Late Cretaceous non-avian dinosaurs from the James Ross Basin,Antarctica:description of new material,updated synthesis,biostratigraphy,and paleobiogeography

Although the fossil record of non-avian dinosaurs from the Cretaceous of Antarctica is the poorest of any continent,fossils representing at least five major taxonomic groups(Ankylosauria,early-diverging Ornithopoda,Hadrosauridae,Titanosauria,and Theropoda)have been recovered.All come from Upper Cretaceous(Coniacian–Maastrichtian)marine and nearshore deposits belonging to the Gustav and Marambio groups of the James Ross Basin at the northern tip of the Antarctic Peninsula.The majority of these finds have come from the Campanian–Maastrichtian Snow Hill Island and López de Bertodano formations of James Ross and Vega islands.Given the rarity of Antarctic Cretaceous non-avian dinosaurs,discoveries of any fossils of these archosaurs,no matter how meager,are of significance.Here we describe fragmentary new ornithischian(ankylosaur and ornithopod)material from the upper Campanian–lower Maastrichtian Cape Lamb Member of the Snow Hill Island Formation and the Maastrichtian Sandwich Bluff Member of the López de Bertodano Formation.One of these specimens is considered to probably pertain to the holotypic individual of the early-diverging ornithopod Morrosaurus antarcticus.We also provide an up-to-date synthesis of the Late Cretaceous non-avian dinosaur record of the James Ross Basin and analyze the biostratigraphic occurrences of the various finds,demonstrating that most(including all named taxa and all reasonably complete skeletons discovered to date)occur within a relatively condensed temporal interval of the late Campanian to early Maastrichtian.Most or all James Ross Basin dinosaurs share close affinities with penecontemporaneous taxa from Patagonia,indicating that at least some continental vertebrates could disperse between southern South America and Antarctica during the final stages of the Mesozoic.

Corrosion resistance of Mg-Al-LDH steam coating on AZ80 Mg alloy:Effects of citric acid pretreatment and intermetallic compounds

In this study,the effects of intermetallic compounds(Mg_(17)Al_(12)and Al_(8)Mn_(5))on the Mg-Al layered double hydroxide(LDH)formation mechanism and corrosion behavior of an in-situ LDH/Mg(OH)_(2)steam coatings on AZ80 Mg alloy were investigated.Citric acid(CA)was used to activate the alloy surface during the pretreatment process.The alloy was first pretreated with CA and then subjected to a hydrothermal process using ultrapure water to produce Mg-Al-LDH/Mg(OH)_(2)steam coating.The effect of different time of acid pretreatment on the activation of the intermetallic compounds was investigated.The microstructure and elemental composition of the obtained coatings were analyzed using FE-SEM,EDS,XRD and FT-IR.The corrosion resistance of the coated samples was evaluated using different techniques,i.e.,potentiodynamic polarization(PDP),electrochemical impedance spectrum(EIS)and hydrogen evolution test.The results indicated that the CA pretreatment significantly influenced the activity of the alloy surface by exposing the intermetallic compounds.The surface area fraction of Mg_(17)Al_(12)and Al_(8)Mn_(5)phases on the surface of the alloy was significantly higher after the CA pretreatment,and thus promoted the growth of the subsequent Mg-Al-LDH coatings.The CA pretreatment for 30 s resulted in a denser and thicker LDH coating.Increase in the CA pretreatment time significantly led to the improvement in corrosion resistance of the coated AZ80 alloy.The corrosion current density of the coated alloy was lower by three orders of magnitude as compared to the uncoated alloy.

