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981.
一种融合地理空间指标的土地需求量预测方法——以佛山市南海区为例 总被引:1,自引:0,他引:1
目前关于土地需求量的预测方法往往忽视地理空间因素。本文提出了一种融合地理空间指标的土地需求量的多因素预测方法,通过在需求量预测计算中引入地理标准距离、标准差椭圆、Moran'' s I指数等与土地利用类型的空间分布和空间形态相关的因素,探讨基于地理空间指标进行土地需求量预测的可行性和准确性。以佛山市南海区历年的土地利用调查数据为基础进行案例研究,结果表明:相对于地理经济指标,引入地理空间指标的土地需求量预测结果准确率更高。但由于数据量的限制,本文所得的结果需要收集更多数据采用多种统计分析方法进一步加以研究验证。 相似文献
982.
Shi-zhen Li Zhi Zhou Hai-kuan Nie Lei-fu Zhang Teng Song Wei-bin Liu Hao-han Li Qiu-chen Xu Si-yu Wei Shu Tao 《China Geology》2022,5(1):110-135
The shale gas resources in China have great potential and the geological resources of shale gas is over 100×1012m3,which includes about 20×1012m3 of recoverable resources.Organic-rich shales can be divided into three types according to their sedimentary environments,namely marine,marine-continental transitional,and continental shales,which are distributed in 13 stratigraphic systems from the Mesoproterozoic to the Cenozoic.The Sichuan Basin and its surrounding areas have the highest geological resources of shale gas,and the commercial development of shale gas has been achieved in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in these areas,with a shale gas production of up to 20×109m3 in 2020.China has seen rapid shale gas exploration and development over the last five years,successively achieving breakthroughs and important findings in many areas and strata.The details are as follows.(1)Large-scale development of middle-shallow shale gas(burial depth:less than 3500 m)has been realized,with the productivity having rapidly increased;(2)breakthroughs have been constantly made in the development of deep shale gas(burial depth:3500-4500 m),and the ultradeep shale gas(burial depth:greater than 4500 m)is under testing;(3)breakthroughs have been made in the development of normal-pressure shale gas,and the assessment of the shale gas in complex tectonic areas is being accelerated;(4)shale gas has been frequently discovered in new areas and new strata,exhibiting a great prospect.Based on the exploration and development practice,three aspects of consensus have been gradually reached on the research progress in the geological theories of shale gas achieved in China.(1)in terms of deep-water fine-grained sediments,organic-rich shales are the base for the formation of shale gas;(2)in terms of high-quality reservoirs,the development of micro-nano organic matter-hosted pores serves as the core of shale gas accumulation;(3)in terms of preservation conditions,weak structural transformation,a moderate degree of thermal evolution,and a high pressure coefficient are the key to shale gas enrichment.As a type of important low-carbon fossil energy,shale gas will play an increasingly important role in achieving the strategic goals of peak carbon dioxide emissions and carbon neutrality.Based on the in-depth study of shale gas geological conditions and current exploration progress,three important directions for shale gas exploration in China in the next five years are put forward. 相似文献
983.
在总结二台子金矿成矿规律的基础上,采用信息量和特征分析方法对矿区及外围进行了综合预测.之后,运用地球化学与构造应力分析相结合方法,对已知矿体进行了深部预测并定位. 相似文献
984.
985.
木星“大红斑”的旋转浅水实验模拟研究 总被引:1,自引:0,他引:1
在具有自由表面的旋转轨物面浅水实验系统上进行了可重复的系列模拟实验,在旋转随动坐标系中拍摄的照片和功率谱分析表明,确有大尺度持续存在的涡旋、漂移与演化产生,在一定条件下,呈现出一个自持的、长寿命的、沿与整体旋转方向相反方向漂移的反气旋孤立波涡旋(Rossby孤立波涡旋),这就是木星“大红斑”的实验室模型,实验结果证实,流体动力学不稳定主要来自于剪切和Coriolis力效应,由于远离平衡态的耗散系统的自组织,涌现出大尺度长寿命相干涡旋结构,受多次实验的启发,从流体动力学基本方程出发,在一定的实验条件下提出一个半经验模型,近似求出了Rossby孤立波涡旋解。 相似文献
986.
Zheng Xiaodong Zhao Jianmin Xiao Shu Wang Rucai Wang Shidang Zhou Weiwu 《中国海洋大学学报(英文版)》2004,3(1):48-52
Thirty-nine isozymes in four tissues (mantle muscle, buccal bulb muscle, eye and liver) of Sepia esculenta were screened for enzymatic analysis using starch gel electrophoretic technique. Eighteen enzymes (G3PDH, LDH, MDH, MEP,
IDHP, PGDH, GRS, NP, AAT, CK, AK, EST, ALP, ACP, FBP, MPI, GPI and PGM) show strong activities and good convergence in zymogram.
They are proved to be suitable genetic markers in Sepia esculenta. Among the tissues used, mantle muscle is the best for electrophoretic analysis of isozymes. Eye and liver are fairly good
for some special enzymes, such as LDH, EST, MPI, etc. Twenty-six loci are detected. The proportion of polymorphic loci is 0.115 in the Qingdao sample and 0.153 in the Rizhao
sample (P<0.99). The mean values of the observed and expected heterozygosity per locus of Qingdao sample are 0.016 and 0.017, while
those of the Rizhao sample are 0.023 and 0.025 respectively. 相似文献
987.
In this paper, we investigate the star formation and chemical evolution of damped Lyman α systems (DLAs) based on the disc galaxy formation model developed by Mo, Mao & White. We propose that the DLAs are the central galaxies of less-massive dark haloes present at redshifts z ∼3, and they should inhabit haloes of moderately low circular velocity. The empirical Schmidt law of star formation rates, and closed box model of chemical evolution that an approximation known as instantaneous recycling is assumed, are adopted. In our models, when the predicted distribution of metallicity for DLAs is calculated, two cases are considered. One is that, using the closed-box model, empirical Schmidt law and star formation time, the distribution of metallicity can be directly calculated. The other is that, when the simple gravitational instability of a thin isothermal gas disc as first discussed by Toomre is considered, the star formation occurs only in the region where the surface density of gas satisfies the critical value, not everywhere of a gas disc. In this case, we first obtain the region where the star formation can occur by assuming that the disc has a flat rotation curve and rotational velocity is equal to the circular velocity of the surrounding dark matter halo, and then calculate the metallicity distribution as in case one. We assume that star formation in each DLA lasts for a period of 1 Gyr from redshifts z =3. There is only one output parameter in our models, i.e. the stellar yield, which relates to the time of star formation history and is obtained by normalizing the predicted distribution of metallicity to the mean value of 1/13 Z⊙ as presented by Pettini et al.. The predicted metallicity distribution is consistent with the current (rather limited) observational data. A random distribution of galactic discs is taken into account. 相似文献
988.
989.
陕西圣人桥附近,复杂多样的褶皱出现在平缓的地台盖层之中。对其成因,争议颇多,或认为推覆作用所致,或认为受断裂作用控制。笔者通过详细研究,认为这些复杂褶皱是一种水底重力滑塌构造。据此,还提出了重力滑动构造新的分类,即重力蠕滑;重力滑塌以及重力滑碎等三类。 相似文献
990.