Robust online temperature estimation of a membrane-wall gasifier

The gasifier temperature is a key parameter in the operation of a slag-tapping entrained-flow gasifier.However,there is no effective method for measuring the operating temperature of a membrane-wall-lined gasifier.In this study,a novel robust method for estimation of the online temperature was developed for a membrane-wall gasifier and applied in an industrial SE gasifier.The industrial test results show that the method can estimate the gasifier temperature within 0.04 s,and its value can be reliably obtained.Based on the combination of bench-scale gasifier validation,commercial-scale gasifier operation experience,and the comparison of different simulation methods,the proposed method is accurate and reliable for measuring the operating temperature of a membrane-wall-lined gasifier.

Multi-objective optimization of the cathode catalyst layer micro-composition of polymer electrolyte membrane fuel cells using a multi-scale,two-phase fuel cell model and data-driven surrogates

Polymer electrolyte membrane fuel cells(PEMFCs)are considered a promising alternative to internal combustion engines in the automotive sector.Their commercialization is mainly hindered due to the cost and effectiveness of using platinum(Pt)in them.The cathode catalyst layer(CL)is considered a core component in PEMFCs,and its composition often considerably affects the cell performance(V_(cell))also PEMFC fabrication and production(C_(stack))costs.In this study,a data-driven multi-objective optimization analysis is conducted to effectively evaluate the effects of various cathode CL compositions on Vcelland Cstack.Four essential cathode CL parameters,i.e.,platinum loading(L_(Pt)),weight ratio of ionomer to carbon(wt_(I/C)),weight ratio of Pt to carbon(wt_(Pt/c)),and porosity of cathode CL(ε_(cCL)),are considered as the design variables.The simulation results of a three-dimensional,multi-scale,two-phase comprehensive PEMFC model are used to train and test two famous surrogates:multi-layer perceptron(MLP)and response surface analysis(RSA).Their accuracies are verified using root mean square error and adjusted R^(2).MLP which outperforms RSA in terms of prediction capability is then linked to a multi-objective non-dominated sorting genetic algorithmⅡ.Compared to a typical PEMFC stack,the results of the optimal study show that the single-cell voltage,Vcellis improved by 28 m V for the same stack price and the stack cost evaluated through the U.S department of energy cost model is reduced by$5.86/k W for the same stack performance.

Hematoma within the Outer Membrane of the Arachnoid Cyst Located in the Middle Fossa: A Mechanism of Development of Chronic Subdural Hematoma Associated with Arachnoid Cysts

It is well known that chronic subdural hematoma (CSDH) occasionally arises in patients harboring an arachnoid cyst (AC) located in the middle fossa. Although the pathogenesis of CSDH associated with ACs remains unknown, several possible mechanisms have been proposed. In many reported cases, the patients with ACs in the middle fossa would be symptomatic according to development of CSDH. A 9-year-old girl presenting with a headache, nausea, and diplopia was referred to our department. Magnetic resonance imaging showed an AC in the left-side middle fossa and ipsilateral CSDH with a remarkable mass effect. Irrigation of the CSDH, partial removal of the outer membrane of the AC and CSDH, and endoscopic cystocisternostomy were performed to relieve her symptoms. Postoperative clinical course was excellent. Histopathological examination of the outer membrane of the CSDH demonstrated an arachnoid cell layer and hemorrhage from the granulation inside the membrane, and collagen fibers outside the membrane. These findings strongly suggested that the membrane and the content of the CSDH were derived from the outer membrane of the AC, and the CSF including the hemorrhage within the membrane, respectively. Laceration and hemorrhage from granulation tissue within the outer membrane of the AC are considered as one of the developmental mechanisms of the CSDH associated with AC in the middle fossa.

