硅酸铝纤维制备高温气体除尘材料的性能

采用真空抽滤并加热处理的方法制备硅酸铝纤维高温气体除尘材料,并通过扫描电子显微镜(SEM)、金相显微镜和压汞仪分别对材料的显微结构、纤维分散性、孔径大小和分布进行了分析.结果表明,在800℃并保温1h加热处理后,材料的抗折强度达到3.14MPa,过滤阻力为79.75Pa/m/min,孔直径在10～80μm的孔占总体积的70.23％,气孔率达到72.99％.硅酸铝纤维多孔陶瓷材料具有较高的抗折强度,孔隙率和较低的过滤阻力,可用于高温条件下粉尘颗粒的过滤.     

水基冷冻干燥工艺制备莫来石结合多孔SiC陶瓷

以微米级SiC和纳米级α-Al2O3为原料,经水基冷冻干燥及原位反应烧结工艺制备莫来石结合多孔SiC陶瓷.XRD分析表明多孔陶瓷主相是α-SiC,结合相是莫来石.多孔陶瓷的孔径分布呈现双峰分布特点,大孔孔径峰值介于3 ～20 μm,小孔孔径峰值为0.5 ～1 μm.体系中SiC固相含量及烧结温度对多孔陶瓷显微结构及性能有显著影响.当SiC固相含量由20vol％增至30vol％时,多孔陶瓷的孔结构由间距为20～ 30 μm、且定向排列的层状结构演变为孔径约为4μm的定向通孔结构.当烧结温度由1200℃升至1500℃时,多孔SiC陶瓷开气孔率由66％下降至64％,抗压缩强度由4.5 MPa升至16 MPa.     

蓝晶石基微孔莫来石陶瓷分离膜支撑体的制备、结构与性能研究

以蓝晶石为主要原料、γ-A12O3为辅料,采用注浆成型技术与反应烧结工艺制备出了具有针状网络结构的微孔莫来石陶瓷分离膜支撑体.系统研究了烧成温度对试样物相组成、显微结构及性能的影响,结果表明:随着烧成温度的升高,试样中莫来石的生成量增多,其形貌逐渐由针状发育成柱状,试样的性能与莫来石的生成量及形貌密切相关.针状莫来石可对基体起强韧化作用,并使气孔的有效半径微细化.在1450 ～ 1500℃,随烧成温度的升高,试样的显气孔率逐渐增大、孔径减小、强度升高.所制支撑体的体积密度为1.38～ 1.60 g,/cm3、显气孔率为46.74％ ～ 53.23％、烧后线变化率为-3.10％～2.24％、气孔孔径集中分布在1～ 20 μm、平均孔径为5.84～9.93 μm、常温耐压强度为30.1～ 37.2 MPa.     

花岗岩粉体烧结钙长石微晶玻璃的强韧化研究

以改性花岗岩粉体为主要原料,烧结法制备钙长石微晶玻璃,添加酸洗石棉、低结晶度莫来石纤维为增韧填料,系统研究微晶玻璃的烧结行为、力学性能及强韧化机理.结果表明:随着纤维添加量增大,微晶玻璃体积密度、断裂韧度和抗弯强度先增大后减小.添加3％酸洗石棉时,微晶玻璃结晶度为79％,钙长石含量为61％,抗弯强度和断裂韧度分别达到144 MPa和3.0 MPa·m1/2.微晶玻璃增韧机理为裂纹偏转和裂纹桥接,增强机理与纤维增韧、结晶度提高以及穿晶断裂有关.     

凝胶注模莫来石/碳化硅复合陶瓷的显微结构与力学性能

以SiC粉和莫来石粉为原料,采用凝胶注模成型工艺制备莫来石/碳化硅复合陶瓷,研究了莫来石含量对复合陶瓷显微结构和力学性能的影响,结果表明:随莫来石含量增加,复合陶瓷气孔率先降低后升高,而力学性能呈相反变化趋势。当莫来石含量为20%(体积分数)时,材料气孔率达到最小值9.4%,线收缩率以及弹性模量达到最大值26.5%和148.6 GPa;在莫来石含量为30%时抗弯强度和断裂韧性达到最大值397.7 MPa和4.17MPa.m1/2。适量莫来石的加入明显改善了材料的力学性能,过多则由于莫来石挥发而在材料中产生缺陷,材料性能下降。     

