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Sedimentary environment can be restored qualitatively or semi-qualitatively by using elements or element combinations that are sensitive to paleoenvironment conditions. By measuring the major elements, trace elements and rare earth elements of 23 shale samples collected from coring wells in the Central Nanpanjiang Basin, we discussed the paleoenvironment conditions, including paleo-water depth, redox conditions, paleoclimate and provenance. La and Co contents indicate that the paleo-water depth in the Central Nanpanjiang Basin gradually deepened during the Late Permian. The ratios of U/Th, Uau, V/Cr, Ni/Co and V/Sc suggest that the Central Nanpanjiang Basin was in an oxic condition in the Late Permian, which was stable during the Permian Longtan and Dalong depositional periods. C-value (Climate index value) and binary diagrams of Sr/Cu and Ga/Rb show that the Central Nanpanjiang Basin was characterized by a warm and arid climate during the depositional of the Permian Longtan Formation, a warm and humid climate in the lower part of the Dalong Formation, and a warm and arid climate again in the upper part of the Dalong Formation. The chemical index of alteration (CIA), plagioclase index of alteration (PIA), index of chemical variability (ICV), and Th/U and K/Rb values can indicate the geological tectonic settings of source regions. From the Longtan period to the Dalong period, the small CIA amplitude and relatively stable ICV indicate that chemical weathering in the source area was constantly slighty weak. However, Th/U increased significantly but PIA increased slightly in the lower Dalong Formation, indicating an obvious climate change in the early deposition of the Dalong Formation. In addition, the geochemical discrimination calculation and plots show that the provenance of the studied shales was related to felsic volcanic rocks and the tectonic settings of the Upper Permian shale source areas in the Central Nanpanjiang Basin were mainly oceanic island arc and continental arc. [ABSTRACT FROM AUTHOR]

To enhance the operating stability of mine hoisting system and provide guidance for the mining shaft deformation (MSD) monitoring, the operating characteristics of the hoisting conveyance (OCHC) under MSD are studied. Firstly, a simplified finite element model is established for analyzing the guide rail (GR) deformation law under MSD, and the deformation result calculated by ANSYS is transformed into the geometric model in the dynamics model. Secondly, the transversal-longitudinal coupling relationship of the guide roller (GRO) is analyzed, and it is deduced that the variation law of the contact relationship between the guide roller and rail (GROR) with its deformation and the HC position. On the basis of the above, the dynamics model of the mine hoisting system established by ADAMS is verified by experiment and used to analyze the operating characteristics (OC) under MSD. The analysis results show that the deformation result transformation of GR can characterize the SD trend and the connection status between bunton, shaft and GR under MSD and can realize the co-simulation of ANSYS and ADAMS, which makes the dynamic model can accurately reflect the OCHC under MSD. The displacement and vibration acceleration of HC in MSD direction, angular displacement (AD) around its vertical axis and buffer relative displacement (BRD) are highly sensitive to the deformation and contain prominent feature, which can realize the characterization of the deformation. The vibration acceleration of hoisting conveyance (VAHC) and the BRD in the deformation direction produce a prominent impact response to the disconnection of bunton and guide rail (BGR). The disconnection between bunton and shaft only changes the frequency and amplitude of the low-frequency oscillation of BRD near disconnection position. It can provide a basis for identifying MSD and mitigating its effect on HC. [ABSTRACT FROM AUTHOR]

To lay a foundation for alleviating the influence of mining shaft deformation (MSD) on the guide rail (GR) and monitoring the shaft deformation state, this paper studies the deformation law and mechanism of the guide rail under the MSD. Firstly, a spring is used to simplify the interaction between the shaft lining and surrounding rock soil mass (SRSM) under MSD, and its stiffness coefficient is deduced by the elastic subgrade reaction method. Secondly, a simplified finite element model is established based on spring element, the stiffness coefficient is calculated by the derivation formula, and its effectiveness is verified. Finally, the deformation law and mechanism of GR are analyzed under different types and degrees of MSD, and the deformation characteristics are studied under the disconnection between the shaft, bunton and guide rail. The results show that the established finite element model can better simulate the interaction between the shaft lining and SRSM, and the calculation efficiency is greatly improved. The guide rail deformation (GRD) has a strong ability to characterize MSD and owns the distinctive feature corresponding to different types and degrees of MSD and the connection state. This research can provide reference and guidance for the shaft deformation monitoring and the maintenance and installation of the GR, and also lays a groundwork for studying operation characteristic of hoisting conveyance under MSD. [ABSTRACT FROM AUTHOR]

