bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-switchable catalysis by a nature-inspired polymer nanoreactor containing Pt nanoparticles
Authors: Zhou Yong , Zhu Maiyong , Li Songjun
Published: February 2014

The proposed nanoreactor was made of Pt nanoparticles and a unique polymer composite of PVI and PTFMA. The self-healing and dissociation of the PVI–PTFMA interaction regulated access to the encapsulated metal nanoparticles, thereby causing self-switchable catalytic ability.
Direct observation of supported W bis-methylidene from supported W-methyl/methylidyne species
Authors: Callens E. , Abou-Hamad E. , Riache N. , Basset J. M.
Published: February 2014

Direct observation of supported W bis-methylidene from supported W methyl/methylidyne species.
An electroactive porous network from covalent metal–dithiolene links
Authors: Cui Jieshun , Xu Zhengtao
Published: February 2014

Direct reaction between a hexathiol and PtCl2 leads to the formation of a covalent metal–organic framework (CMOF) featuring substantial porosity, redox activity and ion exchange capability.
Stochastic atomistic simulation of polycyclic aromatic hydrocarbon growth in combustion
Authors: Lai Jason Y. W. , Elvati Paolo , Violi Angela
Published: February 2014

The Stochastic Nanoparticle Simulator (SNAPS) has been developed to investigate Polycyclic Aromatic Hydrocarbon (PAH) growth in combustion. Simulations elucidated novel, atomistic insight into the chemical composition and morphology of nascent PAHs.
Rare nuclearities in Ni(ii) cluster chemistry: a Ni11 cage from the first use of N-salicylidene-2-amino-5-chlorobenzoic acid in metal cluster chemistry
Authors: Athanasopoulou Angeliki A. , Raptopoulou Catherine P. , Escuer Albert , Stamatatos Theocharis C.
Published: February 2014

The first use of N-salicylidene-2-amino-5-chlorobenzoic acid in metal cluster chemistry has afforded a new NiII11 cage consisting of Ni4 squares and Ni3 triangles.
A high performance polybenzimidazole–CNT hybrid electrode for high-temperature proton exchange membrane fuel cells
Authors: Du He-Yun , Wang Chen-Hao , Yang Chen-Shuan , Hsu Hsin-Cheng , Chang Sun-Tang , Huang Hsin-Chih , Lai Shiau-Wu , Chen Jyh-Chien , Yu T. Leon , Chen Li-Chyong , Chen Kuei-Hsien
Published: February 2014

A well-controlled Pt/PBI–CNT electrode provides not only good interfacial continuity but also numerous edge planes, which has strong electrochemical activity in HT-PEMFCs.
Ser119 phosphorylation modulates the activity and conformation of PRRXL1, a homeodomain transcription factor
Authors: Soares-dos-Reis Ricardo , Pessoa Ana S. , Matos Mariana R. , Falcão Miguel , Mendes Vera M. , Manadas Bruno , Monteiro Filipe A. , Lima Deolinda , Reguenga Carlos
Published: February 2014

PRRXL1 [paired related homeobox-like 1; also known as DRG11 (dorsal root ganglia 11)] is a paired-like homeodomain transcription factor expressed in DRG and dSC (dorsal spinal cord) nociceptive neurons. PRRXL1 is crucial for the establishment and maintenance of nociceptive circuitry, as Prrxl1−/− mice present neuronal loss, reduced pain sensitivity and failure to thrive. In the present study, we show that PRRXL1 is highly phosphorylated in vivo, and that its multiple band pattern on electrophoretic analysis is the result of different phosphorylation states. PRRXL1 phosphorylation appears to be differentially regulated along the dSC and DRG development and it is mapped to two functional domains. One region comprises amino acids 107–143, whereas the other one encompasses amino acids 227–263 and displays repressor activity. Using an immunoprecipitation–MS approach, two phosphorylation sites were identified, Ser119 and Ser238. Phosphorylation at Ser119 is shown to be determinant for PRRXL1 conformation and transcriptional activity. Ser119 phosphorylation is thus proposed as a mechanism for regulating PRRXL1 function and conformation during nociceptive system development.
Artificial magnetic conductor loaded long‐range passive RFID tag antenna mountable on metallic objects
Authors: Park In‐Yong , Kim Dongho
Published: February 2014

