震源参数因素对玉树地震库仑破裂应力图像及其与余震活动统计关系的影响

2010年4月14日青海省玉树发生MS7.1强震,根据国内外3个机构公布的5套玉树地震震源参数,计算了玉树地震产生的库仑破裂应力变化,研究了震源参数的差异对库仑破裂应力变化及其与余震活动关系的影响.结果表明,由于不同来源震源参数存在差异,计算得到的库仑破裂应力变化图像也存在不同程度差异,从而影响库仑破裂应力变化与余震活动的关系.在震源断层参数中,断层滑动角和位错量的影响大于其它参数.此外还发现对余震统计时间的长短也会影响库仑破裂应力变化与余震活动关系的统计结果.

对山东沂水水氡异常变化的分析探讨

在对沂水泉成因探讨、沂水水氡正常变化特征和主要影响因素分析的基础上 ,结合沂水水氡变化的现场分析落实和周围采样点分析结果及构造地质和流动地磁观测结果 ,对山东沂水水氡自 2 0 0 1年 3月 2 8日以来的异常变化从形成机制上进行了分析 ,认为沂水水氡的下降变化与应力活动增强。

Photocatalytic activity of Fe-doped diopside

UV-visible light induced photocatalytic degradation of methylene blue (MB) over Fe-doped diopside was investigated. The structure, composition, morphology and absorption property of UV-visible light of as-prepared samples were characterized using XRD, SEM, FTIR and UV-vis DRS. The experimental results show that doping Fe3+ induced the formation of some new species in diopside, and promoted light adsorption property of diopside in UV-visible region. Photochemical reactivity of Fe-doped diopside obviously depended on the content of doping Fe3+. The diopside with 1.848% Fe3+ exhibited the superior photocatalytic activity with 95% degradation of MB under UV-visible light for 3 h. The photocatalytic degradation kinetics of MB over all samples showed the first-order reaction nature.

Simotang enhances gastrointestinal motility,motilin and cholecystokinin expression in chronically stressed mice

AIM:To investigate the effect of Simotang(Decoction of Four Powered Drugs) on gastrointestinal motility,motilin and cholecystokinin expression in chronically stressed mice.METHODS:Forty mice were randomly divided into control group,stress group(model group),mosapride group and Simotang group,10 in each group.A variety of unpredictable stimulations were used to induce chronic stress in mice.Then,the mice were treated with distilled water,mosapride or Simotang for 7 d.Gastric emptying and intestinal propulsion function were detected.Serum level of motilin was measured by enzyme-linked immunosorbent assay.Expression of cholecystokinin(CCK) in intestine,spinal cord and brain of mice was detected by immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction,respectively.RESULTS:Simotang improved the gastric emptying and intestinal propulsion in chronically stressed mice.Furthermore,the serum motilin level was significantly higher and the expression levels of CCK-positive cells and genes were significantly lower in intestine,spinal cord and brain of Simotang group than in those of model group(P<0.05).No significant difference was found in serum motilin level and expression levels of CCK-positive cells and genes between the mosapride and Simotang groups.CONCLUSION:Simotang enhances the gastrointestinal motility in chronically stressed mice by regulating the serum motilin level and the expression of cholecystokinin.

Classification of microseismic events in high stress zone

For the purpose of having a better understanding of failure mechanisms of rock fracturing in mines, the equivalent point source models of tensile, shear and explosive seismic events were established, and the relationship between far-field seismic displacements of the waves and the corresponding equivalent forces were analyzed as well. Based on the results of a microseismic monitoring carried out in the mining progress of 9202 working face under the upper remnant coal pillar in Sanhejian Mine, the waveform features of the seismic events associated with different failure modes were further analyzed. The results show that the signals corresponding to different failure mechanisms have different radiation patterns of the seismic displacements, and different characteristics in waveform features, such as dominant frequency, energy released, the ratio of S- to P-wave energy, and so on. In addition, the rock burst happened in the high stress zone is mainly the result of the strong shear fracturing in the mining process. The results of this study have significantly improved the understanding of the characteristics of the failures associated with underground mining, and will greatly benefit the prevention and control of rock burst hazards in burst-prone mines.

