Ni-P-纳米金刚石化学复合镀研究

采用制备的粒度150 nm以内的复合镀用纳米金刚石悬浮液进行了Ni-P-纳米金刚石化学复合镀研究,研究了工艺条件包括纳米金刚石加入量、搅拌方式、离子型和非离子型表面活性剂及其组合的加入对复合镀镀速和镀层性能的影响。结果表明:纳米化学复合镀要求镀液有更好的稳定性;镀速与搅拌方式有关,并且随纳米金刚石的加入而提高;组合型表面活性剂对复合镀层性能提高明显;表面形貌分析观察到镀层中纳米金刚石分布均匀,颗粒在100~200 nm左右。     

镍-磷微米金刚石化学复合镀工艺及镀层性能

采用化学复合镀法在低碳钢表面镀覆Ni–P–金刚石复合镀层。化学镀基础镀液含硫酸镍25g/L、次磷酸钠25g/L、结晶乙酸钠15g/L和柠檬酸钠10g/L,pH为4～5,温度80～85°C。金刚石颗粒的平均粒径为5μm。比较了直接复合镀及两步复合镀工艺分别所得镀层的微观形貌。借助材料表面微纳米力学测试仪及磨损试验机研究了复合镀层的性能。先化学镀Ni–P合金30min,然后在机械间歇搅拌下加入金刚石0.4g/L,再复合镀10min,可使金刚石颗粒均匀地镶嵌在镍基镀层中,并有一部分凸出镀层表面,从而增大了镀层的摩擦因数及与GCr15相对面的咬合力。金刚石复合镀层的干摩擦因数可达0.518。动载条件下未出现脱落现象。     

镁合金化学复合镀Ni-P/纳米SiC工艺的研究

在AZ 91D镁合金表面制备Ni-P/纳米SiC化学复合镀层.探讨镀液中纳米SiC微粒的质量浓度对镀速、复合镀层性能等的影响.利用扫描电镜观察镀层表面形貌,采用能谱分析仪进行镀层表面成分的定性分析,采用显微硬度计测试镀层硬度,并对不同工艺下获得的镀层进行快速磨损实验.结果表明:镀液中添加适量的纳米SiC微粒,镀速和镀层硬度都有显著的提高.当镀液中纳米SiC的质量浓度为9 g/L时,镀速可达到25.6 μm/h;当镀液中纳米SiC的质量浓度为7 g/L时,镀层的维氏硬度可达到9 380 MPa;同时镀层的耐磨性能相比于Ni-P合金镀层的也有显著提高.     

镁合金化学镀Ni—P-金刚石镀液稳定性的研究

研究了稳定剂和搅拌强度对镁合金化学镀Ni-P-金刚石敛液稳定性的影响.结果表明:镀液稳定性随稳定剂的质量浓度的增加而增加;随搅拌转速增加而增加,200 r/min时稳定性最好,之后随着转速的增加而降低.镀层中金刚石分布均匀,磷的质量分数为6.00%,镀态下镀层为非晶+微晶结构.     

铜–金刚石复合电镀制备新型切割线的工艺

采用复合电沉积法制备了金刚石切割线,主要工艺流程为:钢丝和金刚石粉的镀前处理,碱性预镀铜,金刚石上砂镀(铜–金刚石复合镀),加厚镀镍,后处理。通过测定镀液的阴极极化曲线以及镀层的表面形貌、力学性能和结合力等,研究了电流密度、镀液中金刚石含量、搅拌速率、电镀时间等工艺参数对金刚石上砂效果的影响。实验表明,随着镀液中金刚石含量的增大,铜–金刚石共沉积的阴极极化曲线负移,相同电位下的电流减小;低电压下,相同电位处的阴极电流随搅拌速率增大而增大,高电压下反之。随着阴极电流密度提高或施镀时间延长,金刚石上砂量呈先增后减的趋势。经200°C热处理2 h后,金刚石切割线的最大拉断力和抗拉强度分别为159.7 N和2 258.8 MPa,力学性能明显改善。在电流密度5~7 A/dm2下制备的金刚石切割线,其镀层和钢基体之间的结合力良好。     