A passive radio frequency identification (RFID) tag antenna providing a long recognition distance is proposed, which is mountable on various types of platforms including metallic and highly dielectric objects. To increase the reading distance, the antenna is installed in a recessed metallic cavity. To reduce further the height of the antenna, an artificial magnetic conductor is placed on the bottom face of the cavity. Consequently, the tag antenna not only can be miniaturised, but also can provide long reading distances on any type of platform objects. The measured maximum reading distance and the minimum sensitivity are 12.2 m and −17 dBm, under a reader transmitting 30 dBm with a 6 dBi antenna. Good agreement between the prediction and experimental results verifies that the approach is fairly effective and useful to substantially increase the reading distance.
Precision irrigation based on wireless sensor network
Authors: Khriji Sabrine , El Houssaini Dhouha , Jmal Mohamed Wassim , Viehweger Christian , Abid Mohamed , Kanoun Olfa
Published: February 2014

The main purpose of this study is to present a complete irrigation solution for the farmer based on wireless sensor network. The challenge is to create an automated irrigation system which can reduce in the same time the water's waste and is cost effective. Different parameters are important to measure in order to calculate the efficient quantity of water needed by plants. In this study, the proposed solution is the use of low‐cost sensor nodes having reduced power consumption able to realise necessary requirements. The system is composed of different types of nodes. Each node consists of a TelosB mote and adequate sensors or actuators. Soil nodes are used to detect the level of moisture and temperature in soil. Weather nodes monitor the climatic changes. Other nodes are connected to actuators which are able to control the opening of the irrigation valve if necessary.
In silico identification of potential targets and drugs for non‐small cell lung cancer
Authors: Huang Chien‐Hung , Wu Min‐You , Chang Peter Mu‐Hsin , Huang Chi‐Ying , Ng Ka‐Lok
Published: February 2014

Lung cancer is one of the leading causes of death in both the USA and Taiwan, and it is thought that the cause of cancer could be because of the gain of function of an oncoprotein or the loss of function of a tumour suppressor protein. Consequently, these proteins are potential targets for drugs. In this study, differentially expressed genes are identified, via an expression dataset generated from lung adenocarcinoma tumour and adjacent non‐tumour tissues. This study has integrated many complementary resources, that is, microarray, protein‐protein interaction and protein complex. After constructing the lung cancer protein‐protein interaction network (PPIN), the authors performed graph theory analysis of PPIN. Highly dense modules are identified, which are potential cancer‐associated protein complexes. Up‐ and down‐regulated communities were used as queries to perform functional enrichment analysis. Enriched biological processes and pathways are determined. These sets of up‐ and down‐regulated genes were submitted to the Connectivity Map web resource to identify potential drugs. The authors' findings suggested that eight drugs from DrugBank and three drugs from NCBI can potentially reverse certain up‐ and down‐regulated genes' expression. In conclusion, this study provides a systematic strategy to discover potential drugs and target genes for lung cancer.
Knowledge discovery for pancreatic cancer using inductive logic programming
Authors: Qiu Yushan , Shimada Kazuaki , Hiraoka Nobuyoshi , Maeshiro Kensei , Ching Wai‐Ki , Aoki‐Kinoshita Kiyoko F. , Furuta Koh
Published: February 2014

Pancreatic cancer is a devastating disease and predicting the status of the patients becomes an important and urgent issue. The authors explore the applicability of inductive logic programming (ILP) method in the disease and show that the accumulated clinical laboratory data can be used to predict disease characteristics, and this will contribute to the selection of therapeutic modalities of pancreatic cancer. The availability of a large amount of clinical laboratory data provides clues to aid in the knowledge discovery of diseases. In predicting the differentiation of tumour and the status of lymph node metastasis in pancreatic cancer, using the ILP model, three rules are developed that are consistent with descriptions in the literature. The rules that are identified are useful to detect the differentiation of tumour and the status of lymph node metastasis in pancreatic cancer and therefore contributed significantly to the decision of therapeutic strategies. In addition, the proposed method is compared with the other typical classification techniques and the results further confirm the superiority and merit of the proposed method.
Efficient harmony search optimization for preventive-maintenance-planning for nuclear power systems
Authors: Rami Abdelkader , Hamdaoui Habib , Sayah Houari , Zeblah Abdelkader
Published: February 2014