Theoretical evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process

Evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process at the standpoint of reaction kinetics and process kinetics was conducted. Theoretical biological nitrogen removal efficiency was deduced based on the mass balance of nitrate in the last stage. The comparison of pre-denitrification process and step feed process in the aspects of nitrogen removal efficiency, volume of reactor and building investment was studied, and the results indicated that step-feed anoxic/oxic activated sludge process was superior to pre-denitrification process in these aspects.

Acute toxicity effects of perfluorooctane sulfonate on sperm vitality,kinematics and fertilization success in zebrafish

Perfluorooctane sulfonate （PFOS） has emerged as one of the most concerning contaminants in recent years. This study aimed to investigate the acute toxicity effect of PFOS on sperm viability, kinematics and fertilization success in zebrafish （Danio rerio）. Sperm were activated in aqueous media containing a range of PFOS concentrations （0, 0.09, 0.9 and 9 mg/L）. Viabilities and kinematics of the sperm exposed to different PFOS treatments were assessed via computer-assisted sperm analysis （CASA） at 20, 40, 60, and 80 s after activation. PFOS exposure decreased the percentage of motile sperm, the curvilinear velocity （VCL）, and the mean angular displacement （MAD） of spermatozoa, but showed no influence on the straight- line velocity （VSL） or the angular path velocity （VAP）. Furthermore, a significant decrease in fertilization success was observed in spermatozoa that were exposed to 0.9 mg/L PFOS or more. These findings indicate that PFOS pollution in natural aquatic environment may be a potential threaten to successful reproduction of fish.

分析研究地震成因,探索防震减灾科学实践与理论,创建防震减灾科学理论体系

通过地震成因的讨论分析与研究,找出地震孕育、发生、发展的规律,剖析各种地震成因说的作用与真伪;确立震源爆炸物质-地壳岩石与地幔岩浆中富集浓缩的核类物质是地震发生的根本决定性因素。地震,地应力与断层活动作用力不是爆炸物质,只会引起的岩石或岩浆平面上的破裂或断裂,而绝不会发生爆炸,也绝对不会产生地震冲击波即不会发生地震;在地震成因分析研究取得突破的基础上,力争在较短的时间内创立起释放地热能转换地震能量防震减灾的科学理论体系。

Solar-heating boosted catalytic reduction of CO_(2） under full-solar spectrum

Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.

Steam reforming of methane over Ni catalysts prepared from hydrotalcite-type precursors: Catalytic activity and reaction kinetics

Ni/Mg–Al catalysts derived from hydrotalcite-type precursors were prepared by a co-precipitation technique and applied to steam reforming of methane. By comparison with Ni/γ-Al2O3 and Ni/α-Al2O3 catalysts prepared by incipient wetness impregnation, the Ni/Mg–Al catalyst presented much higher activity as a result of higher specific surface area and better Ni dispersion. The Ni/Mg–Al catalyst with a Ni/Mg/Al molar ratio of 0.5:2.5:1 exhibited the highest activity for steam methane reforming and was selected for kinetic investigation. With external and internal diffusion limitations eliminated, kinetic experiments were carried out at atmospheric pressure and over a temperature range of 823–973 K. The results demonstrated that the overall conversion of CH4 and the conversion of CH4 to CO2were strongly influenced by reaction temperature, residence time of reactants as well as molar ratio of steam to methane. A classical Langmuir–Hinshelwood kinetic model proposed by Xu and Froment(1989)fitted the experimental data with excellent agreement. The estimated adsorption parameters were consistent thermodynamically.

