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251.
为提高冲击地压预测的效率和准确率,在分析冲击地压影响因素的基础上,提出了一种将遗传算法(GA)与极限学习机(ELM)相结合的冲击地压预测的新方法。为了避免ELM受输入权值矩阵和隐含层偏差随机性的影响,算法采用GA对ELM的输入权值矩阵和隐含层偏差进行优化,建立GA-ELM冲击地压预测模型。利用某矿冲击地压统计数据对该模型进行了实例分析,将ELM、SVM和BP算法预测结果与该模型进行了对比分析。结果表明:GA-ELM模型具有较高的预测精度,可以相对准确、有效地对冲击地压发生的可能性进行预测。 相似文献
252.
Jiaxing Guo Huan Liu Yang Jiang Dongquan He Qidong Wang Fei Meng Kebin He 《Frontiers of Environmental Science & Engineering》2014,8(1):79-88
To understand the household C02 emission level in China, as well as how much the neighborhoods' socio-economic or design factors could influence the CO2 emission, 23 neighborhoods in Jinan were investigated in 2009 and 2010. These neighborhoods fall into four different types: superblock, enclave, grid and traditional. The household CO2 emission includes sources of both in- home energy use and passenger transportation. The average CO2 emission per household is 7.66 t.a^-1, including 6.87 t in-home operational emission and 792 kg transportation emission. The household CO2 emission by neighborhood categories is 10.97, 5.65, 6.49, 5.40 t-household-1. a-1 for superblock, enclave, grid and tradi- tional respectively. Superblock has the highest average emission and also the highest percent (more than 25%) of transportation emission among four different types of neighborhoods. The residential CO2 emission of superb- lock neighborhoods in Jinan has already reached the level in developed countries nearly ten years ago. It is predictable that more superblock neighborhoods would be built in China with the fast urbanization. How to avoid the rapid household CO2 emission growth in the future would be a systematic issue. The study also found that in addition to income and apartment area, household density, land use mix and accessibility to public transportation are three primary factors which have significant impacts on CO2 emission. High density, mixed land use and convenient accessibility to public transportation tend to reduce household CO2 emission. 相似文献
253.
宝钢特种设备计算机管理系统的研究与应用 总被引:4,自引:1,他引:3
简述了宝钢特种设备安全管理理念,提出了宝钢特种设备计算机管理系统的总体思路,并对该系统的应用作了一定描述。 相似文献
254.
对热媒炉导热油系统结垢的原因进行分析.介绍了热媒炉导热油系统清洗的方法,比较各种清洗方法的异同.对清洗更换导热油时的注意事项进行说明,对试运情况及取样化验数据进行分析. 相似文献
255.
收集整理了1993年以来的地震资料,建立M5地震和M6地震两个样本组,选取发震断层、震源复杂性、视应力3个参数,使用模糊等价关系的聚类分析方法对地震进行分类,把具有相同性质的地震归为同一类,研究孤立型、主余型、多震型地震的某些特征性质。结果表明:1孤立型地震性质:震源错动方式简单,应力降高或很高,视应力低或很低,震源区介质非均匀程度低;2多震型地震性质:对于走滑断层地震,震源错动方式复杂,应力降低或很低,视应力偏高或很高,震源区介质非均匀程度较高。 相似文献
256.
257.
The influence of the type of clouds that produce precipitation in the rainwater composition was analyzed. Logroño, a remote station in the North of Spain was chosen for the analyses. Results prove that the rainwater composition from Cumulonimbus is different to the composition of the rainwater from the other clouds. In addition, the source of NO3 ? and SO4 2? is studied in the different types of clouds. It is shown that the source is the soil except Stratocumulus formed from Cumulus in which the source is the gas‐particle conversion. 相似文献
258.
259.
环鄱阳湖浅层地下水水化学特征的时空变化 总被引:5,自引:0,他引:5
系统采集了鄱阳湖周边地下水,分析测定各单元的水化学参数.结果表明,环鄱阳湖浅层地下水整体偏酸性,呈低矿化度,局部地区出现微咸水.环鄱阳湖浅层地下水丰、枯水期的优势阴离子为HCO3-,阳离子为Ca2+和Mg2+.运用SPSS软件做离子相关性分析,各离子间均呈正相关性,说明可能有相同的来源.地下水的水化学类型整体表现为HCO3-Ca-Mg型,丰水期相对于枯水期出现较多的NO3-型和SO24-型水体,局部区域优势阴离子改变,出现了NO3-型、Cl-型地下水,可能受到农业化肥和工业废水排放的影响.整体上地下水的水化学类型受当地岩石类型的影响比较大,个别地区受人为的活动干扰较为强烈. 相似文献
260.
B. Patti A. Bonanno G. Basilone S. Goncharov S. Mazzola G. Buscaino 《Chemistry and Ecology》2013,29(5):365-375
The main results of research work carried out since 1998 with regard to the application of hydro-acoustic technologies for the evaluation of biomass and distribution of small pelagic fish species off the southern coast of Sicily are presented, taking into account information from hydrology and from ecology of the fish populations targeted. The biomass estimates and the population‐density charts presented concern the two main species, i.e. sardine Sardina pilchardus (Walbaum, 1792) and anchovy Engraulis encrasicolus (Linnaeus, 1758). Both the sardine and anchovy populations experienced large inter-annual fluctuations, with biomass estimates ranging from 6000 to over 36,000 tonnes (t) (sardine) and from about 7000 to 23,000 t (anchovy). Acoustic estimates are largely consistent with landings recorded in Sciacca (the main fishing port for small pelagic species in the study area) during the year following the evaluation surveys. In addition, trends in sardine and anchovy biomass estimates appears to be negatively correlated with the mean sea surface temperature calculated over the time intervals January–September (sardine) and June–November (anchovy) of the preceding year, which correspond to larval and juvenile growth periods of target species. Observed patterns would suggest the importance of enrichment processes relevant to the survival of early stages, so determining recruitment success and finally higher population sizes. 相似文献