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1.
准东煤中钠含量高,燃用时锅炉会出现严重结渣问题。通过向准东煤为原料制取的超纯煤中添加灰的模型化合物,得到合成煤。并在此基础上利用热重-差示扫描量热分析法(TG/DTG/DSC)、X射线衍射仪(XRD)和灰熔融温度测定分析手段,研究Na2O含量对煤燃烧特性和灰熔融性的影响。结果表明:钠主要影响合成煤的着火温度(Ti)与焦炭燃烧阶段,钠含量增加使Ti升高,并且Na2O在灰中质量分数由5%升高至8%后,钠含量增加使焦炭燃烧速率先减小后加快,并能够改善煤粉燃尽特性。钠能够降低灰熔融温度,并在Na2O质量分数高于5%后,温度下降更加明显。在三元相图中钠对莫来石的助熔作用是造成灰熔融温度降低的重要原因。XRD分析表明Na2O含量增加,充当骨架作用的石英在钠的助熔作用下与难熔矿物硅钙石、MgO等生成低熔点长石类矿物,这类矿物在高温下有助熔作用,能够降低灰熔融温度。同时还生成助熔性含钠矿物霞石,加剧了灰熔融。  相似文献   
2.
为构建以新能源为主体的新型电力系统,火电机组在保电供热的同时要承担灵活运行、深度调峰的任务。但传统检测和通信技术受限于实时性差、传输慢、投资高等问题,难以支撑火电机组新需求。先进检测技术和以5G为代表的通信技术通过构建完整的检测传输链条,为以锅炉燃烧系统为代表的火电机组状态研判、运行调整等提供了坚实的技术支撑,但也面临建设投资高、专业人才和标准匮乏等问题。只有从生产实际出发,健全机制、转变观念,才能做实先进检测及通信技术的应用效果。作为智慧电厂的重要组成部分,先进检测和5G通信技术必将为火电整体智能化水平提升提供坚实的基础。  相似文献   
3.
Novel phospholipid (PL)-cyclosporine conjugates were prepared and studied as potential prodrugs for inflammatory bowel disease (IBD). Our approach relies on phospholipase A2 (PLA2), which is overexpressed in the inflamed intestinal tissues, as the prodrug activator to potentially release cyclosporine at the site of inflammation. PL-cyclosporine prodrug conjugates with methylene linkers of various lengths between the sn-2 position of the PL and cyclosporine were synthesized and evaluated for in vitro activation. Surprisingly, despite previous work indicating that conjugates with six methylene linkers between the lipid and drug would suffer rapid enzymatic hydrolysis, with cyclosporine this was not observed. However, compounds with longer linkers (n=10, 12 methylene units) display complete release of the drug by PLA2-catalyzed hydrolysis, thus demonstrating the importance and profound impact of structural fine-tuning. This study represents a proof-of-concept for our hypothesis and a first step towards a truly targeted IBD treatment with cyclosporine that could be administered throughout the GI tract.  相似文献   
4.
This paper proposes a system to detect and measure blink rate to determine fatigue levels. The method involved analysing specific frames to determine that a blink occurred, and then monitoring the time between successive blinks. The program was simulated in python using a Raspberry Pi Zero and a standard USB camera. For the blink rate detection block, a gate level schematic was implemented in Cadence software using 65 nm CMOS technology. The design was based around an asynchronous 6-bit based edge counter which was designed using D-flip-flops. The simulation calculated the average blink rate and compared this to the most recent blink rate. The outcome would determine if an alarm signal should be sent to the alarm. The system consumed 130 μA from a 1.2 V power supply.  相似文献   
5.
The objective of the present paper is to study analytically the performance of four-pocket orifice compensated hydrostatic/hybrid journal bearing system of various geometric shapes of recess operating with micropolar lubricant. The modified Reynolds equation for micropolar lubricant is solved using FEM and the Newton-Raphson method along with appropriate boundary conditions. The results suggest that the influence of micropolar effect of lubricant on bearing performance is predominantly affected by the geometric shape of recess and restrictor design parameter. Therefore, the bearing designer must judiciously choose an appropriate geometric shape of recess in order to get an overall enhanced bearing performance.  相似文献   
6.
The purpose of this study was to investigate the plausibility of delivery of cefotaxime to the brain via intranasal administration. In vitro permeation studies were carried out using Franz diffusion cells, and the effect of different concentrations of chitosan (0.1% w/v and 0.25% w/v) on drug permeation across the bovine olfactory mucosa was determined. Samples were collected from the receiver compartment at different time points and analyzed using HPLC. The amount of cefotaxime that permeated across the olfactory mucosa when 0.25% w/v of chitosan was used as a permeation enhancer was ~1.5- and ~2-fold higher at the end of the first hour and second hour, respectively, over control (29.56 ± 6.18 μg/cm(2)). There was no significant enhancement in drug permeation when 0.1% w/v chitosan was used as the permeation enhancer. Pharmacokinetic studies were carried out using Sprague-Dawley rats. Cefotaxime solution with 0.25% w/v chitosan (40 mg/kg) was administered intravenously (i.v.) to rats in groups 1 and 3 and intranasally to those in group 2 and 4. The time course of drug in the brain was investigated by performing microdialysis in rats of groups 1 and 2. Blood samples were withdrawn from rats in groups 3 and 4, and cefotaxime in plasma was analyzed using HPLC after extraction with a hydrochloric acid-chloroform:1-pentanol (3:1) and phosphate buffer solvent system. Pharmacokinetic parameters were calculated using the trapezoidal rule. The results imply that the drug levels attained in the brain following i.v. and intranasal administrations were comparable. These results suggest that intranasal administration of cefotaxime could be a potential method of delivering antibacterial agents because of it being noninvasive and patient compliant.  相似文献   
7.
The physical properties of chalcogenide-containing squarylium (SQ) dyes with long alkyl chains were examined. The SQ dyes were deposited as Y-type films. The SQ dye of a 6-methylselenazole derivative spontaneously forms a J-like aggregate in Langmuir-Blodgett films at ambient conditions.  相似文献   
8.
Highly conducting Langmuir-Blodgett (LB) films of the tetramethyltetrathia-fulvalene- alkyltetracyanoquinodimethane (TMTTF-Cn TCNQ, where Cn represents CnH2n+1) system are reported. The electron affinities of the acceptors CnTCNQ (n=14, 18 or 22) in solution are almost the same and lie between those of TCNQ and dimethylTCNQ. These TCNQ derivatives form solid charge transfer complexes with TMTTF. The limiting areas of the complexes, normalized to the number of TCNQ derivatives at the air-water interface, are almost the same irrespective of the donor-to-acceptor ratio and of the length of the alkyl chain, indicating that the areas are governed by the TCNQ moiety. The monolayers of TMTTF-Cn TCNQ (n=14 or 18) are transferred onto solid substrates as LB films. Polarized UV-visible absorption spectra indicate that the long axis of TCNQ is parallel to the film surface. These LB films exhibit lateral conductivities as high as 0.4 S cm-1 and 0.1 S cm-1 when n=14 and n=18 respectively.  相似文献   
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