The ability of light beams to rotate nano-objects has important applications in optical micromachines and biotechnology. However, due to the diffraction limit, it is challenging to rotate nanoparticles at subwavelength scale. Here, we propose a method to obtain controlled fast orbital rotation (i.e., circumgyration) at deep subwavelength scale, based on the nonlinear optical effect rather than sub-diffraction focusing. We experimentally demonstrate rotation of metallic nanoparticles with orbital radius of 71 nm, to our knowledge, the smallest orbital radius obtained by optical trapping thus far. The circumgyration frequency of particles in water can be more than 1 kHz. In addition, we use a femtosecond pulsed Gaussian beam rather than vortex beams in the experiment. Our study provides paradigms for nanoparticle manipulation beyond the diffraction limit, which will not only push toward possible applications in optically driven nanomachines, but also spur more fascinating research in nano-rheology, micro-fluid mechanics and biological applications at the nanoscale. It has been challenging to rotate nanoparticles orbitally via optical trapping beyond the diffraction limit. Here, the authors take advantage of the nonlinear optical effect and demonstrate fast and controlled orbital rotation at subwavelength scale with a femtosecond pulsed Gaussian beam. [ABSTRACT FROM AUTHOR]

Dolomitization has a profound influence on the quality and distribution of the Changxing Formation reef-shoal gas fields in the south of Upper Permian Kaijiang-Liangping Trough. These gas fields consist of two types of matrix replacement dolomite (D1 and D2) and some saddle dolomite (SD). A comprehensive petrographic and geochemical examination indicates that D1 dolomite is formed by the replacement of matrix limestone by seepage-reflux of penesaline seawater during the syndiagenetic-early diagenetic stage. This interpretation is supported by δ18O values slightly higher than those of dolomites precipitated from coeval seawater and REE patterns similar to those of matrix limestones, reinforced by 87Sr/86Sr ratios that greatly overlap those of matrix limestones and coeval well-preserved fossils. Dolomitization by penesaline seawater rather than by hypersaline evaporated seawater is also supported by the absence of massive evaporites. D2 dolomite, with C-O-Sr isotopes and Fe-Mn concentrations comparable to those of D1, formed through the hydrothermal alteration of D1 at temperatures between 163.2 and 189.3 °C during Early Triassic. SD precipitated directly from hydrothermal fluids at temperatures between 152.4 and 197.8 °C. The hydrothermal origins of D2 and SD are also supported by more negative δ18O values than those of dolomite formed from coeval seawater, higher 87Sr/86Sr ratios, and positive Eu anomalies. [ABSTRACT FROM AUTHOR]

Limestone reservoirs formed by epigenetic karst and dolostone reservoirs formed by dolomitization are both developed in the Middle Permian of Central Sichuan Basin. In recent years, high-yield industrial gas flow has been obtained from these dolostone reservoirs, which makes the Middle Permian become the most realistic succeeding carbonate strata in the basin. Based on petrographic features, geochemical analyses (including C-O-Sr isotopes, trace elements, rare earth elements, and fluid-inclusions), seismic data, and previous studies, origin of dolomite in Middle Permian dolostone reservoirs in Central Sichuan Basin is studied. Three conditions of structurally controlled hydrothermal dolomitization (including two-stage strike-slip basement-rooted faults, underlying Cryogenian aquifers (or Pre-Sinian basement) and overlying Longtan Formation aquitard) are met. The Middle Permian dolostone reservoirs consist of saddle dolomites, fine-medium crystalline dolomites, and hydrothermal minerals, which are formed by hydrothermal dolomitization. The hydrothermal fluid replaces matrix limestone to form fine-medium crystalline dolomite, while saddle dolomite and other hydrothermal minerals are directly precipitated from hydrothermal fluid. Hydrothermal dolomitization fluid reforms matrix limestone in three ways, including dissolution and filling, replacement, and hydraulic fracturing, resulting to various types of reservoir spaces including dissolution vugs (or pores). Hydrothermal dolomitization of the Middle Permian in Central Sichuan Basin mainly occurs at the intersection of high-angle basement-rooted strike-slip faults, and the seismic section shows negative flower structure style. [ABSTRACT FROM AUTHOR]

