水热法合成掺杂氮多孔碳及其超级电容特性

分别以乙二胺、乙酰胺为氮源采用水热法合成掺氮多孔碳材料,利用X射线衍射、傅里叶红外光谱、扫描电子显微镜、比表面测试等对样品的结构、组成、形貌、比表面积进行了分析和表征,通过循环伏安、恒流充放电对样品的电化学性能进行了测试,探讨了不同氮源对多孔碳材料组成、表面形貌、孔径、比表面积以及电化学性能的影响。通过乙酰胺引入氮源的多孔碳材料表面微观形貌呈蜂窝状的多孔结构,孔的内部相连,比表面积为233.1m2/g,孔径约5.1nm。其孔结构丰富,孔尺寸分布单一。作为超级电容器的电极材料,经恒流充放电测试,比容量为188.7F/g。     

树叶基多孔碳材料的制备及其电化学性能研究

开发了一种简单、经济、环保、利用生物质快速生产具有优良电化学性能的碳材料的方法。利用梧桐树叶作为生物质原料制备多孔碳材料,对其结构、形貌和电化学性能进行分析和测试。结果表明:以梧桐叶为原料,碱碳比为3,活化温度为800℃,活化时间为2 h时,制备的多孔碳材料具有大的BET比表面积,其值为2 178 m2/g,孔径分布为2.5 nm,比电容达到304 F/g。当电流密度由0.25 A/g增加至20 A/g时,样品的容量保持率为82.6%。以树叶为原料制备的多孔碳材料展示出高电容和优异的倍率特性,有望在超级电容器等领域得到重要应用。     

猕猴桃果皮制备杂原子掺杂多孔碳材料及其超电性能研究

果蔬企业在生产过程中会产生大量的果皮,这些废弃物目前还没有得到有效利用。本文以废弃猕猴桃果皮为原料,以氢氧化钾为活化剂,制备了杂原子掺杂多孔碳。通过扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、X射线衍射(XRD)、拉曼光谱(Raman)和氮气吸附-脱附(BET)等手段对制备的材料进行了表征,结果表明:采用果皮预碳化、活化的方法可以得到N、O、S杂原子原位共掺杂多孔碳;经过氢氧化钾活化后,碳材料的比表面积大幅增加,比表面积最高可达1698. 6 m~2/g。在三电极体系下对制备的碳材料超级电容器性能的评价结果表明:在氢氧化钾与猕猴桃果皮质量比1∶3时,电极材料具有最佳的超电性能;在扫描速率为5 m V/s时,材料的比电容为221. 1 F/g,同时具有良好的倍率性能和循环稳定性,经过4000次的长循环后,容量保持率为83. 2%。     

氧化铁负载多孔炭材料的制备及其电化学性能

以杨木蒸汽爆破后的固体残渣(SEP)为原料,采用两步协同活化法制备多孔炭材料,并对制备的多孔炭材料的电化学性能进行分析。结果表明:所制备的多孔炭(PC800-4)的比表面积最高(3 282 m~2/g),首次放电比电容也最高,为319 F/g。以此多孔炭材料为前驱体,硝酸铁为铁源对多孔炭材料进行金属离子的负载。采用比表面积及孔径分析仪、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、拉曼光谱技术(Raman)、X射线光电子能谱仪(XPS)对负载有金属氧化物的多孔炭材料进行结构表征并对其电化学性能进行分析。结果表明:α-Fe_2O_3成功负载在所制备的多孔炭材料上,其比电容由原来的319 F/g增加到419 F/g.     

氮掺杂多孔薄层石墨烯的制备、表征及电容性能研究

以氧化石墨烯(GO)为原料、硫酸铵((NH_4)_2SO_4)为动态气体模板剂,采用浸渍结合焙烧工艺制备了氮掺杂多孔薄层石墨烯(p-Gr).利用扫描电镜(SEM)、透射电镜(TEM)、X-射线衍射(XRD)、X-射线光电子能谱(XPS)、拉曼光谱(Raman)、氮气吸附-脱附(N_2adsorption-desorption)等手段对所得材料进行了表征,并考察了不同硫酸铵用量对所制材料电容性能的影响.结果表明,与未活化的石墨烯(Gr)相比(S_(BET)=70.5m~2/g),所制p-Gr-40具有更大的比表面积(S_(BET)=267.3m~2/g)、更为丰富的孔结构以及优异的电化学性能.在三电极超级电容器中,在电流密度为1A/g时,p-Gr-40比电容可达139.2F/g,远远高于Gr(56.5F/g);在对称两电极超级电容器中,在功率密度为160.03W/kg时,p-Gr-40的能量密度为12.98Wh/kg,其比电容在充放电循环10 000圈后仍保持基本不变.这些优异的电化学性能源于其多孔结构及杂原子(如氮)掺杂.     

