重庆巴南区热洞温泉成因探讨

针对重庆巴南区热洞温泉所处的地质背景,从温泉的热储构造、热能来源、地热水的补给、径流、排泄等方面对热洞温泉成因模式进行了分析。研究表明:热洞温泉成因模式是以下三叠统嘉陵江组碳酸盐岩为主要含水层,以上三叠统须家河组的页岩、煤系地层,侏罗系的红色砂岩、泥岩层为上部隔水层、以下三叠统飞仙关组泥岩、页岩层为下部隔水层。大气降水通过岩溶管道、裂隙下渗至含水层,在地热梯度的加热下形成地热水,沿深部断裂构造线由南向北径流,在桃子荡背斜褶皱转折端受上覆隔水层阻挡,而上升于槽谷内的岩溶洞穴中出露。

缝洞型岩溶热储流动传热耦合数值模拟

缝洞型岩溶热储是一种典型的地热能储层,具有出水量大且地热利用后尾水易于回灌的优势,是我国最具开发利用潜力的地热储层类型之一,但由于其储集空间类型多样(孔缝洞),且具有复杂的多尺度、强非均质性、多流态特征,因此对于热采过程中所涉及的流动、传热过程及热采动态等特征的认识尚不清晰。为此,基于缝洞型岩溶热储的特点,提出了基于离散缝洞网络方法的热流耦合数值模拟方法,并进行了模型准确性验证。研究结果表明:①提出了多孔介质渗流区采用达西定律描述,溶洞自由流区域采用Navier-Stokes方程描述,两区域间采用Beavers-Joseph-Saffman边界条件进行耦合的流动传热耦合数值模型;②裂缝网络连通性是控制和评价缝洞型热储流动传热效果的关键参数,而溶洞的存在对热储内的流动传热效果起重要影响;③离散缝洞网络热流耦合模型能够有效地描述缝洞型热储的流动传热过程,并发现裂缝网络连通性控制着缝洞型热储的热流耦合过程;④溶洞的存在会严重影响热储的热流耦合过程,一是增多系统内贯穿的高速流动通道数量,甚至使系统从不连通变为连通,二是增大系统内局部流动通道速度。结论认为,该方法对于研究缝洞型岩溶热储开发特征及其热采性能优化具有重要意义。

湘东北横洞钴矿床钴的富集机制:来自黄铁矿的微区结构、成分和硫同位素证据

世界上典型热液脉型钴矿床,如五元素(Ag-Bi-Co-Ni-As±U)矿床,因其高的钴品位(高达8%)而具有重要的经济价值和研究意义,该类矿床以自然元素和砷化物组合为特征。不同于五元素矿床,湘东北横洞热液脉型钴矿床(中型,品位约0.04%)的矿石矿物组合为黄铁矿+黄铜矿+闪锌矿+方铅矿+磁黄铁矿,目前对该矿床中含钴矿物的特征及钴的富集机制尚不清楚。本文在详细的矿相学工作基础上,采用EPMA、EBSD、LA-ICPMS和LA-MC-ICPMS等多种分析方法,对其黄铁矿开展了精细结构、成分和硫同位素分析。将黄铁矿划分为PyI、PyII和PyIII三个世代。其中,PyII是Co的重要载体,常呈丝带状、不规则状或韵律环带交代PyI或呈细粒状产出,其Co含量高达52141×10^(-6),明显高于其他世代黄铁矿。黄铁矿中Co与Fe具有较好的负相关性,表明Co主要呈类质同象的形式置换Fe存于黄铁矿晶格中。而黄铁矿中高的Co/Ni比值(1.05~393)和Se含量(10.69×10^(-6)~129×10^(-6))则暗示了其热液成因。此外,PyII与PyI之间具有不规则港湾状接触界面、突变的化学成分以及相近的晶体取向,这些暗示了富钴的PyII系含钴流体与围岩及早阶段黄铁矿快速反应的产物,溶解再沉淀的动力学过程是控制PyII的形成机制。不同世代黄铁矿的δ34 S V-CDT值接近,变化范围为-13.12‰~-8.70‰,与围岩地层的硫同位素特征接近。结合湘东北结晶基底高的Co含量(30.4×10^(-6)~72.3×10^(-6))和以往流体包裹体显微测温结果,认为在晚侏罗世-早白垩世期间,NE-ENE向的长沙-平江断裂带走滑剪切活动使得深源热液流体从结晶基底连云山岩群活化萃取了金属钴,富钴热液沿走滑断裂向上运移至成矿部位,再因压力周期性变化引起流体发生不混溶作用进而分离,导致钴金属络合物失稳,最后钴沉淀富集成矿。通过与世界上典型热液脉型钴矿床成矿特征的对比,提出流体低的盐度和低砷、高硫的特征是造成横洞钴矿床矿物组合简单的主要控制因素。