The understanding of pore structures and controlling factors of different oolitic shoal reservoir types in Lower Triassic Feixianguan Formation around Kaijiang-Liangping Trough has been a key issue restricting efficient exploration and development of such reservoirs. Based on thin section identification, scanning electron microscopy, mercury injection, three-dimensional CT scanning, cathodoluminescence analysis, stable isotope, and rare earth element analysis, the Feixianguan Formation oolitic shoal reservoirs are classified into three types: mold-oolitic dolostone type, residual-oolitic dolostone type, and sparry-oolitic limestone type. The residual-oolitic dolostone possesses the best pore structure and reservoir connectivity. By comparison, the pore structure and connectivity of mold-oolitic dolostone and sparry-oolitic limestone are relatively poor. Based on deposition of oolitic shoals, the main controlling factors for pore structure difference are indicated to be meteoric freshwater leaching and dolomitization. The pore structure of mold-oolitic dolostone reservoir is transformed near the exposed surfaces in the upper-middle portion of shallowing-upward meter-scale cyclic sequences. The mold pores are formed by meteoric freshwater leaching, and then transformed by the late dolomitization. The development of residual-oolitic dolostone is not strongly affected by meteoric freshwater leaching effects, while transformed by seepage-reflux dolomitization. Hydrothermal fluids are involved in the dolomitization process of the oolitic dolostones mentioned above. The emplacement of hydrocarbon preserves primary intergranular pore in sparry-oolitic limestone. Other diagenetic effects are less important for the pore structure of oolitic shoal reservoirs in the study area. [ABSTRACT FROM AUTHOR]

Reef-shoal gas reservoirs of Upper Permian Changxing Formation, which are the important targets for increasing gas reserve and production in Sichuan Basin, are highly heterogeneous in Eastern Sichuan Basin. However, because of the complex tectonic situation, the source and accumulation of natural gas are still being controversial. The lack of systematic research and relevant experimental analysis on controlling factors of hydrocarbon accumulation restrict the effective natural gas exploration. Based on petrographic observation, 3D seismic data and geochemistry, the reservoir spaces, fluid-inclusion of filling mineral, reservoir solid bitumen, and restoration of tectonic evolution are analyzed, which indicates that the reef-shoal gas reservoirs of Changxing Formation are fractured-vuggy type and formed mainly by dolomitization. The reservoir porosity system consists of pores, vugs, and fracture network. The gas reservoir boundary is mainly controlled by reef dolomite reservoirs distributed intermittently along the platform-margin. Both water and gas production wells have undergone two-stage accumulation process. The first stage is the crude oil charging of Wujiaping Formation from the Middle Jurassic to the early of the Late Jurassic; the second stage is that the crude oil of Wujiaping Formation was cracked into gas, accompanied with the formation of a large amount of reservoir bitumen from the middle-late of the Early Cretaceous to the middle of the Late Cretaceous. Tectonic-lithologic traps in both east and west side of the Kaijiang-Liangping Trough are formed in the late period of Indosinian. The faulting activity in the Yanshanian period, which gradually dropped in both east and west side of the Trough and slightly increases the tectonic-lithologic traps, is consistent with the peak period of hydrocarbon charging in the Wujiaping Formation source rock. The direct contact with the active fault above and damage to the regional caprock of the 4th member of Feixianguan Formation jointly result in the destruction of the reef-shoal gas reservoir in Changxing Formation. The Himalayan faulting activity, which further elevated the tectonic amplitude of tectonic-lithologic traps in both east and west side, forms the unique northwest–southeast strike faults in the east side of the Trough. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS), Parkinson's disease (PD), Alzheimer's disease (AD), and other neurodegenerative diseases of central nervous system (CNS) disorders are serious human health problems. Rho-kinase (ROCK) is emerging as a potentially important therapeutic target relevant to inflammatory neurodegeneration diseases. This is supported by studies showing the beneficial effects of fasudil, a ROCK inhibitor, in inflammatory neurodegeneration diseases. MS is an autoimmune disease resulting from inflammation and demyelination in the white matter of the CNS. It has been postulated that activation of Rho/ROCK causes neuropathological changes accompanied with related clinical symptoms, which are improved by treatment with ROCK inhibitors. Therefore, inhibition of abnormal activation of the Rho/ROCK signaling pathway appears to be a new mechanism for treating CNS diseases. In this review, we extensively discussed the role of ROCK inhibitors, summarized the efficacy of fasudil in the MS conventional animal model of experimental autoimmune encephalomyelitis (EAE), both in vivo and in vitro, and highlighted the mechanism involved. Overall, the findings collected in this review support the role of the ROCK signaling pathway in neurodegenerative diseases. Hence, ROCK inhibitors such as fasudil can be novel, and efficacious treatment for inflammatory neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

