bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical study on the nonlinear optical properties of phenylenes and influencing factors
Authors: Koch Rainer , Finnerty Justin J. , Bruhn Torsten 
Published: June 2008

AbstractA systematic investigation of the hyperpolarisabilities of substituted p‐poly‐phenylenes is presented using different quantum mechanical approaches, including density functional theory and Møller–Plesset (MP2) methods. A medium‐sized basis set Hartree–Fock (HF) hyperpolarisability calculation based on either a density functional theory (DFT) or MP2 geometry gives reliable results at moderate computational costs when comparing with experimental data. A longer phenylene chain leads to a maximum in the per‐unit increase of the investigated property between 3 and 4 repeat units. Changing the underlying geometry from the minimum helix to a planar orientation leads to a significant increase in β, again dependent on the chain length. Terminal para‐substituents and their influence are studied and categorised. For push–pull groups, the substituent effects are mainly additive, allowing the design of functionalised phenylenes as molecular building blocks for nanofibres with tailored nonlinear optical (NLO) properties. Copyright © 2008 John Wiley & Sons, Ltd.
Multi‐walled carbon nanotubes encapsulated with polyurethane and its nanocomposites
Authors: Wang Xiao , Du Zhongjie , Zhang Chen , Li Congju , Yang Xiaoping , Li Hangquan 
Published: June 2008

AbstractPoly(acryloyl chloride) (PACl) was employed to enhance the surface of multi‐walled carbon nanotubes (MWCNTs). MWCNTs were first acid treated to generate hydroxyl groups on the surface, which was reacted with PACl to obtain an encapsulation. The numerous acryloyl chloride groups on the out layer were esterified with a proper amount of ethylene glycol (EG). Subsequently, 4,4′‐methylenebis (phenylisocyanate) (MDI) and 1,4‐butanediol (BDO) were introduced into the system, and a polyurethane (PU) layer was formed in situ. The formation of PU layers on MWCNTs was confirmed by Fourier transform infrared spectrometer (FTIR) and X‐ray photoelectron spectroscope (XPS). The morphology of encapsulated MWCNTs was observed by transmission electron microscope (TEM) and scanning electron microscope (SEM). Thermo gravimetric analysis (TGA) showed the grafted polymer fraction was up to 90%. On introducing the modified MWCNTs into a PU matrix, an increase in tensile strength by 60.6% and improvement in modulus by 6.3% over neat PU was observed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4857–4865, 2008
Synthesis and characterization of color‐stable electroluminescent polymers: Poly(dinaphtho[1,2‐a:1′,2′‐g]‐s‐indacene)s
Authors: Guo Xin , Yao Bing , Jiang Guoxin , Cheng Yanxiang , Xie Zhiyuan , Wang Lixiang , Jing Xiabin , Wang Fosong 
Published: June 2008

AbstractTwo new stepladder conjugated polymers, that is, poly(7,7,15,15‐tetraoctyldinaphtho[1,2‐a:1′,2′‐g]‐s‐indacene) (PONSI) and poly(7,7,15,15‐tetra(4‐octylphenyl)dinaphtho[1,2‐a:1′,2′‐g]‐s‐indacene) (PANSI) with alkyl and aryl substituents, respectively, have been synthesized and characterized. In comparison with poly(indenofluorene)s, both polymers have extended conjugation at the direction perpendicular to the polymer backbone because of the introduction of naphthalene moieties. The emission color of the polymers in film state is strongly dependent on the substituents. While PONSI emits at a maximum of 463 nm, PANSI with the same backbone but aryl substituents displays dramatically redshifted emission with a maximum at 494 nm. Both polymers show stable photoluminescence spectra while annealing at 200 °C in inert atmosphere. The PONSI‐based devices with the configuration of ITO/PEDOT:PSS/polymer/Ca/Al turn on at 3.7 V, and emit at a maximum of 461 nm with the CIE coordinates of (0.19, 0.26), a maximum luminance efficiency of 1.40 cd/A, and a maximum brightness of 2036 cd/m2 at 13 V. Meanwhile, the emission color of the devices is independent of driving voltage and keeps unchanged during the continuous operation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4866–4878, 2008
Synthesis of star polymer by atom transfer radical polymerization with resorcinol‐core multifunctional initiator: The construction of nanocapsule via hydrolysis and olefin metathesis reaction of the obtained star polymer
Authors: Nagai Atsushi , Hirabayashi Toshiaki , Kudo Hiroto , Nishikubo Tadatomi 
Published: June 2008

