The effects of different strength of MS media in solid and liquid media on in vitro growth of Typhonium flagelliforme

Objective: To determine the effects of different strength of Murashige and Skoog(MS)media(full,1/2and1/4) in solid and liquid media on in vitro growth of Typhonium flagelliforme(T. flagelliforme), whereby an optimum media composition can be provided for mass propagation of T. flagelliforme.Methods: Rhizome bud of T. flagelliforme was obtained from the axenic in vitro established T. flagelliforme plantlets in Plant Tissue Culture Laboratory, Universiti Teknologi MARA, Shah Alam. Rhizome bud was used as explant and cultured onto shoot proliferation medium under different strength of MS media(full,1/2,1/4) in solid and liquid culture media.Results: After 6 weeks of culture, the number of shoot, number of leaf, number of root,height of shoot, fresh weight, dry weight and chlorophyll content of T. flagelliforme were analyzed. A comparison was made between liquid and solid culture media. The results revealed that the liquid culture media were more effective for all the growth parameters(shoot height, shoot number, leaf number, root number, fresh weight, dry weight, chlorophyll a and chlorophyll b content) compared to solid culture media. Apart from that,this study revealed the positive relationship between strength of MS media and type of culture media(solid and liquid media) to the growth of T. flagelliforme. Growth of T. flagelliforme was improved when MS strength was increased in liquid media. In contrast, growth of T. flagelliforme was improved when MS strength was decreased in solid media.Conclusions: Through this study, an optimum media composition for mass propagation of T. flagelliforme had been established by observing effects of MS media strength and type of culture media(solid and liquid media) on the growth of T. flagelliforme.

Basic Ionic Liquid: A Reusable Catalyst for Knoevenagel Condensation in Aqueous Media

An efficient, environmentally friendly procedure was developed for the condensation of aldehydes/ketones and activated methylene compounds with basic ionic liquid as the catalyst in water. This basic ionic liquid catalyst has a very high activity for Knoevenagel condensation to give the corresponding products in 70%-97% isolated yields under mild conditions. The basic ionic liquid catalyst in aqueous system can be reused for six times without any significant loss of activity.

A Scalar Acoustic Equation for Gases, Liquids, and Solids, Including Viscoelastic Media

The work deals with a mathematical model for real-time acoustic monitoring of material parameters of media in multi-state viscoelastic engineering systems continuously operating in irregular external environments (e.g., wind turbines in cold climate areas, aircrafts, etc.). This monitoring is a high-reliability time-critical task. The work consistently derives a scalar wave PDE of the Stokes type for the non-equilibrium part (NEP) of the average normal stress in a medium. The explicit expression for the NEP of the corresponding pressure and the solution-adequateness condition are also obtained. The derived Stokes-type wave equation includes the stress relaxation time and is applicable to gases, liquids, and solids.

Microscale Infrared Observation of Liquid-Vapor Phase Change Process on the Surface of Porous Media for Loop Heat Pipe

Loop Heat Pipe (LHP) performance strongly depends on the performance of a wick that is porous media inserted in an evaporator. In this paper, the visualization results of thermo-fluid behavior on the surface of the wick with microscopic infrared thermography were reported. In this study, 2 different samples that simulated a part of wick in the evaporator were used. The wicks were made by different two materials: polytetrafluoroethylene (PTFE) and stainless steel (SUS). The pore radii of PTFE wick and SUS wick are 1.2 μm and 22.5 μm. The difference of thermo-fluid behavior that was caused by the difference of material was investigated. These two materials include 4 different properties: pore radius, thermal conductivity, permeability and porosity. In order to investigate the effect of the thermal conductivity on wick’s operating mode, the phase diagram on the q-keff plane was made. Based on the temperature line profiles, two operating modes: mode of heat conduction and mode of convection were observed. The effective thermal conductivity of the porous media has strong effect on the operating modes. In addition, the difference of heat leak through the wick that was caused by the difference of the material was discussed.

微多孔铜表面参数对自驱射流强化池沸腾的影响

为强化池沸腾性能,本文基于一种适用于实际池沸腾强化的自驱射流冲击装置,使用R1336mzz(Z)作为工质,微多孔铜表面为加热表面,实验研究了自驱射流装置对沸腾性能的影响,并参数化研究了微多孔表面制备特征对池沸腾性能的影响,如烧结过程中的铜粉粒径尺寸(43µm、66µm、101µm)以及微多孔层厚度与粒径尺寸之比(4、6、10)。研究结果表明,自驱射流装置的置入确保了液体对表面的持续供给以及促进了气泡的脱离,从而有效增强了微多孔铜表面的临界热流密度(CHF)。然而,自驱射流的存在会对沸腾产生抑制作用,从而造成换热性能的轻微恶化,且抑制程度强弱与铜粉粒径尺寸大小呈正相关、与厚度与粒径之比大小呈负相关。参数化研究结果显示,沸腾换热性能随粒径增大而增大、随厚度与粒径之比增大先增大后降低。微多孔铜表面吸液能力均随铜粉粒径以及厚度与粒径之比的增加而提升,并且大部分情形下,搭配自驱射流装置与否,均不会影响其与CHF的线性正相关。但是,当粒径尺寸为101µm时,自驱射流装置会放大其过小的毛细力所带来的润湿劣势,进而造成CHF的偏低。与非微多孔铜表面的标准池沸腾性能相比,本研究的CHF和hNB@CHF提升幅度分别可达189.2%和337.5%,最佳为CHF=72.0W/cm^(2)和hNB@CHF=87.5kW/(m^(2)·K)。

