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Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determination

Qingyun CHANG, Jingwen ZHANG, Xin DU, Jingjun MA, Jingci LI,

《环境科学与工程前沿（英文）》 2010年 第4卷 第2期   页码 187-195 doi: 10.1007/s11783-010-0030-7

摘要： A simple and efficient liquid-phase microextraction (LPME) technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction (USAE-SFODME) combined with flame atomic absorption spectrometry, for the extraction and determination of trace copper in water samples. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. Microextraction efficiency factors (including extraction solvent type, extraction volume, time, temperature, and pH), the amount of the chelating agent, and salt effect were investigated and optimized. Under the optimum extraction conditions, figures of merit of the proposed method were evaluated. The calibration graph was linear in the range of 20–600 g·L with a detection limit of 0.76 g·L. The relative standard deviation (R.S.D) for ten replicate measurements of 20 and 400 g·L of copper was 3.83% and 2.65%, respectively. Finally, the proposed method was applied to tap water, river water, and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

关键词： ultrasound-assisted emulsification     solidified floating organic drop microextraction     flame atomic absorption spectrometry     preconcentration     copper    

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Synthesis and characterization of phosphotungstic acid/activated carbon as a novel ultrasound oxidative

Liyan LIU, Yu ZHANG, Wei TAN

《化学科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 422-427 doi: 10.1007/s11705-013-1353-2

摘要： Phosphotungstic acid/activated carbon (PTA/AC) catalysts with various AC sizes or PTA content have been synthesized and characterized by N physisorption, X-ray diffraction, Fourier transform infrared spectroscopy and temperature programmed desorption of ammonia. These catalysts were then evaluated in terms of the removal of dibenzothiophene (DBT) by ultrasound-assisted oxidative desulfurization process. The results showed that the DBT conversion obviously increased with the decrease of AC support size and the increase of PTA content. After supporting PTA on AC, the DBT conversion can be improved by 38.9% after ultrasound irradiation for 10 min. In addition, the stability tests of PTA/AC showed that the catalytic oxidative activity of PTA/AC was nearly kept constant after ultrasound irradiation for 20 min, which makes it a promising catalyst to use in ultrasound-assisted oxidative desulfurization process.

关键词： phosphotungstic acid     activated carbon     ultrasound-assisted oxidative desulfurization    

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Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Cunwen WANG, Lu CHEN, Bajpai RAKESH, Yuanhang QIN, Renliang LV

《能源前沿（英文）》 2012年 第6卷 第3期   页码 266-274 doi: 10.1007/s11708-012-0193-y

摘要： Recently, biodiesel has received much more attention. Soybean oil, rapeseed oil, palm oil and corn oil are primary feedstock for biodiesel production. However, biodiesel production from these traditional oil-rich crops is limited by land availability, climate, and environmental and social issues regarding the use of feed and food crops for fuel. Oleaginous microorganisms, including microalgae, bacteria, yeast and fungi can be cultivated with high lipid contents and used as promising feedstock for biodiesel production. However, the high cost of biodiesel production using oil microorganisms has been the biggest obstacle for its industrialization. The process of biodiesel production from microorganisms involves many steps, of which the lipids extraction is the most important and costly. Therefore, searching for an effective and economical extraction system is critical. Various approaches of lipids extraction are discussed in this review, including traditional extraction procedures such as solvent extraction, pressing and solvent integrated extraction, as well as some new procedures.

关键词： oleaginous microorganisms     biodiesel     solvent extraction     ultrasound-assisted extraction     microwave-assisted extraction     supercritical fluid extraction (SFE)    

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Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1211-1223 doi: 10.1007/s11705-022-2145-3

摘要： The one-step highly selective oxidation of cyclohexane into cyclohexanone and cyclohexanol as the essential intermediates of nylon-6 and nylon-66 is considerably challenging. Therefore, an efficient and low-cost catalyst must be urgently developed to improve the efficiency of this process. In this study, a Co3O4–CeO2 composite oxide catalyst was successfully prepared through ultrasound-assisted co-precipitation. This catalyst exhibited a higher selectivity to KA-oil, which was benefited from the synergistic effects between Co3+/Co2+ and Ce4+/Ce3+ redox pairs, than bulk CeO2 and/or Co3O4. Under the optimum reaction conditions, 89.6% selectivity to KA-oil with a cyclohexane conversion of 5.8% was achieved over Co3O4–CeO2. Its catalytic performance remained unchanged after five runs. Using the synergistic effects between the redox pairs of different transition metals, this study provides a feasible strategy to design high-performance catalysts for the selective oxidation of alkanes.

