SEEPS基热塑性磁流变弹性体复合材料的制备、结构与性能

选用性能优良的聚(苯乙烯-b-乙烯-b-乙烯-丙烯-b-苯乙烯)(SEEPS)热塑性弹性体代替传统橡胶为基体、软磁性羰基铁粉为磁性填料,采用熔融共混技术制备得到弹性好、磁流变效应高的新型各向同性和各向异性SEEPS基热塑性磁流变弹性体(MRE)复合材料。详细地介绍了两类材料的制备方法,系统地研究了基体分子量、羰基铁含量和外加磁场强度等因素对材料结构和性能的影响。羰基铁粉在各向同性MRE复合材料中呈现无规均匀分散,在各向异性MRE复合材料中呈现明显链状定向有序结构。高分子量基体吸油性优于低分子量基体,柔软度更高,加工性能更好,强度和韧性受高填充羰基铁的影响小,磁流变效应也更高。各向异性MRE比各向同性MRE具有更高的储能模量和磁流变效应。

弹性体SEEPS增韧聚碳酸酯的研究

研究了三种不同分子量三嵌段弹性体SEEPS(po lystyrene-b-po ly(ethy lene/propy lene)-b-po lystyrene)的加入对聚碳酸酯性能的影响。发现三种弹性体都能大大改善基体PC的缺口敏感性高的行为。虽然薄制品的缺口冲击强度随弹性体加入量的增加而降低,但厚制品的缺口冲击强度却大幅度提高,即使弹性体含量达到25%时,厚制品仍然具有优良的抗缺口冲击性能。SEM观察发现材料由原来的冲击波状脆性断裂转变为韧性断裂。SEEPS的加入还能明显改善体系的流变性和抗环境应力开裂性能。

SEEPS结构、性能及应用研究进展

SEEPS相比于SEBS,有更高的拉伸强度,更好的锁油性,更平滑的表面,与聚乙烯更好的相容性,更好的低温性能。SEEPS相比SEPS有更高的强度。对国内外SEEPS的发展现状、加氢用催化剂、SEEPS的结构、种类及用途进行了介绍,SEEPS可广泛应用于聚合物共混、胶粘剂、塑料改性、减震材料及发泡材料等。在我国SEBS及SEPS已实现产业化的基础上建议加大SEEPS开发力度,争取早日工业化,填补我国在该领域的空白。

基于SEEPS方法的重庆地区降水数值预报性能分析

本研究简要介绍了SEEPS方法的具体计算方案,将该方法应用到重庆地区的降水数值预报检验中,对重庆地区常用的3个业务数值模式2017年全年的预报结果进行了检验评估,并对比分析了3个模式降水预报性能的总体差异及时空分布特征.结果表明,综合各个预报时效2017年全年区域平均SEEPS技巧评分的结果, EC模式的降水预报性能最优,其次是SWC-WARMS, CQMFS最差;综合各个预报时效2017年1-12月逐月区域平均的SEEPS技巧评分的结果, SWC-WARMS各月的预报性能均优于CQMFS. SWC-WARMS和CQMFS的降水预报性能在7月和8月总体而言优于EC模式,其余各月均差于EC模式;对于同一区域全年平均的降水数值预报性能, EC模式最优,其次是SWC-WARMS, CQMFS最差.各个模式的SEEPS技巧评分在四川盆地东部偏东地区均存在大值中心. EC模式总体表现出在重庆的东北部偏东地区和中西部偏北地区的SEEPS技巧评分优于重庆的其他地区. SWC-WARMS总体表现出在重庆东南部地区的SEEPS技巧评分优于重庆的其他地区. CQMFS总体表现出在重庆的东南部地区和重庆的中西部偏北地区的SEEPS技巧评分优于其他地区.

