Correlation between car ownership and leukaemia: Is non-occupational exposure to benzene from petrol and motor vehicle exhaust a causative factor in leukaemia and lymphoma?

Although there is widespread agreement that many cancers have environmental causes we are often unable to see associations between specific cancers and exposure to environmental chemicals. One might also speulate that the more widespread, common-place and normal a chemical exposure is perceived to be then the less likely it will be that the exposure is recognised, let alone be considered to cause cancer. Widespread contamination of air by chemicals associated with internal combustion may be an example of one such invisible carcinogenic exposure. Yet evidence is available which suggests that many leukaemia and lymphoma cases, as well as other cancers, may be caused by this mundane and ubiquitous environmental contamination. The hypothesis is developed that leukaemia clustering as well as national leukaemia incidence may be related to non-occupational exposure to benzene formed by petrol combustion and resulting from petrol evaporation¹. The possible association between exposure to fuel vapours, internal combustion products and cancer merits much closer examination than it receives at present.     

香豆素-3-羧酸与1-辛烷磺酸钠共插层LEuH及敏化发光性能?

本文采用水热法合成了NO-3型层状铕氢氧化物(NO3-LEuH),通过离子交换法将去质子的香豆素-3-羧酸和1-辛烷磺酸根离子引入前体LEuH的层间,改变香豆素-3-羧酸和1-辛烷磺酸钠的比例得到了一系列发光强度不同的复合体.采用X-射线粉末衍射仪(XRD),红外吸收光谱仪(IR),和荧光分光光度计(PL)等方法研究了其结构及性质,结果表明香豆素-3-羧酸的插入能有效敏化层板Eu3+的红光发射.     

十二烷基磺酸钠在赤铁矿表面吸附动力学

利用带耗散功能的石英晶体微天平研究十二烷基磺酸钠在Fe2 O3石英晶体谐振器表面的吸附动力学及吸附层构象。结果表明：十二烷基磺酸钠在赤铁矿表面的吸附是一个快速达到吸附平衡的过程,pH值对十二烷基磺酸钠的吸附影响较为明显,pH值在3~9的范围内,随着pH值增加,药剂吸附层黏弹性逐渐增大,吸附层稳定性减弱,赤铁矿回收率逐渐下降,十二烷基磺酸钠的吸附过程只有一个吸附阶段,且吸附过程符合准一级动力学模型,吸附层不发生明显构象变化;当pH值为10和11时,十二烷基磺酸钠吸附量明显增加,赤铁矿回收率也开始回升,吸附过程存在多个吸附阶段,吸附的第一阶段符合准二级动力学模型,吸附的第二阶段符合Elovich方程,并且随着吸附的进行,吸附层发生明显构象变化。     

Synthesis and application of bilayer-surfactant-enveloped Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles: water-based bilayer-surfactant-enveloped ferrofluids

Superparamagnetic carbon-coated Fe₃O₄ nanoparticles with high magnetization (85 emu·g-1) and high crystallinity were synthesized using polyethylene glycol-4000 (PEG (4000)) as a carbon source. Fe₃O₄ water-based bilayer-surfactant-enveloped ferrofluids were subsequently prepared using sodium oleate and PEG (4000) as dispersants. Analyses using X-ray photoelectron spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy indicate that the Fe₃O₄ nanoparticles with a bilayer surfactant coating retain the inverse spinel-type structure and are successfully coated with sodium oleate and PEG (4000). Transmission electron microscopy, vibrating sample magnetometry, and particle-size analysis results indicate that the coated Fe₃O₄ nanoparticles also retain the good saturation magnetization of Fe₃O₄ (79.6 emu·g-1) and that the particle size of the bilayer-surfactant-enveloped Fe₃O₄ nanoparticles is 42.97 nm, which is substantially smaller than that of the unmodified Fe₃O₄ nanoparticles (486.2 nm). UV–vis and zeta-potential analyses reveal that the ferrofluids does not agglomerate for 120 h at a concentration of 4 g·L-1, which indicates that the ferrofluids are highly stable.     

粒度分布对赤铁矿浮选的影响

以赤铁矿为研究对象,通过浮选试验、扩展的DLVO(EDLVO)理论和凝聚动力学研究了粒度分布(粒径小于18μm的微细粒比例)对赤铁矿浮选的影响.浮选结果表明赤铁矿的浮选回收率与粒度的大小和分布有关,粗粒(粒径大于18μm)赤铁矿的粒度较大时或粒度分布均衡时(微细粒与粗粒含量接近)浮选回收率较高.EDLVO理论计算表明微细粒赤铁矿与粗粒赤铁矿之间存在吸引力,且吸引力的大小与粗粒粒度正相关;凝聚动力学分析表明粒度分布均衡时颗粒间的凝聚速率较大.这是粒度分布对赤铁矿的浮选回收率产生影响的主要原因.     

亚甲基蓝测定微量肝素钠的研究

研究肝素钠与碱性亚甲基蓝之间的相互作用，对反应机理进行初步的探讨.结果表明，在pH 4.6的HAc-NaAc缓冲溶液中，肝素钠与亚甲基蓝碱性染料形成离子缔合物时，染料发生明显褪色，并且在最大吸收波长664 nm处的吸光度显著下降，下降程度与肝素钠的含量呈线性关系，建立了测定痕量肝素钠含量的新方法.线性范围0~1.6 mg/L，相关系数为0.9964，相对标准偏差为0.8%.该法简便、快速，对样品中肝素钠的测定令人满意.     

曲克芦丁新工艺合成研究

以甲醇钠作为催化剂,芦丁、环氧乙烷为原料在甲醇中制备曲克芦丁.研究了在不同温度、反应时间及压强条件下对产品纯度和收率的影响.经实验证明,在高压釜内压强0.2 MPa、温度75℃条件下经5h反应,无需精制即可得到外标纯度高达80%的曲克芦丁.     

BPT与常见离子的反应及其对铜和银的定性鉴定

用新试剂Ｎ－丁基－Ｎ′－（对氨基苯磺酸钠）硫脲（ＢＰＴ）与１８种阴离子和２６种阳离子反应．在氨性介质中，与银呈茶色，与Ｃｕ２＋呈蓝色络合物．ＢＰＴ对Ａｇ＋和Ｃｕ２＋的检测，灵敏度高（ｃＡｇ＋＝２μｇ／ｍｌ，ｍＡｇ＋＝０．０５μｇ；ｃＣｕ２＋＝０．５μｇ／ｍｌ，ｍＣｕ２＋＝０．０１７μｇ），选择性好，用于矿石，阳极泥及生物试样分析均获满意结果．     

腐植酸钠阻垢机理与性能的探讨

在静态阻垢法的基础上,使用XRD分析法、透光率法对腐植酸钠(HAS)的阻垢性能进行了综合研究,分别探讨分析了HAS对不同Ca2 浓度体系增溶量的影响,HAS对CaCO3垢样成晶过程的影响,HAS对CaCO3颗粒分散程度的影响。得出HAS的阻垢作用主要为较强的晶格畸变作用与分散作用,其络合增溶作用较弱。最后,通过实验与羟基亚乙基二膦酸(HEDP)、聚马来酸(HPMA)进行复配分析了HAS的协同作用。