关键词： Co3O4–CeO2 composite oxides     cyclohexanone     cyclohexanol     ultrasonic-assisted co-precipitation     selective oxidation     solvent-free    

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Ultrasonic emulsification: basic characteristics, cavitation, mechanism, devices and application

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1560-1583 doi: 10.1007/s11705-022-2160-4

摘要： Emulsion systems are widely applied in agriculture, food, cosmetic, pharmaceutical and biomedical industries. Ultrasound has attracted much attention in emulsion preparation, especially for nanoemulsion, due to its advantages of being eco-friendly, cost-effective and energy-efficient. This review provides an overview for readers to the area of ultrasonic emulsification technology. It briefly introduces and summarizes knowledge of ultrasonic emulsification, including emulsion characteristics, acoustic cavitation, emulsification mechanism, ultrasonic devices and applications. The combination of microfluidics and ultrasound is highlighted with huge advantages in controlling cavitation phenomena and emulsification intensification. A novel scale of dμC0.6/μD0.33−EV is proposed to be able to compare the energy efficiency of emulsion preparation in different devices.

关键词： nanoemulsion     ultrasound     microreactor     multiphase     energy    

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High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersion

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1087-1099 doi: 10.1007/s11705-019-1895-z

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A review on emulsification via microfluidic processes

Yichen Liu, Yongli Li, Andreas Hensel, Juergen J. Brandner, Kai zhang, Xiaoze Du, Yongping Yang

《化学科学与工程前沿（英文）》 2020年 第14卷 第3期   页码 350-364 doi: 10.1007/s11705-019-1894-0

摘要： Emulsion is a disperse system with two immiscible liquids, which demonstrates wide applications in diverse industries. Emulsification technology has advanced well with the development of microfluidic process. Compared to conventional methods, the microfluidics-based process can produce controllable droplet size and distribution. The droplet formation or breakup is the result of combined effects resulting from interfacial tension, viscous, and inertial forces as well as the forces generated due to hydrodynamic pressure and external stimuli. In the current study, typical microfluidic systems, including microchannel array, T-shape, flow-focusing, co-flowing, and membrane systems, are reviewed and the corresponding mechanisms, flow regimes, and main parameters are compared and summarized.

关键词： microfluidics     emulsification     capillary number     droplet breakup    

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Emulsification for castor biomass oil

Dongxiang ZHANG, Yuanping LIN, Anmei LI, V. V. TARASOV

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 96-101 doi: 10.1007/s11705-010-0553-2

摘要： The effect of the emulsifier formula on the stability of castor oil-water system was studied through compounding three groups of emulsifiers from the aspects of stability factor of absorbance, centrifuge stability, demulsification time in quiescence, appearance of the droplets, and viscosity. The best emulsifier formula for castor biomass oil was the composite formula of sorbitan monooleate and polyoxyethylene sorbitan monostearate. Correlation exists between the stability of emulsion and the viscosity/particle size of the droplets, with better stability in the case of greater viscosity or narrower distribution of particle size in the emulsion of castor oil-water system. Methanol added to the castor oil-water system may decrease the viscosity of the emulsion. Comparing the castor oil-water emulsion with methanol-castor oil-water emulsion, the optimal hydrophilic and lipophilic balance (HLB) value based on castor oil-water system was acquired between 6.6 and 7.5, while the optimal HLB value based on the methanol-castor oil-water system was between 5.5 and 6.0. The optimal HLB value of methanol-castor oil-water system gradually moved to that of castor oil-water emulsion with adding more water.

