电化学水处理中碳酸钙结晶形态的研究

研究在电化学水处理中，电场对CaCO3结晶形态的影响。正常情况下， CaCO3形成稳定方解石型，其晶型通常为排列整齐、结构致密、质地坚硬的方解石型，难以去除。但在电场效应作用下，电流为0．3 A、极板间距为50 mm时，电场力能有效地促使CaCO3结晶形式转变为较为疏松的纹石型和球霰石型晶体，使其不容易附着在管道壁上且便于剥离去除。     

重论燃煤发电厂水冲灰管“结垢”机理与其防治的探讨

水力除灰是国内外燃煤电厂普遍采用排灰方式之一。但对于早期兴建电厂而言 ,将水力冲灰进行改造。从投资、场地、环境等都受到一定限制。因此对水冲灰管结垢、防垢、洗垢与防止进行探讨具有一定意义。　　原来对于水冲灰管结垢机理之一 :一般认为是冲灰原水中的重碳酸盐与水作用分解成碳酸盐 ,其反应过程为 :Ca(HCO3 ) 2 Ca CO3 +CO2 +H2 O　　 Ca CO3 从水中分解沉淀出来形成水垢的过程大致认为 :Ca+ 2 CO3 -2 Ca CO3 Ca CO3 Ca CO3溶液过饱和溶液结晶核Ca CO3 Ca CO3无定形体结晶　　过程中的结晶核、无定形体和结晶过程经过…     

多孔碳酸钙微粒的简易制备及其形貌控制

以Na2CO3和Ca(NO3)2为反应物,聚苯乙烯磺酸钠(PSS)为表面活性剂,在室温水溶液中制备了多孔碳酸钙微粒。用FE-SEM对其微观形貌进行观察,发现通过改变PSS用量以及反应物浓度,可以控制微粒的粒径及形貌。在PSS用量为0.5 g?L?1、反应物浓度为0.025 mol?L?1时,合成的Ca CO3为多孔微球,且粒径均一,约为1.2μm。相应的XRD和BET测试显示,多孔Ca CO3微球为球霰石和方解石型的混合晶体。多孔Ca CO3微球表面的纳米孔孔径随反应物浓度增加而减小,比表面积则随之增大。     

SAS/AMPS/IA共聚物阻垢剂对Ca CO3微观形貌影响研究

采用静态阻垢法考察SAS/AMPS/IA在不同pH、浓度下的阻垢性能,并进一步利用X射线衍射(XRD)、扫描电镜(SEM)对投加不同浓度SAS/AMPS/IA时碳酸钙结垢的微观形貌进行分析。结果表明:SAS/AMPS/IA在p H=8、浓度为6mg/L时对碳酸钙阻垢效果最佳,阻垢率达到96.2%。XRD测试Ca CO3晶体特征峰的变化:在一定浓度范围内,随SAS/AMPS/IA的浓度增大,XRD上Ca CO3方解石特征峰峰高显著降低;对应SEM显示Ca CO3晶体破坏程度加大,微观形貌上由方解石逐步向球霰石转变。对SAS/AMPS/IA结构分子式分析表明,其分子链上羧基的吸附作用以及磺酸基的分散作用使得Ca CO3方解石六面体晶面发生扭曲变形,棱角消失,致使结垢体疏松。     

自修复混凝土中微生物矿化方解石的形成机理

分别从矿化产物、pH值、O2、底物4个方面对用于混凝土裂缝自修复的微生物矿化形成方解石机理进行了研究。结果表明:混凝土裂缝自修复细菌矿化产物为方解石型CaCO3,矿化过程需要O2参与;细菌生长过程中pH值从7.0逐渐升高到8.3,碱性环境在细菌矿化过程中起重要作用;CaCO3不是由底物在胞外酶作用下直接分解而得,而是需要经过细菌一系列代谢转换,代谢过程中产生CO2,底物既提供矿化所需的Ca2+源,也提供CO32–来源,其他有机营养物质也可提供CO32–。同时,对该菌株的矿化机理进行了分析,结果表明:细菌生长繁殖过程中创造碱性环境,产生CO2,细菌细胞表面带负电荷,能够吸附Ca2+并作为成核位点,在碱性环境下CO2与Ca2+反应形成CaCO3晶体。     

脉冲和直流电场下阴极结构对CaCO3结晶的影响

电化学诱导循环水系统中的Ca2+在阴极板上以CaCO3的形式沉积,表现出良好的水软化效果。开展阴极板上CaCO3结晶行为的研究有助于提高水软化效率。为探究极板结构和电场形式对CaCO3结晶行为的影响,采用7种不同结构的阴极,分别研究脉冲电场和直流电场中CaCO3的结晶行为。从宏观角度分析不同电场形式下各阴极表面的CaC...     