The distribution and variation in the gas composition of macro-seeps on the near-shore Lingtou Promontory in the South China Sea

Natural hydrocarbon seeps in a marine environment are one of the important contributors to greenhouse gases in the atmosphere,including methane,which is significant to the global carbon cycling and climate change.Four hydrocarbon seep areas,the Lingtou Promontory,the Yinggehai Rivulet mouth,the Yazhou Bay and the Nanshan Promontory,occurring in the Yinggehai Basin delineate a near-shore gas bubble zone.The gas composition and geochemistry of venting bubbles and the spatial distribution of hydrocarbon seeps are surveyed on the near-shore Lingtou Promontory.The gas composition of the venting bubbles is mainly composed of CO_2,CH_4,N_2 and O_2,with minor amounts of non-methane hydrocarbons.The difference in the bubbles＇ composition is a possible consequence of gas exchange during bubble ascent.The seepage gases from the seafloor are characterized by a high CO_2 content（67.35%） and relatively positive δ^（13）C_（V_PDB） values（-0.49×10^（-3）-0.86×10^（-3））,indicating that the CO_2 is of inorganic origin.The relatively low CH_4 content（23%） and their negative δ^（13）C_（V-PDB） values（-34.43×10^（-3）--37.53×10^（-3）） and high ratios of C_1 content to C_（1-5） one（0.98-0.99）as well point to thermogenic gases.The hydrocarbon seeps on the 3.5 Hz sub-bottom profile display a linear arrangement and are sub-parallel to the No.1 fault,suggesting that the hydrocarbon seeps may be associated with fracture activity or weak zones and that the seepage gases migrate laterally from the central depression of the Yinggehai Basin.

Cold Seeps Associated with Structured Benthic Communities: More Accurate Identification and Evaluation Using a New Multibeam Survey Methodology in the Offshore Southern Colombian Caribbean

A new methodology was developed to identify cold seeps and structured benthic communities associated, which was applied for the first time in the offshore southern Colombian Caribbean. The integral method consists on a new processing of double-coverage (200%) high-resolution backscatter data combined with bathymetric information;validation was done correlating identified gas plumes, seabed cores and drift camera surveys. Results showed that the elimination of artefacts and the increased signal of the backscatter data allowed accurate plotting of seep boundaries and categorization of seeps into an activity catalogue, with more than 200 seeps identified. Most seeps have chemosynthetic communities associated and data analysis from a previous survey showed two ridges with hard ground as the only possible areas for the development the of deep- water corals. Seep results were compared with designated Areas of Significance for Biodiversity (ASB) identifying seeps both within and outside the ASBs, and showing that the presence of seeps and chemosynthetic communities associated were driven more by geological processes than for big-scale seabed morphology, since they were found in both plains and ridges. This methodology allows an accurate seabed map of structured benthic communities, which may work as a precise geo-hazard map to ensure the oil & gas industry can avoid these areas of shallow gas for further developments, and as a map of deep-water structured benthic communities with environmental significance.

An examination by GC×GC-TOFMS of organic molecules present inhighly degraded oils emerging from Caribbean terrestrial seeps of Cretaceous age

For our ancestors, oil seeps were both a fascination and a resource but as the planet's reserves of high quality low density oil becomes increasingly depleted, so there is now a renewed interest in heavier,biodegraded oils such as those encountered in terrestrial seeps. One such seep is Pitch Lake in the Caribbean island of Trinidad, which is the largest natural deposit of asphalt in the world. At the northern end of the Caribbean, oil emerges along a tectonic contact on the island on Cuba. The sources of the oils from these seeps are relatively recent and both are subject to intense weathering due to the tropical conditions. When analysed by gas chromatography(GC) both oils appear as unresolved complex mixtures(UCM) and show a very high degree of biodegradation thus presenting an analytical challenge. In this case study, these two Caribbean seep oils were analysed by comprehensive two dimensional GC with time of flight mass spectrometry(GC×GC-TOFMS) to expose many thousands of the individual compounds that comprise the UCM. The high chromatographic resolution of the GC×GC-TOFMS produced good quality mass spectra allowing many compounds including molecular fossil ‘biomarkers' to be identified. Compound classes included diamondoid hydrocarbons, demethylated hopanes and secohopanes, mono-and tri-aromatic steroids. D-ring aromatised structures of the 8,14-seco-hopanes,including demethylated forms were present in both oils but further demethylation, probably at position C-25 during biodegradation, was only observed in the Pitch Lake oil. Many polycyclic aromatic hydrocarbons(PAHs) were absent although the fungal-derived pentacyclic PAH perylene was present in both oils. The presence of the angiosperm biomarker lupane in the Pitch Lake oil constrained the age to the Late Cretaceous. The higher degree of biodegradation observed in the Cuban oil was likely due to relatively slow anaerobic processes whereas oil within Pitch Lake was probably subject to additional more rapid aerobic metabolism within the lake.