Analyzing environmental flow supply in the semi-arid area through integrating drought analysis and optimal operation of reservoir

This study proposes a novel form of environmental reservoir operation through integrating environmental flow supply,drought analysis,and evolutionary optimization.This study demonstrates that simultaneous supply of downstream environmental flow of reservoir as well as water demand is challenging in the semi-arid area especially in dry years.In this study,water supply and environmental flow supply were 40%and 30%in the droughts,respectively.Moreover,mean errors of supplying water demand as well as environmental flow in dry years were 6 and 9 m3/s,respectively.Hence,these results highlight that ecological stresses of the downstream aquatic habitats as well as water supply loss are considerably escalated in dry years,which implies even using environmental optimal operation is not able to protect downstream aquatic habitats properly in the severe droughts.Moreover,available storage in reservoir will be remarkably reduced(averagely more than 30×106 m3 compared with optimal storage equal to 70×106 m3),which implies strategic storage of reservoir might be threatened.Among used evolutionary algorithms,particle swarm optimization(PSO)was selected as the best algorithm for solving the novel proposed objective function.The significance of this study is to propose a novel objective function to optimize reservoir operation in which environmental flow supply is directly addressed and integrated with drought analysis.This novel form of optimization system can overcome uncertainties of the conventional objective function due to considering environmental flow in the objective function as well as drought analysis in the context of reservoir operation especially applicable in semi-arid areas.The results indicate that using either other water resources for water supply or reducing water demand is the only solution for managing downstream ecological impacts of the river ecosystem.In other words,the results highlighted that replanning of water resources in the study area is necessary.Replacing the conventional optimization system for reservoir operation in the semi-arid area with proposed optimization system is recommendable to minimize the negotiations between stakeholders and environmental managers.

Enabling high-efficiency ethanol oxidation on NiFe-LDH via deprotonation promotion and absorption inhibition

Nucleophile oxidation reaction(NOR), represented by ethanol oxidation reaction(EOR), is a promising pathway to replace oxygen evolution reaction(OER). EOR can effectively reduce the driving voltage of hydrogen production in direct water splitting. In this work, large current and high efficiency of EOR on a Ni, Fe layered double hydroxide(NiFe-LDH) catalyst were simultaneously achieved by a facile fluorination strategy. F in NiFe-LDH can reduce the activation energy of the dehydrogenation reaction, thus promoting the deprotonation process of NiFe-LDH to achieve a lower EOR onset potential. It also weakens the absorption of OH-and nucleophile electrooxidation products on the surface of NiFe-LDH at a higher potential, achieving a high current density and EOR selectivity, according to density functional theory calculations. Based on our experiment results, the optimized fluorinated NiFe-LDH catalyst achieves a low potential of 1.386 V to deliver a 10 mA cm^(-2)EOR. Moreover, the Faraday efficiency is greater than 95%, with a current density ranging from 10 to 250 mA cm^(-2). This work provides a promising pathway for an efficient and cost-effective NOR catalyst design for economic hydrogen production.

不同加氧处理对超级稻种子萌发和幼苗农艺性状的影响

对超级稻Y两优1号种子进行不同加氧(机械加氧、化学加氧和电解加氧)实验,结果发现:种子的发芽率、发芽势、发芽速率、发芽指数、活力指数以及整齐度、壮苗指数均有不同程度的升高。低频次的电解加氧处理的发芽率为93%;发芽势为40%;发芽指数为97.77;活力指数为1 061.76;整齐度为91%等指标均优于其他处理,低频次的机械加氧处理的壮苗指数为0.927优于其他处理,说明低频次电解加氧处理对超级稻种子萌发是最佳的加氧处理,低频次机械加氧处理对超级稻幼苗生长是最佳的加氧处理。

增氧灌溉对大棚秋黄瓜生长特性的影响研究

在不同输气灌溉条件下,对大棚秋黄瓜的产量及其发育过程中叶片的生理生化特性进行了比较研究。结果表明,1天3次和1次的输气处理与对照相比,秋黄瓜的产量分别增加30.38%和43.02%,在不同的生育阶段叶片的叶绿素、可溶性蛋白质和可溶性糖的质量分数均有不同程度的增加,叶片的光合速率得到显著增强。输气灌溉促进了秋黄瓜植株的生长,增强了植株根茎叶的整体功能,提高了结实率,最终使得秋黄瓜的产量得到显著增加。

