PLD法制备0-3型xNZF-(1-x)BTO多铁复合薄膜及其极化行为研究（英文）

在采用传统固相烧结工艺制备0-3型x Ni_(0.7)Zn_(0.3)Fe_2O_4-(1-x)BaTiO_3(x=0.00,0.15,0.30,0.45)多铁复合陶瓷靶材和采用PLD技术探索纯相BaTiO_3薄膜溅射工艺的基础上,本文在不同激光能量条件下分别在Pt(111)/Ti/SiO_2/Si、0.5%铌掺杂的钛酸锶(STO:0.5%Nb)和钌酸锶(SRO)衬底上制备了相应配比的0-3型xNi_(0.7)Zn_(0.3)Fe_2O_4-(1-x)BaTiO_3(x=0.15,0.3,0.45)复合薄膜。然后详细研究了这些复合薄膜的极化行为和影响因素,以期获得更优化的PLD工艺参数。     

掺杂量及烧结温度对W掺杂Li7La3Zr2O12陶瓷电解质性能的影响

采用固相反应法制备W掺杂Li_7La_3Zr_2O_(12)(Li_(7-2x)La_3Zr_(2-x)W_xO_(12))陶瓷电解质,探究掺杂量及烧结温度对样品烧结特性、晶体结构、显微形貌及离子电导率的影响。结果表明:W掺杂可以稳定立方相Li_(7-2x)La_3Zr_(2-x)W_xO_(12),当x=0.3时,1 200℃烧结20 h制备的样品30℃下离子电导率达到最高值5.77×10~(-4) S/cm,相较于未掺杂样品提高一个数量级;以x=0.3为固定掺杂量、改变不同烧结温度,1 180℃烧结20 h获得的样品离子电导率达到最高为7.05×10~(-4) S/cm。当x=0.1～0.3时,晶粒尺寸分布均匀,在10～20μm左右;当x=0.4时,产生晶粒熔合现象且有晶体析出,这种特殊的显微形貌导致样品电性能劣化。     

非晶态快离子导体中的“混合碱效应”

通过对0.5[xNa_2O—(1-x)Li_2O]—0.5P_2O_5和0.3[xNa_2O—(1-x)Li_2O]—0.7B_2O_3两个非晶态碱金属离子玻璃体系的制备和测试,证明了非晶态快离子导体中“混合碱效应”的存在,并由实验曲线找出了这两种玻璃材料的转变温度T_8、离子电导率σ_T、幂前因子σ_O和激活能E_a分别与组成该材料的摩尔分数x之间的相互关系。     

Synthesis characterization and improved electrochemical performance of Li_2FeSiO_4/C as cathode for lithium-ion battery by metal doping

In this paper, Li_2FeSi_(0.98)M_(0.02)O_4/C(M = Mg, Zn, Co, Mn, Ni) was synthesized as cathode material for lithium ion battery by solid-state method. The results show that the materials doped with Mg and Zn at the Si-sites have good initial discharge capacity. Then Li_2FeSi_(1-x)M_xO_4/C(M = Mg, Zn; x = 0.01, 0.02, 0.03, 0.05) were also synthesized via solid-state method. It is concluded that Li_2FeSi_(0.99)Mg_(0.01)O_4/C and Li_2FeSi_(0.98)Zn_(0.02)O_4/C have better initial discharge capacity which is 125 mAh/g and 166.2 mAh/g, respectively. The capacity of Li_2Fe_(0.98)Zn_(0.02)SiO_4/C is 157.3 m Ah/g after 10 cycles at 0.1 C, and the capacity retention rate is 94.6%. The Li~+ diffusion coefficient of Li_2FeSi_(0.98)Zn_(0.02)O_4/C is higher than that of pure phase materials by one order of magnitude. The Li_2FeSi_(0.99)Mg_(0.01)O_4/C and Li_2FeSi_(0.98)Zn_(0.02)O_4/C were tested by XRD and SEM. XRD patterns indicate that the crystal structure of Li_2FeSiO_4 is not changed after being doped with metal ion at the Si-site. The SEM image indicates that no obvious agglomeration is detected in these materials. Li_2FeSi_(0.98)Zn_(0.02)O_4/C processes better electrochemical performance analyzed by EDS、XPS and FT-IR spectra. The data prove that Si~(4+) is successfully replaced by Zn~(2+) in the crystal structure of Li_2FeSiO_4.     

