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期刊论文 28

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关键词

(GaxIn1−x)2O3薄膜;带隙可调谐;磁控溅射 1

BSP) 1

VO2薄膜 1

下泄水温公式 1

主动控制 1

仅1吸收 1

光学透明 1

光热纱线 1

分布式结构 1

反馈回路 1

叠梁门 1

可调多波长选择路由器 1

可调微波吸收器 1

可调控供液 1

可调阶梯阻抗谐振器;液晶;共面波导 1

地图匹配,GPS轨迹,可调节,云计算,块同步并行计算(Bulk synchronous parallel 1

大调制深度 1

太阳能界面海水淡化 1

实验分析 1

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一种作为主动控制宽带吸波器的热可调超材料 Article

邢校菖, 曹阳, 田小永, 吴玲玲

《工程(英文)》 2023年 第20卷 第1期   页码 143-152 doi: 10.1016/j.eng.2022.04.028

摘要:

近年来,超材料因其操纵电磁波的强大能力而受到越来越多的关注。然而,大多数先前报道的超材料无法动态调控超宽波段电磁波。在本文中,我们提出了一种使用具有不同相变温度的石蜡基复合材料(PDCs)来实现热可调谐宽带吸波的超材料结构体(T-TBM)。通过在不同相变温度下控制PD-Cs 的固液态,实现了从低频到高频的T-TBM反射损耗峰值的动态调控。T-TBM可以改变吸收峰值带宽(反射损耗值小于−30 dB),并且通过调整T-TBM 的温度依然满足宽带吸波(反射损耗值小于−10 dB)。实验结果表明,T-TBM中PD-Cs的相变恒温效应为在不同热条件下主动控制电磁波吸收响应提供了时间窗口。该器件在电磁吸收、智能超材料、多功能结构器件等领域具有广阔的应用前景。

关键词: 超材料     主动控制     热可调     宽带吸波    

基于图案化 VO2薄膜的透明热可调微波吸收器 Article

陆振刚, 张怡蕾, 王赫岩, 夏超, 刘云菲, 豆书亮, 李垚, 谭久彬

《工程(英文)》 2023年 第29卷 第10期   页码 198-206 doi: 10.1016/j.eng.2022.10.005

摘要:

理想的透明微波吸收器具有高光学透过率和强微波吸收能力,但是若其吸收性能固定,则会限制微波吸收器的应用。本文提出了一种基于二氧化钒(VO2)薄膜的透明热可调微波吸收器。理论计算和实验结果表明,所提出的吸波器在620 nm波长处可以实现84.9%的高光学透过率,同时通过控制温度,15.06 GHz频点处的反射损耗可在-4.257 dB到-60.179 dB范围内调谐并且在523.75 K温度时实现近1吸收。同时,仅通过调控图案化VO2薄膜的占空比即可改变实现近1吸收时的温度。所提出的基于VO2薄膜的吸波器具有组成简单,光学透过率高,微波吸收性能热可调,调制深度大,温度调节范围可控等优点,因此有望应用于可调传感器、热发射器、调制器、热成像仪、辐射热测定器和光电器件中。

关键词: 可调微波吸收器     VO2薄膜     光学透明     仅1吸收     大调制深度    

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0705-3

摘要: As a nondestructive testing technique, terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings (TBCs). However, the invisibility of ceramic/thermally grown oxide (TGO) reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10 μm in TBCs. To detect and monitor TGO in the emergence stage, a time of flight (TOF) improved TGO thickness measurement method is proposed. A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave. The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation. Thus, the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times. The averaged error of 1.61 μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method, making it attractive for condition monitoring and life prediction of TBCs.

关键词: thermal barrier coatings     thermally grown oxide     terahertz spectroscopy     time of flight    

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 720-730 doi: 10.1007/s11705-021-2098-y

摘要: A non-toxic and environmentally safe diluent, acetyl tributyl citrate, was employed to prepare poly(vinylidene fluoride)-co-hexafluoropropylene membranes via thermally induced phase separation. Effects of the polymer concentration on the phase diagram, membrane morphology, hydrophobicity, pore size, porosity and mechanical properties (tensile stress and elongation at break) were investigated. The results showed that the pore size and porosity tended to decrease with increasing polymer concentration, whereas the contact angle, liquid entry pressure and mechanical properties showed the opposite trend. In direct contact membrane distillation operation with 3.5 wt-% sodium chloride solution as the feed solution, the prepared membranes performed high salt rejection (>99.9%). Furthermore, the prepared membranes retained excellent performance in long-term stability tests regarding the permeate flux and salt rejection.