安徽西冲钼矿床细粒花岗岩的岩石定年、岩石化学及与成矿的关系研究

西冲钼矿是大别成矿带东段近年新发现的斑岩型钼-多金属矿床,其矿床学和矿床地球化学研究少见报导。该研究成果丰富了我国斑岩-矽卡岩型钼钨-多金属矿床研究成果,同时对指导区域找矿具有一定意义。本文在详细的野外地质调研基础上,对大别成矿带西冲钼矿区出露的主要岩石单元、矿化和蚀变特征、细粒花岗岩的岩石学、岩石化学和成岩年代学进行了系统的研究。结果表明,矿区出露的主要侵入岩单元由老至新依次为:石英二长岩、细粒花岗岩(130.8±1.1Ma)及双峰式脉岩组合(131.9±1.4Ma和131.3±1.6Ma),其均为燕山期岩浆活动产物,产于华北与扬子陆块拼合后的陆内环境。矿化类型以脉状、网脉状和浸染状为主,为一斑岩型钼-多金属矿床。矿区蚀变发育,包括黑云母-磁铁矿化、钾长石化、硅化、石英-绢云母化、石英-绿帘石化、绿泥石-碳酸盐化和泥化,且空间上具有一定的分带规律。矿区已知矿化、蚀变及Cu-Mo化探异常的空间展布与细粒花岗岩关系密切,且细粒花岗岩中具有高的Mo含量,表明该矿床的形成主要与细粒花岗岩有关。岩石化学结果表明,细粒花岗岩属过铝质-准铝质、高钾钙碱性-钾玄质过渡岩石,锆石U-Pb年龄与双峰式脉岩的在误差范围内一致,表明其均形成于大别造山带大规模伸展背景。

云南个旧卡房蚀变玄武岩金云母^(40)Ar-^(39)Ar同位素年龄研究及意义

云南个旧锡铜多金属矿床是世界级超大型矿床,个旧矿集区内与蚀变玄武岩有关的(似)层状铜矿床是其重要的矿床类型。该类型矿床的围岩玄武岩均发生蚀变,且蚀变强度与矿化关系密切。本文对个旧卡房矿化玄武岩中的金云母进行40Ar-39Ar同位素定年分析,得到其坪年龄为(85.49±0.63)Ma,等时线年龄为(85.62±0.42)Ma,反等时线年龄为(85.59±0.81)Ma,三者基本一致,代表了变玄武岩的蚀变年龄及同期矿化年龄,属于晚白垩世,可与个旧锡铜多金属矿床的成矿时代进行对比。

贵州遵义牛蹄塘组黑色岩系有机质的稀土元素地球化学研究

以贵州遵义寒武纪初牛蹄塘组黑色岩系的有机质为分析对象，对22个样品的稀土元素（REE）组成进行了研究，结果表明：①有机质的ΣREE占全岩ΣREE的10%左右，且其REE标准化配分曲线不同于全岩的。由于有机质主要来自海洋上层水体中的微生物，因而可以认为其REE特征代表的是古海洋上层水体的稀土元素组成特征；②有机质的REE总量变化于11.6×10＆-6-548×10＆-6之间，Ce异常系数变化于0.40-0.92之间，Eu异常系数变化于0.59-1.14之间。有机质的Ce异常系数和LaN/CeN值在剖面上显示明显的变化，指示研究区经历了大陆斜坡到大洋盆地再到大陆边缘的环境，指示在寒武纪初存在一次海侵。

磨粒的三维表面特征描述

介绍了三维表面粗糙度参数和表面纹理指数,采用三维表面高度偏差Sa、均方根Sq、表面斜度Ssk、表面峭度Sku等粗糙度参数和表面纹理指数Stdi描述磨粒的三维表面特征,选用油液分析获得磨粒,对其表面特征进行实例分析.结果表明,运用上述参数能够很好区分不同类型的磨粒表面特征.

