Characteristics of Pegmatite-Related Fluids and Significance to Ore-Forming Processes in the Zhaxikang Pb-Zn-Sb Polymetallic Deposit,Tibet,China

The Zhaxikang Pb-Zn-Sb polymetallic deposit is one of the most important deposits in the newly recognized southern Tibet antimony-gold metallogenic belt.Compared to the porphyry deposits in the Gangdese belt,much less researches have addressed these deposits,and the genesis of the Zhaxikang deposit is still controversial.Based on field investigation,petrographic,microthermometric,Laser Raman Microprobe（LRM） and SEM/EDS analyses of fluid,melt-fluid,melt and solid inclusions in quartz and beryl from pegmatite,this paper documents the characteristics and the evolution of primary magmatic fluid which was genetically related to greisenization,pegmatitization,and silification in the area.The results show that the primary magmatic fluids were derived from unmixing between melt and fluid and underwent a phase separation process soon after the exsolution.The primary magmatic fluids are of low salinity,high temperature,and can be approximated by the H_2O-NaCl-CO_2 system.The presence of Mn-Fe carbonate in melt-fluid inclusions and a Zn-bearing mineral（gahnite） trapped in beryl and in inclusions from pegmatite indicates high Mn,Fe,and Zn concentrations in the parent magma and magmatic fluids,and implies a genetic link between pegmatite and Pb-Zn-Sb mineralization.High B and F concentrations in the parent magma largely lower the solidus of the magma and lead to late fluid exsolution,thus the primary magmatic fluids related to pegmatite have much lower temperature than those in most porphyry systems.Boiling of the primary magmatic fluids leads to high-salinity and high-temperature fluids which have high capacity to transport Pb,Zn and Sb.The decrease in temperature and mixing with fluids from other sources may have caused the precipitation of Pb-Zn-Sn（Au） minerals in the distal fault systems surrounding the causative intrusion.

Fluid Evolution and Ore-forming Processes of the Jiama Cu Deposit, Tibet： Evidence from Fluid Inclusions

The Jiama deposit is a large copper deposit in Tibet. Mineralization occurs in three different host rocks： skarn, hornfels and porphyry. A detailed fluid inclusion study was conducted for veins in the different host rocks to investigate the relationship between fluid evolution and ore-forming processes. Based on examination of cores from 36 drill holes, three types of veins （A, B and D） were identified in the porphyries, four types （I, II, III and IV） in the skarn, and three （a, b and c） in the hornfels. The crosscutting relationships of the veins and that of the host rocks suggest two hydrothermal stages, one early and one late stage. Fluid inclusions indicate that the Jiama hydrothermal fluid system underwent at least two episodes of fluid boiling. The first boiling event occurred during the early hydrothermal stage, as recorded by fluid inclusions hosted in type A veins in the porphyries, type a veins in the hornfels, and wollastonite in the skarns. This fluid boiling event was associated with relatively weak mineralization. The second boiling event occurred in the late hydrothermal stage, as determined from fluid inclusions hosted in type B and D veins in the porphyries, type I to IV veins in the skarns, and type b and c veins in the hornfels. This late boiling event, together with mixing with meteoric water, was responsible for more than 90% of the metal accumulation in the deposit. The first boiling only occurred in the central part of the deposit and the second boiling event took place across an entire interlayered structural zone between hornfels and marble. A spatial zoning of ore-elements is evident, and appears to be related to different migration pathways and precipitation temperatures of Cu, Mo, Pb, Zn, Au and Ag.

