SI数据采集系统简介

经过20多年的实践,煤炭系统已能较好地实现落差≥5m断层、煤层5m起伏的二、三维地震勘探.受大道距（10～20m）、多组合、高频（60Hz、100Hz）检波器的幅频响应、狭长的束状观测系统、炮检方位角变化引起频率降低等因素的影响,极大地约束了分辨率的进一步提高.SI地震数据采集系统,以小道距、不组合、单点宽频数字检波器接收,无采集站的宽频带、高密度、高保真度、高精度的数据采集方法等独有特点,可在更大范围内提高垂向、横向分辨率,探测落差≤5m的断层、控制直径≤15m陷落柱等微小地质构造,适应煤矿回采的要求.     

岳西县改造中低产田初步尝试

岳西是典型的贫困山区县,由于低产土壤分布广,自然灾害频繁,物化投入少等原因导致粮食生产水平低,广大群众没有摆脱贫困。通过耕作制度改革,优化种植结构等措施,已取得显著效果。对于山区低温冷害类型和生理机制等方面研究,也取得较大进展,同时也闯出一条具有山区特色发展高效农业的路子。     

An experimental study on picromerite equilibrium in the five-component brine system K-Na-Mg-C1-SO4-H-2O

This paper presents the results of experiments on the physicochemical conditions for the formation of picromerite in the five-component brine system K-Na-Mg-Cl-SO₄-H₂O and the process of isothermal evaporation-crystallization of picromerite from brines. The metastable phase fields of picromerite at 15.10 and 5°C and its stable equilibrium phase field at -5°C have been established. In addition. the phase equilibrium relationships have also been established for other salt minerals. The lower limit of formation temperature of picromerite has been deduced on the basis of experimental results. The isothermal evaporation crystallization path of the invariant assemblage (point D) of picromerite, epsomite. sylvite and halite at 25, 15, 10 and 5°C has been revealed. Furthermore, some controversial problems are approached concerning the 25°C “solar” diagram and the 25°C metastable phase diagram of this system.     

某新型梁柱节点的装配式钢筋混凝土框架结构基于性能的抗震设计研究

在一种新型无黏结预应力装配式混凝土梁柱框架节点抗震性能试验基础之上，使用基于位移的抗震设计方法对新型框架节点的无黏结预应力装配式钢筋混凝土框架结构进行整体抗震设计研究。首先使用有限元软件sap2000进行预应力三维结构设计并建立相应的有限元模型，同时建立该梁柱节点的梁恢复力模型，进而实现自定义塑性铰本构关系研究该装配式框架结构。使用pushover分析去表征结构的抗震性能，对比研究不同目标位移下的相应性能水平要求。通过施加Y方向均匀分布荷载对结构进行弹塑性推覆分析，对结构的层间位移角、破坏机制进行分析讨论。结果表明：按照"功能良好""生命安全""防止倒塌"三水平的设计均达到预期结果，各层层间位移角和薄弱层的性能均能满足规范的相应要求。并选用三条地震波对结构进行弹塑性动力时程分析，表明基于该新型梁柱节点的装配式结构在基于位移的抗震设计中可以较好满足相关抗震性能水平要求。     

高中生地理实践力培养与评价模式

结合《普通高中地理课程标准(2017年版2020年修订)》《2016地理教育国际宪章》和专家学者的意见,对地理实践力的内涵进行界定,明确培育高中生地理实践力的价值,并提出具体、可操作的培养模式与相应的评价模式。     

Analysis of Influencing Factors of Temperature Field in Freezing Construction of Metro Connecting Passage

Geotechnical and Geological Engineering - With the development of underground space and the continuous development of subways, the emergence of artificial freezing method has solved the problem of...     