关键词： castor oil     biomass oil     emulsification     stability     viscosity     corrosivity    

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High-intensity focused ultrasound tumor ablation: Review of ten years of clinical experience

Lian ZHANG, Zhi-Biao WANG

《医学前沿（英文）》 2010年 第4卷 第3期   页码 294-302 doi: 10.1007/s11684-010-0092-8

摘要： High-intensity focused ultrasound (HIFU) is a technique to destroy tissue at depth within the body, selectively and without harming overlying and adjacent structures within the path of the beam because the ultrasonic intensity at the beam focus is much higher than that outside of the focus. Diagnostic ultrasound is the first imaging modality used for guiding HIFU ablation. In 1997, a patient with osteosarcoma was first successfully treated with ultrasound imaging-guided HIFU in Chongqing, China. Over the last decade, thousands of patients with uterine fibroids, liver cancer, breast cancer, pancreatic cancer, bone tumors, and renal cancer have been treated with ultrasound imaging-guided HIFU. Based on several research groups’ reports, as well as our ten-year clinical experience, we conclude that this technique is safe and effective in treating human solid tumors. HIFU is a promising technique. Most importantly, HIFU offers patients another alternative when those patients have no other treatment available.

关键词： high-intensity focused ultrasound (HIFU)     ultrasound imaging-guided HIFU (USgHIFU)     magnetic resonance imaging-guided HIFU (MRgHIFU)    

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Studies of ultrasound disintegration of residual sludge and its energy consumption in water treatment

SHEN Jinfeng, YIN Xuan, GU Heping, Lv Xiaoping

《化学科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 395-398 doi: 10.1007/s11705-007-0072-y

摘要： To investigate the influence of ultrasound pretreatment on sludge anaerobic digestion, the ultrasound disintegration of residual sludge in water treatment of petrochemical plant was studied, and the mechanisms of ultrasound and medium were introduced. Experimental results indicate that ultrasound cavitation induces the rise of sludge temperature, which improves ultrasound disintegration on sludge. U1trasound pretreatment can advance observably the quantity of chemical oxygen demand in sludge supernatant fluid (SCOD), which increases with ultrasound intensity and sonication time. The degree of ultrasound disintegration increases with the specific energy input. When the specific energy input is l0 000 kJ/kg of total dry solids, the degree of ultrasonic sludge disintegration reaches 40%.

关键词： specific     supernatant     petrochemical     ultrasound intensity     temperature    

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Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

《信息与电子工程前沿（英文）》 2015年 第16卷 第4期   页码 301-310 doi: 10.1631/FITEE.1400205

摘要： Quadrature demodulation is used in medical ultrasound imaging to derive the envelope and instantaneous phase of the received radio-frequency (RF) signal. In quadrature demodulation, RF signal is multiplied with the sine and cosine wave reference signal and then low-pass filtered to produce the base-band complex signal, which has high computational complexity. In this paper, we propose an efficient quadrature demodulation method for B-mode and color flow imaging, in which the RF signal is demodulated by a pair of finite impulse response filters without mixing with the reference signal, to reduce the computational complexity. The proposed method was evaluated with simulation and in vivo experiments. From the simulation results, the proposed quadrature demodulation method produced similar normalized residual sum of squares (NRSS) and velocity profile compared with the conventional quadrature demodulation method. In the in vivo color flow imaging experiments, the time of the demodulation process was 5.66 ms and 3.36 ms, for the conventional method and the proposed method, respectively. These results indicated that the proposed method can maintain the performance of quadrature demodulation while reducing computational complexity.

关键词： B-mode ultrasound imaging     Color flow imaging     Quadrature demodulation     Finite impulse response filter    

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Development of lunar regolith composite and structure via laser-assisted sintering

《机械工程前沿（英文）》 doi: 10.1007/s11465-021-0662-2

摘要： Aiming at the exploration and resource utilization activities on the Moon, in situ resource utilization and in situ manufacturing are proposed to minimize the dependence on the ground transportation supplies. In this paper, a laser-assisted additive manufacturing process is developed to fabricate lunar regolith composites with PA12/SiO2 mixing powders. The process parameters and composite material compositions are optimized in an appropriate range through orthogonal experiments to establish the relationship of process–structure–property for lunar regolith composites. The optimal combination of composite material compositions and process parameters are mixing ratio of 50/50 in volume, laser power of 30 W, scanning speed of 3500 mm/s, and scanning hatch space of 0.2 mm. The maximum tensile strength of lunar regolith composites reaches 9.248 MPa, and the maximum depth of surface variation is 120.79 μm, which indicates poor powder fusion and sintering quality. Thereafter, the mechanical properties of laser-sintered lunar regolith composites are implemented to the topology optimization design of complex structures. The effectiveness and the feasibility of this laser-assisted process are potentially developed for future lightweight design and manufacturing of the solar panel installed on the lunar rover.