The direct measurement of the Mandel parameter of weak laser pulses, with 10 ns pulse duration time and the mean number of photon per pulse &nmacr; being approximately 0.1, is investigated by recording every photocount event. With the Hanbury Brown and Twiss detection scheme, and not more than one photon per pulse being detected during the sample time by single-photon counters, we have found that the single mode diode laser with driving current lower than the threshold yields a sub-Poissonian statistics. In addition, when the diode laser driving current is much higher than the threshold, it is validated that the Mandel parameter QC of the Poissonian coherent state is nearly -&nmacr;/2. The experimental results are in good agreement with theoretical prediction considering the measurement error. [ABSTRACT FROM AUTHOR]

In eastern Longgang area of northeastern Sichuan Basin, the Kaijiang-Liangping trough was deposited with and leveled up by Feixian'guan sediments, where oolitic shoals exhibit progradation and upward migration. These oolitic shoals are classified into oolitic dolostone shoals and oolitic limestone shoals. The dolostone shoals occur within a narrow belt along Changxingian platform margin where the thickness of one single layer can be large; however, the cumulative thickness is rather small. On the contrary, the limestone shoals spread widely along shifted platform margin and is characterized by small thickness of one single layer and large cumulative thickness. Diagenesis has been found to play an important role in oolitic reservoir properties. The origin of low porosity and permeability in this extensive oolitic limestone reservoirs was attributed to burial cementation, while diagenetic processes, such as, reflux and hydrothermal dolomitization, have been identified as the primary factors for generating high-grade oolitic dolostones. Feixian'guan reservoir is characterized by low matrix porosity (which usually ranges from 2 to 3%). Existence of fractures may improve overall porosity and permeability of these reservoirs. The direct influence of these fractures may be to connect originally isolated pores to form a better connected pore-fracture system. Additionally, the fractures may have facilitated the migration of the organic acids that are associated with oil and gas, to help further enhance the quality of the reservoir through corrosion. [ABSTRACT FROM AUTHOR]

Materials possessing high two photon absorption (TPA) are highly desirable for a range of fields, such as three-dimensional data storage, TP microscopy (TPM) and photodynamic therapy (PDT). Specifically, for TPM, high TP excitation (TPE) brightness (σ × ϕ, where σ is TPA cross-sections and ϕ is fluorescence quantum yield), excellent photostability and minimal cytotoxicity are highly desirable. However, when TPA materials are transferred to aqueous media through molecule engineering or nanoparticle formulation, they usually suffer from the severely decrease of quantum yield (QY). Here, we report a convenient and efficient method for preparing polymer-encapsulated quantum dots (P-QD). Interestingly, the QY was considerably enhanced from original 0.33 (QDs in THF) to 0.84 (P-QD in water). This dramatic enhancement in QY is mainly from the efficiently blocking nonradiative decay pathway from the surface trap states, according to the fluorescence decay lifetimes analysis. The P-QD exhibits extremely high brightness (σ × ϕ up to 6.2 × 106 GM), high photostability, excellent colloidal stability and minimal cytotoxicity. High quality cellular TP imaging with high signal-to-background ratio (> 100) and tissue imaging with a penetration depth of 2200 μm have been achieved with P-QD as probe. [ABSTRACT FROM AUTHOR]