川东旅游地质奇观

川东旅游地质奇观有重庆热洞、巫溪夏冰洞、奉节小寨天坑、云阳清水塘龙缸、奉节天井峡地缝、武隆芙蓉洞、重庆龙王洞地下水库、统景地震温泉、重庆恐龙、川东古兽类及巫山人化石等。它们具有十分重要的科学价值、美学价值、旅游价值及探险价值，是大自然的宝贵遗产，是不可多得的珍贵资源，只有在保护的基础上适度开发、科学利用，才能发挥其最大效益。

川东旅游地质奇观及其意义

川东旅游地质奇现包括重庆热洞,巫溪夏冰洞,奉节小寨天坑,云阳清水塘龙缸,奉节天井峡地缝,武隆芙蓉洞,重庆龙王洞地下水库,重庆统景地震温泉,重庆恐龙,川东古兽类及巫山人化石等。它们具有十分重要的科学价值、美学价值、旅游价值及探险价值,是大自然的宝贵遗产,不可多得的珍贵资源,只有在保护的基础上,适度开发,科学利用,才能发挥其最大效益。

Hawking Radiation of Charged Particles in Reissner-Nordstrm Black Hole

We extend the method that Banerjee and Majhi have used to discuss Hawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the charged black hole by a new Tortoise coordinate transformation. Taking the reaction of the radiation of the particle to the spacetime into consideration, we not only derive the radiation spectrum that satisfies the unitary principle in quantum mechanics but also show that the contribution of ingoing particles is equal to the one of outgoing particles on the similar chemical potential term in radiation spectrum caused by charged particles.

Unthermal Hawking Radiation from a General Stationary Black Hole

Using Damour-Ruflini＇s method, Hawking radiation from a general stationary black hole is investigated again deeply. Considering the back reaction of the particle to the space-time and energy conservation, we find that the radiation is not exactly thermal and can take out information from the black hole. This can be used to explain the information loss paradox, and the result is consistent with the works finished before.

Quantum Non-thermal Effect From Kerr-Newman Black Hole

We present a short and direct derivation of Hawking radiation by using the Damour-Ruffini method, as taking into account the self-gravitational interaction from the Kerr-Newman black hole, It is found that the radiation is not exactly thermal, and because the derivation obey conservation laws, the non-thermal Hawking radiation can carry information from the black hole. So it can be used to explain the black hole information paradox, and the process satisfies unitary.

Quasi-Local Energy Distribution and Thermodynamics of Reissner-Nordstrom Black Hole Surrounded by Quintessence

We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstr6m black hole space-time surrounded by quintessence. We use the quasi-local energy distribution from Einstein energy-momentum complex. We plot the variation of the energies, temperature and heat capacity with the state parameter related to the quintessence ωq. We show that due to the presence of quintessence, the total energy of the outer region as well as the temperature and heat capacity decreases with the increase of the density of quintessence, while the total energy of the black hole region increases.

Spin-Dependent Term of Thermodynamic Quantity Around a Black Hole

The entropy density, energy density, pressure, and equation of state of an ideal relativistic gas around the Schwarzschild-anti-de Sitter black hole with a global monopole are investigated by using the brick-wall method. It is shown that the sub-leading term with spin-dependence exists and that the corrected expression for any spin field is very different from that for scalar field. The usual result that these thermodynamical quantities take the same forms as those in fiat spacetime holds only for the leading term.

Quantum Tunneling Radiation of Kerr-NUT Black Hole

Based on particles in a dynamical geometry, extending the Parikh ＇s method of quantum tunneling, radiation, we deeply investigate the quantum tunneling radiation of Kerr-NUT bhck hole. When self-gravitating action, energy conservation, and angular momentum conservation are taken into account, the emission rate of the particle on the event horizon is related to the change of Bekenstein-Hawking entropy and the emission spectrum is not precisely thermal, but is consistent with an underlying unitary theory.

