PP/PP-g-MAH/Talc/EP复合材料的性能

通过熔融共混制备聚丙烯(PP)/马来酸酐接枝聚丙烯(PP-g-MAH)/滑石粉(Talc)/环氧树脂(EP)复合材料,研究了E-51/504/554(55.6/42.4/2,E1)、E-51/EDA/554(92.2/7.8/0.01,E2)、E-20/2E4MZ(100/4,E3)三种EP体系及其含量对复合材料力学性能的影响,结果表明,E-1对复合材料的弯曲模量改善最显著,当加入4%的E1时,复合材料的弯曲模量达到最大值,提高了29.1%。傅里叶红外光谱(FT-IR)分析表明,EP与PP-g-MAH发生了酯化反应。观察复合材料的微观结构,发现EP阻止Talc的凝聚,加强了两相界面作用力。     

GaxIn1 ? xBiyAszSb1 ? y ? z/InSb and InBiyAszSb1 ? y ? z/InSb heterostructures grown in a temperature gradient

Heterophase equilibria in the Ga _x In_{1 − x} Bi _y As _z Sb_{1 − y − z} -InSb and InBi _y As _z Sb_{1 − y − z} -InSb systems have been analyzed within the simple solution approximation. Ga _x In_{1 − x} Bi _y As _z Sb_{1 − y − z} /InSb and InBi _y As _z Sb_{1 − y − z} /InSb heterostructures have been grown in a temperature gradient, and their composition and structural perfection have been assessed.     

On the pseudo-binary systems RexM1−xO2 (M=V,Mo, W)

Phase analysis studies on the $\text{Re}{}_{\mathrm{<mtext>x</mtext>}}\text{M}{}_{\mathrm{<mtext>1?</mtext><mtext>x</mtext>}}\text{O}{}_2$ systems ($\text{M}\text{=}\text{V, Mo, W}$) performed by means of X-ray powder photographs of samples prepared 1000K – 1225K have established the existence of the following phases:

$\text{ReO}{}_2\text{?}\text{VO}{}_2\text{:}\text{REo}{}_2\text{(orh) for 1>}{}_{\mathrm{<mtext>x</mtext>}}\text{>0.94 and}\text{VO}{}_2\text{(mon and tetr) for 0<}{}_{\mathrm{<mtext>x</mtext>}}\text{<0.5}$

$\text{ReO}{}_2\text{?}\text{MoO}{}_2\text{:}\text{ReO}{}_2\text{(orh) for 1>}{}_{\mathrm{<mtext>x</mtext>}}\text{>0.70. No. homogenity range of}\text{MoO}{}_2\text{.}$

$\text{ReO}{}_2\text{?}\text{WO}{}_2\text{: No mutual solubility nor anyintermediary phases}$

Metal-metal distances in the orthorhombic rhenium dioxide phases, derived from powder photographs, show slight changes with the $\text{x}$ value.     

CIIR/ACM/PZT/CB复合材料的阻尼性能

制备了CIIR/ACM/PZT/CB复合材料,通过测试该材料的振动衰减时间对其阻尼性能进行了表征,并探讨了材料不同的电阻与其阻尼性能的关系。结果表明,当材料电阻率在102.5Ω.cm～109.5Ω.cm,且压电陶瓷含量在30%～40%时,该复合材料具有优良的阻尼减振性能。     

Ekonol/G/MoS2/PEEK复合材料的力学性能

用模压方法制备了Ekonol／G／MoS2／PEEK复合材料，并对其力学性能(含拉伸强度、弯曲强度、冲击强度和压缩强度)进行了研究。结果表明：Ekonol的加入，使Ekonol／G／MoS2／PEEK复合材料的压缩强度提高，拉伸强度、弯曲强度和冲击强度有所降低．但并不妨碍其作为结构零件使用；当Ekonol含量为25％左右时，复合材料具有较为理想的综合力学性能。     

Li0.5La0.5TiO3包覆LiNil/3Co1/3Mnl/3O2材料的研究

以Li0.5La0.5TiO3为包覆物,制备了固体电解质包覆的LiNil/3Co1/3Mnl/3O2正极材料。采用XRD、SEM对材料进行了表征:XRD显示未包覆的材料具有α-NaFeO2层状结构,粒径在200～300nm之间,包覆后材料粒径略有增大,包覆层具有ABO3型固体电解质结构。包覆层的致密程度及材料的循环稳定性与热处理温度有关。包覆后400℃热处理得到的材料首次放电比容量为185mAh/g,较未包覆材料容量有所提高,50次循环后其容量仍能达到156.5mAh/g,表明包覆物Li0.5La0.5TiO3对LiNil/3Co1/3Mnl/3O2具有保护作用。     

