Contribution of close double white dwarfs to the Galactic gravitational wave foreground

This paper provides new detailed specifics and characteristics of the close double white dwarfs (CDWDs) LISA foreground noise floor using the newest information on the astrophysics with binary population algorithms, which were judged to satisfy the observations. We use the binary population synthesis approach of CDWDs in combination with the latest findings of synthesis models from Han (Mon. Not. R. Astron. Soc. 296:1019, 1998), here, specifically formation by the three evolutionary channels of (a) stable Roche lobe overflow plus common envelope (RLOF?+?CE), (b) CE plus CE, (c) exposed core plus CE. We collect resulting CDWDs in the frequency range of 10^?8 Hz to 10^?2 Hz and compare strength and number statistics per resolvable frequency bin to derive the properties of the noise floor and the nature of possible outliers that may become individually resolvable. We find resolvable outliers to be solely produced by CE?+?CE evolution; the other two channels contribute only to the unresolvable foreground noise. Within the CE?+?CE evolution a detailed look into the chemical buildup of the stars reveals dominantly double helium (He?+?He) WDs or carbon-oxygen CO?+?He WDs.     

The light-weighted age and metallicity of Galactic globular clusters

Spectra synthesis is entering a new era with the availability of large and high-quality spectroscopic data and full spectrum fitting methods. Establishing the reliability whether the STARLIGHT code (a full spectrum fitting code, Cid Fernandes et al. (Mon. Not. R. Astron. Soc. 358:363, 2005)) is suitable to study the properties of various types of galaxies is vital to galaxy study. In testing this possibility, Galactic globular clusters (GCs) provide an excellent medium. Taking the 40 Galactic GCs as an example in our work, we analyze their integrated spectra from Schiavon et al. (Astrophys. J. Suppl. 160:163, 2005) and obtain their mixtures of stellar populations that best represents their composite nature. Through analyzing the distributions of stellar ages and metallicities respectively, we find that the stellar metallicity distribution is centered at a low value and the stellar age distribution is very scattered. To compare with the literature, we also calculate the light-weighted ages and metallicities of GCs, and we find that the light-weighted metallicities agree with the literature, while the light-weighted ages are lower than those of the literature. This demonstrates that STARLIGHT can be used to obtain the metallicities of GCs.     

辽宁中尺度数值模式产品和T213产品对比检验分析

利用国家级的气象预报产品质量客观检验评价系统,对辽宁中尺度模式预报MM5和T213数值预报的结果分别进行检验分析.检验类型分为历史资料检验和实时资料检验,检验要素包括地面降水、气温和高空500 hPa环流.检验结果显示,对于降水、气温的预报MM5模式预报检验结果优于T213数值预报,而对于500 hPa环流的检验结果T213更可信.     

CIRCULAR-ECONOMY MODELS OF ANIMAL HUSBANDRY INDUSTRY IN JILIN PROVINCE

1INTRODUCTION The circular-economyisan efficient resources metabolic process, based on principles of ecology and system engi- neering.Withcoupledstructure andthe complex ecolo- gical and economic evolution, it has the characteristics of overall integrity, coordination, and circulation (WANG, 2005). Compared with the traditionalecono- mic model, the circular-economy requires the technical model of production process to be changed from the opening flow pattern that is "resourcesconsumption…     

Coupled convection and tidal dissipation in Europa’s ice shell using non-Newtonian grain-size-sensitive (GSS) creep rheology