AbstractOlefin group‐carrying styrene, 1‐but‐3‐enyl‐4‐vinylbenznene (BVB), was polymerized via atom transfer radical polymerization (ATRP) initiated from C‐methylcalix [4]resorcinarene‐based multifunctional initiator (CRA‐bib) at low conversion to produce star polymer [poly(BVB)] with narrow molecular weight distribution (Mw/Mn < 1.35). The copolymerization of styrene (St) with poly(BVB) (Mn = 11,000, Mw/Mn = 1.23) as a macroinitiator afforded star block copolymer [poly(BVB‐b‐St)] with Mn = 35,000 and Mw/Mn = 1.44. The BVB layer of poly(BVB‐b‐St), located between the St shell and the CRA core, was crosslinked by olefin metathesis reaction of olefin groups o the BVB moieties. The removal of the CRA core of the crosslinked poly(BVB‐b‐St) by hydrolysis using KOH as a base gave polymeric hollow sphere [poly(cored crossBVB‐b‐St)] with good solubility in organic solvents. The morphological structure of the poly(cored crossBVB‐b‐St) showed spherical aggregates in THF by scanning electron microscopy (SEM). Furthermore, the nanocapsule structure of poly(cored crossBVB‐b‐St) with hollow spheres was found to be observed by transmission electron microscopy (TEM). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4879–4888, 2008
Synthesis and aggregation behavior of chitooligosaccharide‐based biodegradable graft copolymers
Authors: Gao Ke‐Jing , Li Guangtao , Shi Hongwei , Lu Xinping , Gao Yongbin , Xu Bo‐Qing 
Published: June 2008

AbstractA series of novel “jellyfish‐like” graft copolymers with chitooligosaccharide (COS) as shorter backbone and poly(ε‐caprolactone) as longer branches were synthesized using ring‐opening polymerization of ε‐caprolactone via a protection‐polymerization‐deprotection procedure with trimethylsilylchitooligosaccharide as intermediate and triethylaluminum as catalyst precursor. The obtained chitooligosaccharide‐graft‐poly(ε‐caprolactone) polymers possess amphiphilic structure with hydrophilic COS backbone and hydrophobic polycaprolactone branches. Because of this unique “jellyfish‐like” structure, these graft copolymers could self‐assemble to form various morphologies of aggregates in a mixture solution of water and tetrahydrofuran. The transmission electron microscopy studies revealed that the formed aggregates exhibited necklace‐like, flower‐like onion vesicle, and tubular morphologies. It is found that the hydrogen‐bonding formed by the hydroxyl and amino groups remained on the COS backbone played an important role during the aggregation of these graft copolymers, and their morphologies were changed with the varying length of poly (ε‐caprolactone) branches, the concentration of the graft copolymer, and the self‐assembly process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4889–4904, 2008
The addition of aquatic therapy to rehabilitation following surgical rotator cuff repair: a feasibility study
Authors: Brady Bernadette , Redfern Julie , Macdougal Graeme , Williams Jan 
Published: June 2008

AbstractBackground and Purpose. Rotator cuff tears are frequently encountered in medical outpatient settings and often require surgical repair to achieve desirable functional outcomes. However, the optimal form of post‐operative rehabilitation of rotator cuff repairs remains unidentified by the research literature. The aim of this study was to determine the feasibility of implementing and investigating the effect of a combined aquatic and land‐based rehabilitation programme in the post‐operative rehabilitation of rotator cuff tears. Methods. A cohort of 18 subjects undergoing rotator cuff repair were examined over a treatment period of 12 weeks. Twelve subjects participated in a combined aquatic and land‐based programme, while six subjects received a standard land‐based protocol. Passive range of motion and the Western Ontario Rotator Cuff Index outcomes were measured pre‐operatively and at three, six and 12 weeks, post‐operatively. Subjective responses on patient's assurance and confidence in the value of the exercises (questionnaire using an 11‐point Visual Analogue Scale (VAS)) were collected at 12 weeks for both groups. Results. There was a significant improvement in both range of motion and Western Ontario Rotator Cuff scores in all subjects with treatment (p < 0.001). Furthermore, participation in aquatic therapy significantly improved passive flexion range of motion measures at three weeks (mean 46°, 95% CI 17–75, p = 0.005) and six weeks (30°, 95% CI 8–51, p = 0.01). There was no significant difference in the attendance rates (80% in both groups) or patients perceptions of the programmes (100% confidence and assurance in both groups). Conclusion. The implementation of a combined aquatic and land‐based physiotherapy programme following surgical repair of the rotator cuff is feasible and presents a potential viable alternative to conventional land‐based exercise with comparable outcomes. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of antisense RNA targeting of ODC and AdoMetDC on the synthesis of polyamine synthesis and cell growth in prostate cancer cells using a prostatic androgen‐dependent promoter in adenovirus
Authors: Li Wei , Liu Xianxi , Wang Wei , Sun Hui , Hu Yongmei , Lei Hong , Liu Guanghui , Gao Yanyan 
Published: June 2008