This paper combines the universal generating function UGF with harmony search (HSO) meta-heuristic optimization method to solve a preventive maintenance (PM) problem for series-parallel system. In this work, we consider the situation where system and its components have several ranges of performance levels. Such systems are called multi-state systems (MSS). To enhance system availability or (reliability), possible schedule preventive maintenance actions are performed to equipments and affect strongly the effective age. The MSS measure is related to the ability of the system to satisfy the demand. The objective is to develop an algorithm to generate an optimal sequence of maintenance actions providing system working with the desired level of availability or (reliability) during its lifetime with minimal maintenance cost rate. To evaluate the MSS system availability, a fast method based on UGF is suggested. The harmony search approach can be applied as an optimization technique and adapted to this PM optimization problem.
A location optimization method for aircraft weakly-rigid structures
Authors: Wang Zhong-Qi , Yang Yuan , Kang Yong-Gang , Chang Zheng-Ping
Published: February 2014

Since aircraft weakly-rigid structure has large size and weak stiffness, there has serious deformation during assembly process. The current deformation analysis theory of rigid assembly is not applicable. Based on the N-2-1 (N > 3) locating principle, this paper presents a methodology for weakly-rigid parts. An optimization algorithm combines finite element analysis and nonlinear programming methods to find the optimal number and position of the locating points in order to minimize the assembly deformation. An example application study is presented to demonstrate the optimization procedure and its effectiveness by using the software of ABAQUS.
Facial Gel Complication after Dental Injection: A Case Report
Authors: Pourdanesh Fereydoun , Shams Shahin , Sadeghi Hasan Mir Mohammad
Published: February 2014

Injectable gel is becoming increasingly popular for cosmetic reasons. The polyacrylamide gel (PAAG) is a permanent filler material used worldwide. In spite of the fact that the filler materials used today are considered quite safe, various complications have been reported in the literature. Hence PAAG use in the United States is not popular. As the area is very close to the dental field, a large complication potential is relatively considered following buccal dental injections. The aim of this article is to highlight a rare complication observed following a local anesthetic administration of a simple molar restoration in a healthy 33-year-old woman who had history of a filler augmentation in her cheek approximately 6 years ago.
Tunneling Technique for Expedited Fibula Free Tissue Harvest
Authors: Ducic Yadranko , DeFatta Robert , Wolfswinkel Erik M. , Weathers William M. , Hollier Larry H.
Published: February 2014

Free fibula transfer can be associated with a slow and tedious dissection/harvest due to difficulty in visualizing the deeper structures. The purpose of this article is to review the first author's (Y.D.) experience with a novel technique for expedited harvest of fibula free flaps for mandibular reconstruction. A retrospective chart review was performed using the first author's clinical practice using chart data from September 1997 to August of 2007. All patients with available chart data who had undergone free fibular transfer for oromandibular reconstruction were included in this study. Charts that met the specified inclusion criteria were reviewed for patient demographic information, reason for free tissue transfer, flap loss rates (partial and total) and reasons for flap loss, average fibula harvest time (tourniquet time), and foot and ankle function postoperatively. During this time, a total of 283 fibula free flaps were performed in 276 patients. The average fibula harvest time (tourniquet time) for all cases was 22.6 minutes, with a range of 14 to 29 minutes. A total of 13 flaps were unsuccessful (failure rate of 4.6%, with 5 total and 8 partial flap losses). This newly described technique will allow for expedited and simplified harvest of fibula free flaps.
Efficacy of Transcutaneous Transseptal Orbital Decompression in Treating Acute Retrobulbar Hemorrhage and a Literature Review
Authors: Zimmerer Rüdiger , Schattmann Katrin , Essig Harald , Jehn Philipp , Metzger Marc , Kokemüller Horst , Gellrich Nils-Claudius , Tavassol Frank
Published: February 2014

