南海北部莺歌海盆地新近纪古环境与层序地层格架再认识

利用莺歌海盆地钻井中获得的丰富的有孔虫、钙质超微化石等微体古生物资料,对研究区新近纪各地层沉积时期的古环境及演化进行了研究。结合古环境及地震资料分析,重新认识了莺歌海盆地新近纪各层序界面。S40、S30、S28、S27等界面都具明显的峡谷侵蚀特征。另外,①号断层上升盘地层受峡谷侵蚀搬运后在下部S29界面上形成较好的储层,是下一步油气勘探的重要方向之一。     

Crystal structure of the streptococcal superantigen SpeI and functional role of a novel loop domain in T cell activation by group V superantigens

Superantigens (SAgs) are potent microbial toxins that bind simultaneously to T cell receptors (TCRs) and class II major histocompatibility complex molecules, resulting in the activation and expansion of large T cell subsets and the onset of numerous human diseases. Within the bacterial SAg family, streptococcal pyrogenic exotoxin I (SpeI) has been classified as belonging to the group V SAg subclass, which are characterized by a unique, relatively conserved ∼15 amino acid extension (amino acid residues 154 to 170 in SpeI; herein referred to as the α3-β8 loop), absent in SAg groups I through IV. Here, we report the crystal structure of SpeI at 1.56 Å resolution. Although the α3-β8 loop in SpeI is several residues shorter than that of another group V SAg, staphylococcal enterotoxin serotype I, the C-terminal portions of these loops, which are located adjacent to the putative TCR binding site, are structurally similar. Mutagenesis and subsequent functional analysis of SpeI indicates that TCR β-chains are likely engaged in a similar general orientation as other characterized SAgs. We show, however, that the α3-β8 loop length, and the presence of key glycine residues, are necessary for optimal activation of T cells. Based on Vβ-skewing analysis of human T cells activated with SpeI and structural models, we propose that the α3-β8 loop is positioned to form productive intermolecular contacts with the TCR β-chain, likely in framework region 3, and that these contacts are required for optimal TCR recognition by SpeI, and likely all other group V SAgs.     

Photoluminescent metal-organic framework with hex topology constructed from infinite rod-shaped secondary building units and single e,e-trans-1,4-cyclohexanedicarboxylic dianion

Hydrothermal reaction produced a three-dimensional zinc 1,4-cyclohexanedicarboxylate formulated as Zn₅(μ³-OH)₂(trans-chdc)₄ (chdc = 1,4-cyclohexanedicarboxylic dianion) in high purity and good yield, which is constructed from infinite rod-shaped Zn-O-C secondary building units interconnected by -C₆H₁₂-cyclohexane rings of the ligands. The topology of the framework can be regarded as hex type. Though it is synthesized from 1,4-cyclohexanedicarboxylic acid with mixed conformations (trans and cis), interestingly, the ligands in the compound Zn₅(μ³-OH)₂(trans-chdc)₄ are uniformly in e,e-trans conformation. This may be related to its synthetic conditions. Photoluminescence measurement reveals that the compound exhibits intense violet-blue fluorescent emission at room temperature. Origin of the emission can be assigned to intraligand transitions by comparison of the fluorescent emission bands for the free ligand chdcH₂ and the compound Zn₅(μ³-OH)₂(trans-chdc)₄.     

Assessing the Effects of Invasive Alien Species on Rural Livelihoods: Case Examples and a Framework from South Africa

The detrimental impacts of invasive alien species (IAS) on ecosystem goods and services and local and regional economies are well documented. However, the use of IAS by rural communities is little understood, and rarely factored into IAS control programmes. Understanding the use of IAS by rural communities and factoring these into cost-benefit models is complex, depending upon a range of local-level attributes such as the time since invasion, abundance, and local-level costs and benefits. This paper reports on two case studies examining the role of IAS in rural livelihoods in the Eastern Cape, South Africa. In both cases, rural communities made widespread consumptive use of the IAS and generally would prefer higher densities, except in certain key localities. Several households traded in IAS products to generate supplementary income. We present a conceptual framework to guide interpretation of these and future case studies, considering attributes such as time since invasion, the competitiveness of the species, and the relative costs and benefits.     

简述《2020年后全球生物多样性框架》谈判进展

《生物多样性公约》(简称《公约》)第十五次缔约方大会(COP15)第二阶段会议上将审议通过正在编制的2020年后全球生物多样性框架(简称“框架”)。该框架具有里程碑意义, 对未来全球生物多样性保护、经济和社会发展有重要指导作用。由于生物多样性的持续丧失, 只有通过变革式的转型, 才能实现到2050年人与自然和谐发展的美好愿景。框架以变革理论为基础, 拟制定雄心勃勃又务实平衡的生物多样性保护目标。生物多样性与人类息息相关, 目标的制定将对人类社会的生产、消费等产生重大影响。由于《公约》机制和框架磋商的复杂性等多种原因, 仅极少数人完整地了解框架的内容和谈判进程。经过框架不限成员名额工作组(以下简称“OEWG”) 4次会议的磋商, 框架结构和要素已基本确定, 其中最受关注的是22个2030年行动目标, 包括减少对生物多样性的威胁(行动目标1‒8)、通过可持续利用和惠益分享来满足人的需求(行动目标9‒13)和执行工作和主流化的工具和解决方案(行动目标14‒22) 3个部分。本文介绍了OEWG第四次会议磋商的框架草案中行动目标的谈判进展, 对框架中30 × 30目标、资源调动等核心议题进行了分析, 从而为管理部门、科研机构、企业、社会组织、从事生物多样性教育和保护的广大工作者等社会各界了解全球生物多样性治理对国际经济秩序的重塑提供视角和方法上的参考, 从而更好地把握参与科技、贸易、投资、制造等领域国际竞争的环境政治动态与方向, 促进人与自然和谐共生, 共建地球生命共同体。     