New perspective in statistical modeling of wall-bounded turbulence

Despite dedicated effort for many decades,statistical description of highly technologically important wall turbulence remains a great challenge.Current models are unfortunately incomplete,or empirical,or qualitative.After a review of the existing theories of wall turbulence,we present a new framework,called the structure ensemble dynamics （SED）,which aims at integrating the turbulence dynamics into a quantitative description of the mean flow.The SED theory naturally evolves from a statistical physics understanding of non-equilibrium open systems,such as fluid turbulence, for which mean quantities are intimately coupled with the fluctuation dynamics.Starting from the ensemble-averaged Navier-Stokes（EANS） equations,the theory postulates the existence of a finite number of statistical states yielding a multi-layer picture for wall turbulence.Then,it uses order functions（ratios of terms in the mean momentum as well as energy equations） to characterize the states and transitions between states.Application of the SED analysis to an incompressible channel flow and a compressible turbulent boundary layer shows that the order functions successfully reveal the multi-layer structure for wall-bounded turbulence, which arises as a quantitative extension of the traditional view in terms of sub-layer,buffer layer,log layer and wake. Furthermore,an idea of using a set of hyperbolic functions for modeling transitions between layers is proposed for a quantitative model of order functions across the entire flow domain.We conclude that the SED provides a theoretical framework for expressing the yet-unknown effects of fluctuation structures on the mean quantities,and offers new methods to analyze experimental and simulation data.Combined with asymptotic analysis,it also offers a way to evaluate convergence of simulations.The SED approach successfully describes the dynamics at both momentum and energy levels, in contrast with all prevalent approaches describing the mean velocity profile only.Moreover,the SED theoretical framework is general,independent of the flow system to study, while the actual functional form of the order functions may vary from flow to flow.We assert that as the knowledge of order functions is accumulated and as more flows are analyzed, new principles（such as hierarchy,symmetry,group invariance,etc.） governing the role of turbulent structures in the mean flow properties will be clarified and a viable theory of turbulence might emerge.

Isolation and characterization of a novel wall-associated kinase gene TaWAK5 in wheat(Triticum aestivum)

Wall-associated kinases(WAKs) play an important role in plant defense and development.Considerable progress has been made in understanding WAK genes in Arabidopsis thaliana.However, much less is known about these genes in common wheat. Here, we isolated a novel wheat WAK gene TaWAK5 from sharp eyespot disease-resistant wheat line CI12633,based on a differentially-expressed sequence identified by microarray analysis. The transcript abundance of TaWAK5 was rapidly increased following inoculation with the pathogen Rhizoctonia cerealis. TaWAK5 in resistant wheat lines was induced to higher levels than in susceptible lines at 7 days post inoculation with R. cerealis. The expression of TaWAK5 was also induced by treatments with exogenous salicylic acid, abscisic acid, and methyl jasmonate. The deduced TaWAK5 protein contained a signal peptide, two epidermal growth factor(EGF)-like repeats, a transmembrane domain, and a serine/threonine protein kinase catalytic domain. Subcellular localization analyses in onion epidermal cells indicated that the TaWAK5 protein was localized to the plasma membrane. Virus-induced gene silencing of TaWAK5 in CI12633 plants showed that the silencing of TaWAK5 did not obviously impair wheat resistance to R. cerealis, suggesting that TaWAK5 may be not the major gene in wheat defense response to R. cerealis, or that it is functionally redundant with other genes. This study paves the way for further research into WAK functions in wheat stress physiology.

Thin-Walled Tube Extension by Rigid Curved Punch

Computer model is developed for non-steady and steady-state process of thin-walled tube extension by the rigid punch with curved profile. Rigid-plastic membrane shell theory with quadratic yield criterion is used. Tube material normal anisotropy, work hardening, wall thickness variation and friction effects are considered. FORTRAN programs of the model predict distributions of the thickness, meridian stress, yield stress and pressure along curved generator of deformed tube and the tube extension force versus punch displacement relation. Model predictions are correlated with experimental data.

Optimization the Cell Wall Degrading Enzymes and Technique for Isolation of Protoplasts in Potato

Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a mechanical or an enzymatic process, results in the production ofprotoplast. Protoplasts are useful tools to study the uptake and transport ofmacromolecules and production of somatic hybrids. Protoplasts can be obtained from all types of actively growing young and healthy tissues. The most convenient and widely used source of plant protoplasts is leaf. Juvenile seedling tissues, cotyledons are other alternative tissues most frequently used for protoplasts isolation. All the environmental and genotypic factors, which affect the cell wall thickenings and compactness indirectly, influence the number of protoplasts recovered. Protoplasts are isolated by two methods, mechanical and enzymatic. The enzyme mixture solution of celluiose/macerozyme is used to digest the cell wall. The critical factors affecting the obtaning ofprotoplasts are the kinds of cell wall degrading enzymes, the physiological state of plant leaves, the type of osmotic stabilizers and the composition of reaction solution. With the improvement of technique and enzyme combination rate, the yield of collected protoplasts will be increased higher.