Magnetization Processes of (La0.7Pb0.3MnO3)1?x(SiO2)x Composites

The ceramic composites, (La_0.7Pb_0.3MnO₃)_1−x (SiO₂) _x , with diluted magnetic properties are prepared using solid-sate sintering route. Magnetization processes of (La_0.7Pb_0.3MnO₃)_1−x (SiO₂) _x composites are explored in this study. Ferromagnetism is gradually attenuated due to the magnetic dilution induced by the increase of SiO₂ content. Clearly, irreversible behavior is observed in the zero-field cooling and the field cooling (ZFC–FC) curves at a low field of 100 Oe. Saturation magnetization decreases as x increases while ferromagnetic transition temperature remains around 346 K for all composites. All the composites exhibit ferromagnetic hysteresis behavior which can be modeled by the law of the approach to saturation in the form M=M _S(1−a/H). The term a/H expresses the deviation of magnetization from saturation. The smaller factor a for La_0.7Pb_0.3MnO₃-rich samples results in sharper square curve which should be associated with the long-range spin order of ferromagnetic coupling.     

Fe/Co/N/MWCNTs催化剂的制备及性能

将掺杂铁离子的聚苯胺(PANI)与碳纳米管(MWCNT)复合物在900℃加热,得到含铁的催化剂FeNC;然后将含钴盐的FeNC在不同温度下焙烧,得到复合催化剂FeCoNC。对催化剂的表观结构、比表面积、热稳定性、组成以及氧还原(ORR)电催化活性进行表征,研究了焙烧温度和氮含量等因素对其催化活性的影响。结果表明:随着焙烧温度的升高,催化剂的表面结构趋于均匀,焙烧温度为500℃的催化剂表面结构最为均匀平整,高于500℃时出现烧结;较高的氮含量能改善催化剂的ORR电活性。焙烧温度为500℃的催化剂对ORR的电催化活性最高,在酸性和碱性溶液中ORR的起始电位分别为0.63和-0.12 V(vs SCE),电流密度分别为11.67和9.83 mAmg-1@-0.3 V(vs SCE),并具有较好的热稳定性和催化活性稳定性。分步加入Fe和Co,并在加Co后在500℃焙烧得到的催化剂对ORR具有优异的电催化活性。     

欧盟G/TBT/N/EU/75通报分析

日前,欧盟发布G/TBT/N/EU/75通报,通报了计算机和计算机服务器的ErP指令实施条例草案,规定了计算机和计算机服务器产品的最低能源效率和信息要求,拟批准日期是2013年5月。该实施条例是ErP框架指令(2009/125/EC)下关于计算机产品的具体生态设计要求,该条例要求一旦正式生效,不符合要求的产品将不允许在欧盟市场销售。     

Al_2O_3-ZrO_2/W/Cr/Ni/Co金属陶瓷的断裂韧性

以Al2O3-ZrO2复合粉末、W、Cr、Ni、Co粉末为原料,采用热压烧结工艺制备了性能优良的Al2O3-ZrO2/W/Cr/Ni/Co金属陶瓷复合材料。通过SEM,EDS,XRD等手段分析其微观组织,单边梁开口法(SENB)测量其断裂韧性。实验结果表明在1320℃,20MPa条件下热压烧结制备的Al2O3-ZrO2/W/Cr/Ni/Co金属陶瓷的断裂韧性为7.16±0.4MPa.m1/2,硬度为83.3HRA,横向断裂强度为540MPa,相对致密度为97.4%;对维氏压痕下裂纹扩展进行了分析,其增韧机理为延性金属对裂纹的桥梁作用和氧化锆相变增韧,在裂纹通过时硬质相以沿晶断裂为主。     

合成方法对LiNil/3Co1/3Mn1/3O2电化学性能的影响

采用碳酸盐共沉淀法、草酸盐共沉淀法、溶胶-凝胶法、高温固相法、氢氧化物共沉淀法(pH=10、11、12)制得LiNil/3Co1/3Mn1/3O2正极材料,通过X射线衍射(XRD)、扫描电镜(SEM)和电化学性能测试对样品的结构和性能进行了表征。结果表明,溶胶-凝胶法合成的样品层状结构较完整,阳离子混排程度低,粒径相对较小,颗粒分布均匀;该样品首次放电比容量较高为151mAh·g-1,循环30次后容量保持率达到93.31%。     

Al2O3/ZrO2/ZrSiO4复合材料的研究

在Al2O3颗粒补强锆英石陶瓷的研究基础上,探讨了Al2O3与ZrO2共同对锆英石陶瓷的协同补强增韧行为.制备的锆英石基复合材料的室温抗弯强度和断裂韧性分别可达383.31MPa、4.39 MPa·m12.采用XRD分析了复合材料的相组成,采用SEM观察复合材料的断面形貌.结果显示:ZrSiO4为主要晶相,另外还有少量Al2O3和ZrO2存在;第二种增强体ZrO2的最佳引入量为20％(质量分数);确定复合材料的强韧化是由Al2O3和ZrO2颗粒引起的裂纹偏转、微裂纹增韧与ZrO2颗粒引起的相变增韧共同作用而实现的,断裂方式主要为穿晶断裂.     

