Study of the Seismogenic Structure of the October 12th, 2019 MS5.2 Beiliu Earthquake, Guangxi, China

On October 12~(th),2019,a M_S5.2 earthquake occurred in Beiliu City,Guangxi Zhuang Autonomous Region,China,with a focal depth of 10 km. The epicenter is located in the junction of Guangxi and Guangdong where the moderate-strong earthquakes are relatively active. The highest intensity of this earthquake is estimated up to Ⅵ besides the isoseismic line showed an ellipse shape with a long axis trend in the NW direction.The aftershocks are not evenly distributed. The parameters of the focal mechanism solutions are: strike 346°,dip 85°,rake 19° for the nodal planeⅠ,and strike 254°,dip 71°,rake 175° for the nodal planeⅡ. The type of the coseismic fault is strikeslip. After analyzing these results above and the active faults near the epicenter,we get that the nodal planeⅠ is interpreted as the coseismic rupture plane and the BamaBobai Fault is a seismogenic structure of M_S5.2 Beiliu earthquake.     

近十年地震预测的国际研究进展

跟踪和总结地震预测在国际上的研究进展,是调整优化我国自主进行与地震预测相关的科学研究和推进学科建设的重要方式之一。为反映近10年来国际上地震预测研究的进展与变化趋势,通过文献计量学分析、国际科学研究计划介绍和主要研究成果总结等方式,给出我国地震预测相关研究在国际研究体系中可能的位置,并概括了近10年来在全球性科学研究计划主导下国际上取得的主要科学进展,包括预测模型研发、提升预测可操作性、拓展地震减灾应用等方面,极大地丰富了地震预测相关学科的科学内涵并融入经济社会发展的成效,这些将对我国地震预测相关科学研究有着重要的启发意义。     

宁夏南部干旱-半干旱黄土梁峁区生态环境调查与生态建设模式——以西吉县城郊乡和马建乡生态环境调查为例

宁夏南部黄土高原区严重的水土流失、土地退化对当地的生产、生态、社会发展、人民生活带来极大的困难和危害,因此如何开展生态建设、促进社会经济发展,成为当地政府最为紧迫的任务之一。西吉县城郊乡和马建乡是干旱-半干旱黄土梁峁区典型代表地区,部分地区已经失去了依靠自身力量进行生态恢复和发展的可能性,因而需要在调查研究的基础上,制定合理的规划和生态建设模式,针对性的增加外部投入,进行生态重建。本文在对西吉县城郊乡和马建乡开展生态地质调查的基础上,分析研究了宁夏南部干旱-半干旱黄土梁峁区的主要生态环境问题,依据该区地质、地貌、气候、植被条件,初步总结了该地区适宜的生态建设模式,即高效生态农业建设模式,经济林园艺化管理的农果复合型生态农业建设模式,草灌（木）和畜牧业林木型生态农业模式,林草、林灌（木）和草灌（木）相互结合生态模式。     

贵州省农业地质区划与农业综合区划的关系

贵州农业地质区划是在农业综合区划的基础上,用农业地学的观点以地质环境为主线编制而成,是对农业综合区划的补充和发展。对比贵州农业地质区划与农业综合区划,其目的是取长补短,更好地为贵州农业结构调整、发展优势特色农业服务;以增加农民收入,促进农业可持续发展。     

Pore Size Distribution of a Tight Sandstone Reservoir and its Effect on Micro Pore-throat Structure: A Case Study of the Chang 7 Member of the Xin’anbian Block,Ordos Basin,China

Pore distribution and micro pore-throat structure characteristics are significant for tight oil reservoir evaluation, but their relationship remains unclear. This paper selects the tight sandstone reservoir of the Chang 7 member of the Xin’anbian Block in the Ordos Basin as the research object and analyzes the pore size distribution and micro pore-throat structure using field emission scanning electron microscopy(FE-SEM), high-pressure mercury injection(HPMI), highpressure mercury injection, and nuclear magnetic resonance(NMR) analyses. The study finds that:(1) Based on the pore size distribution, the tight sandstone reservoir is characterized by three main patterns with different peak amplitudes. The former peak corresponds to the nanopore scale, and the latter peak corresponds to the micropore scale. Then, the tight sandstone reservoir is categorized into three types: type 1 reservoir contains more nanopores with a nanopore-to-micropore volume ratio of 82:18;type 2 reservoir has a nanopore-to-micropore volume ratio of 47:53;and type 3 reservoir contains more micropores with a nanopore-to-micropore volume ratio of 35:65.(2) Affected by the pore size distribution, the throat radius distributions of different reservoir types are notably offset. The type 1 reservoir throat radius distribution curve is weakly unimodal, with a relatively dispersed distribution and peak ranging from 0.01 μm to 0.025 μm. The type 2 reservoir’s throat radius distribution curve is single-peaked with a wide distribution range and peak from 0.1 μm to 0.25 μm. The type 3 reservoir’s throat radius distribution curve is single-peaked with a relatively narrow distribution and peak from 0.1 μm to 0.25 μm. With increasing micropore volume, pore-throat structure characteristics gradually improve.(3) The correlation between micropore permeability and porosity exceeds that of nanopores, indicating that the development of micropores notably influences the seepage capacity. In the type 1 reservoir, only the mean radius and effective porosity have suitable correlations with the nanopore and micropore porosities. The pore-throat structure parameters of the type 2 and 3 reservoirs have reasonable correlations with the nanopore and micropore porosities, indicating that the development of these types of reservoirs is affected by the pore size distribution. This study is of great significance for evaluating lacustrine tight sandstone reservoirs in China. The research results can provide guidance for evaluating tight sandstone reservoirs in other regions based on pore size distribution.     