Multi-beam and seismic investigations of the active Haima cold seeps,northwestern South China Sea

To confirm the seabed fluid flow at the Haima cold seeps,an integrated study of multi-beam and seismic data reveals the morphology and fate of four bubble plumes and investigates the detailed subsurface structure of the active seepage area.The shapes of bubble plumes are not constant and influenced by the northeastward bottom currents,but the water depth where these bubble plumes disappear(630–650 m below the sea level)(mbsl)is very close to the upper limit of the gas hydrate stability zone in the water column(620 m below the sea level),as calculated from the CTD data within the study area,supporting the“hydrate skin”hypothesis.Gas chimneys directly below the bottom simulating reflectors,found at most sites,are speculated as essential pathways for both thermogenic gas and biogenic gas migrating from deep formations to the gas hydrate stability zone.The fracture network on the top of the basement uplift may be heavily gas-charged,which accounts for the chimney with several kilometers in diameter(beneath Plumes B and C).The much smaller gas chimney(beneath Plume D)may stem from gas saturated localized strong permeability zone.High-resolution seismic profiles reveal pipe-like structures,characterized by stacked localized amplitude anomalies,just beneath all the plumes,which act as the fluid conduits conveying gas from the gas hydrate-bearing sediments to the seafloor,feeding the gas plumes.The differences between these pipe-like structures indicate the dynamic process of gas seepage,which may be controlled by the build-up and dissipation of pore pressure.The 3D seismic data show high saturated gas hydrates with high RMS amplitude tend to cluster on the periphery of the gas chimney.Understanding the fluid migration and hydrate accumulation pattern of the Haima cold seeps can aid in the further exploration and study on the dynamic gas hydrate system in the South China Sea.

由改进的BSW模型研究SEEPS嵌段共聚物的动态黏弹行为

研究了苯乙烯-[乙烯-(乙烯-丙烯)]-苯乙烯嵌段共聚物(SEEPS)熔体的黏弹行为,求解了一些特征黏弹参数.并用改进的BSW模型模拟了松弛时间谱,给出了弹性体SEEPS最长的松弛时间(τmax).用时温叠加原理得到的储能模量(G′)-频率(ω)曲线在低ω区域出现了明显的“第二平台”.我们认为,平台的出现是由于SEEPS长链分子缠结所致.其中,PS硬段为缠结点,对大分子链的运动产生拓扑限制作用.同时研究结果还表明,可用WLF方程和Arrhenius方程很好地模拟移动因子(αT)随温度的变化,黏流活化能(Ea)为127.88kJ/mol.计算得到的平台模量(GN0)为5.646×104Pa,缠结分子量(Me)为49634.

Report of epibenthic macrofauna found from Haima cold seeps and adjacent deep-sea habitats,South China Sea

This work reports on a preliminary taxonomic study of epibenthic macroinvertebrates collected or observed by underwater video at the Haima cold seeps and in adjacent deep-sea habitats,including a mud volcano feld and Ganquan Plateau,during an expedition in the South China Sea by the Chinese-manned submersible Shenhai Yongshi in May 2018.A total of 41 species belonging to 6 phyla were identifed,among which 34 species were collected from the Haima cold seeps.Mollusks and crustaceans that are specialized in reducing habitats were predominant in biotopes of the Haima cold seeps,whereas sponges and cold-water corals and their commensals were prominent in communities of the mud volcano feld and the slopes of Ganquan Plateau.The distribution and faunal composition of each taxonomic group are discussed.

