Fabrication and Photocatalytic Activities of Morphology-Controlled Titania Nanoobject Arrays by Block Copolymer Templates

Peng, Juan,Li, Xue,Kim, Dong Ha,Knoll, Wolfgang WILEY-VCH Verlag 2007 Macromolecular Rapid Communications Vol.28 No.21

<P>We report a simple scheme to fabricate organic/inorganic hybrid nanostructures with extraordinary morphologies by one-step spin coating, using a PS-b-PEO diblock copolymer as template coupled with sol-gel chemistry. The shape and size of the titania nanoobject can be fine-tuned by controlling the amount of sol-gel precursor relative to PS-b-PEO and the composition of the precursor. Ordered arrays of nanoscopic titania objects such as nanodots, nanobowls, and nanonetworks were obtained from the initial hybrid nanostructures by removing the organic matrix by UV treatment. Photocatalytic activities of the resulting titania nanoobjects were investigated in terms of the degradation of a typical dye.</P><P> <img src='wiley_img/10221336-2007-28-21-MARC200700430-gra001.gif' alt='wiley_img/10221336-2007-28-21-MARC200700430-gra001'> </P>

Development of Nanodomain and Fractal Morphologies in Solvent Annealed Block Copolymer Thin Films

Peng, Juan,Han, Yanchun,Knoll, Wolfgang,Kim, Dong Ha Hu@thig & Wepf 2007 Macromolecular Rapid Communications Vol.28 No.13

<P>We have systematically studied the thin film morphologies of asymmetric polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer subjected to solvent vapors of varying selectivity for the constituent blocks. Upon a short treatment in neutral or PS-selective vapor, the film exhibited a highly ordered array of hexagonally packed, cylindrical microdomains. In the case of PEO selective vapor annealing, such ordered cylindrical microdomains were not obtained. Instead, fractal patterns on the microscale were observed and their growth processes investigated. Furthermore, hierarchical structures could be obtained if the fractal pattern was exposed to neutral or PS selective vapor.</P><P> <img src='wiley_img/10221336-2007-28-13-MARC200700206-gra001.gif' alt='wiley_img/10221336-2007-28-13-MARC200700206-gra001'> </P>

Photocatalytic printing of inorganic nanopatterns <i>via</i> poly(styrene-<i>block</i>-carbosilane) copolymer thin films on titania substrates

Peng, Juan,Garcia Marcos, Alejandra,Jeong, Seong-Jun,Frey, Holger,Kim, Dong Ha Royal Society of Chemistry 2009 Chemical communications Vol.2009 No.9

<P>Well-defined, ordered arrays of nanoscale depressions were obtained in linear-brush-type polystyrene-<I>block</I>-polycarbosilane (PS-<I>b</I>-PCS) diblock copolymer thin films by acetone vapor annealing and silica nanodot arrays were directly obtained from such thin films deposited on a titania substrate by one-step exposure to UV light as a result of transformation of the PCS units to silica, driven by the photocatalytic activity of titania concurrent with removal of the organic matrix.</P> <P>Graphic Abstract</P><P>Ordered arrays of nanoscale depressions were obtained in linear-brush-type polystyrene-<I>block</I>-polycarbosilane diblock copolymer thin films by acetone vapor annealing. Silica nanodot arrays were fabricated from such thin films deposited on a titania substrate by UV treatment. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b816398g'> </P>

From Nanodot to Nanowire: Hybrid Au/Titania Nanoarrays by Block Copolymer Templates

Peng, Juan,Mao, Chun,Kim, Jinheung,Kim, Dong Ha WILEY-VCH Verlag 2009 Macromolecular Rapid Communications Vol.30 No.21

<P>A simple scheme to fabricate 2-D arrays of Au/titania hybrid nanopatterns is presented, using polystyrene-block-poly(ethylene oxide) diblock copolymer (PS-b-PEO) as templates coupled with sol–gel chemistry. Both the functionalized Au nanoparticles (NPs) and titania precursors are selectively incorporated into the PEO domain. A series of morphologies ranging from nanodot to nanowire arrays is formed and the mechanism of morphological evolution is discussed. Such hybrid films exhibit characteristic localized surface plasmon resonance bands originating from the coupling between neighboring Au NPs spatially located in a controlled manner.</P><P> <img src='wiley_img/10221336-2009-30-21-MARC200900209-gra001.gif' alt='wiley_img/10221336-2009-30-21-MARC200900209-gra001'> </P> <B>Graphic Abstract</B> <P>A simple route to fabricate 2-D arrays of Au/TiO2 hybrid nanopatterns is presented, using polystyrene-block-poly(ethylene oxide) diblock copolymer as templates coupled with sol–gel chemistry. A series of morphologies ranging from nanodot to nanowire arrays is formed. Such hybrid films exhibit characteristic localized surface plasmon resonance bands originating from the coupling between neighboring Au nanoparticles spatially located in a controlled manner. <img src='wiley_img/10221336-2009-30-21-MARC200900209-content.gif' alt='wiley_img/10221336-2009-30-21-MARC200900209-content'> </P>

A Meta-Analysis of the Accuracy of Prostate Cancer Studies Which Use Magnetic Resonance Spectroscopy as a Diagnostic Tool

Peng Wang,You-min Guo,Min Liu,Yong-qian Qiang,Xiao-juan Guo,Yi-li Zhang,Xiao-Yi Duan,Qiu-Juan Zhang,Weifeng Liang 대한영상의학회 2008 Korean Journal of Radiology Vol.9 No.5