氮掺杂层次孔碳纳米材料的合成及其电化学储能

为了制备性能优良的电化学储能电极材料,利用分子自组装技术,将甲基丙烯酸甲酯和丙烯腈聚合后的产物进行碳化和活化,得到具有大孔、介孔和微孔的氮杂层次孔碳纳米材料.分别采用扫描电镜、透射电镜、氮气吸附脱附、X线光电子能谱、恒流充放电、循环伏安及交流阻抗等测试方法和手段对材料的形貌、结构及电容性能进行表征.实验结果表明:所得氮杂孔碳纳米材料比表面积为698 m~2/g,孔容为0.42 cm~3/g.在电流密度为0.2 A/g时,该材料比电容量为241.9 F/g,且具有较好的循环稳定性,在2 A/g下循环5 000圈后,比电容值仍能保持在初始容量的93.6%.将其组装为对称超级电容器,能量密度和功率密度分别达到19.6 W·h/kg和200 W/kg,高于目前一些商业化的电容器数值,说明该氮杂层次孔碳纳米材料在超级电容器方面展示出很好的应用前景.     

氮磷共掺杂三维石墨烯的制备及其电化学性能的研究

有机元素共掺杂能有效改善碳材料的电容性能。通过氮、磷共掺杂合成三维石墨烯(N/P-G)电极材料。通过XRD、SEM、TEM、XPS等对样品微观结构和表面物性进行表征。结果表明,当掺杂氮含量为7.03%,磷含量为4.62%,所合成N/P-G的比表面积可达156.138 m2·g-1,其平均孔径为4.45 nm,同时具有三维多孔结构。电化学性能研究表明,在1 A·g-1电流密度下比电容高达145.4 F·g-1,在16 A·g-1电流下比电容仍可保持100.8 F·g-1。所制备的氮磷共掺杂石墨烯作为电极材料可以应用于超级电容器中,前良好。     

离子液体溶解法制备超级电容碳及其电化学性能研究

文章以高纤维素废纸屑为原料，利用无机离子液体进行选择性表面溶解处理，得到具有润胀特性的胶状前驱体，在不同温度条件下热解制备生物质多孔碳。800℃下生物质多孔碳比表面积为1 276.3 m²/g,电化学测试结果表明，其具有较高的比电容(271 F/g),经过1 000次循环，电容保持率为90.3%。为了进一步提升超级电容器的电化学性能，在1 mol/L H₂SO₄电解液中加入15 g (NH₄)₂Fe(SO₄)₂·6H₂O,超级电容器的比电容得到显著提升，电流密度为10 A/g时，比电容为439 F/g,为原电容器(221 F/g)的2倍。研究结果可为生物质多孔碳超级电容器制备提供参考。     

NiCo2O4/RGO复合材料的制备及其电化学性能

采用两步水热法制备NiCo₂O₄/RGO复合材料,并对其电化学性能进行研究.研究结果表明,当电流密度为1 A/g时,NiCo₂O₄/RGO复合材料的比电容高达2 332.40 F/g,约是NiCo₂O₄材料的3倍,当电流密度增加至10 A/g时,其比电容还能保持为1 127.22 F/g,表现出优异的倍率性能.这归因于复合材料特殊的多孔蓬松结构,有效增加了材料的比表面积,NiCo₂O₄的比表面积为56.488 0 cm²/g,而NiCo₂O₄/RGO复合材料的比表面积高达188.604 2 cm²/g,能够提供更多的反应活性位点,同时RGO能够有效提高材料的导电性,两者之间的协同作用使得电化学性能大幅提升.     

MnO@CoMn_2O_4/N-C纳米线复合材料的制备及其作为锂离子电池阳极材料的电化学性能

过渡金属氧化物作为锂离子电池(lithium-ion batteries,LIBs)阳极材料时具有较高的理论容量,但因其电导率低,以及充放电过程中的体积膨胀效应常会导致容量的快速衰减.碳包覆是提升金属氧化物导电性的有效方法,二者之间的协同效应也可以有效提升材料的电化学性能.以MnO_2纳米线为模板制备出MnO_2@ZIF-67有机-无机杂化纳米结构,再通过退火处理合成了氮掺杂碳包覆的MnO@CoMn_2O_4纳米线复合材料(MnO@CoMn_2O_4@N-C).ZIF-67的有机配体在高温煅烧过程中发生碳化反应,产生了氮掺杂碳,提升了导电性.当作为锂离子电池阳极材料时,MnO@CoMn_2O_4/N-C纳米线复合材料在0.1 A/g电流密度下的首次放电比容量为1 594.6 mA·h/g,并且在100次充放电循环后的放电比容量仍保持在925.8 mA.h/g,在0.5 A/g电流密度下经200次充放电循环后的放电比容量仍维持在837.6 mA·h/g,同时具有优异的倍率循环性能.这种优异的电化学储能特性主要来源于复合材料的特殊结构,以及氮掺杂碳的包覆.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.