Interactions of Microplastics and Methane Seepage in the Deep-Sea Environment

Microplastics(MPs)are important exempla of the Anthropocene and are exerting an increasing impact on Earth’s carbon cycle.The huge imbalance between the MPs floating on the marine surface and those that are estimated to have been introduced into the ocean necessitates a detailed assessment of marine MP sinks.Here,we demonstrate that cold seep sediments,which are characterized by methane fluid seepage and a chemosynthetic ecosystem,effectively capture and accommodate small-scale(<100μm)MPs,with 16 types of MPs being detected.The abundance of MPs in the surface of the sediment is higher in methane-seepage locations than in non-seepage areas.Methane seepage is beneficial to the accumulation,fragmentation,increased diversity,and aging of MPs.In turn,the rough surfaces of MPs contribute to the sequestration of the electron acceptor ferric oxide,which is associated with the anaerobic oxidation of methane(AOM).The efficiency of the AOM determines whether the seeping methane(which has a greenhouse effect 83 times greater than that of CO_(2)over a 20-year period)can enter the atmosphere,which is important to the global methane cycle,since the deep-sea environment is regarded as the largest methane reservoir associated with natural gas hydrates.

Seismic monitoring of sub-seafloor fluid processes in the Haima cold seep area using an Ocean Bottom Seismometer (OBS)

The use of ocean bottom seismometers provides an effective means of studying the process and the dynamic of cold seeps by continuously recording micro-events produced by sub-seafloor fluid migration.We deployed a four-component Ocean Bottom Seismometer(OBS)at an active site of the Haima cold seep from 6 November to 19 November in 2021.Here,we present the results of this short-term OBS monitoring.We first examine the OBS record manually to distinguish(by their distinctive seismographic signatures)four types of events:shipping noises,vibrations from our remotely operated vehicle(ROV)operations,local earthquakes,and short duration events(SDEs).Only the SDEs are further discussed in this work.Such SDEs are similar to those observed in other sea areas and are interpreted to be correlated with sub-seafloor fluid migration.In the OBS data collected during the 14-day monitoring period.We identify five SDEs.Compared to the SDE occurrence rate observed in other cold seep regions,five events is rather low,from which it could be inferred that fluid migration,and subsequent gas seepage,is not very active at the Haima site.This conclusion agrees with multi-beam and chemical observations at that site.Our observations thus provide further constraint on the seepage activity in this location.This is the first time that cold seep-related SDEs have been identified in the South China Sea,expanding the list of sea areas where SDEs are now linked to cold seep fluid migration.

Interactions among deep-sea mussels and their epibiotic and endosymbiotic chemoautotrophic bacteria: Insights from multi-omics analysis

Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of these mussels suggests that these host-bacterial relationships may be more complex than previously thought. Using the cold-seep mussel(Gigantidas haimaensis) as a model, we explored this hostbacterial system by assembling the host transcriptome and genomes of its epibiotic Campylobacteria and endosymbiotic Gammaproteobacteria and quantifying their gene and protein expression levels. We found that the epibiont applies a sulfur oxidizing(SOX)multienzyme complex with the acquisition of sox B from Gammaproteobacteria for energy production and switched from a reductive tricarboxylic acid (rTCA) cycle to a Calvin-Benson-Bassham(CBB)cycle for carbon assimilation. The host provides metabolic intermediates, inorganic carbon, and thiosulfate to satisfy the materials and energy requirements of the epibiont, but whether the epibiont benefits the host is unclear. The endosymbiont adopts methane oxidation and the ribulose monophosphate pathway(Ru MP) for energy production, providing the major source of energy for itself and the host. The host obtains most of its nutrients, such as lysine, glutamine, valine,isoleucine, leucine, histidine, and folate, from the endosymbiont. In addition, host pattern recognition receptors, including toll-like receptors, peptidoglycan recognition proteins, and C-type lectins, may participate in bacterial infection, maintenance, and population regulation. Overall, this study provides insights into the complex host-bacterial relationships that have enabled mussels and bacteria to thrive in deep-sea chemosynthetic ecosystems.

