New Boundary Element Method For Analysis Of Surface Subsidence Due To Coal Mining

Rock and coal in coal bearing formation belong to layered sedimentary rocks. Their large-scale subsidence may occur because of coal mining. Thus, it is one of research highlights to develop an analytical tool suitable for these layered rocks. This paper presents a new Boundary Element Method(BEM) for analysis of the surface subsidence due to coal mining. The BEM uses the fundamental solution of layered materials,4-8 noded elements to discretize the boundaries, and effective numerical methods to calculate the singular integrals. An example with exact solutions is used to verify the numerical method. Finally, the numerical method is used to analyze in situ surface subsidence due to coal mining. The result shows that the proposed BEM can analyze the surface subsidence due to coal mining with high efficiency and good accuracy. 煤系地層為成層分布的沉積巖,煤層的開采會引起地表大規模的沉陷,發展適應此類介質的分析方法一直是本領域的研究熱點。本文發展了一種新型的邊界元方法來分析煤層開采引起的地表移動。該邊界元方法基于層狀材料基本解,采用4~8變結點單元離散邊界,并采用有效的數值方法計算各類奇異積分。然后,用有解析解的算例驗證建議數值方法。最后,采用新型邊界元方法分析煤層開采引起的地表移動。本文所建議的方法在分析煤層開采引起的地表沉陷時具有較高的計算精度和效率

Shaping the Urban Traditions: Architectural Education on Open Building 3

The problem of modern cities is nevertheless methodological rather than formalistic. The problem urban design today is extremely exclusive – the dimension of TIME and INTERACTION of people, the two basic elements constructing the traditional cities, are largely ignored. This paper introduces the students implications of Open Building thinking into urban design

A study of chemical properties of rains on the Tibetan Plateau

Natural rains are generally considered as weakly acidic. Measurements in Lhasa and other three small cities on the Tibetan Plateau reveal that the rainwater on the Plateau is alkaline with bicarbonate as the dominant anion and contains few pollutants. On the basis of the measurements on the Tibetan Plateau, the experiments and calculation, the authors believe that the original pH of natural rainwater in arid and semiarid areas on this planet should be weakly alkaline because of the influence of alkaline dusts. 一般認為天然降雨呈弱酸性,但是觀測顯示青藏高原上拉薩及其它3個城市降水呈堿性,以重碳酸鹽陽離子為主,污染物很少.通過對實測資料和試驗結果的分析計算,認為地球上干旱和半干旱地區天然降水的應呈弱堿性,原因是大氣中漂浮著堿性粉塵

Update on Apoptosis Signal Pathway of Retinal Ganglion Cell

视网膜神经节细胞(RGCs)的进行性凋亡是许多视网膜病变和视神经疾病进展到最后的必经之路,是多种眼病致盲的根本原因.RGCs对外界因素的影响异常敏感,外伤、高眼压、炎症和神经毒素等均可造成其不可逆的损伤,而这些细胞外信号又通过不同的途径影响着细胞内部的信号转导,调节细胞内凋亡相关基因的表达,最终造成RGCs的凋亡.本文从细胞外部因素的诱导、细胞内部的信号传递和基因调控3个方面总结病理情况下RGCs凋亡信号转导通路研究的最新进展,旨在为视网膜神经保护药物的开发提供新的思路

Review Radix rule application of heat in clinic

為深入了解柴胡在退熱方面的特點及臨床運用規律,從柴胡的配伍、炮制、用量、煎煮方法以及劑型等方面,對柴胡用治發熱的相關文獻進行歸納分析,探討其臨床特點及運用規律。認為柴胡的退熱配伍不少,然對其藥理研究尚不夠;有關使用炮制柴胡的報道亦較少,且炮制的方法也有爭議;柴胡的用量、煎煮方法對臨床治療發熱性疾病有一定的影響,但研究的深度不夠,各家意見不一,有待進一步研究。link_to_OA_fulltex

