深孔爆破松动技术在八层工作面结核石区应用

结核石,俗称硫磺石,致密坚硬,在八层工作面中经常遇到,而且比较难处理,面积较大需要改造,面积小需要打眼松动爆破,打眼爆破工作量大。采用深孔爆破松动技术提高了八层工作面过结核石区的速度,也是解决这一难题的有效途径之一。

含硬结核薄煤层综采面煤体水力致裂弱化技术

田庄煤矿属薄煤层矿井,所主采的17煤,煤层厚度平均0.95 m,煤层中富含坚硬的硫化铁结核石,严重制约着薄煤层综采的高效安全生产。介绍了在采煤机割煤时,提前对煤体进行湿润软化来降低煤层的整体力学性能,对硫化铁结核石预先松动,减少采煤机截齿消耗,提高煤层的可采效率,实现薄煤层综采工作面的高效安全生产。

响石鉴赏

我国的赏石界,以“石不能言最可人”、“此时无声胜有声”而怡然自得,因无声而人石合一,其妙尽在不言之中。随着赏石业的崛起、兴旺和发达,又发现了响石,它为赏石界提供了一种“石如能言更可人,亦悦耳目亦知音”的新意境。两千多年以前,我国即用玉或磬石制作乐器,这种“石磬”的本质虽属响石范畴,但终因人工雕琢成分过高,已使其天然属性难以看清。本文研究的对象,仅限于作为观赏石的响石,它虽然几千年前就被发现,但引起鉴赏家、

A novel model for assessing the pore structure of tight sands and its application

Pore-structure poses great influence on the permeability and electrical property of tight sand reservoirs and is critical to the petrophysical research of such reservoirs.The uncertainty of permeability for tight sands is very common and the relationship between pore- structure and electrical property is often unclear.We propose a new parameterδ,integrating porosity,maximum radius of connected pore-throats,and sorting degree,for investigating the permeability and electrical properties of tight sands.Core data and wireline log analyses show that this newδcan be used to accurately predict the tight sands permeability and has a close relation with electrical parameters,allowing the estimation of formation factor F and cementation exponent m.The normalization of the resistivity difference caused by the pore- structure is used to highlight the influence of fluid type on Rt,enhancing the coincidence rate in the Pickett crossplot significantly.

Treatment of chronic proliferative cholangitis with c-myc shRNA

AIM： To investigate the feasibility and effectiveness of c-myc shRNA in inhibiting the hyperplastic behavior and lithogenic potentiality of chronic proliferative cholangitis （CPC）, in order to prevent stone recurrence and biliary restenosis. METHODS： An animal model of CPC was established by giving intralumenally 0.5 mL of c-myc shRNA. Then, the effects of c-myc shRNA on hyperplastic behavior and lithogenic potentiality of CPC were evaluated by histological observation, immunohistochemistry, real- time PCR and Western blotting for c-myc, proliferating cell nuclear antigen （PCNA）, procollagen m, mucin 5AC, enzymatic histochemistry for 13-glucuronidase, and biochemistry for hydroxyproline in the diseased bile duct. RESULTS： Treatment with c-myc shRNA efficiently suppressed the hyperplasia of biliary epithelium, submucosal gland, and collagen fiber by inhibiting mRNA and protein expression of c-myc. More importantly, it decreased the lithogenic potentiality of CPC by inhibiting the expression of mucin 5AC and the secretion of endogenous 13-glucuronidase. Further investigation indicated that c-myc shRNA-3 had a better inhibitory effect on CPC. CONCLUSION： Treatment with c-myc shRNA-3 can control CPC and reduce the lithogenic potentiality of CPC.

Numerical simulation for influences of pressure solution on T-H-M coupling in aggregate rock

The pressure solution model of granular aggregates was introduced into a FEM code which was developed for the analysis of thermo-hydro-mechanical(T-H-M) coupling in porous medium. Aimed at creating a hypothetical model of nuclear waste disposal in unsaturated quartz aggregate rock mass with laboratory scale, two 4-year computation cases were designed: 1) The porosity and permeability of rock mass are functions of the pressure solution; 2) The porosity and the permeability are constants. Calculation results show that the magnitude and distribution of stresses in the rock mass of these two calculation cases are roughly the same. And, the porosity and the permeability decrease to 43%-54% and 4.4%-9.1% of their original values after case 1 being accomplished; but the negative pore water pressures in cases 1 and 2 are respectively 1.0-1.25 and 1.0-1.1 times of their initial values under the action of nuclear waste. Case 1 exhibits the obvious effect of pressure solution.