Objective: We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer studies which use magnetic resonance spectroscopy (MRS) as a diagnostic tool. Materials and Methods: Prospectively, independent, blind studies were selected from the Cochrane library, Pubmed, and other network databases. The criteria for inclusion and exclusion in this study referenced the criteria of diagnostic research published by the Cochrane center. The statistical analysis was adopted by using Meta-Test version 6.0. Using the homogeneity test, a statistical effect model was chosen to calculate different pooled weighted values of sensitivity, specificity, and the corresponding 95% confidence intervals (95% CI). The summary receiver operating characteristic (SROC) curves method was used to assess the results. Results: We chose two cut-off values (0.75 and 0.86) as the diagnostic criteria for discriminating between benign and malignant. In the first diagnostic criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI (expressed as area under curve [AUC]) were 0.82 (0.73, 0.89), 0.68 (0.58, 0.76), and 83.4% (74.97, 91.83). In the second criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI were 0.64 (0.55, 0.72), 0.86 (0.79, 0.91) and 82.7% (68.73, 96.68). Conclusion: As a new method in the diagnostic of prostate cancer, MRS has a better applied value compared to other common modalities. Ultimately, large scale RCT randomized controlled trial studies are necessary to assess its clinical value. Objective: We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer studies which use magnetic resonance spectroscopy (MRS) as a diagnostic tool. Materials and Methods: Prospectively, independent, blind studies were selected from the Cochrane library, Pubmed, and other network databases. The criteria for inclusion and exclusion in this study referenced the criteria of diagnostic research published by the Cochrane center. The statistical analysis was adopted by using Meta-Test version 6.0. Using the homogeneity test, a statistical effect model was chosen to calculate different pooled weighted values of sensitivity, specificity, and the corresponding 95% confidence intervals (95% CI). The summary receiver operating characteristic (SROC) curves method was used to assess the results. Results: We chose two cut-off values (0.75 and 0.86) as the diagnostic criteria for discriminating between benign and malignant. In the first diagnostic criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI (expressed as area under curve [AUC]) were 0.82 (0.73, 0.89), 0.68 (0.58, 0.76), and 83.4% (74.97, 91.83). In the second criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI were 0.64 (0.55, 0.72), 0.86 (0.79, 0.91) and 82.7% (68.73, 96.68). Conclusion: As a new method in the diagnostic of prostate cancer, MRS has a better applied value compared to other common modalities. Ultimately, large scale RCT randomized controlled trial studies are necessary to assess its clinical value.

Application of Product Package Design in Safe Cold-Chain Food Logistics

Peng Li Juan 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.10

In order to realize non-contact test of commodity over-package, a commodity over-package test system based on grating projection was designed. First obtain the three-dimensional point cloud of an object using one projector and two high-resolution cameras, then extract the bounding box of object point cloud to obtain algorithm, calculate the volume of bounding box and point cloud, and at last, test whether commodity package is over or not according to volume fraction and voidage. Experimental results showed that the system is capable of generating a bounding box effectively based on point cloud shape, and point cloud volume calculation accuracy reaches up to 95%, with time consumption reduced significantly in comparison with the widely used Poisson method.

Bacillus oceani sp. nov., a new slightly halophilic bacterium, isolated from a deep sea sediment environment

Liu, Yu-Juan,Long, Li-Juan,Huang, Xiao-Fang,You, Zhi-Qing,Wang, Fa-Zuo,Li, Jie,Kim, Chang-Jin,Tian, Xin-Peng,Zhang, Si Springer-Verlag 2013 Antonie van Leeuwenhoek Vol.104 No.5

Evaluation of Anterior Ethmoidal Artery by 320-Slice CT Angiography with Comparison to Three-Dimensional Spin Digital Subtraction Angiography: Initial Experiences

Juan Ding,Gang Sun,Yang Lu,Bing-bing Yu,Min Li,Li Li,Guo-ying Li,Zhao-hui Peng,Xu-Ping Zhang 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. Materials and Methods: From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. Results: The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 ± 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 ± 0.01 mSv) (p < 0.001). Conclusion: 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases. Objective: To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. Materials and Methods: From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. Results: The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 ± 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 ± 0.01 mSv) (p < 0.001). Conclusion: 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.

Calcination and sintering effects on the microstructure and dielectric properties of CaCu3Ti4O12 ceramics

Peng Liu,Lei Cao,Jian-Ping Zhou,Ya-Juan Wang,Li-Na Su,Cheng Liu,Huai-Wu Zhang 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.4

CaCu3Ti4O12 (CCTO) ceramics were fabricated by a conventional solid-state reaction at various calcination and sintering temperatures. Depending on the relative dielectric constant (εr) at 1 kHz, the specimens can be categorized into three types:type A (εr < 5 × 104), type B (5 × 104 < εr < 105) and type C (εr > 105). The value of εr is closely related to the microstructure:type-A specimens show a morphology with large grains embedded in a small-grained matrix, type-B specimens present a network structure and type-C specimens display a core-shell structure. Different dielectric loss variation tendencies are observed in the type-A specimens, which can be well explained by impedance spectroscopy analysis and further confirmed by the EDX results. Also, the proper calcination and sintering temperature ranges needed to achieve good comprehensive properties are given.

Fault Diagnosis and Optimal Fault-Tolerant Control for Systems with Delayed Measurements and States

Juan Li,Hong-Wei Gao,Peng Zhang,Da-Rong Huang 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.1

This note deals with the problems of fault diagnosis and fault-tolerant control for systems with delayed measurements and states. The main contribution consists in two aspects. First, by solving the Riccati equation and Sylvester equation, an optimal fault-tolerant control law is designed for systems with delayed measurements and states. The existence and uniqueness of the optimal fault-tolerant control law are proved. Second, the physically unrealizable problem of the optimal fault-tolerant con-trol law is solved by proposing a novel fault diagnoser for systems with delayed measurements and states. Finally, a numerical example is given to demonstrate the feasibility and validity of the proposed schemes.