Discovery of prenylated indole alkaloid and natural xanthone from cold-seep sediment derived fungus Talaromyces funiculosus SD-523

A new prenylated indole alkaloid 11,17-epi-mangrovamide A(1),a new natural occurring product,1,7-dihydroxy-6-methyl-8-hydroxymethyl-xanthone(2),two known alkaloids,mangrovamide A(3)and mangrovamide G(4),and four known polyketide derivatives(5–8)were isolated and identified from the cold-seep sediment derived fungal strain Talaromyces funiculosus SD-523.Their structures were elucidated by combination of nuclear magnetic resonance(NMR),high resolution electrospray ionization mass spectroscopy(HRESIMS),quantum chemical electronic circular dichroism(ECD),and DP4+probability analysis as well as by comparison of the data with literature reports.All isolated compounds were tested for antibacterial activities.

Quantitative estimation of bubble volume fraction of submarine seep plumes by modeling seismic oceanography data

Submarine seep plumes are a natural phenomenon in which different types of gases migrate through deep or shallow subsurface sediments and leak into seawater in pressure gradient.When detected using acoustic data,the leaked gases frequently exhibit a flame-like structure.We numerically modelled the relationship between the seismic response characteristic and bubble volume fraction to establish the bubble volume fraction in the submarine seep plume.Results show that our models are able to invert and predict the bubble volume fraction from field seismic oceanography data,by which synthetic seismic sections in different dominant frequencies could be numerically simulated,seismic attribute sections(e.g.,instantaneous amplitude,instantaneous frequency,and instantaneous phase)extracted,and the correlation between the seismic attributes and bubble volume fraction be quantitatively determined with functional equations.The instantaneous amplitude is positively correlated with bubble volume fraction,while the instantaneous frequency and bubble volume fraction are negatively correlated.In addition,information entropy is introduced as a proxy to quantify the relationship between the instantaneous phase and bubble volume fraction.As the bubble volume fraction increases,the information entropy of the instantaneous phase increases rapidly at the beginning,followed by a slight upward trend,and finally stabilizes.Therefore,under optimal noise conditions,the bubble volume fraction of submarine seep plumes can be inverted and predicted based on seismic response characteristics in terms of seismic attributes.

Mg/Ca,Ba/Ca,and S/Ca ratios as environmental and growth proxies for bivalve shells from the Haima cold seep,South China Sea

Bivalve shell fossils,cemented by authigenic carbonates,are widely spread in the Haima cold seep,Qiongdongnan Basin of the South China Sea(SCS).In this study,we examined an element profile of Gigantidas platifrons in the Haima cold seeps at a water depth of 1381 m.Based on the scanning electron microscope(SEM)analyses,the prismatic layer and nacreous layer were identified,which are characterized by prismatic structure and stratified structure,respectively.In addition,the profile can be subdivided into two parts:altered and unaltered zones.Laser inductively coupled plasma mass spectrometry(LA-ICP-MS)mapping shows that the element concentrations of the altered zones were influenced by the authigenic carbonate rocks,whereas the element concentrations of unaltered zones remain stable.In-situ X-ray diffraction(XRD)analyses show that the mineral constituent of the prismatic layer is mainly composed of aragonite.Along with the growth profile,Mg/Ca ratios of unaltered zones have minor variations,ranging 0.72-0.97 mmol/mol(mean=0.87 mmol/mol),with estimated temperatures of 3.8-4.1℃,indicating that the temperature of the surrounding seawater remains constant and agree with the measured data of 3.9℃which was conducted by a conductivity-temperature-depth system(CTD).The minor variations of Ba/Ca ratios(0.01-0.06 mmol/mol;mean=0.04 mmol/mol)indicate a relatively stabilized salinity of the surrounding seawater.S/Ca ratios show large variations of 0.04-4.15 mmol/mol(mean=1.37 mmol/mol).S/Ca ratios have regular variations which generally correspond to the variations of the Mg/Ca ratios,highlighting that the S/Ca ratios of bivalve shells show the potential to reflect the growth rate of the Gigantides.However,further studies should be carried out on the understanding of the links between the S/Ca ratios and seepage intensity of cold-seep fluids.