AbstractPURPOSEThis study was designed to investigate the use of a prostatic androgen‐dependent promoter to mediate antisense targeting of ornithine decarboxylase (ODC) and S‐adenosylmethionine decarboxylase (AdoMetDC) and its effects on the synthesis of polyamine. We also examined the potential of this construct for prostate cancer therapy.METHODSpADxsi‐PSES‐AdoMetDC‐ODC‐PolyA AV was constructed and used to infect various cancer cell lines, including LNCaP, HT‐29, H1299, HepG2. The effects of pADxsi‐PSES‐AdoMetDC‐ODC‐PolyA AV on the expression of ODC and AdoMetDC, in addition to the cell cycle, apoptosis and p21 levels, were analyzed through Western blotting and cytometry. A Matrigel invasion assay was used to analyze the effects of the recombinant virus on tumor cell invasion. The effect on polyamine content was also determined, and the relationship between inhibition of cellular ODC and AdoMetDC and decreases in polyamine were also investigated using a polyamine recovery assay.RESULTSTreatment with pADxsi‐PSES‐AdoMetDC‐ODC‐PolyA at an MOI of 90 significantly inhibited the proliferation of LNCaP cells, which could not be recovered through the addition of exogenous putrescine. The expression of ODC and AdoMetDC was also reduced, as was the polyamine content. The G1 phase of LNCaP cells was delayed, but no increase in apoptosis was detected. The down‐regulation of ODC and AdoMetDC led to increased p21 expression.CONCLUSIONSThe pADxsi‐PSES‐AdoMetDC‐ODC‐PolyA AV specifically inhibited the expression of ODC and AdoMetDC and the synthesis of polyamine, while it induced p21 expression, resulting in cell growth arrest in the G1 phase in prostate cancer cells but not in other cells. Prostate 68:1354–1361, 2008. © 2008 Wiley‐Liss, Inc.
Method for the systematical hazard identification
Authors: Lásková Andrea , Tabas Marek 
Published: June 2008

AbstractIndustrial accidents are usually accompanied by negative consequences for human life, property, and environment. Simultaneously, accidents can provide new knowledge of chemical processes and their properties. These accidents and their analysis are usually complicated, but they are important sources of information that highlight the dangers of neglecting safety in chemical companies, and the results are also used to improve risk assessments.The aim of this hazard identification method is to use past accident results to prioritize efforts by focusing on the critical points of a process, prior to making a detailed quantitative assessment.The critical points (for example pipelines, vessels, etc.) are identified before making the detailed analyses such as FMEA, HAZOP, etc. Results of this method are the input to quantitative assessments, including: (a) estimation of event frequency, (b) estimation of the consequences, (c) comparison with the hazards, and (d) decisions and actions. The most difficult and timely step is the estimation of the consequences of accident scenarios. This hazard identification method focuses on the critical points of a process before making quantitative assessments; therefore it enhances the quality of risk assessments while reducing the costs.This article describes a selection method to identify the major sources of potentially serious accidents with consequences beyond the boundaries of the premises. This method can be used to compare different technologies in the assessment process and assist in prioritizing efforts to reduce risks. This method is used for the installation of new equipment and controls, and it is also used to schedule training and maintenance on the systems with the highest potential hazards. The maintenance and training schedules are also prioritized based on the hazard ratings. © 2008 American Institute of Chemical Engineers Process Saf Prog, 2008
Multiwafer atmospheric‐pressure MOVPE reactor for nitride semiconductors and ex‐situ dry cleaning of reactor components using chlorine gas for stable operation
Authors: Tokunaga Hiroki , Fukuda Yasushi , Ubukata Akinori , Ikenaga Kazutada , Inaishi Yoshiaki , Orita Takashi , Hasaka Satoshi , Kitamura Yuichiro , Yamaguchi Akira , Koseki Shuichi , Uematsu Kunimasa , Tomita Nobuyasu , Akutsu Nakao , Matsumoto Koh 
Published: June 2008

