Effects of Conductive Carbon Black on Thermal and Electrical Properties of Barium Titanate/Polyvinylidene Fluoride Composites for Road Application

In the field of roads,due to the effect of vehicle loads,piezoelectric materials under the road surface can convert mechanical vibration into electrical energy,which can be further used in road facilities such as traffic signals and street lamps.The barium titanate/polyvinylidene fluoride(BaTiO_(3)/PVDF)composite,the most common hybrid ceramic-polymer system,was widely used in various fields because the composite combines the good dielectric property of ceramic materials with the good flexibility of PVDF material.Previous studies have found that conductive particles can further improve the dielectric and piezoelectric properties of other composites.However,few studies have investigated the effect of conductive carbon black on the dielectric and piezoelectric properties of BaTiO_(3)/PVDF composites.In this study,BaTiO_(3)/PVDF/conductive carbon black composites were prepared with various conductive carbon black contents based on the optimum ratio of BaTiO_(3)to PVDF.The effects of conductive carbon black content on the morphologies,thermal performance,conductivities,dielectric properties,and piezoelectric properties of the BaTiO_(3)/PVDF/conductive carbon black composites were then investigated.The addition of conductive carbon black greatly enhances the conductivities,dielectric properties,and piezoelectric properties of the BaTiO_(3)/PVDF/conductive carbon black composites,especially when the carbon black content is 0.8%by weight of PVDF.Additionally,the conductive carbon black does not have an obvious effect on the morphologies and thermal stabilities of BaTiO_(3)/PVDF/conductive carbon black composites.

Electrical Percolation of Carbon Black Filled Poly (ethylene oxide)Composites in Relation to the Matrix Morphology

The present work studies the electrical conduction performance of carbon black (CB)filled poly(ethylene oxide) (PEO) composites. The addition of CB leads to reduced matrixcrystallinity as the fillers which are partly situated inside the lamellae and hinder the growth of PEOcrystallites. As a result, the electrical percolation behavior is related with the matrix morphology.

Separation, Purification and Identification of Antioxidant Compositions in Black Rice

To separate, purify and identify the antioxidative compositions of black rice, using total antioxidation capacity （TAC） as an activity-monitoring parameter, different fractions of black rice antioxidative extracts were obtained using solvents of different polarities such as petroleum ether, chloroform, ethyl acetate and normal butyl alcohol. The main anfioxidative components were separated from the strongest antioxidative fractions by using Sephadex LH-20 resin and the structures were analyzed by ultraviolet-vis, infra-red, ESI-MS, ^1H-NMR and ^13C-NMR spectrums. Results showed that the water fraction and normal butyl alcohol antioxidafive extract fraction of black rice had the strongest antioxidation capacities and their TACs reached 383 and 392 ku g^-1, respectively. Four main antioxidative components were separated from the water fraction and their TACs reached 976, 878, 1 134 and 1087 ku g^-, respectively. The spectroscopy analysis indicated that the four active components of the antioxidative extract of black rice were four anthocyanin compounds of malvidin, pelargonidin- 3, 5-diglucoside, cyaniding-3-glucoside and cyaniding-3, 5-diglucoside. It is concluded that the anthocyanin compounds are the most important substantial foundations for antioxidation.

The Joint Use of Electronic Nose and Electronic Tongue for the Evaluation of the Sensorial Properties of Green and Black Tea Infusions as Related to Their Chemical Composition

The objectives of the present study were to determine the effects of the brewing method on the amount of the major catechins, methylxanthines, total polyphenols and antioxidant capacity in green and black teas, and to correlate the chemical composition of tea infusions to their sensorial properties by the combined use of the electronic nose and tongue. For this purpose, tea infusions were prepared from 7 green teas and 6 black teas using different extraction times (3 - 5 and 10 min). The extraction of total polyphenols and catechins was increased by prolonging the infusion time from 3 - 5 to 10 min, while the caffeine amounts did not increase. The antioxidant activity of teas was well correlated with polyphenol content. Electronic tongue and electronic nose were able to discriminate green teas from black teas on the basis of their sensorial properties. Considering the taste, green teas were characterized by astringency and aftertaste-astringency and this sensation was increased by prolonging the infusion time;black teas were perceived as more bitter, sour, salty and the extraction time affected the astringent sensation. The aroma of green and black teas was discriminated by specific sensors and the increase of the extraction time produced more richly flavoured infusions. This work adds information about correlation between sensorial properties, antioxidant capacity and chemical composition of green and black teas.

