重(特)大泄漏事故统计分析及事故模式研究

对新中国成立以来我国化工系统发生的重（特）大、典型泄漏事故进行了统计分析，总结出应优先进行控制和管理的危险性物质，分析了造成这些重（特）大典型泄漏事故的基本原因。结合对已经发生的重（特）大典型泄漏事故的剖析，总结出泄漏扩散事故的7大影响因素，建立了泄漏事故模式，并对各种事故模式的泄漏机理和发生条件进行了研究分析。     

泄漏气体扩散模型的研究与应用

通过对泄漏源模式及泄漏影响因素的分析,以湍流扩散微分方程为基础,对泄漏气体扩散行为模型化,得到有界和无界的烟团和烟羽模型,并进行了实例分析。扩散模式的研究可以确定事故影响范围、危害程度,为事故应急救援,人员撤离等提供参考。     

大型油罐破裂泄漏特征研究

统计了多起油罐破裂事故,并对油罐破裂特征及油品泄漏流场进行分析。通过事故案例统计,总结了三种典型的油罐破裂形式,得到了油罐易发生破裂的位置及原因。对事故案例后果进行分析,将油罐破裂泄漏过程分为两个阶段,并分别对其流场特性进行研究。以平板流动临界雷诺数为判定准则,对油库常见油品泄漏流动雷诺数进行计算,得出泄漏油品的流态绝大多数为完全发展的湍流。     

运输过程中液氨泄漏后果分析及评价研究

选取液氨作为研究对象,在考虑泄漏源的位置、形状大小、运输介质运行状态、风速、大气状况等因素对事故后果的影响,选择适当的事故后果计算模型,并以车辆运行中最常见的连续泄漏事故和瞬间大范围泄漏后的火灾爆炸事故设定事故情景,运用高斯烟羽、烟团模型进行液氨泄漏后果分析,运用蒸气云爆炸模型进行爆炸伤害后果分析。分析车辆运行过程中车辆运行状态、泄漏时间、运行速度等因素对事故后果的影响,采用MAPLE数学计算软件确定中毒和爆炸伤害范围,为制定运输过程中液氨泄漏事故应急预案,指导事故现场人员采取必要的安全防护和进行合理的紧急疏散提供理论依据。     

危险性液体储罐泄漏过程的建模及工程应用

研究建立了2种危险性液体储罐的泄漏源模型及数值方法,通过Visual Basic语言开发了数值模拟软件,结合具体的工程案例进行了数值计算,分析了液面高度、泄漏质量速率、泄漏质量与泄漏时间以及泄漏质量速率、泄漏质量与液面高度的关系,结果表明:建立的模型可以准确描述危险性液体储罐的泄漏过程,且数值模拟软件降低了模型求解时间,具有很强的实用性,从而为危险性液体储罐泄漏事故后果定量风险评价和事故应急救援提供基础数据。     

LNG垂直喷射源连续泄漏扩散的模拟

对液化天然气(LNG)扩散的物理过程进行了理论分析。针对垂直喷射源连续泄漏扩散特点,将液化天然气扩散过程分为重气扩散与被动扩散两个阶段。结合烟羽抬升计算,在两个阶段分别采用SLAB稳态烟羽模型与高斯烟羽模型,建立了液化天然气扩散过程数学模型。研究了垂直喷射源泄漏形式和不同环境条件下的扩散情形。对液化天然气泄漏后混合云团扩散形成的浓度场、温度场和其他特征参数进行了模拟。得到重气扩散阶段随下风向距离增大,扩散云团高度、宽度、温度、密度、云团中液化天然气蒸气含量、水含量的变化规律,被动扩散阶段云团中液化天然气质量分数的变化情况。可以为事故危害范围的测定、事故后人员的疏通和补救工作的指导提供帮助。     

室内燃气泄漏原因及扩散影响因素的分析

以居民住房为研究对象,以各学者的研究成果为依据,深入分析了室内燃气泄漏的基本原因,并且对影响燃气泄露扩散的不同因素,如泄漏源的位置及泄漏方向,泄漏气体的性质,泄漏量,室外风速,障碍物等进行了研究,进而归纳总结了不同影响因素下室内燃气浓度的扩散规律,为事故预防和事故发生后及时采取有效的措施提供依据。     