Scaling of Reduced Energy or Apparent Stress and Its Seismological Significance

Comparison between the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue provides information about apparent stress. In spite of its significant uncertainties and limited reliability, the clues obtained from this comparison seem interesting in the physics of earthquakes. Scaling of apparent stress provides information about the dynamic friction along an earthquake fault. Relation between reduced energy and seismic moment implies that for strike-slip earthquakes, velocity-dependent friction plays a predominant role, while for non-strike-slip earthquakes, slip-dependent friction is predominant. It is also found that strike-slip events with extremely low apparent stress tend to occur “in single”, which is applied to the prediction of the seismic tendency following the 2001 Qinghai-Xizang (Tibet) border M W7.8 earthquake.

Polyethoxylation and polypropoxylation reactions：Kinetics,mass transfer and industrial reactor design

Ethoxylation and propoxylation reactions are performed in the industry to produce mainly non-ionic surfactants and ethylene oxide(EO)–propylene oxide(PO) copolymers.Both the reactions occur in gas–liquid reactors by feeding gaseous EO,PO or both into the reactor containing a solution of an alkaline catalyst(KOH or Na OH).Non-ionic surfactants are produced by using liquid starters like fatty alcohols,fatty acids or alkyl-phenols,while when the scope is to prepare EO–PO copolymers the starter can be a mono-or multi-functional alcohol of low molecular weight.Both reactions are strongly exothermic,and EO and PO,in some conditions,can give place to runaway and also to explosive side reactions.Therefore,the choice of a suitable reactor is a key factor for operating in safe conditions.A correct reactor design requires:(i) the knowledge of the kinetic laws governing the rates of the occurring reactions;(ii) the role of mass and heat transfer in affecting the reaction rate;(iii) the solubility of EO and PO in the reacting mixture with the non-ideality of the reacting solutions considered;(iv) the density of the reacting mixture.All these aspects have been studied by our research group for different starters of industrial interest,and the data collected by using semibatch well stirred laboratory reactors have been employed for the simulation of industrial reactors,in particular Gas–Liquid Spray Tower Loop Reactors.

中国大陆地震成因机理理论与地震预测实践:进展、挑战、展望

本文系统阐述星体运动-行星对应区-五运六气与人体感应四维耦合全球强震预测的原理、方法和实践,探讨人耳能听到地震前兆的“耳鸣”信号问题,分析地震发生前蓝光与气体关系,论述全球大陆板内强震的地球系统动力学机理及其立体监测分析系统,系统分析中国西南地区构造应力场与地震活动及人体感应地震预测的机遇与挑战,中国西南地区大陆大地构造环境及其动力学背景。

Corticotropin-releasing factor stimulates colonic motility via muscarinic receptors in the rat

AIM To measure exogenous corticotropin-releasing factor(CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on CRF-induced motility. METHODS The isolated vascularly-perfused rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers in the proximal and distal colon. At first, exogenous CRF was administered in a stepwise manner and the concentration of CRF yielding maximal colonic motility was selected. After recording basal colonic motility, hexamethonium, phentolamine, propranolol, atropine and tetrodotoxin were infused into the isolated colon. Initially, only the test drug was infused; then, CRF was added. The motility index was expressed as percentage change over basal level. RESULTS Administration of 1.4, 14.4, 144 and 288 pmol/L CRF progressively increased colonic motility in the proximal and distal colon. Infusion of atropine or tetrodotoxin reduced CRF-induced motility of both the proximal and distal colon, whereas hexamethonium, phentolamine and propranolol had no effect.CONCLUSION CRF-induced colonic motility appears to be mediated by local cholinergic signaling via muscarinic receptors. Muscarinic receptors are potential targets for counteracting CRF-induced colonic hypermotility.

Obstacles Facing the Implementation of Functional Magnetic Resonance Imaging （fMRI） of Brain in Jeddah City

fMRI （Functional Magnetic Resonance Imaging） is a relatively new technique that uses MRI （Magnetic Resonance Imaging） to measure the hemodynamic response （change in blood flow） related to neural activity in the brain. This paper aims to explore and identify the obstacles facing the implementation and applications of IMRI in radiology departments within Jeddah city by analyzing related data received by direct questionnaires and interviews with all the people working in MRI units in Jeddah city and finds that the major obstacle is lacking of awareness of fMRI among medical professionals and their training.