Effects of dietary supplementation of Ulva pertusa and non-starch polysaccharide enzymes on gut microbiota of Siganus canaliculatus

Fishes represent the highest diversity of vertebrates; however, our understanding of the compositions and functions of their gut microbiota is limited. In this study, we provided the first insight into the gut microbiota of the herbivorous fish Siganus canaliculatus by using three molecular ecology techniques based on the 16 S r RNA genes(denaturing gradient gel electrophoresis, clone library construction, and highthroughput Illumina sequencing), and the Illumina sequencing technique is suggested here due to its higher overall coverage of the total 16 S r RNA genes. A core gut microbiota of 29 bacterial groups, covering 99.9% of the total bacterial community, was found to be dominated by Proteobacteria and Firmicutes in fish fed three dif ferent diets with/without the supplementation of U lva pertusa and non-starch polysaccharide(NSP) enzymes(cellulase, xylanase, and β-glucanase). Diverse potential NSP-degrading bacteria and probiotics(e.g., R uminococcus, Clostridium and Lachnospiraceae) were detected in the intestine of the fish fed U. pertusa, suggesting that these microorganisms likely participated in the degradation of NSPs derived from U. pertusa. This study supports our previous conclusion that U. pertusa-based diets are suitable for the production of S. canaliculatus with lower costs without compromising quality.     

Preparation and Certification of Re-Os Dating Reference Materials: Molybdenites HLP and JDC

Two Re-Os dating reference material molybdenites were prepared. Molybdenite JDC and molybdenite HLP are from a carbonate vein-type molybdenum-(lead)-uranium deposit in the Jinduicheng-Huanglongpu area of Shaanxi province, China. The samples proved to be homogeneous, based on the coefficient of variation of analytical results and an analysis of variance test. The sampling weight was 0.1 g for JDC and 0.025 g for HLP. An isotope dilution method was used for the determination of Re and Os. Sample decomposition and pre-concentration of Re and Os prior to measurement were accomplished using a variety of methods: acid digestion, alkali fusion, ion exchange and solvent extraction. Negative thermal ionisation mass spectrometry and inductively coupled plasma-mass spectrometry were used for the determination of Re and ¹⁸⁷Os concentration and isotope ratios. The certified values include the contents of Re and Os and the model ages. For HLP, the Re content was 283.8 ± 6.2 μg g⁻¹, ¹⁸⁷Os was 659 ± 14 ng g⁻¹ and the Re-Os model age was 221.4 ± 5.6 Ma. For JDC, the Re content was 17.39 ± 0.32 μg g⁻¹, ¹⁸⁷Os was 25.46 ± 0.60 ng g⁻¹ and the Re-Os model age was 139.6 ± 3.8 Ma. Uncertainties for both certified reference materials are stated at the 95% level of confidence. Three laboratories (from three countries: PR. China, USA, Sweden) joined in the certification programme. These certified reference materials are primarily useful for Re-Os dating of molybdenite, sulfides, black shale, etc.     

1∶50000空间数据缩编更新方案设计

现势性是地图的基本特性之一。为保持1:50000空间数据的现势性,国家实施了全国1:50000数据库的更新项目,以甘肃永昌测区为例阐述了利用1:10000DLG数据直接缩编更新1:50000空间数据的方法。     

寒区高吸力非饱和土的破坏准则研究

针对北方寒旱区路基边坡时常因拉剪强度不足而发生浅层滑坡的现象,通过常规三轴试验探究了冻融和高吸力对非饱和土的强度特性影响。结果表明：随着冻融次数的增加,非饱和土的土-水特征曲线逐渐下移,抗拉强度与抗剪强度逐渐减小;随着基质吸力的增加,抗剪强度逐渐增大,抗拉强度逐渐降低。鉴于传统的抗拉抗剪联合公式不能很好地反映经冻融作用之后高吸力非饱和土抗拉区破坏包线的实际情况,通过引入“界值”概念,提出一种新的抗拉区绘制破坏包线的方法对传统公式进行修正,修正后的公式具有很好的适用性,可以为寒旱区非饱和土边坡稳定性计算提供可靠的理论依据。