliage layer and wind extinction coefficientwithin the canopy.Only for crops with short stem and moderate foliage density,can the relations d= 0.64h,z_0=0.08hkeep stable.In addition,for long stem crops or sparse canopies,the fairly large shear stress at the soil surface and the va-riation of the exponent in the relationship between drag coefficient and wind speed undoubtedly influence the accuracyof CPM to a certain extent.  相似文献