Oxygen pressure acid leaching of artificial sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation

The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the sintering of ZnS and FeS and used for the pressure acid leaching experiment.The variations in the potential of the pressure leaching system were investigated by using a self-designed potential autoclave.The results showed that compared to the non-iron sphalerite,there was a violent redox reaction between the 25.70%Fe-artificial sphalerite and dissolved oxygen during the process of pressure leaching;and the catalytic mechanism was attributed to the redox couple Fe^3+/Fe^2+,where Fe3+oxidizes the H2S gas film and the reduced Fe2+state is subsequently oxidized by the dissolved oxygen.Furthermore,the effect of temperature,H2SO4 concentration,and oxygen partial pressure on the artificial sphalerite with different iron contents was studied.The sphalerite samples with iron content were observed to dissolve more easily in sulfuric acid compared to the non-iron samples.Moreover,the activation energy of artificial sphalerite was observed to be lower in the sample with 25.70%iron content(22.26 kJ/mol)compared to that with no iron(32.31 kJ/mol);and the apparent reaction orders were obtained with respect to H2SO4 concentration(1.10 and 1.36)and oxygen partial pressure(1.29 and 1.41),respectively.A comprehensive kinetic model was developed on the basis of the experimental data and the fitted leaching ratio plot;and the kinetic equations for the leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation were determined.

A Review of Aftershock Mechanism Research

In this paper,research of aftershock mechanisms is reviewed,including heterogeneity of medium and stress,mechanical loading,fluid intrusion and stress corrosion,and ratestate dependence.Previous studies have indicated that the heterogeneity of media and stress is the basic premise of aftershocks generated.From the point view of mechanics,transient creep and afterslip can explain the decay of aftershocks in a short time after a mainshock and the relaxation of stress tends to interpret the characteristics of long-term aftershocks.Fluid intrusion and stress corrosion control the evolution process of the aftershocks under certain conditions.The interaction between the faults perturbed by the mainshock always exists during the aftershock activities.All kinds of models and the theories want to comply with the two basic power-law relationships---the G-R law and Omori law to some extent.

Increasing effect of metamorphism on rock properties

This work studied the effect of increasing degree of metamorphism on the properties of rocks.The properties investigated are the physical,mechanical and dynamic parameters.They are important inputs in the design of many mining and civil engineering techniques such as in tunnelling,slope stability and dynamic activities associated with seismicity and fragmentation.This work compared the degree of metamorphism examined through petrographic studies of the Transvaal Sequence in South Africa with the properties of the rocks.The study shows that as the effect metamorphism increases,the state of stress,compaction of grains,cementation and the brittleness of the rocks increases.In addition,increase in the metamorphic effect increases the value of the rock property.The degree of metamorphism of an outcrop is the key factor influencing its property value.Therefore the metamorphism effect of an outcrop may act as a guide to its engineering properties.

Quantitative Seismic Risk Evaluation on Blind Faults in Offshore Areas of Tianjin,China

Based on faults surveying and research data in the Tianjin offshore areas,through studying tectonic structure,Quaternary activity,deep structure,stress and strain fields and seismicity in the Tianjin offshore areas,the activity and tectonic features of the faults are determined synthetically.Using seismo-geological data,and the historical and modern seismicity data,the frequency-magnitude relationship model normalized by 500a is established and based on the relationship between the upper limit of maximum magnitude M u and a t/b,the maximum magnitudes of the sea section of the Haihe river fault and the Haiyi fault are calculated.Then Poisson probability model is adopted and the quantitative parameters,such as the maximum magnitude,occurrence probability,recurrence cycle of the faults in the south Tianjin offshore areas in the coming 50～200a,are calculated.