A Novel Method for Preparing Polyurethane Based Conductive Composites with Low Percolation Threshold

A novel method for preparing conductive carbon black fllled polymer composites with low percolation threshold from polyurethane emulsion are reported in this paper. The experimental results indicate that with a rise in carbon black concentration the insulator-conductor transition in the emulsion blended composites occurs at 0.8-1.4vol%. In contrast, the solution blended composites exhibit drastic increase in conductivity at conducting filler fraction as high as 12.3-13.3vol%. It is demonstrated that the composites microstructure rather than chemical structure of the matrix polymer predominantly determines the electrical conduction performance of the composites.

Association of Bovine Fatty Acid Desaturase 2 Gene Single-Nucleotide Polymorphisms with Intramuscular Fatty Acid Composition in Japanese Black Steers

Beef from Japanese Black cattle (JBK), is popular in Japan and valued for its highly marbled fat content. In JBK, genes affecting oleic acid content in meat have been studied mainly to lower the fat melting point and improve tenderness;however, there has been no direct correlation demonstrated between beef taste and oleic acid. To investigate genes affecting other fatty acids other than oleic acid, polymorphisms of the fatty acid desaturase 2 (FADS2) gene were genotyped and associations with fatty acid profile in JBK beef were investigated. Amplifications of 5’-flanking regions, 12 exons, and 3’-untranslated regions of the FADS2 gene in three Japanese and five Western cattle breeds via PCR, were amplified, sequenced and SNPs were identified using specific TaqMan genotyping assay. Fatty acid composition of intramuscular adipose tissue of the Trapezius muscle was analyzed in JBK steers. Six of the 15 identified SNPs are novel and have never been registered in any public bovine SNP database. A non-synonymous SNP (rs211580559;C > T;294 Ala > Val) in exon 7 was examined in order to evaluate its association with fatty acid profiles. The data showed that highly significant association existed between rs211580559 and C18:2 (n-6) composition, and accounted for 22.3% of the variation. There were no significant relationships between rs2115-80559 and the other fatty acids. It was concluded that rs211580559 of the FADS2 gene may be a useful selection marker for reducing unfavorable volatiles generated from linoleic acid in JBK beef during the cooking process.

Chemical composition of the Tertiary black shales of West Sabah, East Malaysia

The X-ray fluorescence and ICP methods were used to analyze 60 outcrop samples of black shale, of which 15 were collected from Belait, 15 from the Setap Shale, 15 from Temburong, and 15 from the Trusmadi for- mations. The average compositions of the shales from the study area are 64.62%, 63.95%, 62.32%, 63.84% SiO2, 1.84%, 2.14%, 2.04%, 1.99% MgO, 2.55%, 3.12%, 2.89%, 2.72% K2O, 0.32%, 0.30%, 0.32%, 0.53% CaO, 5.86%, 6.06%, 7.14%, 6.60% Fe2O3, 207×10-6, 180×10-6, 213×10-6, 200×10-6 Rb, and 56×10-6, 49×10-6, 50×10-6, 32×10-6 Sr for the Setap Shale, Temburong, Belait and Trusmadi samples, respectively. The high Rb/Sr ratios of 3.8, 3.7, 4.2, and 6.1 are attributed to the lowest contents of Sr due to reducing conditions prevailing. The high Rb/K ratio sug- gests either brackish marine or rapid deposition that prevented equilibrium between Rb and K in the shales and ma- rine waters.