AbstractWe describe an atmospheric‐pressure MOVPE reactor with a capacity of 2 inch by 10 or 3 inch by 8. In this reactor, the parasitic reaction of particulate generation is suppressed by adopting a high‐flow‐speed design. As a result of suppressing of the parasitic reaction, we have also grown GaN at a growth rate of more than 28 μm/hr at atmospheric pressure. It is also important to grow a heterostructure of Al‐containing alloys continuously to enable device applications, while maintaining the proper growth conditions for other layers such as GaN:Mg. An Al0.09Ga0.91N layer has been grown at a growth rate of 1 μm/h at atmospheric pressure. In the production environment, it is also essential to operate a reactor under a stable condition. To this end, we have adopted ex‐situ dry cleaning of all reactor components with deposits on them after every growth run. Dry cleaning was conducted using chemical etching of the deposit by chlorine gas in a hot tube reactor at about 800 °C. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic anisotropy of ferromagnetic semiconductor [(InGa)Mn]As thin films
Authors: Yokoyama M. , Ohya S. , Tanaka M. 
Published: June 2008

AbstractWe investigated the magnetic anisotropy of a series of 10‐nm‐thick [(Iny Ga1–y )1–x Mnx ]As thin films with the Mn content x of 0.12 and with the In content y of 0.38, 0.40, 0.44, 0.48, and 0.54, grown on InP (001) substrates. The tensile‐strained [(Iny Ga1–y )1–x Mnx ]As thin films with y = 0.38 – 0.44 have the easy magnetization axis perpendicular to the film plane. With the increase of y, the in‐plane component of the magnetic anisotropy becomes more dominant. Using planar Hall effect measurements, we found that the compressively strained [(Iny Ga1–y )1–x Mnx ]As thin films with y = 0.48 and 0.54 have the in‐plane uniaxial magnetic anisotropy along the [$ \bar 1 $10] direction. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonradiative processes at low temperature in Er,O‐codoped GaAs grown by organometallic vapor phase epitaxy
Authors: Fujita A. , Tokuno T. , Hidaka K. , Fujii K. , Tachibana K. , Ichida H. , Terai Y. , Kanematsu Y. , Fujiwara Y. 
Published: June 2008

AbstractEr‐related photoluminescence (PL) properties have been investigated in Er,O‐codoped GaAs (GaAs:Er,O) grown by organometallic vapor phase epitaxy. The GaAs:Er,O which was slightly doped with Er exhibited both strong Er‐related and band‐edge luminescence. In the temperature dependence of the Er‐related PL intensity, the intensity decreased with increasing temperature from 4.2 K to 30 K. The temperature region was quite coincident with the region where the Carbon‐related PL intensity decreased. This behaviour implies the existence of a Carbon‐related nonradiative process in GaAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface plasmon enhanced light emission from semiconductor materials
Authors: Okamoto Koichi , Scherer Axel , Kawakami Yoichi 
Published: June 2008

AbstractSurface plasmon (SP) coupling technique was used to enhance light emissions from semiconductor nanocrystals with evaporated metal layers. We found that the SP coupling can increase the internal quantum efficiencies (IQE) of emission from CdSe‐based nanocrystals regardless of the initial efficiencies. This suggests that this technique should be much effective for various materials that suffer from low quantum efficiencies. We also obtained 70‐fold enhancement of emission from silicon nanocrystals in silicon dioxide. Obtained IQE value is 38%, which is as large as that of a compound semiconductor with direct transition. The SP coupling technique would bring a great improvement to silicon photonics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of deep levels in GaN grown by RF‐MBE on GaN template by capacitance DLTS
Authors: Mitsunaga T. , Yagishita Y. , Kurouchi M. , Kishimoto S. , Osaka J. , Mizutani T. 
Published: June 2008

AbstractThe dependence of deep levels in GaN epitaxial layer grown by molecular beam epitaxy on the V/III ratio was studied by capacitance deep level transient spectroscopy (DLTS). Four peaks corresponding to the electron traps were observed in the unintentionally n‐doped GaN films grown at various growth conditions. The deep level concentrations of T1 (0.31 eV) and T4 (0.21 eV) traps increased with decrease of the V/III ratio. This suggests that T1 and T4 traps are related to the N‐vacancies. Those of T2 (0.84 eV) and T3 (1.13 eV) traps did not show obvious dependence on the V/III ratio, but the concentration of the T2 and T3 traps increased with increase of the residual carrier concentration. T2 and T3 traps might have some correlation with the residual donor species. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Properties of Ga2O3‐based (Inx Ga1–x)2O3 alloy thin films grown by molecular beam epitaxy
Authors: Oshima Takayoshi , Fujita Shizuo 
Published: June 2008

