Measuring global energy-related sulfur oxides emissions embodied in trade: a multi-regional and multi-sectoral analysis

Sulfur oxides (SO_X) emissions embodied in trade (SEET) may play an important role in affecting national responsibilities toward pollutant emission reduction within the context of global greenhouse gas emission policy. This paper analyzes the change of the SEET associated with energy consumption from the perspective of a country and a sector between 1995 and 2011, exploring the evolution characteristic of the sources and flows of the SEET for 39 countries, as well as measuring the production-based and consumption-based global SO_X emissions’ inventory and investigating the impact of international trade on the allocation of national pollutant emissions’ reduction obligations. One important finding is that the volume of SO_X emissions embodied in global trade increased dramatically from 1995 to 2011, and the global SO_X emissions stemming from anthropogenic energy consumption are mostly from China and the USA. Another important finding is that, referring to specific sectors, whether seen from the total SEET or from the sources of SEET or from the total SO_X emissions occurring from economic consumption and production, energy sectors, like electricity, gas, and water supply and coke, refined petroleum, and nuclear fuel, are the main contributors to the increase in the global SO_X emissions. Notably, however, our results show that the sector of agriculture, hunting, forestry, and fishing should be allocated more SO_X emission reduction responsibilities under a consumption-based emissions’ accounting inventory.

     

Microbial D-amino acids and marine carbon storage

In nature, there are two conformational types of amino acids: L- and D-isomers. The L-amino acids are the predominant form and are used mainly for protein synthesis, while the D-amino acids are few in quantity but more diverse in terms of their biological functions. D-amino acids are produced by many marine microbes, which are important players in carbon and energy cycles in the ocean. As the major constituent of the marine organic carbon pool, D-amino acids can persist in the water column for a long time before being further transformed by chemical or biological processes or transported through physical processes (such as absorption and aggregation). This article reviews the microbial synthesis of D-amino acids, their physiological function and metabolism in microbes, and the contribution of D-amino acids as a carbon source to the oceanic carbon reservoir.     

依法保护矿权提高煤炭资源保障程度

分析了福建省的煤炭资源概况、地勘工作的干扰因素、产生的危害性及其产生的主要原因,论证了提高煤炭资源保障程度的重要性和必要性,并就如何依法保护矿权,提高煤炭资源保障程度方面,作了积极有益的探索.     

Numerical simulations of transport of non-ergodic solute plumes in heterogeneous aquifers

Transport of non-ergodic solute plumes by steady-state groundwater flow with a uniform mean velocity, μ, were simulated with Monte Carlo approach in a two-dimensional heterogeneous and statistically isotropic aquifer whose transmissivity, T, is log-normally distributed with an exponential covariance. The ensemble averages of the second spatial moments of the plume about its center of mass, <S _{i i} (t)>, and the plume centroid covariance, R _{i i} (t) (i=1,2), were simulated for the variance of Y=log T, σ _Y ²=0.1, 0.5 and 1.0 and line sources normal or parallel to μ of three dimensionless lengths, 1, 5, and 10. For σ _Y ²=0.1, all simulated <S _{i i} (t)>−S _{i i} (0) and R _{i i} (t) agree well with the first-order theoretical values, where S _{i i} (0) are the initial values of S _{i i} (t). For σ _Y ²=0.5 and 1.0 and the line sources normal to μ, the simulated longitudinal moments, <S ₁₁(t)>−S ₁₁(0) and R ₁₁(t), agree well with the first-order theoretical results but the simulated transverse moments <S ₂₂(t)>−S ₂₂(0) and R ₂₂(t) are significantly larger than the first-order values. For the same two larger values of σ _Y ² but the line sources parallel to μ, the simulated <S ₁₁(t)>−S ₁₁(0) are larger than but the simulated R ₁₁ are smaller than the first-order values, and both simulated <S ₂₂(t)>−S ₂₂(0) and R ₂₂(t) stay larger than the first-order values. For a fixed value of σ _Y ², the summations of <S _{i i} (t)>−S _{i i} (0) and R _{i i} , i.e., X _{i i} (i=1,2), remain almost the same no matter what kind of source simulated. The simulated X ₁₁ are in good agreement with the first-order theory but the simulated X ₂₂ are significantly larger than the first-order values. The simulated X ₂₂, however, are in excellent agreement with a previous modeling result and both of them are very close to the values derived using Corrsin's conjecture. It is found that the transverse moments may be significantly underestimated if less accurate hydraulic head solutions are used and that the decreasing of <S ₂₂(t)>−S ₂₂(0) with time or a negative effective dispersivity, defined as , may happen in the case of a line source parallel to μ where σ _Y ² is small.     