关键词: poly(vinylidene fluoride)-co-hexafluoropropylene     thermally induced phase separation     non-toxic diluent     direct contact membrane distillation    

Oxidative treatment of aqueous monochlorobenzene with thermally-activated persulfate

Qishi LUO

《环境科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 188-194 doi: 10.1007/s11783-013-0544-x

摘要: The oxidation of aqueous monochlorobenzene (MCB) solutions using thermally- activated persulfate has been investigated. The influence of reaction temperature on the kinetics of MCB oxidation was examined, and the Arrenhius Equation rate constants at 20°C, 30°C, 40°C, 50°C, and 60°C for MCB oxidation performance were calculated as 0, 0.001, 0.002, 0.015, 0.057 min , which indicates that elevated temperature accelerated the rate. The most efficient molar ratio of persulfate/MCB for MCB oxidation was determined to be 200 to 1 and an increase in the rate constants suggests that the oxidation process proceeded more rapidly with increasing persulfate/MCB molar ratios. In addition, the reactivity of persulfate in contaminated water is partly influenced by the presence of background ions such as Cl , , , and . Importantly, a scavenging effect in rate constant was observed for both Cl and but not for other ions. The effective thermally activated persulfate oxidation of MCB in groundwater from a real contaminated site was achieved using both elevated reaction temperature and increased persulfate/MCB molar ratio.

关键词: persulfate     monochlorobenzene     advanced oxidation process    

Formation of microporous polymeric membranes via thermally induced phase separation: A review

Min Liu,Shenghui Liu,Zhenliang Xu,Yongming Wei,Hu Yang

《化学科学与工程前沿(英文)》 2016年 第10卷 第1期   页码 57-75 doi: 10.1007/s11705-016-1561-7

摘要: A review of recent research related to microporous polymeric membranes formed via thermally induced phase separation (TIPS) and the morphologies of these membranes is presented. A summary of polymers and suitable diluents that can be used to prepare these microporous membranes via TIPS are summarized. The effects of different kinds of polymer materials, diluent types, cooling conditions, extractants and additive agents on the morphology and performance of TIPS membranes are also discussed. Finally new developments in TIPS technology are summarized.

关键词: polymer     microporous membrane     thermally induced phase separation    

Degradation of carbon tetrachloride in thermally activated persulfate system in the presence of formic

Minhui XU,Xiaogang GU,Shuguang LU,Zhouwei MIAO,Xueke ZANG,Xiaoliang WU,Zhaofu QIU,Qian SUI

《环境科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 438-446 doi: 10.1007/s11783-015-0798-6

摘要: The thermally activated persulfate (PS) degradation of carbon tetrachloride (CT) in the presence of formic acid (FA) was investigated. The results indicated that CT degradation followed a zero order kinetic model, and was responsible for the degradation of CT confirmed by radical scavenger tests. CT degradation rate increased with increasing PS or FA dosage, and the initial CT had no effect on CT degradation rate. However, the initial solution pH had effect on the degradation of CT, and the best CT degradation occurred at initial pH 6. Cl had a negative effect on CT degradation, and high concentration of Cl displayed much strong inhibition. Ten mmol·L promoted CT degradation, while 100 mmol·L inhibited the degradation of CT, but promoted CT degradation in the presence of FA. The measured Cl concentration released into solution along with CT degradation was 75.8% of the total theoretical dechlorination yield, but no chlorinated intermediates were detected. The split of C-Cl was proposed as the possible reaction pathways in CT degradation. In conclusion, this study strongly demonstrated that the thermally activated PS system in the presence of FA is a promising technique in in situ chemical oxidation (ISCO) remediation for CT contaminated site.