增氧灌溉对秋黄瓜种子萌发及幼苗生长的影响

以大棚秋黄瓜为研究对象,采用大棚盆栽试验,设3个处理,处理1(T1)为早中晚三次增氧灌溉,处理2(T2)早上一次增氧灌溉,处理3(CK)为对照组(不增氧),研究探明增氧灌溉处理对大棚秋黄瓜种子萌发及幼苗生长的影响。各处理均采用调亏灌溉,常规施肥与管理,主要研究结果为:第3d高峰发芽速率T1、T2分别高出CK27.50%和26.25%,发芽势T1、T2分别高出CK 10.18%和9.72%,第7d发芽率T1、T2分别高出CK 9.72%和4.16%、发芽指数T1、T2分别高出CK 18.15%和14.18%,活力指数T1、T2分别高出CK 27.73%和22.06%,发芽整齐度T1、T2分别高出CK 36.04%和3.55%。因此,增氧对大棚秋黄瓜种子的种子发芽力指标、种子活力指标以及发芽整齐度均有显著影响。

一例并殖吸虫病患者的虫卵DNA序列分析鉴定(英文)

[目的 ]运用分子生物学技术分析虫卵基因序列鉴定并殖吸虫病类型。 [方法 ]先从并殖吸虫病患者痰中分离出虫卵 ,然后PCR扩增出虫卵中完整的核糖体DNA第二间隔区基因 (ITS2 ) ,并直接用于测序从而获得该基因的核苷酸序列。同时 ,亦用同法分别从动物宿主粪便中分离出的卫氏并殖吸虫和斯氏狸殖吸虫虫卵中获得ITS2基因序列作为DNA参照分析。此外 ,本文也对从患者痰中分离出的虫卵进行详细的形态学特征描述分析。 [结果 ]来自患者的虫卵ITS2基因序列与参照的卫氏并殖吸虫虫卵的基因序列 10 0 %一致 ,而与来自斯氏狸殖吸虫虫卵的基因序列只有 92 %核苷酸相同。此外 ,从形态学上讲 ,来自患者的虫卵形态特征更与卫氏并殖吸虫虫卵相似。 [结论 ]通过基因序列分析 ,可确诊患者所患的是卫氏并殖吸虫病。

关于第14届材料磨损国际会议的简要评述

对第14届材料磨损会议重点涉及的生物摩擦学、金属磨损、表面涂层、冲蚀、纳米摩擦学、复合材料以及磨损监测等研究领域的最新进展进行了评述,对摩擦学领域今后的研究重点进行了展望.

中国珊瑚藻的多样性及分布研究现状

珊瑚藻是海洋生态系统中一类重要的钙化红藻,且具有海洋初级生产力和生态服务功能,已经成为当前热点研究生物之一。目前,世界各国有关珊瑚藻的种类、分布等正在逐渐明晰,而我国海域珊瑚藻的分布研究尚属空白,许多种类的多样性信息也需要更新。中国珊瑚藻本底信息的匮乏也阻碍了我国在各个层面上开展珊瑚藻研究与保护工作。为此,文章对中国海域珊瑚藻种类和分布现状进行了汇总与分析。结果表明,中国现有珊瑚藻种类记录162种,合并同物异名种后共计112种,隶属于10科26属,约占全球珊瑚藻种类数的15%;其中大陆有79种,台湾岛66种,香港10种。我国珊瑚藻的分布从渤海到南海均有分布,呈现出明显的热带与亚热带分布特征;其中辽宁、山东、浙江、福建、广东和香港海域记载较少(<20种),而台湾岛、海南岛和三沙海域则较多(>30种)。研究能为明确我国珊瑚藻的种类、数量及分布特征等方面提供良好的参考资料。