天然气管道泄漏研究现状分析

天然气管道发生泄漏将造成重大经济损失和环境污染,严重危害泄漏点附近的人民的生命财产安全。因此,在天然气管道发生泄漏后及时准确的检测出泄漏点,以及研究天然气在不同介质中的扩散模型具有重大意义。概述了近年来在天然气管道泄漏方面的多项研究现状;其中最主要的方面在于利用CFD软件结合扩散模型对管道泄漏进行仿真研究。     

液氯储罐泄漏事故后果评价

针对某化工企业液氯储罐泄漏环境风险事故进行后果计算及预测。通过对液氯储罐泄露源强计算及风险事故后果计算,预测出液氯储罐泄漏事故发生后对周围环境的影响,确定了半致死浓度范围和应急撤离半径。     

高压储氢罐不同位置泄漏扩散的数值模拟研究

随着氢能广泛的应用,储氢容器将日益增多,泄漏破坏等事故将不可避免.今建立了高压储氢罐泄漏扩散的模型,提出了研究高压储氢罐泄漏扩散的数值模拟方法.通过对高压储氢罐不同位置发生泄漏扩散的数值计算,得到了不同位置泄漏后的扩散特性.对比数值模拟结果,认为储氢罐侧面与底面位置发生泄漏时,其危险性要远大于储罐顶部发生泄漏.通过数值分析,得出了该模拟条件下的危险区域在射流方向的传输距离与时间的近似关系公式.数值模拟结果可以为加氢站等场所处理氢气泄漏事故提供参考.     

Kinetic models applied to soluble vitamins delivery systems prepared by spray drying

The incorporation of bioactive nutrient compounds such as vitamins into food systems can provide a simple way to develop new functional foods. In this work, the controlled release of two vitamins (vitamins B₁₂ and C), microencapsulated by a spray-drying process, is studied. With a properly designed controlled-release system, the compounds are released at the desired site and time, and at a desired rate. The main kinetic release models are applied and discussed. Also, the main mechanisms associated to the release were identified. The use of models to predict in vivo bio-performance is an advantage in the development of new products.     

生物可降解聚合物纳米微囊微球的制备与应用

对生物可降解聚合物纳米微囊微球的特点、分类、选材、制备、释放机理、应用等各方面进行了系统的阐述。     

微胶囊释放机制概述

控制释放在保护药物免受内在或外界条件的影响,提高药物有效利用率,延长持效期等方面起了重要作用。微囊化是控制释放的一种有效途径,微囊化技术多种多样,微囊化所用壁材也不尽相同,伴随的微胶囊释放机制亦各不相同。文中对几种微胶囊控释机制进行了详细论述,以期对探索高功效、智能化微囊化技术提供参考依据。     

Description of Release Process of Doxorubicin from Modified Carbon Nanotubes

The article discusses the release process of doxorubicin hydrochloride (DOX) from multi-wall carbon nanotubes (MWCNTs). The studies described a probable mechanism of release and actions between the surface of functionalized MWCNTs and anticancer drugs. The surface of carbon nanotubes (CNTs) has been modified via treatment in nitric acid to optimize the adsorption and release process. The modification efficiency and physicochemical properties of the MWCNTs+DOX system were analyzed by using SEM, TEM, EDS, FTIR, Raman Spectroscopy and UV-Vis methods. Based on computer simulations at pH 7.4 and the experiment at pH 5.4, the kinetics and the mechanism of DOX release from MWNT were discussed. It has been experimentally observed that the acidic pH (5.4) is appropriate for the efficient release of the drug from CNTs. It was noted that under acidic pH conditions, which is typical for the tumour microenvironment almost 90% of the drug was released in a relatively short time. The kinetics models based on different mathematical functions were used to describe the release mechanism of drugs from MWCNTs. Our studies indicated that the best fit of experimental kinetic curves of release has been observed for the Power-law model and the fitted parameters suggest that the drug release mechanism of DOX from MWCNTs is controlled by Fickian diffusion. Molecular dynamics simulations, on the other hand, have shown that in a neutral pH solution, which is close to the blood pH, the release process does not occur keeping the aggregation level constant. The presented studies have shown that MWCNTs are promising carriers of anticancer drugs that, depending on the surface modification, can exhibit different adsorption mechanisms and release.     

