Molar-tooth Carbonate Sequences and Sr Isotopes in the Neoproterozoic for Stratigraphic Correlation: Research in the Jilin-Liaoning-Xuzhou-Huaiyang Area of the Sino-Korean Plate and Its Correlation with the Yangtze Plate

Based on a study of Neoproterozoic carbonates in the Jilin-Liaoning-Xuzhou-Huaiyang area, especially its cyclic sequence stratigraphy and Sr isotopes, two maximum sea flooding events (at 820 Ma and 835 Ma) have been identified. The resulting isochronous stratigraphic correlation proves that these Precambrian strata were connected between the Qingbaikou and the Nanhuan systems with a time range from 750 Ma to 850 Ma. The disappearance of microsparite carbonate and coming of a glacial stage offer important evidence for worldwide stratigraphic correlation and open a window for further correlation of the stratigraphic successions across the Sino-Korean and Yangtze Plates. A new correlation scheme is therefore provided based on our work.

3D Monte-Carlo model to study the transport of hot electrons in the context of inertial confinement fusion. Part Ⅰ

We describe the development of a 3D Monte-Carlo model to study hot-electron transport in ionized or partially ionized targets,considering regimes typical of inertial confinement fusion.Electron collisions are modeled using a mixed simulation algorithm that considers both soft and hard scattering phenomena.Soft collisions are modeled according to multiple-scattering theories,i.e.,considering the global effects of the scattering centers on the primary particle.Hard collisions are simulated by considering a two-body interaction between an electron and a plasma particle.Appropriate differential cross sections are adopted to correctly model scattering in ionized or partially ionized targets.In particular,an analytical form of the differential cross section that describes a collision between an electron and the nucleus of a partially ionized atom in a plasma is proposed.The loss of energy is treated according to the continuous slowing down approximation in a plasma stopping power theory.Validation against Geant4 is presented.The code will be implemented as a module in 3D hydrodynamic codes,providing a basis for the development of robust shock ignition schemes and allowing more precise interpretations of current experiments in planar or spherical geometries.

产品的生命周期和环境:从产业生态学到家庭生态学

与人口变化相关的生活水平的提高表现为对商品和服务日益增长的需求.生态系统恶化的原因与对原料总是更多的攫取、与小生态环境的改变、与对包括人类在内的生物群落有损害的产品日益增加的排放有关.旨在降低环境风险的解决办法基于对社会生态学机制的更好理解,基于制定评价的工具和方法以及有效的介入.与在企业中的环境管理举措相补充,家庭生态学能够提供有助于决策的恰当的整体的要素.

房颤导管消融后膈神经损伤的特征及结局:一项多中心研究

Objectives: The purpose of this study was to characterize the occurrence of phrenic nerve injury(PNI) and its outcome after radiofrequency(RF) ablation of atrial fibrillation(AF). Background: It is recognized that extra-myocardial damage may develop owing to penetration of ablative energy. Methods: Between 1997 and 2004, 3,755 consecutive patients underwent AF ablation at five centers. Among them, 18 patients(0.48%; 9 male, 54±10 years) had PNI(16 right, 2 left). The procedure consisted of pulmonary vein(PV) isolation in 15 patients and anatomic circumferential ablation in 3 patients, with additional left atrial lesions(n=11) and/or superior vena cava(SVC) disconnection(n=4). Results: Right PNI occurred during ablation of right superior PV(n=12) or SVC disconnection(n=3). Left PNI occurred during ablation at the left atrial appendage. Immediate features were dyspnea, cough, hiccup, and/or sudden diaphragmatic elevation in 9, and in the remaining the diagnosis was made after ablation owing to dyspnea(n=7) or on routine radiographic evaluation(n=2). Four patients(22%) were asymptomatic. Complete recovery occurred in 12 patients(66%). Recovery occurred within 24 h in the two patients with left PNI and in one patient with right PNI occurring with SVC disconnection. In the other nine patients, right PNI recovery occurred after 4±5 months(1 to 12 months) with respiratory rehabilitation. After a mean follow-up of 36±33 months, six patients have persistent PNI(three with partial and three with no recovery). Conclusions: In this multicenter experience, PNI was a rare complication(0.48%) of AF ablation. Ablation of the right superior PV, SVC, and left atrial appendage were associated with PNI. Complete(66%) or partial(17%) recovery was observed in the majority.