HYGROTHERMAL PERFORMANCE ASSESSMENT OF ICF WALLS WITH DIFFERENT MOISTURE CONTROL STRATEGIES AND WALL DESIGNS

The initial high moisture content of concrete and the low vapor permeability of insu-lation layers on both sides of the concrete complicate the drying process of Insulated Concrete Forms(ICF).In order to facilitate the moisture transport and enhance the drying process,different moisture control stratcgics and wall designs can be implc-mented.The application of an air and vapor barrier is one of the most common moisture control stratcgics.In this paper,the impact of vapor permcance of an air and vapor barriers on the hygrothermal performance of an ICF wall in three differ cnt cold and wet climates is examined using a validated Hcat-Air-Moisture transfer model.The hygrothermal performance of an ICF wall assembly with different types of barriers and locations in the wall system for scveral wall designs is invcstigated.Results indicate that a smaller thickness of insulation on the outside facilitates remov-ing the moisture towards the outside and installing low permcance air/vapor barrier systems on the outside prohibits drying and drives the moisture to the inside.Our findings also show that with the proper sclection of insulation thickncss and vapor control stratcgy moisture-related problems can be avoided.

A cellular scale numerical study of the effect of mechanical properties of erythrocytes on the near-wall motion of platelets

The effect of mechanical properties of erythrocytes on the near-wall motion of platelets was numerically studied with the immersed boundary method. Cells were modeled as viscous-fluid-filled capsules surrounded by hyper-elastic membranes with negligible thickness. The numerical results show that with the increase of hematocrit, the near-wall approaching of platelets is enhanced, with which platelets exhibit larger deformation and orientation angle of its near-wall tank-treading motion, and the lateral force pushing platelets to the wall is increased with larger fluctuation amplitude. Meanwhile the near-wall approaching is reduced by increasing the stiffness of erythrocytes.

锅炉捕渣屏失效原因分析及预防措施

通过宏观特征、化学成分、力学性能分析,以及金相检验、硬度检测和电镜观察等技术手段,对捕渣屏水冷壁管爆管和断管失效原因进行分析。结果表明,锅炉炉顶落焦导致管道韧性断裂,产生断口。断口管与爆口管为同一水冷壁壁管,由于断口处工质泄漏,管道中的介质流量减少,导致管壁温度迅速上升,材料性能急剧下降,最终发生爆管。建议电厂在运行期间控制结焦,在检修期间加强对泄漏部位和水冷壁外敷设的耐热材料的检查,并及时修复脱落的耐热材料。

猬木霉M6-5挥发性物质对香梨采后链格孢细胞膜和细胞壁的影响

本研究探讨了猬木霉M6-5挥发性物质对香梨采后黑斑病菌链格孢(Alternaria alternata)细胞膜和细胞壁的影响。首先将生长5 d的猬木霉培养基与含链格孢菌饼培养基对扣,测定30℃培养3、5、7 d的抑菌效果;通过扫描电镜和透射电镜观察处理组和对照组链格孢菌丝体;收集两组链格孢菌丝体,采用碘化丙啶(propidiumiodide,PI)染色法观察链格孢细胞膜完整性,测定电导率等细胞膜相关指标;使用钙荧光白(calcofluor white,CFW)染色法测定链格孢顶端生长细胞的形态变化,并进行碱性磷酸酶(alkaline phosphatase,AKP)活力和N-乙酰葡糖胺质量浓度分析。结果表明:在培养期间内,猬木霉产生的挥发性物质对链格孢均具有良好的抑菌效果,处理组链格孢菌丝出现皱缩、肿胀和部分断裂的现象,细胞质基质减少情况比对照组更严重,局部伴有质壁分离现象;而对照组菌丝则生长正常,孢子结构完整,切面结构清晰,胞质均匀,细胞壁和细胞膜结构正常。经猬木霉M6-5挥发性物质处理后,处理组链格孢电导率、丙二醛水平、蛋白质和核酸泄漏量均显著高于对照组;PI染色观察到处理组链格孢菌丝体发出红色荧光,说明猬木霉挥发性物质破坏了链格孢细胞膜的完整性,导致细胞内容物外泄,细胞膜的正常功能受到显著破环。CFW染色观察到两组链格孢菌丝体荧光强度无明显差异,处理组和对照组的AKP活力和N-乙酰葡糖胺质量浓度也无显著差异,说明猬木霉挥发性物质对链格孢细胞壁未产生破坏作用,其主要作用靶位也并不是细胞壁。综上,猬木霉M6-5挥发性物质的抑菌靶点是链格孢的细胞膜。