Decreasing visual acuity secondary to orbital trauma may be caused by sudden space-occupying or expanding intraorbital lesions, including retrobulbar hemorrhage (RBH), herniation, or swelling. RBH must be diagnosed and treated immediately. This article addresses the efficacy of transcutaneous transseptal orbital decompression in a combination with a systematic review of the literature for a comparison of this method with existing treatment options. For this study the department's database was retrospectively screened for patients with acute RBH who were treated between 2009 and 2011 using the authors’ approach. Patients presenting with RBH were classified into RBH classes I to III according to three different clinical and radiological manifestations of acute RBH. The efficacy of transcutaneous transseptal orbital decompression was assessed by postoperative visual acuities. The literature review was performed by using the MEDLINE database. The time period for the study was between 2009 and 2011 during which 10 patients were diagnosed with suspected RBH and 9 were treated with the authors’ technique. Visual acuities were reconstituted or maintained in almost 86% of patients who were diagnosed and treated according to the authors approach and who survived initial trauma. It was concluded that transcutaneous transseptal orbital decompression provides an efficient and rapid approach for treating patients with acute RBH. By distinguishing three different manifestations of acute RBH, the authors present a diagnostic tool that may facilitate classification of RBH and determination of treatment options.
Three-Dimensional Volumetric Restoration by Structural Fat Grafting
Authors: Clauser Luigi C. , Consorti Giuseppe , Elia Giovanni , Galié Manlio , Tieghi Riccardo
Published: February 2014

The use of adipose tissue transfer for correction of maxillofacial defects was reported for the first time at the end of the 19th century. Structural fat grafting (SFG) was introduced as a way to improve facial esthetics and in recent years has evolved into applications in craniomaxillofacial reconstructive surgery. Several techniques have been proposed for harvesting and grafting the fat. However, owing to the damage of many adipocytes during these maneuvers, the results have not been satisfactory and have required several fat injection procedures for small corrections. The author's (L.C.) overview the application of SFG in the management of volumetric deficit in the craniomaxillofacial in patients treated with a long-term follow-up.
Management of Temporomandibular Joint Reankylosis in Syndromic Patients Corrected with Joint Prostheses: Surgical and Rehabilitation Protocols
Authors: Clauser Luigi C. , Consorti Giuseppe , Elia Giovanni , Tieghi Riccardo , Galiè Manlio
Published: February 2014

Temporomandibular joint ankylosis (TMJA) is a severe disorder described as an intracapsular union of the disc-condyle complex to the temporal articular surface with bony fusion. The management of this disability is challenging and rarely based on surgical and rehabilitation protocols. We describe the treatment in two young adults affected by Goldenhar syndrome and Pierre Robin sequence with reankylosis after previous surgical treatments. There are three main surgical procedures for the treatment of TMJA: gap arthroplasty, interpositional arthroplasty, and joint reconstruction. Various authors have described reankylosis as a frequent event after treatment. Treatment failure could be associated with surgical errors and/or inadequate intensive postoperative physiotherapy. Surgical treatment should be individually tailored and adequate postoperative physiotherapy protocol is mandatory for success.
Ratio of Simple versus Comminuted Lateral Wall Fractures of the Orbit
Authors: Barta Ruth J. , Schubert Warren
Published: February 2014