话说木鱼石

电影《木鱼石的传说》主题歌中唱到“有一个美丽的传说,精美的石头会唱歌……”。大自然无奇不有,除了“石不能言最可人”的石头之外,还有会唱歌的、会响的石头,这就是木鱼石。木鱼石,因形似和尚念经时所敲的木鱼而得名,是药物学家给起的,在《地质辞典》中找不到,却流传甚广,在人民群众中有很高的知名度。奇特之处在于有些木鱼石不用敲击。用手一摇即可发出响声,故又称响石、空石、空心石、空青石。依据其形状特征,又有石斛、石罐、石匣、石屉、石子盂、滴砚石、锅底石、石胆、

Thyroid dysfunction, either hyper or hypothyroidism, promotes gallstone formation by different mechanisms

We have investigated comprehensively the effects of thyroid function on gallstone formation in a mouse model. Gonadectomized gallstone-susceptible male C57BL/6 mice were randomly distributed into three groups each of which received an intervention to induce hyperthyroidism, hypothyroidism, or euthyroidism. After 5 weeks of feeding a lithogenic diet of 15% （w/w） butter fat, 1% （w/w） cholesterol, and 0.5% （w/w） cholic acid, mice were killed for further experiments. The incidence of cholesterol monohydrate crystal formation was 100% in mice with hyperthyroidism, 83% in hypothyroidism, and 33% in euthyroidism, the differences being statistically significant. Among the hepatic lithogenic genes, Tr~ was found to be up-regulated and Rxr down-regulated in the mice with hypothyroidism. In contrast, Lxra, Rxr, and Cyp7al were up-regulated and Fxr down-regulated in the mice with hyperthyroidism. In conclusion, thyroid dysfunction, either hyperthyroidism or hypothyroidism, promotes the formation of cholesterol gallstones in C57BL/6 mice. Gene expression differences suggest that thyroid hormone disturbance leads to gallstone formation in different ways. Hyperthyroidism induces cholesterol gallstone formation by regulating expression of the hepatic nuclear receptor genes such as Lxra and Rxr, which are significant in cholesterol metabolism pathways. However, hypothyroidism induces cholesterol gallstone formation by promoting cholesterol biosynthesis.

A distinctive Eocene Asian monsoon and modern biodiversity resulted from the rise of eastern Tibet

The uplift of eastern Tibet,Asian monsoon development and the evolution of globally significant Asian biodiversity are all linked,but in obscure ways.Sedimentology,geochronology,clumped isotope thermometry,and fossil leaf-derived numerical climate data from the Relu Basin,eastern Tibet,show at~50–45 Ma the basin was a hot(mean annual air temperature,MAAT,~27℃)dry desert at a low-elevation of 0.6±0.6 km.Rapid basin rise to 2.0±0.9 km at 45–42 Ma and to 2.9±0.9 km at 42–40 Ma,with MAATs of~20 and~16℃,respectively,accompanied seasonally varying increased annual precipitation to>1500 mm.From~39 to 34 Ma,the basin attained 3.5±1.0 km,near its present-day elevation(~3.7 km),and MAAT cooled to~6℃.Numerically-modelled Asian monsoon strength increased significantly when this Eocene uplift of eastern Tibet was incorporated.The simulation/proxy congruence points to a distinctive Eocene Asian monsoon,quite unlike that seen today,in that it featured bimodal precipitation and a winter-wet regime,and this enhanced biodiversity modernisation across eastern Asia.The Paleogene biodiversity of Asia evolved under a continually modifying monsoon influence,with the modern Asian monsoon system being unique to the present and a product of a long gradual development in the context of an ever-changing Earth system.

Formation of magnesium calcite mesocrystals in the inorganic environment only by using Ca^(2+)and Mg^(2+)and its biological implications

Magnesium calcite(Mg-calcite)mesocrystal is widespread in the biominerals with specific functions.Until now,it remains challenging to obtain Mg-calcite mesocrystals without organic additives and the formation mechanism of Mg-calcite mesocrystals in the ocean is not clear yet.We report here the synthesis of corn-like Mg-calcite mesocrystals from pure amorphous calcium carbonate(ACC)via a facile method only by using Ca^(2+)and Mg^(2+).The obtained Mg-calcite is composed of many nanocubes with common crystallographic orientation,which shows very good single crystal feature.In the crystallizing procedure,the ACC nanospheres rapidly agglomerate into Mg-calcite corn-like mesocrystal by oriented attachment(OA)in a certain direction,which belongs to the non-classical nucleation.By this method,the molar ratio of Ca^(2+)and Mg^(2+)plays a vital role in the whole crystallization procedure,which may shed a new light on disclosing the mechanism behind for the effect of seawater in the formation of biological Mg-calcite in nature.