关键词: persulfate     carbon tetrachloride     thermal activation     formic acid     carbon dioxide radical anion    

Recovering humic substances from the dewatering effluent of thermally treated sludge and its performance

Yuning YANG,Huan LI

《环境科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 578-584 doi: 10.1007/s11783-015-0827-5

摘要: The biologic treatment of the dewatering effluent from thermally treated sludge is difficult due to the high concentration of refractory humic substances. On the other hand, humic substances are an important source of organic fertilizer. In this study, a novel process using ferric coagulant was developed to recover humic substances from dewatering effluent for use as an organic fertilizer. When ferric coagulant was applied to raw dewatering effluent, up to 70% of humic substances were enmeshed by hydrolyzed ferric ions at an optimum pH of 4.5. The proper mass ratio of iron ions to humic substances was 0.6. In the recovered material, humic substances accounted for 24.2% of the total dry solids, and the amount of phosphorus (equivalent phosphorus pentoxide) was 6.2%. Heavy metals and other components all met the legal requirements for organic fertilizer. When the recovered material was applied to soybeans, the germination and growth of the seeds was significantly improved.

关键词: sewage sludge     humic substances     recovery     phosphorus     fertilizer    

Effective regeneration of thermally deactivated commercial V-W-Ti catalysts

Xuesong SHANG, Jianrong LI, Xiaowei YU, Jinsheng CHEN, Chi HE

《化学科学与工程前沿(英文)》 2012年 第6卷 第1期   页码 38-46 doi: 10.1007/s11705-011-1167-z

摘要: An effective method for the regeneration of thermally deactivated commercial monolith SCR catalysts was investigated. Two types of regenerated solutions, namely NH Cl (1 mol/L) and dilute H SO (0.5 mol/L), were employed to treat the used catalyst. The effects of temperature and the regeneration process on the structural and textural properties of the catalysts were determined by X-ray diffraction, scanning electron microscopy, N adsorption/desorption, elemental analysis and Fourier transform infrared spectroscopy. The results suggest that the anatase phase of the used catalyst is maintained after exposure to high temperatures. Some of the catalytic activity was restored after regeneration. The catalyst regenerated by aqueous NH Cl had a higher activity than that of the catalyst treated by dilute H SO . The main reason is that the NH generated from the decomposition of NH Cl at high temperatures can be adsorbed onto the catalyst which promotes the reaction. The aggregated V O were partially re-dispersed during the regeneration process, and the intrinsic oxidation of ammonia with high concentrations of O is a factor that suppresses the catalytic activity.

关键词: V2O5-WO3/TiO2 catalysts     thermal deactivation     regeneration     NH4Cl     dilute H2SO4 solution    

稳定线性热分层环境下火灾烟气羽流积分解及实验分析

方俊,疏学明,袁宏永,郑昕

《中国工程科学》 2004年 第6卷 第1期   页码 37-43

摘要:

对稳定线性热分层环境下湍浮力羽流无量纲积分方程首次采用数值解法进行求解,得出浮力通量、动量通量等参量在轴线上的变化规律以及羽流中性浮力点的高度和羽流最大上升高度。2种不同尺度空间及不同烟气羽流出口条件的实验表明,实际火灾烟气羽流最大上升高度与理论计算结果及文献经验公式相符,从而表明积分模型数值解的有效性,并为高大空间火灾烟气输运规律研究及探测技术发展提供了理论及实验依据。

关键词: 稳定线性热分层环境     火灾烟气羽流     积分解     实验分析    

Fe3O4 encapsulated mesoporous silica nanospheres with tunable size and large void

Tingting LIU, Lihong LIU, Jian LIU, Shaomin LIU, Shi Zhang QIAO

《化学科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 114-122 doi: 10.1007/s11705-014-1413-2

摘要: Magnetic Fe O and mesoporous silica core-shell nanospheres with tunable size from 110–800 nm were synthesized via a one step self-assembly method. The morphological, structural, textural, and magnetic properties were well-characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N adsorption-desorption and magnetometer. These nanocomposites, which possess high surface area, large pore volume and well-defined pore size, exhibit two dimensional hexagonal ( 6mm) mesostructures. Interestingly, magnetic core and mesoporous silica shell nanocomposites with large void pore (20 nm) on the shell were generated by increasing the ratio of ethanol/water. Additionally, the obtained nanocomposites combined magnetization response and large void pore, implying the possibility of applications in drug/gene targeting delivery. The cell internalization capacity of NH -functionalized nanocomposites in the case of cancer cells (HeLa cells) was exemplified to demonstrate their nano-medicine application.