Strength Performance and Microstructure Characteristic of Naturally-Bonded Fiberboard Composite from Malaysian Bamboo(Bambusa vulgaris)

This study investigated the mechanical properties and microstructural characteristics of fiberboard composite produced by naturally-bonded Malaysian bamboo fiber(Bambusa vulgaris).The components that obtained through soda pulping of bamboo culms such as fiber and black liquor,were used for the preparation of high-density fibreboard composite at two target densities of 850 and 950 kg/m^(3).The bamboo fiberboard composite(BFC)were then produced at 200°C and two pressing parameters of 125 and 175 s/mm.The mechanical properties,e.g.,flexural strength and internal bonding(IB)of BFC samples were evaluated according to BS EN 310:1993 and BS EN 319:1993,respectively.It was found that the mechanical performance of the composite with 850 kg/m^(3)density was significantly higher than 950 kg/m^(3)ones,especially for the samples with 125 s/mm pressing parameter.Microstructure characteristic of the BFC samples illustrated that the fiber linkages were cracked in the composites with higher density,e.g.,the composite with the density of 950 kg/m^(3)and also black liquor were slightly degraded at longer pressing time,which led to the reduction in mechanical properties,especially in IB strength.

Preparation of Polymer Composite Particles by Phase Separation Followed by Suspension Polymerization

The novel method for preparing the polymer composite particles has been developed. It was tried to prepare polymer composite particles composed of polystyrene and carbon black with the phase separation method followed by suspension polymerization. In order to prepare the polymer composite particles with the more uniform diameter, the styrene monomer droplets containing carbon black were formed with phase separation emulsification in which ethyl alcohol and water were used as the good solvent and the poor solvent for styrene monomer, respectively. In the experiment, the surfactant species and their concentrations, the pouring velocity of water and the weight ratio of carbon black to styrene monomer were mainly changed. Water was poured at the given pouring velocity into ethyl alcohol in which styrene monomer and an initiator were dissolved and carbon black was dispersed beforehand. The spherical polymer composite particles containing carbon black were prepared with Tween 20 and Tween 80 of nonionic surfactants and the irregular polymer composite particles were prepared with PVA, SDS and Kotamine. The diameters of polymer composite particles increased with the pouring velocity of water and with the weight ratio of carbon black to styrene monomer.

Textile-Based Sensors for Inspection of Composite Materials

The monitoring of mechanical deformation and damage of composite materials is normally performed by established analytical methods,such as strain gauges and optical and piezoelectric sensors.However,large areas outside of the measuring cell remain unconsidered.A large-area sensitive sensor for composites is presented,which is simply generated by printing a carbon layer on the reinforcing glass fiber fabrics or on any composite itself.Such printed sensors enable to determine mechanical deformations and damages of the entire component and it responds with a measurable electrical resistance to external tension or pressure without any hysteresis.The strongest influence on sensor signal was identified with low carbon concentration and thin layers.The sensors signal linearly correlates with the degree of deformation and bending velocity whereas bending direction can be identified through signal change under residual tensile stress or compressive stress.

POSITIVE TEMPERATURE COEFFICIENT PHENOMENON OF CARBON LOADED NBR COMPOSITES

The resistivity of conductive composites of NBR(Butadiene nitrile rubber) filled with conductive carbon black and two kinds of special organic fillers was measured from room temperature to 90℃. In such semiconduc-tive systems. A positive temperature coefficient (PTC) phenomenon is observed, whose intensity depends on the type concentration and other physical and chemical properties of carbon black. Two empirical formulae are obtained by a the-oretical fitting method from the experimental data. One is for the resistivity of NBR/CB composites at room temperature and the other is for the resistivity of NBR/ N550 composites with relatively high concentrations N550 carbon blick in the temperature range of 30 ~ 90℃. The stability of resistivity is also discussed.