锌掺杂对包碳磷酸钒锂电化学性能的影响

以Li_2CO_3、V_2O_5、NH_4H_2PO_4和ZnO为原料,用葡萄糖作为碳源和还原剂,然后通过高温煅烧法制备了Li_3V_(2-x)Zn_x(PO_4)_3/C(x=0,0.05,0.10)。用X射线衍射、扫描电子显微镜和高分辨透射电子显微镜,对制得的样品进行物相、结构和微观形貌分析表征。用恒电流充放电、循环伏安和电化学阻抗谱法测试样品的电化学性能。研究结果表明:掺杂Zn~(2+)不会改变Li_3V_2(PO_4)_3的结构。适量地掺杂Zn~(2+)能使Li_3V_2(PO_4)_3颗粒更加均匀、结构更稳定,同时显著改善其电化学性能。当x=0.05时,样品的首次放电比容量为123.1 m A·h·g~(-1),并且以0.5C充放电循环20圈后容量保持率仍达99.76%。     

Na_(0.7)Ni_(0.5)Mn_(0.3)Fe_(0.2)O_2正极材料的制备及其储钠性能

为提升钠离子电池的储钠性能,采用溶胶-凝胶法合成了Na_(0.7)Ni_(0.5)Mn_(0.3)Fe_(0.2)O_2层状金属氧化物正极材料,并探讨了柠檬酸含量对材料形貌、结构和电化学性能的影响.形貌和结构分析表明,所得电极材料的成分主要为多晶Na_(0.7)Ni_(0.5)Mn_(0.3)Fe_(0.2)O_2,并伴有少量Ni O;随着柠檬酸含量的增加,Na_(0.7)Ni_(0.5)Mn_(0.3)Fe_(0.2)O_2的颗粒尺寸减小但团聚现象更加明显.电化学测试结果表明,当柠檬酸与金属氧化物的物质的量比为0.3∶1时,所得Na_(0.7)Ni_(0.5)Mn_(0.3)Fe_(0.2)O_2正极材料具有最优的电化学性能,其首圈放电比容量高达128.1 mA·h/g,经50次充放电循环后,仍能释放出91.6 mA·h/g的可逆比容量.此外,Na_(0.7)Ni_(0.5)Mn_(0.3)Fe_(0.2)O_2正极材料还拥有良好的倍率特性,在1.0 C高倍率下,其放电比容量可达84.4 m A·h/g,在快速充放电钠离子电池应用方面展现出良好的前景.     

红格钒钛磁铁矿氧化物相转变及非等温氧化动力学

在对红格钒钛磁铁矿基础特性研究基础上,探讨了其球团氧化过程物相的存在形式和转变过程,并通过热分析法研究了红格矿非等温氧化动力学.结果表明:红格钒钛磁铁矿属于高铬型钒钛磁铁矿,Cr_2O_3的质量分数为1.48%,连晶强度为625 N;主要物相组成为磁铁矿、钛磁铁矿、钒磁铁矿、铬铁矿;温度低于300℃时其氧化速率缓慢;球团氧化过程有价组元物相迁移变化历程为:Fe_3O_4→Fe_2O_3;Fe_2VO_4→(Cr_(0.15)V_(0.85))_2O_3;Fe_(2.75)Ti_(0.25)O_4→FeTiO_3→Fe_9TiO_(15);FeCr_2O_4→(Fe_(0.6)Cr_(0.4))_2O_4,Fe_(0.7)Cr_(1.3)O_3,(Cr_(0.15)V_(0.85))_2O_3.红格矿非等温氧化动力学研究表明:当升温速率为10℃/min时,温度在220~380℃,380~500℃和500~800℃时,反应活化能分别为47.02,14.95和30.36 kJ·mol~(-1).     