3D Monte-Carlo model to study the transport of hot electrons in the context of inertial confinement fusion. Part Ⅱ

We describe two numerical investigations performed using a 3D plasma Monte-Carlo code,developed to study hot-electron transport in the context of inertial confinement fusion.The code simulates the propagation of hot electrons in ionized targets,using appropriate scattering differential cross sections with free plasma electrons and ionized or partially ionized atoms.In this paper,we show that a target in the plasma state stops and diffuses electrons more effectively than a cold target(i.e.,a target under standard conditions in which ionization is absent).This is related to the fact that in a plasma,the nuclear potential of plasma nuclei has a greater range than in the cold case,where the screening distance is determined by the electronic structure of atoms.However,in the ablation zone created by laser interaction,electrons undergo less severe scattering,counterbalancing the enhanced diffusion that occurs in the bulk.We also show that hard collisions,i.e.,collisions with large polar scattering angle,play a primary role in electron beam diffusion and should not be neglected.An application of the plasma MonteCarlo model to typical shock ignition implosions suggests that hot electrons will not give rise to any preheating concerns if their Maxwellian temperature is lower than 25–30 keV,although the presence of populations at higher temperatures must be suppressed.This result does not depend strongly on the initial angular divergence of the electron beam set in the simulations.

Multibeam laser-plasma interaction at the Gekko XII laser facility in conditions relevant for direct-drive inertial confinement fusion

Laser–plasma interaction and hot electrons have been characterized in detail in laser irradiation conditions relevant for direct-drive inertial confinement fusion.The experiment was carried out at the Gekko XII laser facility in multibeam planar target geometry at an intensity of approximately 3×10^(15)W/cm^(2).Experimental data suggest that high-energy electrons,with temperatures of 20–50 keV and conversion efficiencies ofη<1%,were mainly produced by the damping of electron plasma waves driven by two-plasmon decay(TPD).Stimulated Raman scattering(SRS)is observed in a near-threshold growth regime,producing a reflectivity of approximately 0.01%,and is well described by an analytical model accounting for the convective growth in independent speckles.The experiment reveals that both TPD and SRS are collectively driven by multiple beams,resulting in a more vigorous growth than that driven by single-beam laser intensity.

In Vivo Therapeutic Silencing of Hypoxia-Inducible Factor 1 Alpha(HIF-1)Using Single-Walled Carbon Nanotubes Noncovalently Coated with siRNA

A new approach is described for delivering small interfering RNA(siRNA)into cancer cells by noncovalently complexing unmodifi ed siRNA with pristine single-walled carbon nanotubes(SWCNTs).The complexes were prepared by simple sonication of pristine SWCNTs in a solution of siRNA,which then served both as the cargo and as the suspending agent for the SWCNTs.When complexes containing siRNA targeted to hypoxia-inducible factor 1 alpha(HIF-1)were added to cells growing in serum containing culture media,there was strong specific inhibition of cellular HIF-1 activity.The ability to obtain a biological response to SWCNT/siRNA complexes was seen in a wide variety of cancer cell types.Moreover,intratumoral administration of SWCNT-HIF-1 siRNA complexes in mice bearing MiaPaCa-2/HRE tumors signifi cantly inhibited the activity of tumor HIF-1.As elevated levels of HIF-1 are found in many human cancers and are associated with resistance to therapy and decreased patient survival,these results imply that SWCNT/siRNA complexes may have value as therapeutic agents.