碎屑流高风险区桩群防护结构优化布局研究

桩群是一种可有效耗散碎屑流运动能量,抑制碎屑流运动距离及速度的山地灾害防护结构。在碎屑流沟口与受灾体之间构建一组桩群减速带,可达到保护受灾体的目的。以物理模型试验为基础,开展弧型桩群、方型桩群和圆型桩群的沟槽型碎屑流冲击动力响应研究。讨论了3种不同类型的桩群对沟槽型碎屑流运动形态的影响,进一步开展弧型桩群的结构优化研究。结果表明：采用桩群结构可有效减小沟槽型碎屑流堆积距离并抑制其运动速度;3种不同形状桩群之间,弧型桩与方型桩的拦挡效果明显优于圆型桩;弧型桩由于凹槽式外型,对沟槽型碎屑流堆积面积、淤埋深度的抑制效果稍优于方型桩;在相同高度、直径等几何参数下,弧型桩体积比圆型桩小22.6%,比方型桩小39.2%,因此弧型桩的制作成本也相对较低;弧型桩排数从1排增加到3排,桩群拦挡率分别提升7.2%、4.5%;适量增加槽口与桩之间距离Ld可以有效提高弧型桩群防护结构的能量耗散效率。该研究可为桩群在沟槽型碎屑流防治工程中的应用提供理论及技术支持。     

大坝运行对水库消落带土壤环境影响研究进展

水库消落带土壤环境对水库水位变化的响应非常明显。通过分析大坝运行下水库消落带土壤理化性质、重金属、微生物特性和土壤侵蚀变化特征,总结水位波动对消落带土壤性质的影响过程与趋势。研究表明水库消落带土壤历经长时期干湿交替过程后,其物理性质发生较大改变,但具体变化过程和趋势仍存争议。土壤化学性质中,碳、氮和磷元素迁移转化趋势明显,但各不相同。土壤重金属元素时空分异特征改变。土壤微生物总体上呈减少趋势,并且在海拔梯度上差异显著。土壤侵蚀是消落带面临的主要环境问题。未来应采用物理模型方法,定量分析水位与土壤性质相关关系,并加强对西南高山峡谷区高坝大库消落带的研究。     

半滑舌鳎病原鳗利斯顿氏菌表型及分子特征研究半滑舌鳎病原鳗利斯顿氏菌表型及分子特征研究

2008年12月,江苏赣榆某渔场养殖半滑舌鳎出现大量死亡,症状主要表现为：头部、鳃盖及鳍基出血, 尾鳍腐烂,腹腔膨胀并积有大量腹水,部分病鱼肠管脱出肛外。从病鱼肝脏、腹水中分离出大量优势生长的 细菌,人工感染试验证明其对半滑舌鳎有较强的致病性。对3株分离菌进行了形态特征、理化特性、胞外酶及溶血素活性等表型生物学性状检验;测定了代表菌株的16S rRNA和gyrB基因序列,分析了16 S rRNA和gyrB两种基因序列的同源性,并构建了系统发生树,比较了两种基因对分离菌的鉴定能力;结果表明gyrB基因用于细菌种间鉴定更具优越性;基于16S rRNA和gyrB基因的系统发育学分析表明分离菌与鳗利斯顿氏菌具有高同源性,根据分离菌的表型及分子特征,判定分离菌为利斯顿氏菌属（Listonella MacDonell and Colwell 1986）的鳗利斯顿氏菌\[Listonella anguillarum ( Bergeman 1909)MacDonell and Colwell 1986\]。胞外酶活性及溶血活性检测表明3株分离菌均具有淀粉酶、蛋白酶、卵磷脂酶等胞外酶活性,在含7%家兔脱纤血液营养琼脂培养基上呈β型溶血,PCR检测3株供试菌均可扩增出大小约493 bp的溶血素基因和大小约248 bp的金属蛋白酶基因。分离菌的耐药谱测定结果显示,对供试49种抗菌药物中的青霉素G等13种药物耐药,对羧苄青霉素等6种药物存在敏感与耐药的株间差异。     

江苏废黄河口光学后向散射浊度计的沉积物标定

以往的光学后向散射浊度计(Optical Backscatter,OBS)标定,多用其输出的浊度值进行研究,此研究目的是对OBS的原始输出的值进行了标定。利用在江苏北部废黄河口获得的表层沉积物样品和水样悬沙数据,分别对OBS的原始输出的值进行了室内标定和现场标定。结果表明:OBS值与悬沙含量呈强的线性关系,特别是在近岸悬浮体含量较高的水域。此外,室内用表层沉积物标定结果获得的悬沙含量值比实有含沙量高。像OBS的浊度值一样,OBS的原始输出的值能应用于悬沙的分析。这说明,即使没有浊度标定文件,使用OBS获得的数据也可以进行悬沙含量分析。     

余氯排海浓度预测及渔业损失计算

在潮流数值模拟的基础上,建立余氯的二维输运-扩散模型.并将模型应用于胶南发电厂温排水工程,预测了胶南发电厂温排水中余氯排海后在海洋中的浓度分布,并计算其造成的渔业损失量,为我国以自然水为冷却用水的企业确定水体加氯浓度和制定冷却水余氯排放标准提供科学依据,并为电厂的渔业资源补偿提供参考.