肥料养分释放性能快速测试方法研究

研究了一种肥料养分释放性能的快速测定方法。依据"淋溶法"原理设计了淋溶装置,考察了淋溶液流量对肥料氮、磷、钾与养分累积释放率的关系,并采用此装置测试了3种不同肥料的氮、磷、钾累积释放率,与实际效果完全一致。研究表明,采用"淋溶法",通过改变淋溶液流量可以实现肥料养分释放性能的快速检测。     

Controlled release from polyurethane films: Drug release mechanisms

In this study, polyurethane-films loaded with diclofenac were used to analyze the drug release kinetics and mechanisms. For this purpose, the experimental procedures were developed under static and dynamic conditions with different initial drug loads of 10, 20, and 30%. In the dynamic condition, to better simulate the biological flow, drug release measurements were investigated at flow rates of 7.5 and 23.5 ml/s. These values indicate the flow rate of the internal carotid artery (ICA) for a normal state of a body and for a person during the exercise, respectively. The experimental data were analyzed and adjusted by Higuchi, Korsmeyer–Peppas, First-order, zero-order, and Peppas–Sahlin models in order to understand the mechanisms contributed. Finally, drug release mechanisms were specified by investigating the model correlation coefficients. Experimental results showed that increasing the flow rate and initial drug loads enhance drug liberation. In addition, the rate of release is more influenced by the drug dosage in the static state. The analysis revealed that diffusion, burst, and osmotic pressure are the principal mechanisms contributed. Moreover, Fickian type was the dominant mechanism at all duration of release. However, it was discovered using Peppas–Sahlin model that the contribution of the diffusion mechanism decreases with increasing flow rate and initial dosage. Furthermore, the tests at different drug dosages showed that the number of stages in medication release profile is independent of the flow rate and the medicine percentage. One can conclude that the drug release kinetic in static state is more influenced by drug dosage compared with dynamic state.     

Attraction of bark beetles (Coleoptera: Scolytidae) to a pheromone trap

The movement of bark beetles near an attractive pheromone source is described in terms of mathematical models of the diffusion type. To test the models, two release experiments involving 47,000 marked spruce bark beetles [Ips typographus (L.)] were performed. The attractive source was a pheromone trap, surrounded by eight concentric rings with eight passive trap stations on each ring. Captures were recorded every 2–10 minutes for the pheromone trap and once for the passive traps. The models were fitted to the distribution in time of the central pheromone trap catch and to the spatial distribution of catch among the passive traps. The first model that gives a reasonable fit consists of two phases: Phase one—After release the beetles move according to a diffusion process with drift towards the pheromone trap. The strength of the drift is inversely proportional to the distance from the traps. Phase two—those beetles attracted to, but not caught by, the pheromone trap are no longer influenced by the pheromone, and their movement is described by a diffusion process without drift. In phase two we work with a loss of beetles, whereas the experiment seems to indicate that the loss of beetles in phase one is negligible. As a second model, the following modification of phase one is considered: After release the beetles move according to a diffusion process without drift, until they start responding to the pheromone (with constant probability per unit time), whereafter they start moving according to a diffusion process with drift. This study, like other release experiments, shows that the efficiency of the pheromone trap is rather low. What is specific for the present investigation is that we try to explain this low efficiency in terms of dynamic models for insect movement. Two factors seem to contribute: Some beetles do not respond to pheromone at all, and some beetles disappear again after having been close to the pheromone trap. It also seems that the motility of the beetles decreased after they ceased responding to the pheromone. Furthermore, the data lend some support to the hypothesis that flight exercise increases the response of the beetles to pheromone.     

景观水体底泥释放分析

根据景观水体的补水情况、水质变化情况,通过控制不同温度和不同的上覆水水质来模拟底泥释放试验说明景观水体的污染源特性、底泥释放污染物(营养盐N、P、COD_(Mn))的规律.得出了温度和上覆水质对底泥释放的影响曲线.同时也说明景现水体内源磷对景观水体的水质存在着潜在的危险性,为预测景观水体的水质变化情况和换水或补水量、补水时间的确定提供必要的依据.     

玉米醇溶蛋白作为阿司匹林缓控释骨架材料的研究

以阿司匹林（Aspirin）为模型药物,玉米醇溶蛋白（Zein）作为骨架材料,采用混合压片法制备了不同配方的药物片剂。紫外比色法测定释放效果,根据药片溶出实验结果进行数理统计,模拟释药方程。结果表明：Zein作为骨架材料的片剂释药时间都达到了6h以上,控制药剂配方中阿司匹林和分散剂淀粉用量的比例,就可以实现不同的控释效果。实验结果表明了玉米醇溶蛋白是一种良好的天然药物缓控释骨架材料。