Cleaning of Marine Sediment Samples for Large Diatom Stable Isotope Analysis

Diatom stable isotope analysis offers considerable potential in palaeoceanography, par-ticularly where carbonate material is scarce or absent. However, extracting pure diatom frustules free of external labile organic matter from marine sediments is an essential requirement for their applica-tions as paleoenvironmental proxies. Here, based largely on previous work, we developed a method in-cluding physical separation and chemical oxidation steps to concentrate and clean pure large diatoms from laminated diatom mat and diatomaceous clay sediment samples for their stable isotope analysis. Using the physical separation techniques consisting of the removal of carbonate and excess organic matter, sieving, differential settling, and heavy liquid floatation, pure diatoms can be successfully iso-lated from the sediment samples with opal concentration more than 10%. Subsequent time oxidation experiment shows that labile organic matter coating pure diatom valves can be effectively removed with 30% H2O2 at 65 ℃ for 2 h. Measurements of δ13C after every step of physical separation demonstrate that contaminants and lost diatoms can influence the original diatom stable isotope signal, highlighting the importance of a visual check for dominant diatom size in the initial sample and purity in the final sample. Although the protocol described here was only applied to diatom mats or diatom oozes con-taining large diatoms （Ethmodiscus rex）, we believe that this method can be adapted to common dia-toms of general marine sediment samples.

Reactive optical matter: light-induced motility in electrodynamically asymmetric nanoscale scatterers

From Newton’s third law,which is known as the principle of actio et reactio1,we expect the forces between interacting particles to be equal and opposite for closed systems.Otherwise,“nonreciprocal”forces can arise.2 This has been shown theoretically in the interaction between dissimilar optically trapped particles that are mediated by an external field.3 As a result,despite the incident external field not having a transverse component of momentum,the particle pair experiences a force in a direction that is transverse to the light propagation direction.3,4 In this letter,we directly measure the net nonreciprocal forces in electrodynamically interacting asymmetric nanoparticle dimers and nanoparticle structures that are illuminated by plane waves and confined to pseudo one-dimensional geometries.We show via electrodynamic theory and simulations that interparticle interactions cause asymmetric scattering from heterodimers.Therefore,the putative nonreciprocal forces are actually a consequence of momentum conservation.Our study demonstrates that asymmetric scatterers exhibit directed motion due to the breakdown of mirror symmetry in their electrodynamic interactions with external fields.

HIGH-FREQUENCY DIELECTRIC SPECTROSCOPY OF BaTiO_(3)CORE-SILICA SHELL NANOCOMPOSITES:PROBLEM OF INTERDIFFUSION

Three types of BaTiO3 core-amorphous nanoshell composite ceramics were processed from the same core-shell powder by standard sintering,spark-plasma sintering and two-step sintering techniques and characterized by XRD,HRSEM and broadband dielectric spectroscopy in the frequency range 10^(3)-10^(13)Hz including the THz and IR range.The samples differed by porosity and by the amount of interdiffusion from the cores to shells,in correlation with their increasing porosity.The dielectric spectra were also calculated using suitable models based on effective medium approximation.The measurements revealed a strong dielectric dispersion below the THz range,which cannot be explained by the modeling,and whose strength was in correlation with the degree of interdiffusion.It is assigned to an effect of the interdiffusion layers,giving rise to a strong interfacial polarization.It appears that the high-frequency dielectric spectroscopy is an extremely sensitive tool for detection of any gradient layers and sample inhomogeneities even in dielectric materials with negligible conductivity.

A Free Streaming Contact Preserving Scheme for the M_(1) Model

The present work concerns the numerical approximation of the M_(1) model for radiative transfer.The main purpose is to introduce an accurate finite volume method according to the nonlinear system of conservation laws that governs this model.We propose to derive an HLLC method which preserves the stationary contact waves.To supplement this essential property,the method is proved to be robust and to preserve the physical admissible states.Next,a relevant asymptotic preserving correction is proposed in order to obtain a method which is able to deal with all the physical regimes.The relevance of the numerical procedure is exhibited thanks to numerical simulations of physical interest.