Phosphatidylserine:An overview on functionality,processing techniques,patents,and prospects

Phosphatidylserine(PS)is the part of cell structure in the body and has many beneficial functions especially in brain-related aging diseases.Although daily foods can provide PS to human body,the amount is very limited due to its poverty in most foods.To overcome the issue,numerous studies based on PS have been reported to develop PS-related supplements.In this review,PS was comprehensively and critically reviewed from the view of resources,functions,processing techniques,patents,and prospects.For resources,animal,plant,and microorganism origins were all covered with their differences in composition profiles.For functions,benefits regarding memory,cognitive enhancement,exercise performance,reducing Alzheimer’s disease,and attention-deficit hyperactivity disorder symptoms were covered as well as the functional differences among animal-,plant-,and microorganism-based PS-related supplements.For processing techniques,traditional extracting methods from animal,plant,and microorganism tissues were comparatively discussed with enzymatic synthesis based on different reaction systems.Finally,patents of PS-related supplements were evaluated as well as their applications.This review could provide scientific and valuable support for PS industry.

Dynamics of Ore-Forming Processesof the Stratabound Skarn Copper Depositsof Tongling, Anhui Province

The skarn and ore bodies of the stratabound skarn copper deposits of Tongling, Anhui Province, are both controlled by definite stratigraphic horizons, and they are concordant with the strata. They occur as layers and layer-like bodies in permeable carbonate rocks of the Middle-Upper Carboniferous Huanglong and Chuanshan Formations which are underlain by impermeable shale or siliceous rocks of the Upper Devonian Wutong Formation. The authors study the dynamics of ore-forming processes of the ore deposits with the dynamic model of coupled transport and reaction, and the following results are obtained: The salinity gradient and flow rate of the ore-forming fluids can both promote the mixing and reaction of juvenile water and formation water, and the permeable strata are favourable sites for the intense transport-reaction of mixing and the formation of deposits. (2) As isothermal transport-reaction took place along the bedding of strata, the moving transport-reaction front formed at the contact between the ore-forming fluids and the rocks advanced slowly along the permeable strata, and then stratiform skarn and ore bodies concordant with the strata were formed. (3) The gradient transport-reaction taking place across the isotherms in the cross-bedding direction caused the mineralogical composition to alter gradually from magnesian skarn to sulphide ore bodies.

Research Progress and Prospects for the Evolution Process and Treatment Technology of Urban Black and Smelly Water

Water is an important material resource for human survival,and with the increasing development of society,the amount of urban industrial wastewater and domestic sewage is gradually increasing.However,wastewater collection and treatment facilities lag behind,so that a large number of wastewater enters urban water,making urban water become gradually black and smelly.In order to provide a good living environment for human beings,a large number of scholars actively explore the treatment technology of black and smelly water.In this paper,the evolution process of black and smelly water was introduced firstly,and then the treatment technology of black and smelly water was summarized.Finally,the prospects for the development of the treatment technology were put forward.

Genesis, metallogenic model, and prospecting prediction of the Nibao gold deposit in the Guizhou Province, China

Southwestern Guizhou province is one of China’s most important distribution areas of Carlin-type gold deposits. The Nibao deposit is a typical gold deposit in southwestern Guizhou. To elucidate the genesis of the Nibao gold deposit, establish a metallogenic model, and guide prospecting prediction, we systematically collected previously reported geological, geochemical, and dating data and discussed the genesis of the Nibao gold deposit,based on which we proposed the metallogenic model.Earlier works show that the Nibao anticline, F1 fault, and its hanging wall dragged anticline(Erlongqiangbao anticline) were formed before or simultaneously with gold mineralization, while F2, F3, and F4 faults postdate gold mineralization. Regional geophysical data showed extensive low resistivity anomaly areas near the SBT(the product of tectonic slippage and hydrothermal alteration)between the P2/P3 and the strata of the Longtan Formation in the SSE direction of Nibao anticline in the lower plate of F1 and hanging wall dragged anticline(Erlongqiangbao anticline), and the anomaly areas are distributed within the influence range of anticlines. Simultaneously, soil and structural geochemistry show that F1, Nibao anticline,Erlongqiangbao anticline, and their transition areas all show good metallogenic elements(Au, As, and S) assemblage anomalies, with good metallogenic space and prospecting possibilities. There are five main hypotheses about the source of ore-forming fluids and Au in the Nibao gold deposit:(1) related to the Emeishan mantle plume activity;(2) source from the Emeishan basalt;(3) metamorphic fluid mineralization;(4) basin fluid mineralization;(5) related to deep concealed magmatic rocks;of these, the mainstream understanding is the fifth speculation. It is acknowledged that the ore-forming fluids are hydrothermal fluids with medium–low temperature, high pressure, medium–low salinity, low density, low oxygen fugacity, weak acidity, weak reduction, and rich in CO_(2)and CH_(4). The fluid pressure is 2–96.54 MPa, corresponding to depths of 0.23–3.64 km. The dating results show that the metallogenic age is ~141 Ma, the extensional tectonic environment related to the westward subduction of the Pacific Plate. Based on the above explanation, the genetic model related to deep concealed magmatic rocks of the Nibao gold deposit is established, and favorable prospecting areas are outlined;this is of great significance for regional mineral exploration and studying the genesis of gold deposits.