关键词: mesoporous silicas     magnetic nanoparticles     core-shell nanoparticles     cell uptake    

Sorption of aromatic organophosphate flame retardants on thermally and hydrothermally produced biochars

Ziwen Du, Chuyi Huang, Jiaqi Meng, Yaru Yuan, Ze Yin, Li Feng, Yongze Liu, Liqiu Zhang

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1220-6

摘要: TPhP showed faster and higher sorption on biochars than TPPO. Pyrochars had higher sorption capacity for TPPO than hydrochar. Hydrophobic interactions dominated TPhP sorption by biochars. The π-π EDA and electrostatic interactions are involved in sorption. Aromatic organophosphate flame retardant (OPFR) pollutants and biochars are commonly present and continually released into soils due to their increasingly wide applications. In this study, for the first time, the sorption of OPFRs on biochars was investigated. Although triphenyl phosphate (TPhP) and triphenylphosphine oxide (TPPO) have similar molecular structures and sizes, TPhP exhibited much faster and higher sorption than TPPO due to its stronger hydrophobicity, suggesting the dominant role of hydrophobic interactions in TPhP sorption. The π-π electron donor–acceptor (EDA) interactions also contributed to the sorption process, as suggested by the negative correlation between the sorption capacity of the aromatic OPFRs and the aromatic index (H/C atomic ratios) of biochar. Density functional theory calculations further showed that one benzene ring of aromatic OPFRs has no electrons, which may interact with biochar via π-π EDA interactions. The electrostatic attraction between the protonated P = O in OPFRs and the negatively charged biochar was found to occur at pH below 7. This work provides insights into the sorption behaviors and mechanisms of aromatic OPFRs by biochars.

关键词: Organophosphate flame retardants     Hydrochar     Pyrochar     Adsorption     Emerging contaminants     Biochar    

Electrochemical performance of thermally-grown SiO

X. D. HUANG, X. F. GAN, Q. A. HUANG, J. Z. YANG

《能源前沿(英文)》 2018年 第12卷 第2期   页码 225-232 doi: 10.1007/s11708-018-0556-0

摘要: Direct integration of lithium-ion battery (LIB) with electronic devices on the same Si substrate can significantly miniaturize autonomous micro systems. For achieving direct integration, a barrier layer is essential to be inserted between LIB and the substrate for blocking Li diffusion. In this paper, the feasibility of thermal SiO film as the barrier layer is investigated by electrochemical characterization and X-ray photoelectron spectroscopy (XPS). Due to the negligible side reactions of thermal SiO with electrolyte, the solid electrolyte interphase (SEI) layer formed on the surface of the barrier layer is thin and the SEI content mainly consists of hydrocarbon together with slight polyethylene oxide (PEO), Li PO F , and Li CO . Although 8-nm thermal SiO effectively prevents the substrate from alloying with Li , the whole film changes to Li silicate after electrochemical cycling due to the irreversible chemical reactions of SiO with electrolyte. This degrades the performance of the barrier layer against the electrolyte penetration, thus leading to the existence of Li (in the form of F-Si-Li) and solvent decompositions (with the products of hydrocarbon and PEO) near the barrier layer/substrate interface. Moreover, it is found that the reaction kinetics of thermal SiO with electrolyte decrease significantly with increasing the SiO thickness and no reactions are found in the bulk of the 30-nm SiO film. Therefore, thermal SiO with an appropriate thickness is a promising barrier layer for direct integration.

关键词: autonomous micro system     direct integration     barrier layer     thermal SiO2 film     X-ray photoelectron spectroscopy (XPS)    

A thermally flexible and multi-site tactile sensor for remote 3D dynamic sensing imaging

Guoting Xia, Yinuo Huang, Fujiang Li, Licheng Wang, Jinbo Pang, Liwei Li, Kai Wang

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 1039-1051 doi: 10.1007/s11705-019-1901-5

摘要: A flexible, multi-site tactile and thermal sensor (MTTS) based on polyvinylidene fluoride (resolution 50 × 50) is reported. It can be used to implement spatial mapping caused by tactile and thermal events and record the two-dimensional motion trajectory of a tracked target object. The output voltage and current signal are recorded as a mapping by sensing the external pressure and thermal radiation stimulus, and the response distribution is dynamically observed on the three-dimensional interface. Through the mapping relationship between the established piezoelectric and pyroelectric signals, the piezoelectric component and the pyroelectric component are effectively extracted from the composite signals. The MTTS has a good sensitivity for tactile and thermal detection, and the electrodes have good synchronism. In addition, the signal interference is less than 9.5% and decreases as the pressure decreases after the distance between adjacent sites exceeds 200 µm. The integration of MTTS and signal processing units has potential applications in human-machine interaction systems, health status detection and smart assistive devices.