多孔材料抑制氢气爆轰实验装置研究

由于氢气具有点火能低、燃烧范围宽的特性,因此其爆轰产生的破坏力巨大,在氢气输送管道中安装多孔材料,可阻碍氢气爆轰产生的爆轰波的传播。该文搭建了预混气爆轰实验系统,在圆形光滑管道中改变初始压力、多孔材料的孔隙度及材料类型,研究多孔材料抑制氢气爆轰的性能。使用压力传感器、烟膜和数据采集系统采集爆轰波数据,分析爆轰波的传播速度、侧壁烟膜结果、胞格线与传播方向的夹角以及胞格结构等,得到了多孔材料对氢气爆轰抑制作用的规律,对减轻氢气爆炸事故造成的危害具有理论意义和工程应用价值,有助于推动氢能源的大规模利用。

抗菌肽LL-1对肺炎克雷伯菌ATCC 700603的抗菌机制

【目的】探明新抗菌肽LL-1对肺炎克雷伯菌(Klebsiella pneumoniae)的抗菌效果和机制。【方法】测定抗菌肽LL-1对肺炎克雷伯菌的最小抑菌浓度(minimum inhibitory concentration,MIC),通过抑菌曲线评价抗菌肽LL-1对肺炎克雷伯菌的体外抗菌效果;通过检测碱性磷酸酶(ALP)、β-半乳糖苷酶(β-galactosidase)、核酸、蛋白质的泄露,评价抗菌肽LL-1对肺炎克雷伯菌细胞膜和细胞壁的影响;通过核酸凝胶电泳检测抗菌肽LL-1与肺炎克雷伯菌DNA的结合作用;通过扫描电子显微镜观察抗菌肽LL-1对肺炎克雷伯菌菌体形态的影响。【结果】抗菌肽LL-1对肺炎克雷伯菌具有良好的抗菌活性,MIC为50μg/mL;抑菌曲线表明,抗菌肽LL-1对肺炎克雷伯菌具有生长抑制作用,且2 MIC的抗菌肽LL-1在6 h内能完全抑制肺炎克雷伯菌;抗菌肽LL-1能导致肺炎克雷伯菌的ALP和β-半乳糖苷酶发生泄漏,且1/4 MIC的抗菌肽LL-1即可导致其泄漏量极显著高于对照组(P<0.01);核酸和蛋白质泄露的检测结果进一步证实抗菌肽LL-1能导致肺炎克雷伯菌胞内容物外流;此外抗菌肽LL-1还能与肺炎克雷伯菌DNA结合;扫描电子显微镜观察显示,抗菌肽LL-1会导致肺炎克雷伯菌表面变得粗糙、菌体变形等。【结论】抗菌肽LL-1能增加肺炎克雷伯菌细胞壁和细胞膜的通透性,并结合其DNA,从而发挥抗菌作用,本研究结果将为深入研究抗菌肽LL-1对肺炎克雷伯菌的抗菌机制奠定基础。

The connection of cytoskeletal network with plasma membrane and the cell wall

The cell wall provides external support of the plant cells, while the cytoskeletons including the microtubules and the actin filaments constitute an internal framework. The cytoskeletons contribute to the cell wall biosynthesis by spatially and temporarily regulating the transportation and deposition of cell wall components. This tight control is achieved by the dynamic behavior of the cytoskeletons, but also through the tethering of these structures to the plasma membrane. This tethering may also extend beyond the plasma membrane and impact on the cell wall, possibly in the form of a feedback loop. In this review, we discuss the linking components between the cytoskeletons and the plasma membrane, and/or the cell wall. We also discuss the prospective roles of these components in cell wall biosyn- thesis and modifications, and aim to provide a platform for further studies in this field.

镉胁迫对酵母细胞质膜功能和细胞壁结构的影响

为了探究重金属镉(Cd)污染的细胞毒性及Cd超富集微生物的选育,以最常用的模式生物酿酒酵母为研究对象,探索了Cd胁迫细胞毒害的靶点及相关基因过表达对细胞抗性的影响。通过基因突变菌株对Cd胁迫生长抑制分析,细胞内活性氧(ROS)和脂质过氧化(MDA)水平的生化检测,探究Cd毒的机制;采用ICP-AES、GC-MS和扫描电子显微镜检测Cd胁迫对细胞内Na/K离子平衡、膜脂组成、细胞壁结构的影响。影响膜脂合成和细胞壁完整性的基因MGA2、PAH1和CHS1突变对Cd敏感,细胞内ROS和MDA水平随Cd处理浓度升高而提高;Cd胁迫破坏细胞Na/K离子平衡,影响细胞脂质代谢,棕榈酸升高、油酸降低;细胞壁的破损率增加,过表达几丁质合成关键基因CHS2有利于维护细胞壁的完整性、提高细胞对Cd的抗性。细胞质膜和细胞壁是Cd胁迫最重要的靶点,为Cd污染的生物治理提供理论基础。