Reduction of a fracture may be relatively easy with a simple, noncomminuted fracture along the zygomaticofrontal suture, zygomaticomaxillary buttress, or the inferior rim of the orbit. When one or more of these key landmarks is comminuted, it becomes more important to confirm that the fracture commonly seen between the greater wing of the sphenoid and the zygoma is properly repositioned. The zygomaticosphenoidal suture is an excellent landmark with a simple lateral orbital wall fracture (LOWF), but it may not be reliable in patients with a comminuted fracture. The purpose of this study is to determine the frequency that the lateral orbital wall (LOW) is a reliable landmark in the reduction of a zygoma fracture by determining the ratio between simple versus comminuted LOWF. To identify 100 patients with a LOWF, the authors reviewed consecutive midface computed tomography images of 877 patients performed over a 25-month period from one of our city's primary Level I trauma and teaching hospitals. A total of 121 LOWF were identified in 100 patients. In 60.3% of cases the facture was a simple, noncomminuted LOWF. In 39.7% of cases the fracture was comminuted ( p = 0.023). Simple LOWF are significantly more common than comminuted fractures. In 39.7% of fractures the LOW is comminuted. This suggests that there are many fractures in which other modalities may be much more important to use to confirm the proper reduction of the zygoma.
Skeletal Stability after Bilateral Sagittal Split Advancement and Setback Osteotomy of the Mandible with Miniplate Fixation
Authors: Rao SrinivasanHanumantha , Selvaraj Loganathan , Lankupalli Arathy S.
Published: February 2014

The purpose of this study was to evaluate intraorally placed mini plates and monocortical screws in terms of postoperative skeletal stability after bilateral sagittal split advancement and setback osteotomy of the mandible. Ten patients were included in this study with five requiring advancement (group I) and five requiring setback of the mandible (group II). Bell and Epker modified surgical technique was followed for all the patients. All the patients underwent pre- and postsurgical orthodontics. Cephalometric radiographs were taken preoperatively, immediate, 3, 6, and 12 months postoperatively. Cephalometric tracings were performed by one individual examiner using a modified burstone analysis. Statistical analysis was performed using the student paired t-test. In advancement patients, SNB (sella, Nasion, B point) angle showed relapse at 12th month postoperative period which was statistically significant (2.4 degrees). No changes were observed in anterior facial height, posterior facial height, Frankfort-mandibular incisor angle (FmiA), and overjet during the follow-up period. In setback patients, posterior facial height ( p < 0.05), angles between the lower incisors and mandibular plane and pogonion had a statistically significant change position of 1.4 mm (paired t-test, p = 0.03). The SNB angle, anterior facial height, interincisal angle, and FmiA remained constant (0.8–1.2 degrees) during the follow-up period. In advancement cases, the relapse was seen from the third month postoperative period but in setback cases, the relapse was noted from the sixth month onward and the skeletal relapse in these cases were noticed cephalometrically.
Complication of Anterior Iliac Bone Graft Harvesting in 372 Adult Patients from May 2006 to May 2011 and a Literature Review
Authors: Almaiman Manar , Al-Bargi Hamed H. , Manson Paul
Published: February 2014

Autogenous bone graft from the iliac is considered the gold standard graft material in maxillofacial surgery. The common and the rare complications associated with harvesting bone from anterior iliac crest were reviewed; we recommend a safe technique to avoid these complications. A retrospective analysis of 372 adult patients who had undergone anterior iliac bone graft harvesting from May 2006 to May 2011. The patients age range from 21 to 63 years. Out of the 372 patients, 200 were male with age range from 21 to 63 years and 172 were female with age range from 22 to 59 years. Two major complications (fracture and seroma) occurred, a fracture of the anterior superior iliac spine was observed in two patients (0.538%); one male and one female. One female patient (0.269%) developed seroma. One minor complication occurred in three patients (0.806%); one female and two females who suffered from temporary sensory disturbance. All patients (100%) suffered pain maximum for the first 15 days postoperative. In our study; the morbidity after anterior iliac bone graft harvesting was found to be low due to the technique, utilizing the proper instruments, gentle and minimal mobilization of the graft.
Immediate Loading of One-Piece Implants in Conjunction with a Modified Technique of Inferior Alveolar Nerve Lateralization: 10 Years Follow-Up
Authors: Eldibany Riham , Rodriguez Joaquin G.
Published: February 2014

