浅谈静电及其防护

静电危害的严重性和防范的必要性，日益受到人们的注意和重视。本文从静电的产生，静电危害、静电防护等几方面探讨有关静电和静电防护、检测的一些问题。     

静态顶空气相色谱法对土壤中乙醛等物质分析及研究

研究用静态顶空技术处理土壤,从而建立了静态顶空-气相色谱(GC-FID)测定土壤中的乙醛、丙烯醛、丙烯腈和吡啶的检测分析方法。在一定的静态顶空和气相色谱条件下,进行了顶空的时间和温度优化,确定了静态顶空气相色谱法测定土壤中乙醛、丙烯醛、丙烯腈和吡啶方法的检出限,并取得了满意的分离效果、线性回归方程、精密度和准确度。结果表明:用顶空气相色谱法处理土壤样品,可以减少土壤中待测有机物的损失,提高实验分析的灵敏度和准确度。     

钡渣中钡离子的淋溶释放规律

采用静态浸渣正交实验和动态淋溶实验 ,研究了钡渣中钡离子的淋溶释放规律。结果表明 ,在 p H为 5 .6、固液比 1∶ 7、浸取时间 60 min时 ,静态最大浸出率达到 92 .8% ,Ba2 + 的浸出浓度为 42 680 mg/L。动态淋溶释放规律 :淋溶初期当液固比 x<5时呈二次多项式 ,x >5后符合指数衰减模型 C=C0 ·Ψ· e- bx ,p H为 2 .6、5 .6时的模拟雨水下最大 Ba2 +淋溶浓度分别出现在 x为4.0、3 .76处。     

What need to be known about the therapy with static magnetic fields

During the last three decades the interest toward clinical application of magnetic and electromagnetic stimulation increased worldwide. Numerous publications have discussed the possibility of exogenous magnetic fields to initiate beneficial effects on various biological processes, which are of critical importance for healing of different injuries and pathologies. Today, magnetic and electromagnetic fields are increasingly utilized for the treatment of numerous musculoskeletal injuries and pathologies. For example, selected magnetic fields were reported to be beneficial in the treatment of musculoskeletal injuries and post-surgical, post traumatic and chronic wounds, reduction of edema, in the acceleration of pain and stress relief, and thus contribute to healing processes. The application of this modality could be facilitated by establishing the exact dosimetry of application and by searching for biophysical mechanisms of action, as well. It should be remembered that “not all magnets are equal”, therefore the specific medical problem requires a proper diagnostics, a selection of the magnetic field to be applied and a design of the appropriate protocol for treatment. The paper advised that every study and report should carefully explain both the medical problem and the parameters of the applied magnetic field and cautions against generalized statements like “Magnetic field does/does not cause biological response”.     

压装高聚物粘结炸药湿法筛分的研究

针对高聚物粘结炸药的粒度分级 ,研究了一种以水为介质而具有本质安全性的筛分方法 ;根据界面化学原理采用添加润湿剂和消泡剂的技术使筛分工艺进一步完善。数种配方的应用表明 ,该法不仅具有安全、高效的特点 ,而且有利于提高产品的使用性能和安全性     

用于气相色谱分析的样品导入技术及其应用

综述了几种用于气相色谱分析的绿色环保型样品导入技术,如静态顶空技术、吹扫捕集技术、固相微萃取技术和热脱附技术的原理及应用情况,并对这几种方法进行了比较。     

TOF–SIMS surface analysis of chemical components of size–fractioned urban aerosols in a typical heavy air pollution event in Beijing

Size–fractioned atmospheric aerosol particles were collected during a typical heavy air pollution event in Beijing. The organic and inorganic components on the surfaces of the samples were analyzed using time–of–flight secondary ion mass spectrometry(TOF–SIMS).The variation characteristics of the surface chemical composition and influencing factors were studied, and the possible sources of these chemical compositions were identified through principal component analysis. The results showed that inorganic components such as crustal elements and sulfate, and organic components such as aliphatic hydrocarbons and oxygen–containing organic groups were present. Some surface components, such as polycyclic aromatic hydrocarbons, heavy metals and fluorides may exert adverse effects on human health. The species and relative percentages of the chemical components varied with particle size, diurnal and pollution progress. During a heavy pollution event, the species and relative percentages of secondary components such as oxygen–containing organic groups and sulfurous compounds increased, indicating that particles aged during this event. The surface chemical composition of the aerosol particles was affected mainly by emissions from coal combustion and motor vehicles. In addition, air pollution, meteorological factors, and air mass transport also exerted a significant effect on the surface chemical composition of aerosol particles.     

静态液相微萃取-气质联用测定烷基酚方法优化

采用静态液相微萃取前处理方法与气相色谱—质谱联用技术相结合对水样中烷基酚测定方法进行优化。     

Hemming process with counteraction force to prevent creepage

Creepage, a typical phenomenon in the hemming process, can be defined as undesired roll-in of the panel at the bending line. Creepage also reduces the final panel width and makes the hemming radius larger. In this study, experimental observations are reported, and a finite element model, based on the LS-DYNA^® two dimensional plane strain solid formulation, is utilized to study the mechanics of how the hem flange bends and folds during the hemming process. A novel hemming process incorporating a counteraction force is proposed in order to prevent the creepage phenomenon during the hemming process. An experimental hemming tool was designed according to this concept, and optimization of the tooling geometry was carried out utilizing the finite element model. An experimental study was conducted to confirm that the new hemming process can prevent creep be employed to help retain a sharp radius during flanging operation.     

顶空气相色谱分析原理与技术

系统讨论了静态顶空气相色谱的原理,包括多次相平衡法、改变相比法和标准加入定量法。测定了挥发性有机物在气液两相间的分配常数及其在水中的含量。提出了通过测定分配常数作为分析准确度的判据。研究了温度、相比、分配常数和无机盐对顶空分析灵敏度的影响。采用顶空色谱测定了河流底泥中的可酸挥发硫化物。