电石渣浸取液制备超细CaCO_3的碳化工艺研究

以NH_4Cl溶液浸取电石渣得到的Ca⁽²⁺⁾溶液为钙源,以Na_2CO_3为碳化剂,制备超细CaCO_3。研究了Ca(2+)溶液为钙源,以Na_2CO_3为碳化剂,制备超细CaCO_3。研究了Ca⁽²⁺⁾浓度、碳化剂的滴加速度、反应温度、反应时间、pH、[CO32-]/[Ca(2+)浓度、碳化剂的滴加速度、反应温度、反应时间、pH、[CO32-]/[Ca⁽²⁺⁾]摩尔比对CaCO_3产率的影响。结果表明,在Ca(2+)]摩尔比对CaCO_3产率的影响。结果表明,在Ca⁽²⁺⁾浓度0.3 mol/L,Na_2CO_3滴速30 mL/min,温度40℃,反应时间30 min,Ca(2+)浓度0.3 mol/L,Na_2CO_3滴速30 mL/min,温度40℃,反应时间30 min,Ca⁽²⁺⁾溶液的pH为9,[CO32-]/[Ca(2+)溶液的pH为9,[CO32-]/[Ca⁽²⁺⁾]摩尔比1.1的条件下,CaCO_3产率92.07%,纯度97.35%。经X射线衍射和扫描电镜分析,合成的CaCO_3以方解石型为主,并含有部分球霰石型。方解石型含量为62.85%,颗粒为表面光滑致密的立方体结构,粒径为4～9μm,平均晶粒尺寸60 nm;球霰石型含量为37.15%,颗粒为表面不圆滑的球形结构,粒径3～8μm,平均晶粒尺寸28 nm。     

油酸在CaCl2和Ca(OH)2反应体系中对CaCO3晶型和形貌的调控

分别在CaCl2碳化体系中(以CaCl2、CO2、NH3·H2O和油酸为原料)和Ca(OH)2碳化体系中(以Ca(OH)2、CO2和油酸为原料)采用微孔分散碳化法于室温下制备了微纳米CaCO3,并采用XRD、TEM和SEM等表征手段重点研究了油酸对CaCO3晶型和形貌的影响和调控.结果表明:在不添加油酸的CaCl2反应体系中,反应初期生成方解石相,随着反应的进行,球霰石相的含量逐渐增加,而油酸的加入使得该体系整个碳化过程中产物均为球霰石相.另外,油酸的加入还可以加速反应过程,使得球形颗粒的形成时间缩短.而Ca(OH)2反应体系中,整个碳化过程中产物均为方解石相,油酸的加入对晶体类型没有明显影响.     

不同粒径的超细碳酸钙在ABS黄色母粒中的应用

以3种不同粒径的规格型号为CC–1250,CC–2500和CC–6000的超细Ca CO3替代20%的联苯胺黄颜料应用于ABS黄色母粒中,研究了这3种超细Ca CO3对ABS黄色母粒色彩性能的影响。结果表明,超细Ca CO3粒子的粒径越小,其对色母粒的色彩性能影响越小;由含有粒径最小的CC–6000型超细Ca CO3的色母粒所制备的ABS样板反射率曲线及明度值与未加超细Ca CO3的最为接近,且两者的色差最小;由含有CC–6000型和CC–1250型超细Ca CO3的色母粒所制备的ABS薄膜透过率曲线与未加超细Ca CO3的也最为接近。     

聚环氧琥珀酸衍生物对CaCO_3垢的阻垢性能及缓蚀性能研究

使用静态阻垢、缓蚀和电导率法研究了聚环氧琥珀酸衍生物(LCY-PESA)对碳酸钙结晶过程及晶型的影响,发现经LCY-PESA处理后,碳酸钙结晶过程初期晶体生长速度缓慢,存在一个稳定期。在60和80℃时,稳定期可达3 h。碳酸钙垢的SEM和IR分析结果表明,经LCY-PESA处理后的水垢中球霰石的含量增加,方解石含量减少。晶体稳定期的存在和球霰石型碳酸钙的增多,主要是因为LCY-PESA使Ca CO3晶格发生扭曲和分散所致,当LCY-PESA的用量为6 mg?L-1时,阻垢率为96.9%。静态失重实验、电化学实验和SEM分析结果表明:当LCY-PESA的用量在120 mg?L-1时,缓蚀率为63.1%;作为一种以抑制阴极为主混合型缓蚀剂,LCY-PESA的缓蚀作用归因于在金属表面形成了保护膜。     

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.