Monoterpinenes as terrigenous markers in Okinawa Trough sediments

Monoterpinenes were isolated from Okinawa Trough sediments at the 1000-m water depth by thin-layer chromatography (TLC) and identified by gas chromatography (GC) and gas chromatography-mass spectrometry-data system (GC-MS-DS). Identification has revealed cyclohexene, 1-methyl-5-(1-methylethenyl), cyclohexene, 1-methyl-3-(1-methylethenyl), and cyclohexane, 1-methyl-4-(1-methylethylidene). These monoterpinenes are believed to have been derived from terrigenous higher plant detritus, which may serve as new terrigenous markers.     

容量法测定水样中硫酸根

本文对EDTA滴定过量Pb间接测定SO_4~(2-)的方法作了改进。加入乙醇抑制PbSO_4沉淀的溶解,使滴定不需分离沉淀而直接进行。用六次甲基四胺调节控制pH为5.2—5.4,可避免大量共存Ca~(2+)、Mg~(2+)的干扰。改进后的方法简单、快速,准确度和精密度均好,可适用SO_4~(2-)含量高于1mg/L的天然水分析。     

Rapid report of the 8 January 2022 ​MS 6.9 Menyuan earthquake,Qinghai, China

The M_S 6.9 Menyuan earthquake in Qinghai Province, west China is the largest earthquake by far in 2022. The earthquake occurs in a tectonically active region, with a background b-value of 0.87 within 100 ?km of the epicenter that we derived from the unified catalog produced by China Earthquake Networks Center since late 2008. Field surveys have revealed surface ruptures extending 22 ?km along strike, with a maximum ground displacement of 2.1 ?m. We construct a finite fault model with constraints from InSAR observations, which showed multiple fault segments during the Menyuan earthquake. The major slip asperity is confined within 10 ?km at depth, with the maximum slip of 3.5 ?m. Near real-time back-projection results of coseismic radiation indicate a northwest propagating rupture that lasted for ～10 ?s. Intensity estimates from the back-projection results show up to a Mercalli scale of IX near the ruptured area, consistent with instrumental measurements and the observations from the field surveys. Aftershock locations (up to January 21, 2022) exhibit two segments, extending to ～20 ?km in depth. The largest one reaches M_S 5.3, locating near the eastern end of the aftershock zone. Although the location and the approximate magnitude of the mainshock had been indicated by previous studies based on paleoearthquake records and seismic gap, as well as estimated stressing rate on faults, significant surface-breaching rupture leads to severe damage of the high-speed railway system, which poses a challenge in accurately assessing earthquake hazards and risks, and thus demands further investigations of the rupture behaviors for crustal earthquakes.     

Implementation of perfectly matched layers in an arbitrary geometrical boundary for elastic wave modelling

The perfectly matched layer (PML) absorbing boundary condition is incorporated into an irregular-grid elastic-wave modelling scheme, thus resulting in an irregular-grid PML method. We develop the irregular-grid PML method using the local coordinate system based PML splitting equations and integral formulation of the PML equations. The irregular-grid PML method is implemented under a discretization of triangular grid cells, which has the ability to absorb incident waves in arbitrary directions. This allows the PML absorbing layer to be imposed along arbitrary geometrical boundaries. As a result, the computational domain can be constructed with smaller nodes, for instance, to represent the 2-D half-space by a semi-circle rather than a rectangle. By using a smooth artificial boundary, the irregular-grid PML method can also avoid the special treatments to the corners, which lead to complex computer implementations in the conventional PML method. We implement the irregular-grid PML method in both 2-D elastic isotropic and anisotropic media. The numerical simulations of a VTI lamb's problem, wave propagation in an isotropic elastic medium with curved surface and in a TTI medium demonstrate the good behaviour of the irregular-grid PML method.