关键词： in situ manufacturing     laser-assisted powder fusion process     mechanical properties     topological structure design    

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Guidelines for navigation-assisted spine surgery

Bo Liu, Da He, Yajun Liu, Xiaoguang Han, Jingwei Zhao, Mingxing International Society for Computer Assisted

《医学前沿（英文）》 2020年 第14卷 第4期   页码 518-527 doi: 10.1007/s11684-020-0775-8

摘要： Spinal surgery is a technically demanding and challenging procedure because of the complicated anatomical structures of the spine and its proximity to several important tissues. Surgical landmarks and fluoroscopy have been used for pedicle screw insertion but are found to produce inaccuracies in placement. Improving the safety and accuracy of spinal surgery has increasingly become a clinical concern. Computer-assisted navigation is an extension and application of precision medicine in orthopaedic surgery and has significantly improved the accuracy of spinal surgery. However, no clinical guidelines have been published for this relatively new and fast-growing technique, thus potentially limiting its adoption. In accordance with the consensus of consultant specialists, literature reviews, and our local experience, these guidelines include the basic concepts of the navigation system, workflow of navigation-assisted spinal surgery, some common pitfalls, and recommended solutions. This work helps to standardize navigation-assisted spinal surgery, improve its clinical efficiency and precision, and shorten the clinical learning curve.

关键词： guidelines     spine surgery     computer-assisted navigation    

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Using ultrasound to improve the sequential post-synthesis modification method for making mesoporous Y

Rongxin Zhang, Peinan Zhong, Hamidreza Arandiyan, Yanan Guan, Jinmin Liu, Na Wang, Yilai Jiao, Xiaolei Fan

《化学科学与工程前沿（英文）》 2020年 第14卷 第2期   页码 275-287 doi: 10.1007/s11705-019-1905-1

摘要： Mesoporous Y zeolites were prepared by the sequential chemical dealumination (using chelating agents such as ethylenediaminetetraacetic acid, H EDTA, and citric acid aqueous solutions) and alkaline desilication (using sodium hydroxide, NaOH, aqueous solutions) treatments. Specifically, the ultrasound-assisted alkaline treatment (i.e., ultrasonic treatment) was proposed as the alternative to conventional alkaline treatments which are performed under hydrothermal conditions. In comparison with the hydrothermal alkaline treatment, the ultrasonic treatment showed the comparatively enhanced efficiency (with the reduced treatment time, i.e., 5 min vs. 30 min, all with 0.2 mol·L NaOH at 65°C) in treating the dealuminated Y zeolites for creating mesoporosity. For example, after the treatment of a dealuminated zeolite Y (using 0.1 mol·L H EDTA at 100°C for 6 h), the ultrasonic treatment produced the mesoporous zeolite Y with the specific external surface area ( ) of 160 m ·g and mesopore volume ( ) of 0.22 cm ·g , being slightly higher than that by the conventional method (i.e., = 128 m ·g and = 0.19 cm ·g ). The acidic property and catalytic activity (in catalytic cracking of -octane) of mesoporous Y zeolites obtained by the two methods were comparable. The ultrasonic desilication treatment was found to be generic, also being effective to treat the dealuminated Y zeolites by citric acid. Additionally, the first step of chemical dealumination treatment was crucial to enable the effective creation of mesopores in the parent Y zeolite (with a silicon-to-aluminium ratio, Si/Al= 2.6) regardless of the subsequent alkaline desilication treatment (i.e., ultrasonic or hydrothermal). Therefore, appropriate selection of the condition of the chemical dealumination treatment based on the property of parent zeolites, such as Si/Al ratio and crystallinity, is important for making mesoporous zeolites effectively.