增氧灌溉对秋黄瓜根系生理生化特性的影响研究

以秋黄瓜为研究对象,采用增氧灌溉技术和大棚盆栽试验,研究了增氧灌溉对大棚秋黄瓜根系生理生化特性的影响。结果表明,不同处理(T1:早中晚3次增氧灌溉,T2:早上1次增氧灌溉)对秋黄瓜根系生理生化指标均有显著影响,从幼苗期到结瓜期,根系活力表现为T1处理>T2处理>CK;结瓜末期,根系中过氧化氢酶活性、脱落酸、可溶性蛋白表现为T1处理>T2处理>CK,可溶性糖表现为CK>T2处理>T1处理;相关分析表明,增氧灌溉大棚秋黄瓜结瓜末期根系生理特征指标具有较高的相关性,过氧化氢酶、可溶性蛋白、脱落酸和根系活力之间显著正相关,可溶性糖与过氧化氢酶、脱落酸、根系活力之间显著负相关;通径分析表明,增氧灌溉条件下,根系中过氧化氢酶(X1)对根系活力(y)的直接影响最大,且与可溶性蛋白质(X3)、脱落酸(X4)对根系活力均有决定性的正向作用;可溶性糖(X2)对根系活力的直接负影响最大,对根系活力有决定性的负向作用。

侧加热腔体内重力波演化过程的数值模拟

利用二维数值模拟的方法研究了侧加热腔体内的自然对流．基于数值模拟结果,描述了水平热入侵流(intrusion)的整个演化过程,并对该过程的物理机制进行了讨论．结果表明：当热入侵流抵达腔体冷壁后,由于冷壁无法卷入所有的热入侵流,热入侵流在冷上角堆积并产生一个反向流动,在冷壁边界层附近形成一个顺时针涡,该涡在浮力效应驱动下可返回热壁,并在腔体的冷热壁之间形成了腔体尺度的流体振荡,即内重力波．

基于激光共焦扫描显微镜方法的磨损表面三维数字化描述

表面形貌的精确描述在许多领域诸如材料、生物医学、摩擦学和机器状态监测等领域变得越来越重要。开发了一种基于激光共焦显微镜和图像处理技术的研究磨损表面及表面参数的新方法。首先用B io-rad Rad iance 2000激光共焦显微镜方法获得精确的三维表面形貌,然后用计算机辅助图像分析技术自动计算出表面特征参数。应用示例表明本文所研究的方法是可靠的,能对工程表面的表面粗糙度特征进行精确描述。

社会比较对疼痛应对及耐力的影响

目的:探讨社会比较对疼痛耐力及疼痛应对策略使用频率的影响。方法:113名女性被试随机分为上行组(39名),对照组(37名)和下行组(37名),进行两次冷痛实验。实验结束后,所有被试者均填写疼痛强度量表和应对策略问卷。在第一次冷痛结束后,上行组和下行组予以社会比较。结果:社会比较后,上行组和下行组的疼痛耐力显著高于对照组;在疼痛应对策略中,上行组使用积极应对策略(分心、自我鼓励和忽视)的频率高于对照组(P<0.05);下行组灾难化得分显著低于对照组(P<0.05)。但痛觉强度上没有存在组间差异。结论:上行比较会通过提高积极应对策略,提高疼痛耐力;下行比较会通过降低消极应对策略,提高疼痛耐力。多种因素共同影响着疼痛。

威胁性疼痛认知评价对接受应对策略效果的影响

目的:本研究探讨接受策略是否有助于提高个体的疼痛忍受能力,其效果是否会受到威胁性疼痛认知的削弱。方法:实验采用2×2的被试间设计,因素一为疼痛认知评价(威胁性认知/安全性认知),因素二为策略使用类型(接受/无策略)。101名健康被试被随机分到四个组,共接受两次受冷测试(the cold pressor task,CPT),测量指标包括疼痛忍耐时间,疼痛强度和应对策略的使用频率。结果:接受策略-安全性认知组的第二次CPT疼痛忍耐时间及疼痛忍耐值显著高于无策略-安全性认知组和无策略-威胁性认知组。但是在威胁性认知条件下,接受策略组的第二次CPT疼痛忍耐时间以及忍耐提高值低于接受策略-安全认知组。并且仅显著高于无策略-安全认知组。接受策略-威胁性认知组使用接受策略的频率显著低于接受策略-安全性认知组。结论:研究表明接受策略有助于提高疼痛忍受能力,但是威胁性疼痛认知评价削弱了接受策略在提高疼痛忍耐力和疼痛应对能力上的效果。

澳大利亚水产养殖产地环境管理分析

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