Development Prospects of Processing and Utilization of Longtan Pearl Plum

Longtan pearl plum, as a new dominant fruit industry in Guangxi, has developed rapidly in recent years and become one of the major economic sources of fruit growers in Guangxi. It has a positive effect on promoting economic development and helping farmers to get out of poverty in Guangxi. But there is almost nothing to do with the processing and utilization. Taking the route of processing and utilization is an inevitable trend of development of Longtan pearl plum industry with the increase of the planting area and yield year by year. In this paper, based on the analysis of edible value of Longtan pearl plum, the development direction of processing and utilization of Longtan pearl plum was expounded, and some suggestions on the problems existing in the processing and utilization were put forward to provide reference for the processing and utilization of Longtan pearl plum.

Large Deviations for Heavy-tailed Random Variables in Prospective-loss Process

In this paper, we study the precise large deviations for the prospectiveloss process with consistently varying tails. The obtained results improve some related known ones.

Current Status and Prospect of Process Research in CISRI

The Central Iron and Steel Research Institute(CISRI),directly under the Ministry of Metallurgical Industry(MMI),is a comprehensive research institute mainly engaged in the research and development of new metallic materials and new iron and steel process.With the rapid development of China’s iron and steel industry,CISRI has also made a great progress since it was established more than 40 years ago.In 1994,the steel output of

Ultra-high Temperature Ceramic Coatings:A Review on Preparation Technology and Development Prospect

Ultra-high temperature ceramic coatings have ultra-high melting points,excellent mechanical properties and high temperature ablation resistance.These unique performance combinations turn it into a promising material for use in extreme environment structures in rockets and hypersonic vehicles,particularly nozzles,leading edges and engine components.In this paper,various preparation methods of ultra-high temperature ceramic coatings were reviewed,including plasma spraying,chemical vapor deposition,pack cementation,slurry sintering,hot pressing and their research progress.Meanwhile,some new preparation methods of high temperature coatings,such as ion beam deposition,ultrasonic spraying,metal organic frame work coating,and magnetron sputtering,were introduced.The development trend of ultra-high temperature coatings was prospected as well.

月球资源开发利用的进展与展望

中国探月工程“绕、落、回”三步走圆满收官,后续将建立国际月球科研站,并进一步规划建立月球基地。月球探测任务由探测勘察进入到开发利用新阶段,月面资源的勘查、开发和利用是未来月球探测的重点任务。总结了月球资源开发利用方面的国内外重要进展,涉及月球资源勘探、水冰等挥发分分析、月球矿物冶炼与材料制备、月面建造与月壤3D打印等四个方面。同时,月球资源开发利用面临极端月面环境、独特月壤理化特性、全流程无人自主控制等重大挑战,为解决这些问题,提出了未来月球资源开发利用的重点任务和研究思路,可为后续科学研究和工程任务实施提供参考。