基于梯度孔隙率的楔形鼻锥相变发汗冷却研究

为提高飞行器鼻锥驻点处的发汗冷却效率,提出了一个孔隙率呈梯度分布的楔形多孔鼻锥,在不同冷却剂注入率下,在亚声速条件下对相变发汗冷却进行了试验与数值研究。结果表明,梯度孔隙率的设置可以有效提高驻点处的冷却效率和多孔表面的整体温度均匀度。冷却剂注入率M=0.125%时,驻点处冷却效率提高了52.4%,整体冷却效率提高了31.7%。数值结果表明,梯度孔隙率通过使多孔内最大压力值从驻点后移来提高前缘处的冷却剂流量,改善冷却剂的流动分布,冷却剂注入率为M=0.150%时,驻点处冷却剂流量提高了76%。此外,冷却剂流出多孔结构后在外表面形成的气膜分布更为均匀。

Liquid-mediated Ostwald ripening of Ag-based clusters supported on oxides

Reconstruction of supported nanocatalysts often occurs in gas-solid reactions and significantly affects the catalytic performance,yet it is much less explored in liquid-phase environment.Herein,we find that highly-dispersed Ag nanocatalysts,i.e.,AgOx clusters,supported on alumina,silica,and titania,can aggregate into larger Ag or Ag2O particles after immersing in liquid-phase media at room temperature.The spontaneous aggregation of AgOx clusters in liquid water is attributed to liquid-phase Ostwald ripening through dissolution of AgOx clusters into water and subsequent redeposition to form Ag2O particles.The immersion into organic solvents such as ethanol leads to reduction of AgOx clusters and further growth into Ag particles.This work reveals that liquid-phase reaction media can induce substantial structural evolution of supported nanostructured catalysts,which should be carefully considered in liquid-solid interface catalytic reactions such as electrocatalysis,environmental catalysis,and organic synthesis in liquid phase.

多孔介质-文丘里气泡发生器产气特性

将多孔介质发泡技术与文丘里气泡发生器相结合开发多孔介质-文丘里气泡发生器,以去离子水和空气为工质进行产气特性可视化实验研究,拍摄观察区域内气泡行为,分析多孔介质-文丘里气泡发生器产气规律,讨论水流量和气流量的影响规律。实验结果表明,与传统文丘里气泡发生器相比,在相同入口Reynolds数下,多孔介质-文丘里气泡发生器产生的气泡Sauter平均直径缩小25.3%~47.4%,标准差缩小24.4%~62.2%,说明改进的气泡发生器气泡Sauter平均直径更小,气泡粒径更均匀。水流量由5.01 m^(3)/h增大到14.98 m^(3)/h,多孔介质-文丘里气泡发生器产生的气泡Sauter平均直径由0.89 mm减小至0.29 mm,标准差由0.32 mm减小至0.085 mm;气流量由0.30 L/min增大到1.79 L/min,多孔介质-文丘里气泡发生器产生的气泡Sauter平均直径由0.33 mm增大到0.48 mm。说明水流量增大或气流量减小时,气泡发生器产生的气泡平均直径变小,气泡粒径分布更均匀。相关研究成果可为文丘里气泡发生器的优化提供新思路。

液体阻尼对薄壁零件加工颤振的影响分析

为了减轻零件的重量,航空类零件多设计为薄壁零件,薄壁零件加工过程中易发生加工颤振现象,影响加工质量和加工效率。文章提出了通过液体阻尼介质提高系统阻尼比来抑制薄壁零件加工振动的方法。建立了考虑液体介质等效阻尼的频率响应函数模型,开展了施加液体介质的薄壁零件模态试验,获取了系统的模态参数。在获取模态参数的基础上,建立了加工系统稳定性预测模型,预测并分析了加工系统的稳定性。结果表明,液体介质等效阻尼能够降低系统的加速度响应,提高加工系统的稳定性,对铣削加工颤振具有抑制效果。

Improvement of Sporulation Conditions of a New Strain of Bacillus amyloliquefaciens in Liquid Fermentation