Vertical CoP Nanoarray Wrapped by N,P‐Doped Carbon for Hydrogen Evolution Reaction in Both Acidic and Alkaline Conditions

Hydrogen evolution reaction (HER) is a key reaction in water splitting, and developing efficient and robust non‐noble electrocatalysts for HER is still a great challenge for large‐scale hydrogen production. Herein, a vertically aligned core–shell structure grown on Ti foil with CoP nanoarray as a core and N,P‐doped carbon (NPC) as a shell (CoP/NPC/TF) is first reported as an efficient electrocatalyst for HER. Results indicate that CoP/NPC/TF only demands the overpotentials of 91 and 80 mV to drive the current density of 10 mA cm^?2 in acidic and alkaline solutions. The electrochemical measurements and theoretical calculations show that the synergy of CoP nanorod core and porous NPC shell enhances HER performance significantly, because the introduction of porous NPC shell not only offers more active sites but also improves the electrical conductivity and durability of the sample in acidic and alkaline solutions. Density functional theory calculation further reveals that all the C atoms between N and P atoms in CoP/NPC are the most efficient active sites, which greatly improve the HER performance. The identification of active species in this work provides an effective strategy to design and synthesize the low‐cost, high‐efficient, and robust CoP‐based electrocatalysts.     

Biomass‐Derived 3D Carbon Aerogel with Carbon Shell‐Confined Binary Metallic Nanoparticles in CNTs as an Efficient Electrocatalyst for Microfluidic Direct Ethylene Glycol Fuel Cells

Flexible and 3D carbon aerogels (CAs) composed of carbon nanotubes (CNTs) with carbon shell‐confined binary palladium–nickel (Pd_x–Ni_y) nanocatalysts on carbon fibers (Pd_x–Ni_y/NSCNT/CA) have been developed through a facile chemical vapor deposition method. The 3D porous carbon network and the synergistic effect of carbon shell‐confined bimetal nanoparticles of rationally constructed aerogels facilitate enhanced electrocatalytic and antipoisoning activities toward ethylene glycol (EG) oxidation reaction compared to the commercial Pt/C catalyst. With the 3D morphological features and direct growth of Pd–Ni bimetallic nanoparticles encapsulated CNTs on carbon fibers, the Pd₅₂–Ni₄₈/NSCNT/CA delivers a maximum microfluidic direct ethylene glycol fuel cell (µDEGFC) power density and durability of, respectively, 62.8 mW cm^?2 and 60 h. The superior performance observed, with Pd₅₂–Ni₄₈/NSCNT/CA amongst the catalysts reported in the literature, opens an exciting research avenue towards powering next‐generation, portable electronics.     

Metal–Organic Framework: A Novel Material for Triboelectric Nanogenerator–Based Self‐Powered Sensors and Systems

The triboelectric nanogenerator (TENG) offers a simple and cost‐effective method to harness waste energy and works on the principle of contact electrification and electrostatic induction. The performance and application of TENG depend to a great extent on the material used for fabrication. The most widely used materials include polymers and a few metals, well‐arranged in the triboelectric series so as to promote electrification upon contact. New triboelectric materials are important for extending the applications and specificity of the TENG. A TENG based on a metal–organic framework (MOF) of the zeolitic imidazole family is reported here. The zeolitic imidazole framework‐8 (ZIF‐8) and Kapton are used as the active materials for MOF–TENG fabrication. Surface potential, structural, morphological and electrical measurements reveals detailed characteristics of ZIF‐8, confirming the MOF as a potential candidate for TENG applications. The MOF–TENG generates a sustainable output of 164 V and 7 µA in vertical contact–separation mode. Finally, a self‐powered UV counterfeit system and a tetracycline sensor are successfully developed and demonstrated with the MOF–TENG. The sensor is highly selective and reusable simply by washing.     

Directed Self‐Assembly of MOF‐Derived Nanoparticles toward Hierarchical Structures for Enhanced Catalytic Activity in CO Oxidation

The controllable self‐assembly of nanomaterials remains a great challenge in nanotechnological applications, especially for the hierarchical structure with high complexity. Herein, by taking the advantage of highly dispersed metal nodes and mild thermal stability of metal‐organic frameworks (MOFs), the self‐assembly of nanoparticles is directed from MOFs to construct CuO hierarchical structures, which have an inherited octahedral framework consisting of the microspheres, nanowires, and polyhedrons, respectively. Unlike the conventional self‐assembly in a solution media (such as solvent and molten solid), the assembly in this work is the first demonstration through a solution‐free approach. Moreover, compared to the general MOF‐derived CuO octahedron, the assembled hierarchical CuO structure exhibits much enhanced catalytic activity in CO oxidation thanks to the exposure of more active sites during the assembly.