不锈钢硫酸盐镀液体系电镀纳米晶铜镀层的研究

在硫酸盐镀液体系中进行不锈钢表面电镀铜实验,分别研究了镀液组成、搅拌方式对镀层宏观形貌及微观形貌的影响,同时研究了脉冲电流密度对镀层织构的影响。结果表明:镀液组成、搅拌方式对镀层的宏观形貌及微观形貌有较大影响;脉冲电流密度(1~7A/dm2)对镀层的晶面择优取向无影响。在含有适量添加剂的硫酸盐镀液体系中,采用超声波搅拌并在脉冲电流密度为1A/dm2的条件下,得到光亮度良好、结晶致密、晶粒尺寸为70nm左右的纳米晶铜镀层。     

化学复合镀中金刚石颗粒的分散对复合镀层性能的影响

通过数值仿真,研究了镀槽结构与搅拌速率对镀液流场和镀液中金刚石颗粒分布特性的影响,并制备了镍–磷–金刚石复合镀层,研究了镀槽结构与搅拌速率对镀层中金刚石含量、粒径分布以及镀层显微硬度和耐磨性的影响。结果表明,镀槽中添加挡板和提高搅拌速率,可以明显改善镀液流场的均匀性,有利于金刚石颗粒在镀液与镀层中的分散与均匀分布,显著提高复合镀层的显微硬度与耐磨性;当镀槽中有挡板、搅拌速率为600 r/min时,所制备的微米金刚石–镍–磷复合镀层经400°C热处理1 h后,显微硬度高达1 442 HV,镀层几乎无磨损。     

电沉积Cu-Sn-Zn-PTFE复合镀层及其性能的研究

针对Cu-Sn-Zn合金镀层自润滑性能差的缺点,在Cu-Sn-Zn合金镀液中加入聚四氟乙烯(PTFE)乳液,采用电沉积方法在45#钢表面制备了Cu-Sn-Zn-PTFE复合镀层。镀液组成和工艺条件为:焦磷酸铜24g/L,氯化锌12g/L,甲基磺酸锡15g/L,焦磷酸钾20g/L,酒石酸钾钠22g/L,全氟辛基磺酸钾18g/L,PTFE乳液32g/L,温度50~60℃,pH值11.5,电流密度1.2A/dm~2,搅拌转速300~600r/min,时间120min。考察了镀液中PTFE的质量浓度对镀层的耐磨性、显微硬度、结合力、PTFE的质量分数、外观的影响,并表征了Cu-Sn-Zn-PTFE复合镀层的表面形貌、结构和成分。随着镀液中PTFE的质量浓度的增加,镀层的耐磨性改善,显微硬度和结合力下降,PTFE的质量分数先增大然后保持不变。镀液中PTFE的最佳质量浓度为32g/L,在此条件下制得的Cu-Sn-Zn-PTFE复合镀层的综合性能最佳。     

电沉积Ni-Fe纳米合金工艺研究

采用直流电沉积方法在镀液中加入复合有机添加剂制备了镍铁纳米合金镀层。利用扫描电镜分析镀层形貌及晶粒尺寸,研究了硫酸亚铁铵浓度、电流密度、pH值对镀层中铁含量的影响,测定了镀层的耐腐蚀性能及结合力。结果表明,该纳米镀层表面致密、平整,且结合强度、耐腐蚀性能优良。     

碳钢表面铜-碳化硅纳米复合镀层的制备及其性能研究

在Q235碳钢表面先预浸镀铜,然后采用超声-电沉积方法获得Cu-SiC纳米复合镀层。研究了纳米SiC含量对纳米复合镀层表面形貌的影响,讨论了阴极电流密度、超声功率、温度和电沉积时间对复合镀层显微硬度的影响,获得了较佳的工艺条件:镀液中SiC纳米颗粒含量9g/L,阴极电流密度6A/dm2,超声波功率200W,镀液温度30°C,电沉积时间40min。在此条件下制备Cu-SiC纳米复合镀层,测试了镀层的结合力,并与普通铜镀层进行比较,研究了复合镀层的表面形貌、显微硬度以及在3.5%NaCl溶液中的电化学阻抗谱(EIS)。结果表明,所制备的复合镀层结合力良好,其表面颗粒尺寸在0.5～1.0μm之间(小于普通铜镀层的1～4μm),显微硬度和反应电阻分别为294.6HV和2446.5.cm2(大于普通铜镀层的162.0HV和1538.7.cm2)。Cu-SiC纳米复合镀层具有较好的机械性能和耐腐蚀性能。     

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.     

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.     

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.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.