桑叶粉及桑叶提取物的功效和应用现状

桑叶为药食同源性食品,具有多种药理作用。近年来,随着人们对健康饮食需求的不断增加,桑叶粉及桑叶提取物作为一种新型的保健食品,在食品药品加工中的应用越来越广泛。通过文献综述和案例分析,介绍了桑叶粉及桑叶提取物的加工工艺、营养价值、功能特点和在食品药品加工中的应用现状及研究进展,展望了桑叶粉及桑叶提取物的未来发展方向,以期为进一步推动桑叶产业的发展,促进其在食品药品加工中的应用提供参考。

机器学习视角下风味分子研究及其在茉莉花茶中的应用

旨在探讨机器学习在风味分子研究领域的应用,尤其是其在茉莉花茶风味分析中的实践。风味分子的研究是理解和优化食品、特别是茶类饮品味道和品质的基础。机器学习技术的引入为风味分子的识别和分析打开了新的视野。概述了风味分子的基本概念和研究方法,详细讨论了机器学习在解析分子结构与风味特性关系、茉莉花茶品质预测与控制、风味分析、预测与优化、智能化加工等方面的应用,并提出了研究展望,以期为提升茉莉花茶的品质和茶产业发展提供技术支持。

中国农业区划发展的历史回溯与未来展望

农业区划作为指导农业因地制宜生产和因势利导合理配置资源的有效手段,对于优化要素利用、提振乡村产业和加快农业农村现代化建设具有重要意义。中国农业区划有着深厚的历史积淀和发展根基,按其思想演变、学术研究和实践历程可以划分为古代早期农业分区思想萌芽与涉农土地利用实践、近代农业区划科学发轫与起步探索和新中国成立后政府工作实务及体系化建设三个发展阶段。针对目前农业生产资源环境和社会经济条件出现的新变化,未来中国农业区划需要与时俱进,围绕全球气候变暖、城乡地理空间格局变化、农业新生产要素发展、农业废弃物资源化利用、农业生产组织方式转变等内容,为国家宏观农业发展计划的实施提供前瞻性战略支撑。

矿井探地雷达背景杂波抑制方法综述

随着中国煤炭安全高效智能开采需求的不断提升,矿井探地雷达(ground-penetrating radar, GPR)作为一种高精度物探方法,在煤矿井下探测中有广阔的应用前景。由于探地雷达目标回波信号受系统内部噪声、外部电磁干扰、巷道回波、地下介质不均匀等干扰影响,虚警率较高。尤其对于小尺寸目标,其回波信号为弱信号,容易淹没在强烈的背景杂波中,成为目前制约探地雷达探测性能的主要因素之一,进一步实现井下煤层、构造探测、提高探测精度的关键在于对背景杂波的抑制。从对消法、滤波法、分解法和网络法出发,综述这些杂波抑制方法的基本原理、优缺点及其在探地雷达干扰抑制领域的研究进展,并探讨各种方法的适用范围和发展潜力。杂波抑制技术的不断创新将进一步提高探地雷达的信噪比与灵敏度,使其在煤矿井下探测中发挥更大的应用价值。

艰难的转型:上海三十余年课改的经验与展望

通过持续不断的教育改革,促进基础教育高质量发展,是建设教育强国的必由之路。上海的课改分为“破冰试水期”(1988—1997年)、“攻坚克难期”(1998—2018年)、“并轨合流期”(2019年至今)三个时期。上海课改的基本经验是:始终牢牢把握正确的改革方向;在改革中寻求教育的内在规律;保持改革的连续性与递进性;敢为人先、为全国探路先行先试。展望未来,上海的课程改革尚需进行,教学改革任重道远。

中华人民共和国成立75年来大学生思想政治教育发展的历程、逻辑与展望

中国共产党历来高度重视大学生思想政治教育工作。作为国家意识形态建设的重要组成部分,大学生思想政治教育以其鲜明的政治性,与党和国家的发展密切相连,并呈现出不同的阶段性特征。系统梳理中华人民共和国成立75年以来大学生思想政治教育经历的起步探索期、曲折前行期、科学发展期和创新发展期等历程,深入把握其在育人目标、育人内容、育人载体和育人格局的逻辑变迁,深化大学生思想政治教育发展的规律性认识,着力探寻新时代大学生思想政治教育建设发展的未来路径,以期推动新时代大学生思想政治教育工作的创新发展。