关键词： zeolite Y     mesoporous zeolite     post-synthesis treatment     ultrasound     chemical dealumination treatment     alkaline desilication treatment    

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Ultrasound-mediated targeted microbubbles: a new vehicle for cancer therapy

Junxiao YE, Huining HE, Junbo GONG, Weibing DONG, Yongzhuo HUANG, Jianxin WANG, Guanyi CHEN, Victor C YANG

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 20-28 doi: 10.1007/s11705-013-1311-z

摘要： With the hope of overcoming the serious side effects, great endeavor has been made in tumor-targeted chemotherapy, and various drug delivery modalities and drug carriers have been made to decrease systemic toxicity caused by chemotherapeutic agents. Scientists from home and abroad focus on the research of targeted microbubbles contrast agent, and the use of the targeted ultrasound microbubble contrast agent can carry gene drugs and so on to the target tissue, as well as mediated tumor cell apoptosis and tumor microvascular thrombosis block, etc., thus plays the role of targeted therapy. Recent studies have elucidated the mechanisms of drug release and absorption, however, much work remains to be done in order to develop a successful and optimal system. In this review, we summarized the continuing efforts in understanding the usage of the ultrasound triggered target microbubbles in cancer therapy, from release mechanism to preparation methods. The latest applications of ultrasound-triggered targeted microbubbles in cancer therapy, especially in gene therapy and antiangiogenic cancer therapy were discussed. Moreover, we concluded that as a new technology, ultrasound–triggered targeted microbubbles used as drug carriers and imaging agents are still energetic and are very likely to be translated into clinic in the near future.

关键词： ultrasound-mediated     targeted microbubbles     cancer    

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标题 作者 时间 类型 操作

Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determination

Qingyun CHANG, Jingwen ZHANG, Xin DU, Jingjun MA, Jingci LI,

期刊论文

Synthesis and characterization of phosphotungstic acid/activated carbon as a novel ultrasound oxidative

Liyan LIU, Yu ZHANG, Wei TAN

期刊论文

Technologies for extracting lipids from oleaginous microorganisms for biodiesel production

Cunwen WANG, Lu CHEN, Bajpai RAKESH, Yuanhang QIN, Renliang LV

期刊论文

Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective

期刊论文

Ultrasonic emulsification: basic characteristics, cavitation, mechanism, devices and application

期刊论文

High-gravity-assisted emulsification for continuous preparation of waterborne polyurethane nanodispersion

Weihong Zhang, Dan Wang, Jie-Xin Wang, Yuan Pu, Jian-Feng Chen

期刊论文

A review on emulsification via microfluidic processes

Yichen Liu, Yongli Li, Andreas Hensel, Juergen J. Brandner, Kai zhang, Xiaoze Du, Yongping Yang

期刊论文

Emulsification for castor biomass oil

Dongxiang ZHANG, Yuanping LIN, Anmei LI, V. V. TARASOV

期刊论文

High-intensity focused ultrasound tumor ablation: Review of ten years of clinical experience

Lian ZHANG, Zhi-Biao WANG

期刊论文

Studies of ultrasound disintegration of residual sludge and its energy consumption in water treatment

SHEN Jinfeng, YIN Xuan, GU Heping, Lv Xiaoping

期刊论文

Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

期刊论文

Development of lunar regolith composite and structure via laser-assisted sintering

期刊论文

Guidelines for navigation-assisted spine surgery

Bo Liu, Da He, Yajun Liu, Xiaoguang Han, Jingwei Zhao, Mingxing International Society for Computer Assisted

期刊论文

Using ultrasound to improve the sequential post-synthesis modification method for making mesoporous Y

Rongxin Zhang, Peinan Zhong, Hamidreza Arandiyan, Yanan Guan, Jinmin Liu, Na Wang, Yilai Jiao, Xiaolei Fan

期刊论文

Ultrasound-mediated targeted microbubbles: a new vehicle for cancer therapy

Junxiao YE, Huining HE, Junbo GONG, Weibing DONG, Yongzhuo HUANG, Jianxin WANG, Guanyi CHEN, Victor C YANG

期刊论文