硫化物氧化兼性自养金色链霉菌LD48培养的影响因素研究

硫化物氧化、兼性自养金色链霉菌LD48在以Na3S为唯一硫源的条件下对硫化物氧化酶产生的最适接种量为1％。在试验的pH值范围内,起始培养最适pH值为7．4。随着培养液中乙醇体积分数由1％～5％增加,菌体生长和硫化物氧化活性的积累都在下降。酵母提取物是一有效的生长刺激因子,在无机氮源(NH4)2HPO4的基础上添加0.15％的酵母提取物,能够提高菌体生物量95％。S2O3^2-与SO4^2-对菌体生长和代谢产物积累都有严重的抑制作用。培养过程分析表明,培养56h硫化物氧化酶产生达到稳定水平。     

水泥硬化体在(NH4)2SO4溶液中的溶解动力学

水泥基材料在服役过程中会受到来自外界的腐蚀,其中(NH4)2 SO4腐蚀是一种较为严重的硫酸盐腐蚀.通过测定水溶液中的pH值的变化分析水泥硬化体在(NH4)2 SO4溶液中的溶解过程.结果表明,水泥硬化体粉末在(NH4)2 SO4溶液中的pH值的变化趋势符合Avrami溶解模型,即pH值随时间的增加而增加,从而得出水泥硬化体粉末的溶解速率与(NH4)2 SO4溶液的浓度之间的关系.     

用副产硫酸亚铁生产优质氧化铁

介绍了以钛白粉厂副产的硫酸亚铁为原料,制备氧化铁的工业化生产新工艺。以自制的除杂剂,废铁皮作还原剂,硫酸和氨水调节pH值,PN-133为絮凝剂,有效的去除了各种杂质,尤其是S iO2的去除效果显著,得到精制FeSO4。制备FeCO3条件:反应温度不大于42~43℃,FeSO4溶液密度1.19~1.21 g/cm3,NH4HCO3溶液密度1.07 g/cm3,n(FeSO4)∶n(NH4HCO3)=0.7∶1,开始10~20 m in,FeSO4溶液先以15 L/m in的流速加入到NH4HCO3溶液中,然后再以30 L/m in的流速加入,反应时间1 h。FeCO3经水洗、干燥,在650~700℃煅烧30 m in,得产品Fe2O3,含量99.45%,活性高,质量符合HG/T2574-94优等品的标准。     

铝合金化学镀Ni-Fe-P-B工艺研究

研究了以铝合金为基体，化学镀Ni-Fe-P-B合金工艺及镀速，镀层组成和耐蚀性，通过控制NaH2PO2,KBH4，丁二酸的浓度，金属盐的比率（NH4）2Fe(SO4)2/[(NH4)2Fe(SO4)2 NiSO4]及pH值得到理想的镀层，在NaH2PO230g/L,KBH41.0g/L，金属盐的比率0.4，丁二酸8g/L,pH值9.0-10时，镀速最高，镀层主要为非晶态结构，且与基体结合力优良；耐蚀性良好，在100%NaOH溶液中的耐蚀性能优于在1mol/LHCl和3.5%NaCl溶液中的耐蚀性能；该镀层合金中铁，磷和硼的质量分数分别为27.14%，2.57%和6.07%。     

含硫酸亚铁废溶液的生物氧化过程中氮源对溶解性Fe(Ⅲ)生成量的影响

利用嗜酸性氧化亚铁硫杆菌将含硫酸亚铁废溶液中的Fe2+氧化成Fe3+后用于脱除H2S,同时实现了含硫酸亚铁废溶液的循环利用和H2S的脱除。而溶解性Fe3+较高的生成量是保证该处理系统连续高效运行的关键因素。但在充足氮源和K+条件下大量Fe3+以黄铁矾沉淀形式存在。因此,本文通过控制氮源种类及投加浓度,减少沉淀生成,增大溶解性Fe3+生成量,以期提高H2S的去除效率。结果表明(NH4)2HPO4可替代以往研究中的(NH4)2SO4作为氮源,确定适宜菌体生长的氮源浓度范围为0.33~1 g·L-1。在1 g·L-1(NH4)2HPO4条件下细菌生长无明显停滞期、Fe2+平均氧化速率为0.221~0.229 g·(L·h)-1,Fe3+生成量为7.62~7.72 g·L-1,沉淀量为1.17 g·L-1,因此确定(NH4)2HPO4为1 g·L-1时最能保证H2S的脱除效率。为降低工艺成本,最低可采用0.33 g·L-1为运行浓度。该优化方案不仅保证了菌体的Fe2+氧化活性,而且有效地减少了菌体培养过程中沉淀的产生,获得了较高的Fe3+生成量和增速,为使用含硫酸亚铁废溶液处理H2S的工艺条件优化提供了依据。     