Species composition and influencing factors of understory woody species in Robinia pseudoacacia plantations on the Loess Plateau

Black locust(Robinia pseudoacacia L.)plantations have contributed significantly to soil and water conservation and ecological reconstruction on China’s Loess Plateau.Understanding the impact of stand and environment on species composition of understory woody plants will improve the stability of existing black locust plantations.Ten stands were selected in second-generation black locust plantations in tableland and gully areas of the Loess Plateau.The number of understory tree species in the tablelands was significantly lower than in the gully stands.Regenerated black locust(19.76%)and Rubus corchorifolius L.f.(64.85%)were the most abundant understory tree and shrub species,respectively,in the tableland stands;Broussonetia papyrifera(L.)L’Hér.ex Vent.(6.77%)and Acanthopanax senticosus(Rupr.Maxim.)Harms.(37.22%)were most abundant in the gully stands.Species richness(S),Shannon diversity(H),and evenness index(J)of the understory plants were significantly lower in the tableland stands than in the gully stands.More diverse understory species and community structures occurred in the gully stands.Differences in species diversity among landform positions may be attributed to differences in soil moisture.In addition,77.57%of the variation in understory species composition was explained,among which shrub and herb coverage,stand age,leaf area index,slope and total soil phosphorus in the 10-20 cm layer were the main factors.Soil organic carbon and total potassium significantly impacted S,H and J.Considering the environmental conditions and the biological characteristics of the plants investigated,R.corchorifolius should be given priority in the development of tableland stands,while B.papyrifera and Celtis sinensis Pers.should form mixed forests with black locust in gully stands.This management could promote biodiversity and stability of the existing black locust plantations but also optimize regional landscape patterns.

黑蒜多酚的提取方法及应用研究进展

在国家经济高速发展的今天,人们对食物的需求也在逐步提高,对健康和保健的认识也在逐渐增强。目前,黑蒜的食用价值与经济价值被逐渐挖掘,黑蒜多酚在食品行业的研究提取已成为诸多研究热点。对黑蒜多酚的功效、提取方法及未来的市场发展进行了综述,为提高人们对黑蒜多酚的认识,以及在各领域黑蒜多酚物质的创新开发和利用提供参考和思路。

光热双响应形状记忆聚氨酯/炭黑纳米复合材料的制备及性能研究

选用聚己内酯为预聚物,炭黑(CB)纳米颗粒作为光响应功能性填料,通过溶液聚合制备了一种光热双响应形状记忆聚氨酯(SMPU)/CB纳米复合材料。利用IR、SEM、DSC和DMA对其结构、形貌、热学性能和形状记忆性能进行表征。研究结果表明,SMPU/CB纳米复合材料展示出优异的形状记忆性能,其形状固定率和形状回复率均在97%以上。此外,由于CB的光热效应,SMPU/CB纳米复合材料在红外光的照射下具有快的响应速度及大的弯曲变形角度,在航空航天、智能驱动等领域具有潜在的应用前景。

混炼工艺对炭黑/天然橡胶复合材料性能的影响

选用干法密炼机混炼、湿法开炼机混炼、湿法密炼机混炼和湿法连续混炼四种混炼工艺,通过测定硫化特性、物理机械性能、动态力学性能和炭黑分散度等探究不同混炼工艺对炭黑/天然橡胶复合材料性能的影响。结果表明,湿法混炼胶的综合性能优于干法混炼胶,湿法连续混炼工艺制备的混炼胶的性能最佳,同时提高了混炼各个工序之间的连续性和自动化程度。

2种鲜食黑糯玉米营养组分及香气的比较

为了比较2种鲜食黑糯玉米的营养组分和风味物质之间的差异,对海南产地与江苏产地连黑甜糯2110和江苏产地苏科糯1505的基本营养成分和矿物质元素进行测定,采用顶空固相微萃取气相色谱质谱联用技术(HS-SPME-GC-MS)对风味物质进行鉴定和检测,结合气味活度值(OAV)和偏最小二乘判别分析(PLS-DA)法对挥发性风味物质进行多元统计分析。结果表明:不同鲜食黑糯玉米中灰分、淀粉、总糖和花色苷的含量有显著差异(P<0.05),铁、锌、硒等矿物质元素含量较高且没有显著差异(P>0.05)。在鲜食黑糯玉米中共鉴定出了44种挥发性风味物质,其中特征性风味物质包括1-辛烯-3-醇、异戊醛、戊醛、正己醛、2-辛烯醛、壬醛、2-壬烯醛、癸醛和3-羟基-2-丁酮;最后确定了正己醛、庚醛、2-庚酮和3-辛烯-2-酮是区分不同品种鲜食黑糯玉米的标志性化合物。