关键词: tactile/thermal sensor     piezoelectric/pyroelectric effects     high resolution     spatial mapping     motion monitoring    

热致相分离法高性能聚偏氟乙烯中空纤维膜先进制备技术及应用

唐元晖,林亚凯,王晓琳

《中国工程科学》 2014年 第16卷 第12期   页码 24-34

摘要:

膜分离技术已经成为国际上市政污水和工业废水处理的核心技术。十年来清华大学化学工程系在先进膜材料制备及应用技术研究上开展了大量工作,以膜材料配方设计、膜材料先进制造、膜组件设计与应用为主线,突破多个技术难题和瓶颈,实现了热致相分离(TIPS)法高性能聚偏氟乙烯(PVDF)中空纤维膜的工业化。首先,基于对TIPS法成膜过程的热力学及动力学研究,制备出具有大通量、高强度、亲水性好的PVDF微孔膜;接着,有机结合材料加工和单元操作,形成PVDF中空纤维膜先进制造技术;最后针对不同的工业环境和市政要求,开发出不同规格的高性能膜组件。研究成果表明TIPS法突破了传统非溶剂致相转化法的限制,可以作为市政污水和工业废水处理的首选膜材料制备技术。

关键词: 热致相分离     聚偏氟乙烯     水处理     膜制备    

标题 作者 时间 类型 操作

一种作为主动控制宽带吸波器的热可调超材料

邢校菖, 曹阳, 田小永, 吴玲玲

期刊论文

基于图案化 VO2薄膜的透明热可调微波吸收器

陆振刚, 张怡蕾, 王赫岩, 夏超, 刘云菲, 豆书亮, 李垚, 谭久彬

期刊论文

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

期刊论文

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

期刊论文

Oxidative treatment of aqueous monochlorobenzene with thermally-activated persulfate

Qishi LUO

期刊论文

Formation of microporous polymeric membranes via thermally induced phase separation: A review

Min Liu,Shenghui Liu,Zhenliang Xu,Yongming Wei,Hu Yang

期刊论文

Degradation of carbon tetrachloride in thermally activated persulfate system in the presence of formic

Minhui XU,Xiaogang GU,Shuguang LU,Zhouwei MIAO,Xueke ZANG,Xiaoliang WU,Zhaofu QIU,Qian SUI

期刊论文

Recovering humic substances from the dewatering effluent of thermally treated sludge and its performance

Yuning YANG,Huan LI

期刊论文

Effective regeneration of thermally deactivated commercial V-W-Ti catalysts

Xuesong SHANG, Jianrong LI, Xiaowei YU, Jinsheng CHEN, Chi HE

期刊论文

稳定线性热分层环境下火灾烟气羽流积分解及实验分析

方俊,疏学明,袁宏永,郑昕

期刊论文

Fe3O4 encapsulated mesoporous silica nanospheres with tunable size and large void

Tingting LIU, Lihong LIU, Jian LIU, Shaomin LIU, Shi Zhang QIAO

期刊论文

Sorption of aromatic organophosphate flame retardants on thermally and hydrothermally produced biochars

Ziwen Du, Chuyi Huang, Jiaqi Meng, Yaru Yuan, Ze Yin, Li Feng, Yongze Liu, Liqiu Zhang

期刊论文

Electrochemical performance of thermally-grown SiO

X. D. HUANG, X. F. GAN, Q. A. HUANG, J. Z. YANG

期刊论文

A thermally flexible and multi-site tactile sensor for remote 3D dynamic sensing imaging

Guoting Xia, Yinuo Huang, Fujiang Li, Licheng Wang, Jinbo Pang, Liwei Li, Kai Wang

期刊论文

热致相分离法高性能聚偏氟乙烯中空纤维膜先进制备技术及应用

唐元晖,林亚凯,王晓琳

期刊论文