Cobalt single-atom catalyst tailored ceramic membrane for selective removal of emerging organic contaminants

Water reuse is an effective way to solve the issues of current wastewater increments and water resource scarcity.Ultrafiltration,a promising method for water reuse,has the characteristics of low energy consumption,easy operation,and high adaptability to coupling with other water treatment processes.However,emerging organic contaminants(EOCs)in municipal wastewater cannot be effectively intercepted by ultrafiltration,which poses significant challenges to the effluent quality and sustainability of ultrafiltration process.Here,we develop a cobalt single-atom catalyst-tailored ceramic membrane(Co1-NCNT-CM)in conjunction with an activated peroxymonosulfate(PMS)system,achieving excellent EOCs degradation and anti-fouling performance.An interfacial reaction mechanism effectively mitigates membrane fouling through a repulsive interaction with natural organic matter.The generation of singlet oxygen at the Co-N3-C active sites through a catalytic pathway(PMS/PMS*/OH*/O*/OO*/1 O_(2))exhibits selective oxidation of phenols and sulfonamides,achieving>90%removal rates.Our findings elucidate a multi-layered functional architecture within the Co1-NCNT-CM/PMS system,responsible for its superior performance in organic decontamination and membrane maintenance during secondary effluent treatment.It highlights the power of integrating Co1-NCNT-CM/PMS systems in advanced wastewater treatment frameworks,specifically for targeted EOCs removal,heralding a new direction for sustainable water management.

An ultrasound simulation method for carotid arteries with a wall structure of three membranes

Ultrasound simulation for carotid arteries is helpful to the performance assessments of vessel wall detection and signal processing methods by using ultrasound techniques. An ul- trasound simulation method of carotid artery wall with a three-membrane structure is proposed in present study. According to the ultrasound speckle distributions varying with the shapes and densities of scatterer distributions, as well as the statistic results of the clinical images, the parameters of distributions, densities and intensities of scatterers for different kinds of tissues in the carotid artery phantoms are determined. Each region is acoustically characterized using FIELD II software to produce the radio frequency echo signals, from which ultrasound images are derived. The results based on 30 simulations show that the echo distributions of the intimae, mediae, adventitias and blood are consistent with the clinical ones. Moreover, compared with the results from the central frequency of 8 MHz, the mean measurements for thicknesses of the intima, media and adventitia membranes, as well as the lumen diameter from the simulation images based on 12 MHz are the same as the preset ones, and the maximum relative errors are the 4.01%, 1.25%, 0.04% and 0.15%, respectively. The simulation under this condition is more realistic.

地下连续墙作防渗结构新的思考与实践

一般地下连续墙具有挡土、防渗的作用,但是其结构存在着施工冷缝等不利因素。因此,亟需探索新的地下连续墙结构,补足地下连续墙结构上的不足。基于相关实践,对防渗膜地下连续墙、钢箱地下连续墙以及钢筋笼附膜地下连续墙3种工艺进行了介绍,并与一般地下连续墙进行了包括防渗能力、结构整体性、综合受力能力以及施工难易程度、施工成本等方面的对比。相关工艺可以为类似工程项目施工提供参考。

侧吹炉烟道结构分析及设计要点

侧吹炉生产中若原料所含杂质成分过多、工艺控制不当等,易导致侧吹炉烟道内黏接严重,从而影响侧吹炉的作业率,甚至对安全生产会有影响。通过分析侧吹炉烟道内黏结形成的原因,对比了目前国内冶炼厂均有实际应用的3种侧吹炉烟道结构形式,分析其各自的结构特点和优缺点。对侧吹炉砖砌烟道的方案设计提出需要认真考虑的设计要点。

膜式壁堆焊设备在锅炉制造行业中的应用研究

在锅炉制造行业中,膜式壁堆焊设备的应用较为常见。阐述堆焊的特点及其应用,分析膜式壁堆焊设备的工艺规范和设备要求,希望能够为膜式壁堆焊设备在锅炉制造行业中的应用提供参考。