The author systematically studies the distributive Law of front abutment pressure and its main influential factor in Top-coal caving face by analysing theory,experimenting similar model,and observing spot.

運(yùn)用理論分析aa的网站、相似模型實(shí)驗(yàn)和現(xiàn)場實(shí)測国产综合男女视频一区二区，系統(tǒng)研究了放頂煤采場前支承壓力的分布規(guī)律及其主要影響因素啊v在线观看亚洲国产，得出支承壓力表達(dá)式( 3)操肥熟、( 7)是可信的操女人网站，塑性區(qū)寬有利于頂煤壓裂欧美真人一级99，峰值低影響硬煤冒放羞羞网站在线观看入口免费，放頂煤一次采厚是有限

Through similar simulation test of block top-coal drawing, the influence of coal block size and block position in top coal on the recovery ratio and drawing manner is studied. It is found that the drawing manner has the different adaptation to the top coal which has different block distribution. The caving capacity is mainly decided by the block size. The top-coal which has layer difference of block with the same size has different recovery ratio. It is shown, that, to the given top-coal blocks, the recovery ratio of uniformly mixed blocks is maximal in the manner of drawing at interval of one support.

研究表明，頂煤塊體大小是影響頂煤回收效果的主要因素欧美国产亚洲白丝一二三，在頂煤塊徑一定的條件下一级片免费黄色网站，塊體層位分布不同是造成頂煤回收率差異的主要原因，研究表明各級塊度均勻混合時(shí)頂煤回收效果最好77777青操网，塊度從下向上增大分布次之久久精品囯产AV，大塊為中位頂煤時(shí)回收效果最差；各種放煤方式的適應(yīng)性不同一区二区裸体，各級塊度均勻混合的頂煤適合用間隔放煤毛片影片；塊度從下向上增大適合用順序放煤；大塊在頂煤中位分布時(shí)人人干97精品，中硬煤以下適合用間隔放煤日韩手机自拍无码AV，硬煤應(yīng)采用順序放煤方式。

Both of the new hard coking coal assessments reflect quality of 64% minimum coke strength after reduction, 9% maximum air dried ash, and 25.5% maximum air dried volatile matter, with recognized premium hard and hard coking coals of differing quality normalized to the Platts specification basis.

上述兩種新硬煉焦煤估價(jià)反映的質(zhì)量均為還原后強(qiáng)度不小于64%黄色网站视频一区二区三区，風(fēng)干灰分不大于9%国产亚洲欧美，風(fēng)干水分不大于25.5%，認(rèn)可的優(yōu)質(zhì)硬煉焦煤和質(zhì)量不同的硬煉焦煤按照普氏的規(guī)格基準(zhǔn)進(jìn)行正彻粕镀谙呤悠担化處理午夜一级黄色片网站。

And proposes that f value is regarded as the classification quota of hard coal and tectonic soft coal.

并提出將f值作為硬煤和構(gòu)造軟煤的分類指標(biāo)。

Coal, mining, construction machinery categories: processing, manufacturing coal pulverizer Dao, the knife's edge spray super-hard alloy, to improve the life of more than five times.

煤碳免费a黄色片、采礦人人精品视频、建筑機(jī)械類：加工、制造煤碳粉碎機(jī)刀把人人超碰人人操，在刀刃上噴焊超硬合金男人桶爽女人30分钟视频动态图，使用壽命能提高五倍以上。

It is important to reduce the span of the hard roof to avoid its impact load on supports. However, at longwall top coal caving face, the periodical weight of roof is a main factor that crushes the top coal, which is beneficial to the top coal recovery. How to use the roof pressure safely is of crucial importance in top coal caving. Based on field monitoring, theoretical analysis of strata movement, the numerical model of compound structure of hard roof stepped cantilever and the top coal cantilever beam is built, and the parameters of the model are also determined. The elasto-plastic finite element method is used to analyze the effect of hard coal fracture under the abutment pressure of hard roof, and the cracking coefficient is defined according to the stress state of the element.

通過對巖層移動的現(xiàn)場觀測www.黄色网，建立了&兩硬&條件綜放采場臺階懸臂—懸臂梁組合的煤巖組合結(jié)構(gòu)力學(xué)模型国产免费自拍，并以此煤巖結(jié)構(gòu)為基礎(chǔ)，建立&兩硬&條件綜放采場頂煤壓裂的有限元數(shù)值模型色爽www色色，分析了堅(jiān)硬頂板不同來壓步距對堅(jiān)硬頂煤的壓裂效應(yīng)黄黄视频免费观看，并確定了合理的支架阻力，從而對堅(jiān)硬頂板進(jìn)行有效的控制黄片视频免费区，消除堅(jiān)硬項(xiàng)板對采場的沖擊隱患欧美老妇人性爱网，同時(shí)保證采場礦壓對堅(jiān)硬頂煤的有效壓裂，達(dá)到提高頂煤回收率之目的女人一级毛片人A片，由此形成了堅(jiān)硬頂煤在线日韩素人自拍网页观看视频、堅(jiān)硬頂板條件下綜放采場圍巖控制的基本理論和方法。

The top coal fracture is described distinctly under the condition of different roof span and mining technology parameters. Through orthogonal experiment of numerical simulation, the rational pretreatment span of hard roof is determined, and the rational working resistance of support is selected also. As a result: the hard roof is effectively controlled not only to protect the working face but also to promote the caving of hard top coal to increase the recovery ratio.

在有效控制堅(jiān)硬頂板的基礎(chǔ)上，利用數(shù)值模擬正交試驗(yàn)法亚洲幼小激情视频图片小说在线播放网站，研究了采高、采放比在线观看福利小视频国产、支架阻力人人超碰人人双人人舔、放煤步距等工藝參數(shù)對頂煤壓裂效果的影響規(guī)律，從而對工作面工藝參數(shù)進(jìn)行優(yōu)化自拍下一页；并根據(jù)實(shí)驗(yàn)所得放煤方式對塊體頂煤的適應(yīng)性規(guī)律九久视频精品免费，選擇&兩硬&綜放面的放煤工藝，從而形成了系統(tǒng)北京一级黄片、完善的&兩硬&條件綜放工藝AAAα黄色视频。

Front of industry of whole Europe hard coal is facing the economic situation of 20 century later period.

整個(gè)歐洲硬煤工業(yè)正面臨著20世紀(jì)后期的經(jīng)濟(jì)形勢。

Evonik is a global leader in specialty chemicals, an expert in power generation from hard coal and renewable energies, and one of the largest private residential real estate companies in Germany.

贏創(chuàng)是全球領(lǐng)先的特種化學(xué)品供應(yīng)商美女操比视频网站，也是硬煤與可再生能源發(fā)電方面的專家www.婷婷五月情.com，同時(shí)還是德國最大的私人房地產(chǎn)公司之一。

Hard coal and coke - Mechanical sampling - Part 7: Methods for determining the precision of sampling, sample preparation and testing

硬煤和焦炭機(jī)械化采樣第7部分：采樣精度測定方法国产很爽的超薄丝袜脚交网站，樣品制備方法及試驗(yàn)方法