XRCD/K2/JVC的真谛

近年来,随着进一步提高 CD 音质的呼声日渐高涨,各CD 厂商纷纷推出自己的方案和产品。按照兼容程度,大致可以分为三类:第一种是彻底推翻传统的音乐 CD 而另起炉灶,例如 DVD-Audio 和 SACD 就是这样,完全不能在原有的 CD 机上播放(特别制作的除外);第二种是可以在普通 CD 机上播放,但需要在 CD 机中增加相应的电路才能体现出更高一筹的音质,否则将仍然是普通 CD 的音质。例如 HDCD 就是这样;第三种则具有最好的兼容性,无需对原有的 CD 播     

Superconductivity of YBa2?xNdxCu3Oy Solid Solution

The solubility of Nd at the Ba sites and the superconductivity of YBa_2–x Nd _x Cu₃O _y were investigated by X-ray powder diffraction and measurements of the electrical resistance and ac susceptibility. The single Re123 phase was obtained for x0.30. The onset transition temperature is insensitive to the Nd content x in the region of x0.40. All are higher than 95 K. The zero resistance transition temperatures , however, exhibits two-step variation with the increase of x. For x0.25, are all above 92 K. The highest of 94 K was obtained for x=0.25. For x0.3 drops sharply to about 84 K. Finally falls to 30 K and is below 10 K for x=0.5. The two-step variation of T _c might be an indication of the existence of two trap levels for holes.     

Relation of Structure and Superconductivity in Self-compensated Y1?xCaxBa2Cu3?xAlxOz System

The co-doped compounds of Y_1−x Ca _x Ba₂Cu_3−x Al _x O _z , with x from 0.1 to 0.4, were synthesized through a solid-state reaction method. Structural and superconducting properties have been investigated by X-ray diffraction, Rietveld refinement, and DC magnetization measurement. The lattice constant a decreases while b increases with the addition of x. The difference between a and b diminishes gradually. Careful study of the crystalline structure shows that the critical temperature (T _c ) changes monotonically with some local structural parameters, such as the difference between Ba and Cu(2) atoms’ Z coordinates, the bond length of Cu(2)–O(4), and the bond angle of Cu(2)–O(2)–Cu(2), which are all closely related to the interaction between the perovskite block and the rock salt block in the unit cell. The results indicated that the influence of the crystalline structure on superconductivity is important and independent of the carrier concentration.     

Characterizations of InzGa1?z As1?x?yN xSbyP-i-N structures grown on GaAs by molecular beam epitaxy

The GaAs-based double-heterojunction P-i-N structures using In_zGa_1–zAs_1–x–yN_xSb_y as the i-layer is investigated for the first time using solid source molecular beam epitaxy. High quality coherent bulk InGaAsN_3.45%Sb (0.5 m) with a lattice-mismatch of 2.6 × 10^–3 can be achieved due to the surfactant properties of antimony, while the bulk InGaAsN_2% at 0.5 m with 1.06× 10^–3 mismatch is fully relaxed. Rapid thermal annealing (RTA) resulted in 25 meV low temperature (LT) photoluminescence (PL) full-width half-maximums (FWHM) for the bulk InGaAsNSb layers. InGaAsNSb experiences 30% less blueshifting with subjected under the same annealing conditions as InGaAsN with similar N content. Room temperature (RT) absorption measurements are in the range of 0.9–1.4 eV. The absorption edge of 1.41 m is achieved for sample D4.     

尼龙1212/SEBS-g-MA/DIDP/BSBA共混体系的结晶行为

用W AXD、PLM及DSC研究了尼龙1212/SEBS-g-M A/D IDP/BSBA共混体系的结晶行为。W AXD结果显示,增韧剂的加入改变了尼龙1212的晶型。PLM观察表明共混体系中由于M A与尼龙之间的相互作用,增韧剂充当了成核剂,使得尼龙1212球晶向细晶化发展。用修正A vram i方程的Jez iorny法研究共混体系的非等温结晶动力学,发现共混体系的半结晶时间t1/2缩短,增韧剂对尼龙1212有明显的异相成核作用。     

纳米Al2O3掺杂对LiNi1/3Co1/3Mn1/3O2性能的影响

为提高LiNi1/3Co1/3Mn1/3O2正极材料的循环性能和倍率性能,采用在底液中添加纳米Al2O3的方法,在氢氧化物共沉淀法制备前驱体过程中进行铝元素掺杂,并考察了铝掺杂量对材料形貌和电化学性能的影响。电化学性能测试结果表明,当铝掺杂量为0.02(n Al:∶n Li=0.02)时,在电压范围2.7~4.2V和0.2C倍率下,循环50次后容量保持率高达95.7%,高于未掺杂的81.5%,同时材料的倍率性能也明显提高。