The desirable active ingredients for the development of bioproducts based in Bacillus sp. for the control of soil pathogens are the spores because these structures exhibit more resistance and stability to conditions present during the fermentation, formulation, and storage processes. To improve the sporulation of a native strain of Bacillus amyloliquefaciens (Bs006) using liquid fermentation, some modifications in the concentrations of the components in a previously standardized culture media were made. Subsequently, five sporulation inducers (iron nitrate, mixture of salts, peroxide hydrogen, temperature, and initial cell concentration) were evaluated. The treatment with a mixture of salts in combination with an initial cell concentration of 1 × 108 cells/ml was selected because a final spore concentration of 1.05 × 1010 spores/ml after 66 hours with a fully substrate consumption and sporulation efficiency of 88.7% was obtained. To demonstrate the biological activity of B. amyloliquefaciens Bs006 in Cape gooseberry seedlings, a greenhouse bioassay was conducted, and statistical differences in plant growth-promoting parameters compared with previous media were not found. Additionally, the proposed modified media (coded as JM) presented a benefit-cost ratio 2.65 times higher compared with the baseline media.

媒介仪式视角下液态监视对数字时代性别平等的形塑

党的二十大报告明确提出男女平等及女性全面发展是全面建成社会主义现代化强国的重要基础,有关媒介对性别平等的形塑问题,当前传播界的学者已从宏观视角展开深入研究,数字化媒介形态衍生的数字景观建构了新的伦理范式,在数字环境的介入下演化出更为复杂多元的社会问题。文章以媒介仪式作为理论视角,阐述了液态监视对数字时代性别平等的干预。研究发现在个体层面,液态监视的宰制促使个体进行自我量化与异化,个人完成了生命治理的自动化与智能化;在社会层面,监视的权力运作促使社会风险在媒介空间中不断蔓延与铺展,符号暴力、谣言在液态监视的催化下施权于性别之上,影响着数字空间的性别走向。然而液态监视并非只是负面的媒介现象,其对性别平等仍旧能够产生积极影响,相对弱势的性别群体在液态监视的见证下通过身体的政治实践及多元媒介叙事能力对权力的压制进行反抗。

成形网对液压过滤材料性能稳定性的影响

液压过滤材料在过滤过程中会出现过滤比严重下降的问题,极大影响了滤材过滤性能的稳定性。首先利用Geodict软件模拟了滤材孔径分布不均匀对过滤性能的影响,结果表明,在平均孔径一定的情况下,滤材的最大孔径越大,滤材过滤性能的稳定性越差;然后采用实验探究了成形网目数对滤材孔径分布以及液体过滤性能的影响,结果表明,当成形网的目数大于等于400目时,不同直径、不同定量的滤材在成形过程中的流失率和孔径分布逐渐趋于稳定,在滤材的物理参数和过滤精度接近时,500目成形网制备的滤材过滤性能的稳定性要高于80目成形网制备的滤材。

有机液体储氢技术现状及其脱氢催化研究进展

有机液体储氢技术因其高效、安全的特点成为氢能储运领域的重要研究方向。本文综述了有机液体储氢技术的主要研究进展,重点探讨了作为储氢介质的芳烃类和杂环类化合物的特性及其脱氢反应的催化机制。文章分析了脱氢催化剂活性组分的选择、催化剂载体的作用以及脱氢反应器设计对有机液体储氢过程的优化作用。文章指出,未来研究应聚焦于开发更高效、低成本的催化剂和优化反应器设计,以推动LOHC技术的商业化应用,为氢能经济的发展提供支持。

蒲地蓝消炎口服液联合洛美沙星治疗急性化脓性中耳炎的效果

目的探究蒲地蓝消炎口服液联合洛美沙星治疗急性化脓性中耳炎的效果。方法采用随机数字表法将2020年8月至2021年10月于泉州市第一医院就诊的96例急性化脓性中耳炎患者分为对照组(n=46)和观察组(n=50),对照组给予盐酸洛美沙星滴耳液,观察组在对照组基础上加用蒲地蓝消炎口服液,疗程为14 d。比较两组疗效、肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)、白细胞介素8(IL-8)等炎性因子、咽鼓管功能评分、不良反应发生率及复发率的变化。结果治疗后,与对照组相比,观察组总有效率更高,观察组IL-1β、IL-8、TNF-α水平更低,观察组治疗1个月、3个月、6个月时的咽鼓管功能评分(ETS)更高,观察组复发率更低(P<0.05);两组不良反应发生率组间比较差异无统计学意义(P>0.05)。结论蒲地蓝消炎口服液联合洛美沙星能提高临床疗效,减轻炎性反应,提高咽鼓管功能评分,降低疾病复发率且安全性较高。