Thermodynamics of Third Order Lovelock-Born-Infeld Black Holes

We here explore black holes in the third order Lovelock gravity coupling with nonlinear Born-Infeld electro- magnetic field. Considering special second and third order coefficients （＆g = 363 = a2）, we analyze the thermodynamics of third order Lovelock-Born-Infeld black holes and, in 7-dimensional AdS space-time, discuss the stability of black holes in different event horizon structures. We find that the cosmological constant A plays an important role in the distribution of black hole stable regions.

Thermodynamics of Third Order Lovelock Anti-de Sitter Black Holes Revisited

We compute the mass and temperature of third order Lovelock black holes with negative Gauss-Bonnet coefficient a2 〈 0 in anti-de Sitter space and perform the stability analysis of topological black holes. When k = -1, the third order Lovelock black holes are thermodynamically stable for the whole range r＋. When k = 1, we found that the black hole has an intermediate unstable phase for D = 7. In eight dimensional spacetimes, however, a new phase of thermodynamically unstable small black holes appears if the coefficient a is under a critical value. For D ≥ 9, black holes have similar the distributions of thermodynamically stable regions to the case where the coefficient ＆ is under a critical value for D = 8. It is worth to mention that all the thermodynamic and conserved quantities of the black holes with fiat horizon do not depend on the Loveloek coefficients and are the same as those of black holes in general gravity.

Thermodynamics of DBI Black Holes in Anti-de Sitter Spacetime

Through the gauge field theory, we obtain the solution of the DBI-AdS black hole, In the meantime, according to the relations between the action and the grand partition function, we obtain the grand partition function in the DBI-AdS black hole. The temperature and the potential of the DBI-AdS black hole are gained from differential of the grand partition function. With the thermodynamic relations, other thermodynamics are also obtained. The solution and the thermodynamics of the DBI-AdS black hole are turned out that they can reduce to the case of a charged black hole in four-dimensional spacetimes.

Thermodynamic Curvature and Phase Transitions from Black Hole with a Coulomb-Like Field

In this paper, we first investigate the thermodynamic features of the black hole with a coulomb-like field. Moreover, we obtain the geometric description of the black hole thermodynamics. We find that for the black hole with a coulomb-like field the Weinhold geometry is fiat, whereas its Ruppeiner geometry is curved. For the heat capacity and curvature calculation shows the Ruppeiner geometry has a transition point.

Quantum Non-thermal Effect from Black Holes Surrounded by Quintessence

We present a short and direct derivation of Hawking radiation as a tunneling process across the horizonand compute the tunneling probability.Considering the self-gravitation and energy conservation,we use the Keski-Vakkuri,Kraus,and Wilczek(KKW)analysis to compute the temperature and entropy of the black holes surrounded byquintessence and obtain the temperature and entropy are different from the Hawking temperature and the Bekenstein-Hawkingentropy.The result we get can offer a possible mechanism to deal with the information loss paradox becausethe spectrum is not purely thermal.

Regular Black Holes with Cosmological Constant

We present a class of regular black holes with cosmological constant A in nonlinear electrodynamics. Instead of usual singularity behind black hole horizon, all fields and curvature invariants are regular everywhere for the regular black holes. Through gauge invariant approach, the linearly dynamical stability of the regular black hole is studied. In odd-parity sector, we find that the A term does not appear in the master equations of perturbations, which shows that the regular black hole is stable under odd-parity perturbations. On the other hand, for the even-parity sector, the master equations are more complicated than the case without the cosmological constant. We obtain the sufficient conditions for stability of the regular black hole. We also investigate the thermodynamic properties of the regular black hole. and find that those thermodynamic quantities do not satisfy the differential form of first law of black hole thermodynamics. The reason for violating the first law is revealed.

Natural Ventilation by Air Captors and Extractors Sheds in Hospitals in Brazil： Wind Tunnel Measurements

Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect Joao Filgueiras Lima, Lele, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro.

Ruppeiner Geometry of (2+l)-Dimensional Spinning Dilaton Black Hole

In this paper, we study the geometrothermodynamics of （2 ＋ 1）-dimensional spinning dilaton black hole. We show that the Ruppeiner curvature vanishes, which implies that there exist no phase transitions and thermodynamic interactions. However when the thermodynamics fluctuation is included, the geometry structure is reconsidered. The non-vanishing Ruppeiner curvature is obtained, which means the phase space is non-flat. We also study the phase transitions and show that it can indeed take D/ace at some points.