碱金属掺杂橄榄石型NaFePO_4的第一性原理研究

采用基于密度泛函理论(DFT)的第一性原理方法研究了钠离子电池正极材料橄榄石型NaFePO_4及其碱金属(Li、Na)掺杂体系的结构稳定性、电子结构、充放电过程结构演化及相关电化学性质.计算结果显示,NaFePO_4可掺杂适量Li、Na,且掺杂后结构稳定.脱钠相结构形成能的计算模拟了NaFePO_4及其掺杂体系充电过程中的相变,NaFePO_4在充电过程中存在Na_5/_6FePO_4与Na_2/_3FePO_42个中间相,铁位锂掺杂体系存在Na_3/_4(Li_1/_(12)Fe_(11)/_(12))PO_4、Na_1/_2(Li_1/_(12)Fe_(11)/_(12))PO_4、Na_1/_6(Li_1/_(12)Fe_(11)/_(12))PO_43个稳定中间相,铁位钠掺杂体系存在Na_5/_(12)(Na_1/_(12)Fe_(11)/_(12))PO_4、Na_1/_6(Na_1/_(12)Fe_(11)/_(12))PO_4、Na_(1/12)(Na_(1/12)Fe_(11/12))PO_43个稳定中间相.此外,通过分析电子结构,还发现Li、Na掺杂体系中有部分O~(2-)发生氧化参与电荷补偿,这使得掺杂体系的充电电压略高于未掺杂的NaFePO_4.     

Sm_2(Zr_(0.7)Ce_(0.3))_2O_7纳米热障涂层材料的制备及其热物性能研究

Sm_2(Zr_(0.7)Ce_(0.3))_2O_7是一种三元稀土氧化物材料,具有耐腐蚀性能好、熔点高、热导率低、热稳定性良好等优点,在热障涂层领域有着潜在的应用前景.以Sm_2O_3,ZrOCl_2·8H_2O和Ce(NO_3)3·6H_2O为原材料,通过水热合成法制备了Sm_2(Zr_(0.7)Ce_(0.3))_2O_7是纳米材料,并与同样方法制备的Sm_2Zr_2O_7的相关性能进行了对比.通过TG-DSC、XRD、Raman、SEM等测试手段对材料的热行为、相结构、晶粒尺寸和形貌等参数进行了表征.结果表明:Sm_2(Zr_(0.7)Ce_(0.3))_2O_7纳米材料在高温热处理后为烧绿石结构,初始样品的晶粒尺寸为5.43 nm,比表面积为103.11 m2g~(-1).同时对热导率、热膨胀系数等热物性能进行了研究,其热导率为1.04 W m~(-1)K~(-1),热膨胀系数为10.86×10~(-6)K~(-1),这些性能均满足热障涂层的标准.与Sm_2Zr_2O_7相比,Sm_2(Zr_(0.7)Ce_(0.3))_2O_7具有更优异的性能,是一种具有广泛应用前景的纳米热障涂层材料.     

具有非晶态结构的锂离子导体

到目前为止,已有不少关于非晶态快离子导体的报道。关于B_2O_3-xLi_2O-yLiCl系統也已有人作了初步研究,确定出它的玻璃态形成范围为O≤x≤0.85,O≤y≤0.85,其中Li_4B_7O_(12)Cl在300℃时的电导率可达10~(-2)((?)cm)~(-1)。为了将非晶态与晶态材料进行对比,我們研究了B_2O_3-0.7Li_2O-0.7LiCl的电导率和激活能。結果表明:此种成分的非晶样品与多晶样品相比,电导率高两个数量級,激活能低16%。     

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.     

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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。     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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