丹皮酚的合成工艺改进

目的改进丹皮酚的合成工艺。方法以间苯二酚为原料,经乙酰化、甲基化反应,后经重结晶,得到丹皮酚针状结晶。结果合成丹皮酚总收率68%(纯度99.99%)。所得产品经熔点、质谱和核磁共振氢谱等方法确证结构。结论本工艺制备得到高纯度、高收率丹皮酚。制备过程操作简单,适合工业化生产。     

澳大利亚昆士兰州1744勘查区无煤分析与地层对比

1744勘查区首次开展地质勘查工作,但施工钻孔中地层界限不明,所见煤层煤质差。通过对区内无煤成因分析,利用邻区的煤层气勘探深孔,展开了地层对比,最终实现了对本区地层及含煤地层的认识,也为下一步地质工作奠定了基础。     

基于统计推断的惯性定位精度评估方法对比

在对惯导系统精度评估标准统一化研究中,在一定的假设条件下,推导、归纳、整理了四类定位精度的评估算法(TRMS、RMS、σ和CEP)及相应的7个指标间的工程换算关系;利用某型捷联旋转惯导4次实际导航数据进行了仿真分析,从推断算法、指标间换算关系、精度折合效果等方面进行了对比验证,基于理论分析和仿真验证结果表明TRMS评估算法及试验简单且易于转换,并对其精度折合给出合理化建议。     

A pilot study on ^99mTc-3PRGD2 scintigraphy in diagnosis of brain glioma

The ^99mTc-3PRGD₂ targeted SPECT/CT scanning was of significance in detecting differentiated glioma.In this work,the diagnostic value of ^99mTc-3PRGD₂ scintigraphy in brain glioma was evaluated by the ten clinically verified brain glioma patients after obtaining informed consent.The patients first accepted X-ray imaging to localize the detecting regions before administrating with ^99mTc-3PRGD₂ at a mean radioactivity of 849±115 MBq via single intravenous bolus injection 2 h prior to SPECT/CT imaging.Tumor samples for detectingαvβ3 were collected by surgical operations two weeks after the scintigraphy.The results of CT and SPECT scanning were merged and compared.The correlation between tumor occupation（T/N ratio） andαvβ3 expression level were analyzed.The T/N ratios in brain glioma were proportionally correlated to av(33 positive cell percentage（R²=0.9253,p<0.05）.This study primarily evaluated the clinical application of ^99mTc-3PRGD₂ SPECT scintigraphy on brain glioma.The more pathological types and detecting strategies covering a large amount of samples would aid to clarify the potentials.     

Influence of Inactivation Treatment of Ship's Ballast Water on Corrosion Resistance of Ship Steel Plate

The effect of seawater after ultraviolet inactivation on corrosion of a shipbuilding steel plate was investigated by means of natural corrosion potential experiments and immersion corrosion test. The effects of natural seawater and treated seawater after ultraviolet inactivation on corrosion of the selected steel plate samples were compared with each other. The results showed that there was no obvious change in the chemical composition of treated seawater compared with natural seawater. The corrosion potential slightly increased by 10 mV, whereas the corrosion rate rose significantly by 20%. The experiments verified the naturally formed biofilm in the natural seawater for the inhibition of corrosion on the shipbuilding steel plate. The possible influences of ballast water treatment on biofilm by ultraviolet and electrolysis inactivation under the condition of practical usage were also investigated. And it was found that ballast water treatment methods with no continuous disinfection could protect original tank biofilm structure, reducing the intensity of tank corrosion.     

人工神经网络用于电除盐产水水质预测研究

为了实现化工行业高纯水全自动生产,本文利用电除盐（electrodeionization,EDI）技术替代传统的混床技术,并研究了人工神经网络对EDI产水过程模拟仿真的可行性,采用误差反向传播网络（BP网络）建立了进水流量、电导率、pH值以及工作电压与EDI透过水电阻率之间关系的动态模型,并对不同的训练样本归一化方法和训练方法进行比较。结果表明,在网络隐含层层数为1、节点数为13时,采用归一化方法三能够较好的预测EDI透过水电阻率,且该模型可用于EDI除盐过程的动态描述,为实现化工行业高纯水全自动生产奠定了基础。     

基于VB与PCI-1712采集卡的电流监视系统设计与实现

在分析了目前船载雷达天线伺服系统电机电流监视中存在不足的基础上,提出了基于VB与PCI-1712采集卡的电机电流监视系统设计方案,详细说明了PCI-1712数据采集卡的主要驱动函数和特征,搭建了硬件平台并对监视系统的数据采集、数据处理、图形输出、故障报警、数据库、记录输出进行了详细的介绍.     

Effect of ethanol in the coagulation bath on the structure and performance of PVDF-g-PEGMA/PVDF membrane

This report investigated the effect of ethanol content in the coagulation bath on the surface composition, membrane pore size structure, pure water flux, and permeability of the amphiphilic polymer polyvinylidene fluoride (PVDF)-g-poly (ethylene glycol) methyl ether methacrylate (PEGMA)-modified PVDF membrane. The study found that pore size and their distribution and, as a result, membrane permeability, can also be easily controlled by adjusting ethanol content in the coagulation bath. Membrane water fluxes formed by the coagulation baths with 0, 10, 20, and 30% of ethanol were 1843.65, 2774.61, 4391.88, and 5142.35 L (m⁻²·h⁻¹). When the content of ethanol in the coagulation bath is high, the surface enrichment of PEGMA slightly decreases, and the surface becomes rougher. Thus, the decrease of the hydrophilic functional groups on the surface of the membrane and the increase of the roughness leads to the deterioration of the hydrophilicity of the membranes surface. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47380.     

VHF波段60W高效率功率放大器的工程实现

介绍了甚高频(VHF)波段基于BLF647/60W高效率放大器的工程设计与实现方案,在满足总体指标要求下对各级功率放大器的增益进行了合理分配,并在设计中对放大器的效率、带宽和输出功率等指标做了合理的处理。针对关键器件,重点分析了直流偏置电路,输入输出匹配电路,并给出了详细的测试数据,最后介绍了该放大器的散热设计以及在调试过程中需要注意的问题。经测试,各项指标满足要求。     

Research on HTML5 application cache poison attack

HTML5 application cache (AppCache) allowed Web browser to access Web offline.But it also brought a new method of cache poisoning attack that was more persisting.As for websites which used the AppCache,a novel poisoning method RFTM (replace file twice method),in which the attacker replaced the manifest file twice to poison the client’s AppCache,was proposed.Compared with the original attack,the legal server would not receive abnormal HTTP requests from the client in the attack.Therefore,changing the server configuration could not prevent the client from the RFTM AppCache poisoning.To avoid the attack mentioned above,a lightweight signature defense scheme Sec-Cache in application layer was designed.Furthermore,experiments show that it has good performance and compatibility.