9个不同使用类型木薯品系在合浦县的适应性研究

为筛选适宜在合浦县推广的木薯品系,本研究以主栽品种‘南植199’为对照,对9个木薯新品系的生物学特性进行了观察,并测定其农艺性状和经济性状,同时进行相关性分析。结果表明,9个品系分枝角度小、块根长度适中和主茎高度中等以上;‘RC4’的块根产量显著高于对照,其余8个品系与对照差异不显著;‘RC4’等8个品系的淀粉产量高于对照;9个品系的淀粉含量高于对照,其中‘RC3’等5个品系的淀粉含量显著或极显著高于对照;9个木薯品系的直链淀粉含量显著或极显著低于对照‘;RC6’等6个品系的氢氰酸含量低于50 mg/kg。相关性分析结果表明:块根产量与生长中期株高、成熟期株高、块根直径呈极显著正相关,与茎粗呈显著正相关;淀粉含量与生长中期株高、成熟期株高、茎粗呈显著正相关;淀粉产量与生长中期株高、成熟期株高、茎粗、块根直径、块根产量呈极显著正相关,与淀粉含量呈显著正相关。综合来看,这9个木薯新品系的综合表现良好,适合在合浦县进行推广。其中‘,RC3’、‘RC4’和‘RC7’可作为加工型品系;‘RC5’和‘RC10’可作为食用品系;‘RC2’、‘RC6’、‘RC11’和‘RC12’可作为鲜食加工兼用品系;‘RC2’和‘RC5’作为食用品系具有很好的推广前景。

上海城市轨道交通既有线改造工作回顾与展望

上海因城市轨道交通开通较早而成为国内既有线改造领域的先行者,其既有线改造经历以及经验教训对国内其他城市有一定参考价值。为此,首先回顾上海城市轨道交通既有线改造历程,主要呈现关注重点逐渐从个体向全局过渡、改造内容逐渐多元化和系统化、契合城市与网络发展目标的改造需求持续深化和拓展的发展趋势。其次,总结上海城市轨道交通开展既有线改造工作的要点,改造前以系统思维制定改造计划、改造中以保障施工安全和质量为前提尽量减少对乘客的影响、改造后积极开展后评估。然后从资金支持有限、内外沟通协调效率要求高、项目管理难度大、技术积累不足等方面剖析上海城市轨道交通开展既有线改造工作的难点。最后,展望上海城市轨道交通未来的既有线改造重点工作:探寻更多的既有线改造资金渠道、开展既有线改造项目施工计划与管理机制的改进与创新研究、深化既有线网评估工作、攻关未预留条件的地下车站不停运改扩建技术。

融合成矿过程数值模拟信息的三维成矿预测方法研究:以安徽宣城茶亭地区为例

茶亭地区位于长江中下游成矿带南陵-宣城矿集区东北部,近年来陆续发现了多个斑岩型和矽卡岩型矿床,显示深部具有很好的热液矿床成矿潜力。目前传统的矿产勘查方法对区内隐伏矿的勘查效果不佳,制约了进一步的找矿突破。三维成矿预测是近年来隐伏矿找矿的重要手段之一,但三维预测信息的缺乏在一定程度上制约了该方法的预测效果。三维成矿过程数值模拟方法能为三维成矿预测方法提供新的预测信息,但对多元数值模拟信息的联合应用以及对三维成矿预测方法的支持能力等均有待深入研究。本文以安徽宣城茶亭地区为例,在力-热-流多场耦合的条件下对热液成矿过程进行三维数值模拟;通过将体应变增量、剪切应变增量等数值模拟变量信息与其他预测信息进行融合,实现深部找矿靶区的圈定。结果显示,成矿过程数值模拟方法可为三维成矿预测提供有效的预测信息,能显著提高预测能力;圈定的找矿靶区可为进一步的深部找矿勘查提供更为有效和可靠的线索和方向。