HPLC同时测定舒筋通络黑膏药9个成分含量

目的 建立HPLC同时测定舒筋通络黑膏药中α-玉柏碱、阿魏酸、羟基红花黄色素A、苯甲酰新乌头原碱、苯甲酰乌头原碱、杠柳毒苷、4-甲氧基水杨醛、山柰酚、齐墩果酸含量的方法。方法 采用HPLC同时测定舒筋通络黑膏药70%甲醇提取液中9个成分,使用Waters SunFire C18色谱柱(4.6 mm×250 mm,5μm),流动相为乙腈-0.2%磷酸水溶液,梯度洗脱,流速1.0 mL/min,柱温25℃,检测波长230 nm。结果 9个成分在各自范围内线性关系良好(r≥0.999 7),平均加样回收率为98.06%~100.56%,RSD为0.48%~2.56%。结论 本研究建立的方法重复性好,简便快速,可用于舒筋通络黑膏药的质量控制。

三种江西工夫红茶香气成分分析

文章利用顶空-固相微萃取(HS-SPME)结合气相色谱-质谱(GC-MS)对三种江西工夫红茶的香气成分进行检测分析,并比较了三种红茶香气成分的差异性和特点。红茶样经GC-MS鉴定共获得主要挥发性香气成分40个,检出醇类16个、醛类12个、酯类4个、酮类4个、烯烃类2个、酸类1个和杂氧化合物1个。不同茶样各类挥发性成分含量不同,主成分分析结果表明,40个成分可分为5个主成分,各主成分方差贡献分别为29.26%、21.05%、15.87%、14.14%和9.06%,累积方差贡献为89.38%,可以代表三种红茶样品的香气特征;主成分得分结果表明,主成分因子A38、A7、A10、A13、A32对主成分PC1正向影响,主要是花香与清甜类香气成分;A8、A18、A28、A29、A1、A30、A24、A25对主成分PC2正向影响,主要以花香与甜香类香气化合物为主;A16、A35、A39、A37、A19、A25对主成分PC3正向影响,主要以花果香类香气化合物为主。感官结果表明,河红茶香气主要清甜和花香为主基调,浮红茶主要以嫩甜和花香为主基调,宁红茶主要以果香和甜香为主基调;载荷结果表明,A1、A3、A5、A10和A38为花香型香气物质,A2、A7、A13和A18为果香型香气物质,A8、A9、A10、A14和A22为清甜、花香香气物质。

饲粮中添加金银花渣和茉莉花渣对隆林黑山羊生长性能、肌肉品质及营养成分的影响

试验旨在探索金银花渣和茉莉花渣对隆林黑山羊生产性能和肉品质的影响。试验选择20只3月龄(断奶)、体重接近且健康的隆林黑山羊,随机分为试验组和对照组,每组10个重复,每个重复1只羊。对照组饲喂基础饲粮,试验组在基础饲粮中添加5%的金银花渣和茉莉花渣。试验期1年。结果显示:与对照组相比,试验组黑山羊的胴体重、净肉重、骨重以及春、夏、冬季的平均日增重显著增加(P<0.05),体高、体长、胸围、末重、屠宰率及净肉率有增加的趋势(P>0.05),肌肉pH值、熟肉率、多不饱和脂肪酸与n3多不饱和脂肪酸含量显升高(P<0.05),肌肉导电系数、粗脂肪含量显著降低(P<0.05)。试验组肌肉粗蛋白含量、天门冬氨酸、苏氨酸、赖氨酸及鲜味氨基酸含量高于对照组(P>0.05)。研究表明,在饲料中添加金银花渣和茉莉花渣能够促进隆林黑山羊的生长发育,改善肉品质。