电针刺激脊髓损伤患者穴位的脊髓磁共振功能成像激活区特征

背景:研究发现脊髓功能激活区域和电生理等理论对应区域相一致,多数学者认为使用功能磁共振技术检测脊髓神经功能是可行的。目的:检测电针刺激脊髓损伤患者的脊髓磁共振功能成像激活区特征,验证使用脊髓磁共振功能成像技术来客观评价针灸治疗脊髓损伤疗效的可行性。方法:使用电针同时刺激3例脊髓损伤患者和5名健康志愿者的右手合谷穴和曲池穴,采用组块设计方法,使用SPM2软件得到患者和健康志愿者脊髓内真实的激活区,分析激活区在矢状位和横断位上的分布特征,并与健康志愿者的激活分布对比,找出患者的激活分布差异。结果与结论:5名健康志愿者在脊柱C2、C5段均重复出现激活信号,在C6段4名出现激活;3例脊髓损伤患者在脊柱C2,C6段均出现均重复出现激活,其中1例患者与健康志愿者激活分布特征基本一致。可以观察到针灸刺激脊髓损伤患者的脊髓功能激活,因此可以根据功能激活区的分布及强度,在一定程度上客观评价针灸治疗脊髓损伤的疗效。

Seep/w在坝基墙幕结合防渗体系结构优化中的应用

在墙幕结合的防渗体系中,上部防渗墙和下部帷幕灌浆的结构尺寸大多是凭经验取得的.文章主要从工程防渗效果及安全性、经济性等方面出发,应用渗流有限元数值模拟软件Seep/w,采用图解最大梯度法,对墙接幕防渗体系的结构尺寸进行优化,得出既能满足防渗要求,又能确保工程安全、经济的最优化深度.

基于SEEP/W的吊江岩水电站闸坝渗流稳定分析

针对吊江岩水电站首部枢纽布置和闸址处河床覆盖层复杂的地质条件,采用SEEP/W软件对闸基进行了渗流稳定性分析。结果表明,设计防渗体系是合理可行的,为闸坝稳定性提供科学依据。

四川理县欢喜村冰水堆积体降雨条件下变形机理研究

四川理县欢喜村具有干暖河谷气候特征,降雨量少、蒸发量大,冰水堆积体在降雨作用下的变形特征及机理与以往降雨型滑坡有较大差异。通过水土化学试验、矿物成分检测、电镜扫描(SEM)、降雨模拟-现场中剪试验等手段查明冰水堆积物遇水结构损伤机理,以及由此引起的强度衰减特征及幅度,在此基础上,采用SEEP/W模块分析堆积体降雨条件下地下水浸润、饱和特征及孔隙水压力变化趋势,结合地质环境条件归纳总结堆积体变形机理及过程。研究表明:冰水堆积物遇水后,细粒组分内矿物(以石膏为主)溶解、颗粒重排列共同导致充填细粒土结构弱化、损伤,进一步发展促使大颗粒间相互作用程度减弱,加之粒间水的润滑、软化最终引起土体整体强度大幅度衰减,其中c值降低20.6%,φ值降低34.1%,c值下降幅度弱于φ值;此外,研究区特殊的地质环境条件导致缓坡段降雨入渗效果优于陡坡段,饱和时间、范围、深度的不同形成土体强度差异变化,加之前缘良好的临空条件,导致坡体近前缘端表层易朝临空方向产生蠕滑变形,变形体后缘形成拉张裂缝,并为降雨入渗提供通道,多次降雨-蠕滑变形累积作用使变形体前缘锁固段减小,形成失稳破坏。