AbstractA series of Ga2O3‐based (Inx Ga1–x )2O3 alloy thin films have been grown on c‐plane sapphire substrates with a thin Ga2O3 buffer layer by plasma‐assisted molecular beam epitaxy. At growth temperatures of 700 °C and higher, even with a slight inclusion of In2O3 to Ga2O3, for example, the film of (In0.08Ga0.92)2O3, exhibited a rough surface and degraded transmission spectrum resulting from phase separation of In2O3. Due to low temperature growth at 600 °C, however, the phase separation was suppressed for the In composition up to 35%, which was confirmed by X‐ray diffraction measurement, and the films exhibited high transmittance over 85% with sharp absorption edges. The bandgap could be tuned form 5.0 to 4.0 eV. The results encourage the application of (Inx Ga1–x )2O3 thin films in short‐wavelength optical devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of oxygen deficient amorphous oxide semiconductor a‐InGaZnO4–x: Optical analyses and first‐principle calculations
Authors: Kamiya Toshio , Nomura Kenji , Hirano Masahiro , Hosono Hideo 
Published: June 2008

AbstractDefect states in a representative amorphous oxide semiconductor, a‐InGaZnO4, were studied by optical analyses and first‐principle calculations. The optical analyses suggested that the as‐deposited a‐IGZO film have weak subgap absorptions around 0.6 and 2 eV. Local density approximation calculations showed that an oxygen defect works as an electron trap as well as a shallow donor depending on its local structure. It suggests that a large vacancy space remained in an oxygen deficient structure forms a deep levels in the band gap and traps electrons, while if such a large space is annihilated e.g. by a film growth process and post thermal annealing, oxygen deficiency may form a shallow donor level. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An approach for single crystalline zinc oxide thin films with fine channel mist chemical vapor deposition method
Authors: Kawaharamura Toshiyuki , Fujita Shizuo 
Published: June 2008

AbstractEfforts of fabricating single crystalline ZnO thin films by the mist chemical vapor deposition (CVD) method have been reported in this paper. In our previous research, by using the water solution of zinc acetate as the Zn source, we have not succeeded in obtaining ZnO thin films of single crystalline structure under the reasonable growth rate. In our recent attempts reported here, the solvent of Zn source (zinc acetate) has been changed from water to methylacetate. This was greatly effective and successive to fabricate single crystalline and high quality ZnO thin films at increased growth rate. As far as X‐ray diffraction 2θ/ω, ω, in‐plane ϕ and 2θχ/ϕ scan spectra have been carefully investigated, it is reasonable to conclude that we could have obtained single crystalline ZnO thin films. The mist CVD technology features high partial pressure of oxygen in the reaction area and this may lead to fabricate high quality ZnO thin films with low density of oxygen vacancies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of electric double layer and crystal shapes of electrochemically grown zinc oxide
Authors: Uno Kazuyuki , Kanda Tadayuki , Aisu Masashi , Asaoka Takayuki , Ina Tsutomu , Tanaka Ichiro , Yamashita Munenori 
Published: June 2008

AbstractZinc oxide (ZnO) films were electrochemically deposited on n‐Si(001) substrates and indium‐tin oxide substrates with various concentrations of electrolytes. The crystal shape and orientation of ZnO were depends both on the type of substrates and the concentration. Denser film was obtained using more concentrated electrolyte or using substrate with lower resistivity. For a unified treatment, we investigate the thickness of the electric double layer (EDL) on the growth surface by measuring the capacitance between two electrodes.The dependence between the thickness of EDL and the crystal shapes indicates that the mass transport beyond the EDL region would govern the electrochemical growth of ZnO. Selective growths on 1 μm/1 μm line and space patterns were demonstrated as a trial. Crystal shapes were similar to those grown on non‐patterned substrates. Control of the crystal orientation is necessary for the application of optoelectronic devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Epitaxial lateral overgrowth of InGaAs on SiO2 from (111) Si micro channel areas
Authors: Hoshii Takuya , Deura Momoko , Sugiyama Masakazu , Nakane Ryosho , Sugahara Satoshi , Takenaka Mitsuru , Nakano Yoshiaki , Takagi Shinichi 
Published: June 2008

AbstractIn this paper, we demonstrate that micro selective area growth (μSAG) is effective in improving the crystal quality of InGaAs on (111) Si through the decrease in the number of the nuclei on a selective growth Si area. It is found that smaller selective areas are better in the morphology of the epitaxial films, while the pitch of selective areas yields a trade‐off relationship between the selectivity and the lateral growth length. It is demonstrated that InGaAs films with good morphology and large lateral growth areas have been obtained by μSAG on (111) Si dot areas with the diameter of 2 μm and the pitch of 5 μm using metal‐organic vapor phase epitaxy (MOVPE). This result suggests that μSAG using MOVPE is a promising technique for III‐V‐On‐Insulator structures on Si substrates. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)