开放建筑教育课题二: 设计建筑的灵活性

The previous paper addressed methods to help students conceptualize the permanency of public buildings with an emphasis on massing, fa?ade and structure. This paper investigates methods to teach building flexibility. Three sequential exercises follow an introduction of the 'open building' concept as critic of traditional architectural design concepts. The first exercise is a warm-up that familiarizes students with the design of mobility. The second exercise introducesthe fl exible infi ll systems of a given structure. The third exercise asks students to develop ideas for a new structure which can adapt the infi ll systems produced in the previous exercise. The adaptability of structure and adaptability in infi ll system are observed with the intention to construct a harmony and long sustainability in the given site. The paper is concluded with a dialogue with students

提高全民對食品營養及安全的認知是解決食品安全問題的關鍵

本文結合最近發生的食品安全事件及嬰幼兒食品的營養及安全問題,指出食品安全問題在我國大有日趨嚴重之勢,并建議國家有關部門、媒體和社會各界共同配合,對廣大消費者和食品生產者進行食品營養和食品安全知識和法規的教育及宣傳,以提高他們的認知水平,這是解決食品安全問題的關鍵。 The recent food safety incidents and the infant food nutrition and safety issues indicate that food safety has become worse and worse in China.The article suggests that the key to solving the food safety problems fundamentally is to educate the consumers and food manufacturers,with the concerted efforts of government,media and the public,in order to enhance their understanding of food nutrition and safety

地下工程事故紧急搜救的快速气冲钻孔和实时监测

如何以最快的速度搜救地下工程事故中的被困人員,是完成救援任務的關鍵,筆者提出了自動監測鉆孔過程的DPM方法。該方法在以高壓空氣作為動力的潛孔錘旋轉沖擊鉆孔中,能夠自動、連續地對鉆孔過程實時數字監測和記錄。這種智能型監測鉆孔可以實時建立沿鉆孔深度各點的巖土體力學強度與空間分布,從而準確地測定地下洞室或巷道的位置及范圍。該技術起到快速搜索以及輸送新鮮空氣的作用,鉆成的孔洞可以將食物和水傳遞給被困人員。十多年來,實際數字鉆孔監測結果表明,這項研究的確可以精確測定和給出地下巖土體的力學強度。該方法可以有效地、具體地應用到地下工程事故緊急搜救工作中。 This paper presents a brief idea for an effective searching and rescuing people trapped in sealed underground spaces such as caverns and tunnels due to collapse of surrounding rock and soil masses.The idea is based on the fast construction hole drilling and its automatic digital monitoring.The drilling device is the compressed air-flow driven percussive-rotary drilling associated with a down-the-hole hammer.The drilling process monitoring allows an accurate and effective delinearing of the soil and rock strength and quality along the drill hole in real time,thus making it possible to quickly determine the location of the buried underground space and reach the people in the underground space,with the result that the compressed air-flow can flow into the buried underground space through the holes in the bit of the hammer.It follows that the method can come into effective and practical use for emergent searching and rescuing people trapped in buried underground space

五份新見藏文注音西夏文殘片校釋

夏藏對音殘片是研究西夏語音的重要材料,目前能確認的殘片有25份,其中20份殘片的內容此前已見整理刊布。本文整理最后5份新見的藏文注音西夏文殘片內容,其中有2份來自俄藏黑水城文獻,另外3份屬大英圖書館收藏。至此,所有能確認的藏文注音西夏文殘片均已作全文刊布。 Tangut fragments with Tibetan transcription are important materials for the study of Tangut pho-nology. Currently it is known to have 25 fragments of this kind, in which20 of them have been collated. Thispaper provides the collated edition of 5 newly seen Tangut fragments with Tibetan transcription, among them2 fragments come from the Russian collection, and the rest 3 fragments are now preserved in the British Li-brary. The collation of all identified Tangut fragments with Tibetan transcription is thus completed