We present self-consistent, fully coupled two-dimensional (2D) numerical models of thermal evolution and tidal heating to investigate how convection interacts with tidal dissipation under the influence of non-Newtonian grain-size-sensitive creep rheology (plausibly resulting from grain boundary sliding) in Europa’s ice shell. To determine the thermal evolution, we solved the convection equations (using finite-element code ConMan) with the tidal dissipation as a heat source. For a given heterogeneous temperature field at a given time, we determined the tidal dissipation rate throughout the ice shell by solving for the tidal stresses and strains subject to Maxwell viscoelastic rheology (using finite-element code Tekton). In this way, the convection and tidal heating are fully coupled and evolve together. Our simulations show that the tidal dissipation rate can have a strong impact on the onset of thermal convection in Europa’s ice shell under non-Newtonian GSS rheology. By varying the ice grain size (1-10 mm), ice-shell thickness (20-120 km), and tidal-strain amplitude (0-4 × 10⁻⁵), we study the interrelationship of convection and conduction regimes in Europa’s ice shell. Under non-Newtonian grain-size-sensitive creep rheology and ice grain size larger than 1 mm, no thermal convection can initiate in Europa’s ice shell (for thicknesses <100 km) without tidal dissipation. However, thermal convection can start in thinner ice shells under the influence of tidal dissipation. The required tidal-strain amplitude for convection to occur decreases as the ice-shell thickness increases. For grain sizes of 1-10 mm, convection can occur in ice shells as thin as 20-40 km with the estimated tidal-strain amplitude of 2 × 10⁻⁵ on Europa.     

平顶山盐田勘探开发工作回顾与展望

该文对平顶山盐田的发现及地质勘探开发过程进行了简明扼要的综述。对前人地质工作作了评论,对目前地质勘探程度、盐田地质特征和开发利用现状进行了总结,对盐田今后发展方向进行了具体分析,指出了应采取的措施。     

Macroalgae blooms and their effects on seagrass ecosystems

Seagrass decline caused by the macroalgae blooms is becoming a common phenomenon throughout temperate and tropical regions. We summarized the incidence of macroalgae blooms throughout the world and their impact on seagrass beds by direct and indirect ways. The competition for living space and using resources is the most direct effect on seagrass beds when macroalgae are blooming in an aquatic ecosystem. The consequence of macroalgae blooms (e.g., light reduction, hypoxia, and decomposition) can produce significant indirect effects on seagrass beds. Light reduction by the macroalgae can decrease the growth and recruitment of seagrasses, and decomposition of macroalgae mats can increase the anoxic and eutrophic conditions, which can further constrict the seagrass growth. Meanwhile, the presence of seagrass shoots can provide substrate for the macroalgae blooms. Controlling nutrient sources from the land to coastal waters is a general efficient way for coastal management. Researching into the synergistical effect of climate change and anthropognic nutrient loads on the interaction between searsasses and macroalgae can provide valuable information to decrease the negative effects of macroalgae blooms on seagrasses in eutrophic areas.     

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The Influence of Two Kinds of El Niño Events on the Strong Tropical Cyclone Generation and Strength in the Pacific Ocean

This paper focuses on the effects of two types of El Niño events on tropical cyclone activity. We classified El Niño events from 1961 to 2015 according to their sea surface temperature (SST) anomalies into an eastern type and a central type. Then we selected strong tropical cyclones to statistically analyze the tropical cyclone characteristics during different events and their effects, as well as to study the possible mechanisms related to thermodynamic and dynamic factors. The tropical cyclone generation areas were found to be very similar during the two kinds of events. The average number of tropical cyclone in the eastern event is more than that in central event, and the hurricane in northeastern Pacific (HNP) has more energy than the typhoon in northwestern Pacific (TNP) in all cases. The seasonal distribution of the TNP high-incidence centers during central El Niño events is opposite to that of the HNP. The TNP accumulated cyclone energy (ACE) intensity is similar in the fall and summer, and the HNP ACE intensity in the summer is greater than that in the fall. The SSTs are consistent with the TNP and HNP movement trends. The Walker circulation intensity was strongly affected by the eastern events, but it quickly returned to its normal state, while the intensity was slightly reduced in the central events, and it slowly returned to its normal state. The vertical velocity distributions in the Pacific are different at different stages of both events, and the distributions of vertical velocity anomalies for typhoons and hurricanes are consistent.