鸡脚脱脂除杂蛋白预处理工艺

以脱脂率、胶原蛋白损失和除杂蛋白效果为指标,研究超声波辅助下对鸡脚进行脱脂除杂蛋白的预处理工艺.采用HPLC测定了鸡脚处理前后羟脯氨酸、脯氨酸、甘氨酸含量.考察了V(石油醚):V(乙醇)=1:1/NaCl溶液法、碱性脂肪酶溶液法、NaOH溶液法对脱脂率的影响.对料液比及超声时间/次数进行优化,得出采用V(石油醚):V(乙醇)=1:1/NaCl溶液法脱脂率最高,其次为碱性脂肪酶溶液法,NaOH溶液法胶原蛋白损失最大.进一步设计V(石油醚):V(乙醇)=1:1与碱性脂肪酶溶液结合的两步法,得到较佳工艺为:第一步,V(石油醚):V(乙醇)=1:1,料液比1:4(g:mL),超声萃取3次,每次用新的溶剂超声10 min;第二步,质量分数为2.5％的脂肪酶溶液(含0.05 mol/L NaOH,pH=8),料液比1:2(g:mL),超声处理40 min;在此工艺下鸡脚脱脂率为96.48％,胶原蛋白损失率为9.31％,处理后鸡脚中羟脯氨酸、脯氨酸、甘氨酸占比与从鸡脚中热水提取的明胶相似.     

碱式碳酸锌生产工艺改进

研究了以菱锌矿为原料通过酸浸、除杂、中和、沉淀、干燥制备碱式碳酸锌和活性氧化锌的生产工艺。以有机沉淀剂SC-1和有机螯合剂QK-8为除杂剂，除铁、锰、重金属等杂质，经过滤、中和、沉淀和干燥得碱式碳酸锌。最佳工艺条件为：有机沉淀剂用量1％（有机沉淀剂占硫酸锌溶液体积分数），有机螯合剂用量1％（有机螯合剂占硫酸锌溶液体积分数）。碱式碳酸锌在600～650℃煅烧3～4h，得到氧化锌质量分数为98.3％～98.5％的活性氧化锌。     

化学共沉淀法制备NiCuZn铁氧体前驱体的热力学分析

对于用化学共沉淀法制备NiCuZn铁氧体前躯体,确定反应体系的共沉淀区域是确保铁氧体组分准确且性能优良的关键.通过对Me-NaOH-H2O(Me=Fe,Ni,Cu,zn)以及Me-NH4HCO3-NH3-H2O体系的热力学分析,得到各金属离子浓度[Me2+]与pH值的关系,确定了体系的完全共沉淀区域.热力学分析表明:在Me-NaOH-H2O体系中,当pH=10～11时,各金属离子可完全共沉淀.在Me-NH4HCO3-NH3-H2O体系中,Ni2+,Cu2+,Zn2+这3种离子和NH3的络合能力很强,在含有NH3的体系中很难实现共沉淀.以NaOH为沉淀剂,pH=10.5的条件下,用氢氧化物共沉淀法制备出了颗粒细小,粒度均匀的NiCuZn铁氧体前驱体微粉.     

对水热合成LiFePO4母液脱磷除铁的研究

水热合成LiFePO4母液中含有大量的Li2SO4和少量的PO4^3-、Fe^2＋,需脱磷除铁后回收硫酸锂。本文选用聚合硫酸铁为絮凝剂和沉淀剂,通过调节Fe／P物质的量比、溶液pH值,可同时去除母液中PO4^3、Fe^2＋得到纯净的硫酸锂。在Fe／P=1．2、pH=10时,净化所得的Li2SO·H2O产品中PO4^3-含量小于0．01％,Fe^2＋含量小于10^-5％。     

YAG超细粉体的制备与表征

以Y2O3、Nd2O3、Al(NO3)3·9H2O、(NH4)2SO4为原料,分别采用碳酸氢铵和碳酸铵两种沉淀剂,通过共沉淀法制备了YAG超细粉体.采用热重-差热分析(TG-DTA)与红外光谱(IR)对前驱体进行分析研究.对不同温度下煅烧的粉体进行X射线衍射(XRD)与透射电镜(TEM)分析.研究结果表明:采用碳酸氢铵作为沉淀剂得到的前驱体经1000 ℃煅烧可获得纯YAG相,颗粒尺寸为60～150 nm;而采用碳酸铵作为沉淀剂得到的前驱体经900 ℃煅烧即可获得纯YAG相,颗粒尺寸较小,约为40～50 nm,具有良好的分散性.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.