浅谈电梯技术的发展

在现代化城市的高速发展中,一幢幢高楼拔地而起。电梯是楼房里上下运送乘客或货物的垂直运输设备。随着电梯技术的发展,绿色化、低能耗、智能化、网络化、蓝牙技术的电梯一定能为人类提供更好的服务。无齿轮,远程监控技术将是电梯工业的主要研究方向。     

Silicon Isotopic Compositions of Archean Banded Si-Fe Formation (BIF)in the Gongchangling Ore Deposit, Liaoning Province, China

The results of silicon isotope analyses of Precambrian BIF are reported for the first time. The δ~(30)Si values of magnetite-quartzite in the Gongchangling ore deposit are between —0.9 and —2.2‰, which are obviously different from those in host rocks (0.2——0.6‰). It is suggested that the BIF may be a product of chemical precipitation in Archean submarine hydrothermal environment. There is a possibility of using silicon isotopes to distinguish the protolith of metamorphic rocks and trace the origin of silicon of altered minerals.     

辽宁弓长岭太古代条带状硅铁建造(BIF)的硅同位素组成特征

本文首次对前寒武纪条带状硅铁建造的硅同位素组成进行了研究。弓长岭矿床磁铁石英岩的δ~(30)Si值为-0.9‰至-2.2‰,明显低于围岩地层值(0.2‰至-0.6‰)。分析表明它是在太古代海盆的热水沉积环境中化学沉淀的产物。利用硅同位素组成还有可能用于区分正、负变质岩,用于判明蚀变矿物形成的硅质来源。     

Extraterrestrial ~3He in marine polymetallic nodules: a potential method for measuring growth rate of nodules

The comparative measurements of helium isotope compositions between marine poly-metallic nodules and their surrounding sediments, their magnetic fractions and bulk from C-C Zoneof the East Pacific Basin are reported. The ~4He content and ~3He/~4He ratio of polymetallic nodulesand their surrounding sediments are extremely high; the ~3He, ~4He concentrations and most~3He/~4He ratios of magnetic fractions in nodules and sediments are apparently higher than those inbulk. The helium isotope data points of nodules and sediments are all distributed along or closelyto the mixing curve of the interplanetary dust particles (IDPs) and the terrigenous sediments in thechart of ~3He-~3He/~4He. In the same sampling site, the ~3He/~4He ratios of nodules and their surround-ing sediments are very similar, and the changes of both ratios are synchronous. It shows that thehigh ~3He/~4He ratios in nodules and sediments may all result from IDPs. So, if the flux of extrater-restrial ~3He into the nodules and sediments is constant, the growth rate of polymetallic nodules andthe sedimentation rate of sediments can be independently calculated according to the concentra-tion of extraterrestrial ~3He in nodules and sediments.     

超远距离下组煤层超前开采覆岩应力及裂隙演化规律研究

为探究平煤股份八矿超远距离下组煤层超前开采对上覆煤岩层的影响,采用相似材料模拟实验分析超远距离下组煤层超前开采上覆煤岩层裂隙及应力演化规律,并进行现场验证。研究结果表明：超远距离下组煤层超前开采条件下,随工作面推进,上覆煤岩层裂隙率呈先上升后平稳的趋势,当工作面从187 m推进至272 m,裂隙发育最快;超远距离下组煤层超前开采对上覆煤岩层有卸压效果,但与常规情况下相比卸压滞后距离较大;上覆岩层卸压比戊组煤层大;通过现场验证发现,随工作面推进,矿压呈先上升再下降后稳定的趋势,并将工作面区域分为未干扰区、应力集中区、卸压区和稳定区。研究结论可为平煤矿区远距离下组煤层超前开采、上组煤层工作面瓦斯防治和采区工作面采掘部署提供参考。