Transport Study of Cu （Ⅱ） Through Hollow Fiber Supported Liquid Membrane

The transport of Cu(II)from aqueous solutions containing buffer media through hollow fiber supported liquid membrane(HFSLM)using di(2-ethylhexyl)phosphoric acid(D2EHPA)dissolved in kerosene as membrane phase and hydrochloric acid as striping phase was investigated.A set of factors were studied,including tube side velocity,shell side velocity,pH of the feed phase,Cu(II)concentration in the feed phase,buffer media concentration and D2EHPA concentration in the membrane phase.Experimental results indicate that the mass transfer coefficient increases with increasing both carrier concentration in the organic phase and flow rates on the tube side and shell side,and decreases with increasing initial Cu(II)concentration in the feed phase.With increasing pH value and acetate concentration in the feed phase,the mass transfer coefficient reaches a maximum value then decreases.The optimal operating conditions are obtained at pH value of 4.44 and 0.1 mol·L -1 acetic ion concentration in feed phase,and carrier volume fraction of around 10%in kerosene as organic phase.A mathematical model of the transport mechanism through HFSLM is developed.The modeled results agree well with the experimental ones.

气液双介质电火花线切割精加工研究

往复走丝电火花线切割采用大气介质代替传统的液体介质,对Cr12MoV模具钢进行电火花线切割精加工,较液体介质可获得更高的表面加工质量,但也存在电蚀表面碳化、加工不稳定、电极丝热疲劳损伤大等问题。为解决上述问题,尝试采用气液双介质对模具钢进行电火花线切割精加工实验研究。结果表明,在相同电参数条件下,选择合适的进给速度、切削深度、运丝速度和液膜厚度,气液双介质中加工表面质量较液中明显提高,电极丝损耗较气中明显降低。

骨架结构对固液相变蓄热性能影响的LBM研究

固液相变材料通过潜热的形式存储能量,被大规模应用于热能存储领域,然而传统相变材料的热导率普遍较小,添加高热导率的多孔骨架可以提高蓄热性能。为了探究骨架结构对蓄热性能的影响,本工作采用基于焓法的格子Boltzmann双分布模型,在孔隙尺度上研究了骨架孔隙率和方向生长概率对熔化过程的影响,提出了无量纲蓄热功率作为评价参数。结果表明:随着孔隙率的降低,复合材料的熔化速率加快,无量纲蓄热功率增大。当孔隙率处于0.80以下时,无量纲蓄热功率较纯相变材料得到提高。选择合适的方向生长概率可以有效改善换热速率。主生长方向为1,3方向的骨架所需完全熔化时间较均匀骨架时缩短13.9%。本工作为多孔骨架复合相变材料的设计和应用提供了理论依据和数据参考。

Isolation and Identification of a Taxol-producing Endophytic Fungus Identified from Taxus media

[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp. through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp. M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.

气侵后井底初始气泡平均直径预测模型实验研究

为了提高气侵后井筒气液两相流动计算结果的准确性,实验分析了气侵后井底初始气泡直径分布特征,建立了初始气泡平均直径预测模型。用不同质量分数黄原胶溶液模拟钻井液,用多孔介质模拟地层,实验分析了不同液相流变性、地层平均孔隙直径和不同气侵速度下井筒底部气泡群的直径分布特征。实验结果表明:模拟钻井液切力越大、气侵速度越大,生成的初始气泡直径范围越大,出现频率最高的气泡直径和最大气泡直径均增大;地层孔隙直径对初始气泡直径影响不明显。基于实验结果,综合考虑钻井液黏度、气体流量和表面张力等因素的影响,得到了侵入井底初始气泡平均直径实验预测模型;并考虑实际钻井过程中井壁处气体径向侵入特征和井斜角的影响,建立了侵入井底初始气泡平均直径预测模型。井底初始气泡直径预测模型的建立,为气侵后井筒气液两相流动精确计算提供了理论支撑。

裂褶菌的鉴定及液体发酵技术优化

以采集到的裂褶菌标本为试材,采用正交实验和响应面优化试验,研究了裂褶菌液体发酵工艺,以期获得适于工厂化生产的液体发酵工艺技术。结果表明:该菌PCR产物长度为615 bp,结合ITS序列比对确定该菌株为裂褶菌(Schizophyllum commune);以得到的菌种为研究对象进行液体发酵试验,以菌丝干质量为标准,通过正交实验确定了裂褶菌液体菌种发酵的最优培养基配方为可溶性淀粉30 g·L^(-1),牛肉膏8 g·L^(-1),KH_(2)PO_(4)0.75 g·L^(-1),MgSO_(4)0.25 g·L^(-1),pH自然;通过单因素筛选、Plackett-Burman试验、最陡爬坡试验和Box-Behnken试验得出最佳培养条件为温度26℃,装液量109 mL,初始pH 6.3。结合正交实验和响应面优化试验后,培养的菌丝球密度大、大小适宜、活力强,适合作为菌种进行工厂化栽培。