高温陶瓷纤维膜材料的制备及影响因素分析

本文以多晶莫来石纤维、SiO2/B2O3体系结合剂为主要原料，采用真空旋转抽滤成 型工艺，制备了高温陶瓷纤维膜材料，研究了浆料性能、结合剂加入量、成型压力对陶瓷纤维 膜材料各项性能的影响。实验结果表明：浆料粘度、结合剂量及成型压力对纤维膜材料的性能 有显著影响。当浆料的粘度为 2000 mPa?s ~ 2500 mPa?s、结合剂含量为 39 wt% ~ 42 wt%、成型 压力为 ?0.04 MPa 时，可获得均匀结构的陶瓷纤维过滤材料。材料气孔率大于 88%，透气阻力 为 82 Pa，抗压强度为 1.75 MPa，可几孔径为 90 μm。     

兼有脱硫性能陶瓷过滤元件的制备及其研究

以刚玉为骨料,高岭土、钾长石为烧结助剂,活性炭为造孔剂,铁酸锌为脱硫剂,通过等静压成型,制备出具有双层结构的兼有脱硫性能的陶瓷过滤元件,研究了骨料粒度及铁酸锌脱硫剂对试样孔径、气孔率、强度的影响,以及骨料对铁酸锌脱硫剂脱硫性能的影响.并用SEM分析了试样的断面形貌,压汞仪测定了试样的孔径、气孔率.结果表明: 骨料粒度为80 μm,外层加20%的铁酸锌制备出的双层结构多孔陶瓷过滤元件,平均孔径为20 μm,气孔率49%,外层抗弯强度为10 MPa,内层不加脱硫剂抗弯强度达到28 MPa,界面结合较好,能满足高温煤气除尘脱硫的需要.     

多孔堇青石中空纤维陶瓷膜的制备与表征(英文)

采用相转化和烧结法,通过一步成型制备了新颖的堇青石中空纤维陶瓷膜,并对制备的中空纤维膜微观结构、孔隙率和孔径分布、抗弯强度、纯净水通量和氮气渗透性等结构与性能进行了表征。结果表明:堇青石中空纤维膜为多孔非对称结构,由内部大孔层和外部海绵状多孔层组成。在1360℃保温2h制备的堇青石中空纤维膜孔隙率为39.2%,抗弯强度为76.5MPa。0.10MPa压差下的纯净水和氮气渗透性分别达到61.34m3/(m2·h·MPa)和7824m3/(m2·h·MPa)。实验证明,采用较大粒径的廉价工业级粉体为原料,可制备非对称的中空纤维陶瓷微滤膜。     

矾土基合成莫来石质多孔陶瓷的研制

采用发泡法与添加造孔剂相结合,以高铝矾土和高岭土为骨料,长石作熔剂,并添加适量的煤、MgSO4和CaSO4作发泡剂,煤为造孔剂,PVA为粘结剂,干压成型后于1500℃左右烧成制备了莫来石质多孔陶瓷。制得的多孔陶瓷莫来石生成量高达90%以上,其气孔分布均匀,孔径分布范围为100～300μm;气孔率高达52.3%（闭孔气孔率为38.7%,开孔气孔率为13.6%）;体积密度为0.9731g/cm3;抗压强度为25.1317MPa;导热系数为0.143W/（m.K）的多孔陶瓷。     

高温气体净化用陶瓷纤维过滤材料的制备及性能

本文采用真空旋转抽滤成型工艺，以莫来石纤维为主要原料制备了高温气体净化 用陶瓷纤维过滤材料，研究了纤维浆料搅拌时间和烧结温度对纤维膜材料性能的影响，评价其 过滤及热震性能。实验结果表明：当纤维膜浆料搅拌 2 h 时，在 1000?C 下烧结可以制备出过抗 压强度为 4.75 MPa、透气阻力 95 Pa、气孔率为 85%、平均孔径为 70 ?m、显微结构均匀的纤维 膜材料，其除尘效率可达 99.99%，且具有良好的热震性能。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。