唯物史观视域下的“低欲望群体”:形成、影响及其引导

从唯物史观的角度看,人民日益增长的美好生活需要和不平衡不充分的发展之间的社会主要矛盾,是生产力和生产关系、经济基础和上层建筑的辩证矛盾在当代中国的集中体现。受此影响,青年中产生了因物质条件得到改善、阶层流动受到限制、价值观念集体迷失等影响而形成的"低欲望群体"。该群体具有自我怀疑、自我否定、自我安慰、自我关爱等主要特征,需要辩证分析、正确引导。新时代青年应在奋斗中释放激情、追逐理想,真正跑好历史传递的接力棒。各界应高度重视青年工作,积极为青年的发展创造条件,使青年"有条件、有动力、有可能"成为实现中华民族伟大复兴进程中的奋进者、开拓者、奉献者。

习近平调查研究重要论述的逻辑理路与实践指向

调查研究是我们党的传家宝,是我们做好各项工作的基本功。进入新时代,习近平科学谋划和部署党和国家事业发展全局,对调查研究作出一系列重要论述,系统回答了“新时代为什么要重视调查研究、怎样进行调查研究”等重大理论和实践问题,不仅明确了新时代调查研究的逻辑理路,也为顺利推进社会主义现代化建设事业提供了科学的方法论指导。新时代深入开展调查研究,要始终坚定人民立场,坚持问题导向性,与时俱进创新方法举措,推进调查研究制度化经常化。

Genesis of Silica-phosphatic Nodules with Small Shelly Fossils Preserved in the Lowermost Cambrian of South China

Silica-phosphatic nodules are abundant in black shales of the Yanjiahe Formation in the Three Gorges Area of South China,which is correlated to the Fortunian Stage,Terreneuvian Series,Cambrian System.The nodules are rich in small shelly fossils and hence attract the attention of numerous paleontologists and sedimentary geologists.However,the genesis of the nodules and the preservation of the small shelly fossils are poorly understood.Here we analyze morphological,structural,mineralogical and chemical features of the nodules in multiscale using a combination of micro-X-ray fluorescence spectroscopy,X-ray diffraction,scanning electron microscopy and confocal laser Raman spectroscopy.Results reveal that nodules are concentric in chemical and mineralogical compositions,comprising a silica-phosphatic core encrusted sequentially by a phosphatic zone,a siliceous zone and a very thin pyrite outer rim.The black shales hosting the nodules demonstrate a laminated texture of alternating clayey and silty laminae,which were respectively deposited in sulfidic/less sulfidic,high/low production,intense/weak chemical weathering conditions.The phosphogenesis of the nodules resulted in the phosphatization of small shelly fossils,which prevented the fossils from being dissolved during diagenesis,whereas the silica encrustation sealed the fossils within the nodules and thus protected the fossils from alteration by deep burial and surface weathering.

音频大地电磁法和氡气测试在某地热勘察中的应用

近年来,音频大地电磁法和土壤氡气测试,在大深度地质及区域构造调查领域内取得了优异的勘探效果。该文介绍了应用音频大地电磁法和氡气测试法两种手段对川西某地热构造进行探测的实例,通过数据处理及解译,综合分析判断,查明了该岩浆岩地区地热分布情况,经钻探验证,成功开采出地热水。该实例表明,音频大地电磁法和氡气测试法,在地热勘察中具有较高的实用和推广价值。

Terminal Ediacaran anoxia in deep-ocean: Trace element evidence from cherts of the Liuchapo Formation, South China

Here we report a detailed trace element study of the cherts from Liuchapo Formation, which is a terminal Ediacaran (551-542 Ma) succession in South China deposited in deep-water basinal setting. The REE of Liuchapo cherts shows similar features as observed for anoxic modern seawater (but not for hydrothermal fluids), characterized by positive La anomaly (LaN/CeN = 0.83–1.91, average 1.37), moderately negative Ce anomaly (0.53–1.1, average 0.73), positive Gd anomaly (average 1.08), positive Y anomaly (average 1.21), and depleted LREE and MREE. In addition, the Liuchapo cherts have low ΣREE (3.36–56.13 ppm, average 20.6 ppm), low Al2O3, Ti, Th and Zr concentrations, and high Y/Ho ratios (up to 43.9). The redox-sensitive trace elements concentrations in the cherts do not correlate with detrital input proxies. All of these features suggest that the redox-sensitive trace elements in the cherts were authigenically concentrated in water column and their concentrations thus are excellent indicators of ancient redox conditions. Very low Th/U ratios, high V/(V+Ni) and Fe?/Al ratios, enrichments of redox-sensitive trace elements (U, V, Mo), and low concentration of Mn in the cherts imply anoxia in the deep seawater. Our data reveal that the terminal Ediacaran ocean was not completely oxidized and the deep ocean was still anoxic, at least in South China. We propose that although the oxidative events existed in the terminal Ediacaran oceans, decomposition of organic matter prolonged anoxia in the deep ocean.

Iron speciation in cherts from the Laobao Formation,South China:Implications for anoxic and ferruginous deep-water conditions

Cherts in the Laobao Formation in the Silikou section,South China were deposited in terminal Ediacaran deep-water.The speciations of iron in cherts,such as pyrite Fe(FeP),HCl-extractable Fe(FeH),and total Fe(FeT),and their interrelationships,are proxies for distinguishing oxic,anoxic but ferruginous,and sulfidic conditions,which is an effective method for studying the terminal Ediacaran ocean environment.For chert samples from the Laobao Formation,pyrite concentrations are generally low(<0.56%),degree of pyritization(DOP)ranges from<0.01 to 0.78 and most are<0.45;(FeP+FeH)/FeT ratios are between 0.27 and 0.84 and most exceed 0.38,and most of FeT/Al ratios range from 0.55 to 5.87(averaging 1.1).Relatively high content of highly reactive Fe and low content of pyrite indicate a scarcity of H2S and Fe-enriched deep-water.These features suggested that the deposition setting of Laobao cherts was anoxic and ferruginous.Terminal Ediacaran deep-water in the South China Basin was most likely anoxic and ferruginous,which played a key role in the emergence and evolution of early multicellular life.

枯草芽孢杆菌通过抑制NF-κB通路改善LPS诱导的小鼠乳腺炎

乳腺炎是乳品行业最严重的疾病之一,在世界范围内造成巨大经济损失。大肠杆菌是引起乳腺炎最主要的病原体之一。枯草芽孢杆菌(B.subtilis)可以抑制病原体的定植并改善炎症水平,但其对乳腺炎的作用尚未报道。本研究旨在探讨B.subtilis对LPS诱导的小鼠乳腺炎的保护作用。通过对小鼠乳头导管注射LPS建立乳腺炎模型,注射前使用B.subtilis预处理2 h。采用苏木精-伊红(H&E)染色评价乳腺的病理改变;使用试剂盒检测髓过氧化物酶(MPO)活性;通过酶联免疫吸附试验(ELISA)检测促炎细胞因子TNF-α、IL-1β含量。通过Western blot检测核转录因子κB(NF-κB)的表达。结果表明,B.subtilis预处理降低了LPS诱导的小鼠乳腺中性粒细胞浸润,炎性细胞因子TNF-α、IL-1β的分泌,以及NF-κB p65和IκB的磷酸化水平。综上所述,B.subtilis能改善LPS诱导的乳腺炎,为乳腺炎的防治制剂研究提供了新的方向。