This report describes a treatment modification for a patient presented with severely resorbed bilateral edentulous posterior mandible and mobility of the anterior teeth. There was less than 8 mm of bone between the crest of the alveolar ridge and the mandibular canal as revealed by radiographic examination. A modified technique for inferior alveolar nerve lateralization (IANL) in conjunction with ridge expansion was performed using threaded bone expanders, which allowed for better primary stability and placing longer implants. A total of four postextraction implants were in the anterior region of the mandible. The mandible received a total of nine one-piece implants to allow for immediate nonfunctional loading. The definitive ceramometallic prosthesis was delivered 3 months postoperatively. The 10 years clinical and radiographic assessment showed minimal bone resorption around osseointegrated implants. One-piece implants showed great success rate and minimal bone resorption following the modified technique of IANL and immediate implantation.
Computer-Assisted Mandibular Reconstruction using a Patient-Specific Reconstruction Plate Fabricated with Computer-Aided Design and Manufacturing Techniques
Authors: Wilde Frank , Cornelius Carl-Peter , Schramm Alexander
Published: February 2014

We investigated the workflow of computer-assisted mandibular reconstruction that was performed with a patient-specific mandibular reconstruction plate fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) techniques and a fibula flap. We assessed the feasibility of this technique from virtual planning to the completion of surgery.

Computed tomography (CT) scans of a cadaveric skull and fibula were obtained for the virtual simulation of mandibular resection and reconstruction using ProPlan CMF software (Materialise®/DePuy Synthes®). The virtual model of the reconstructed mandible provided the basis for the computer-aided design of a patient-specific reconstruction plate that was milled from titanium using a five-axis milling machine and CAM techniques. CAD/CAM techniques were used for producing resection guides for mandibular resection and cutting guides for harvesting a fibula flap. Mandibular reconstruction was simulated in a cadaveric wet laboratory.

No problems were encountered during the procedure. The plate was fixed accurately to the residual bone without difficulty. The fibula segments were attached to the plate rapidly and reliably. The fusion of preoperative and postoperative CT datasets demonstrated high reconstruction precision.

Computer-assisted mandibular reconstruction with CAD/CAM-fabricated patient-specific reconstruction plates appears to be a promising approach for mandibular reconstruction. Clinical trials are required to determine whether these promising results can be translated into successful practice and what further developments are needed.
Validation of accuracy of WAsP in vertical wind profile prediction
Authors: Boopathi K. , Hari Bhaskaran A. , Krishnan B. , Bastin J.
Published: February 2014

Wind, the most industrialized form of renewable energy is always fond of extrapolations and predictions. The imperfection in extrapolation and prediction techniques may feed the uncertainty in wind speed values and hence have a great negative influence in energy estimation. The wind shear profile prediction methodology of the software tools and the topographical nature of the site are the significant reasons for these erroneous outcomes. This paper tries to throw some light on the reliability of the commonly used wind flow modeling software WAsP in wind profile prediction in different terrain conditions by utilizing data from three 120 m high masts which are selected to replicate three different types of terrain. The results of the study enhance the confidence level on WAsP vertical wind profile prediction methods in these three sites. Further the outcomes are expected to provide some awareness regarding the usage of lower height anemometric values for prediction.
Application of magneto-optical Kerr effect to first-order reversal curve measurements
Authors: Gräfe Joachim , Schmidt Mathias , Audehm Patrick , Schütz Gisela , Goering Eberhard
Published: February 2014

First-order reversal curves (FORC) are a powerful method for magnetic sample characterization, separating all magnetic states of an investigated system according to their coercivity and internal magnetic interactions. A major drawback of using measurement techniques like VSM or SQUID, typically applied for FORC acquisition, is the long measurement time, limiting the resolution and the number of measurements due to time constraints. Faster techniques like MOKE result in problems regarding measurement stability over the curse of the acquisition of many minor loops, due to drift and non-absolute magnetization values. Here, we present an approach using a specialized field shape providing two anchor points for each minor loop for applying the magneto-optical Kerr effect (MOKE) technique to FORC measurements. This results in a high field resolution while keeping the total acquisition time to only a few minutes. MOKE FORC measurements are exemplarily applied to a simple permalloy film, an exchange-bias system, and a Gd/Fe multilayer system with perpendicular magnetic anisotropy, showcasing the versatility of the method.
Reactive cluster model of metallic glasses
Authors: Jones Travis E. , Miorelli Jonathan , Eberhart Mark E.
Published: February 2014

Though discovered more than a half century ago metallic glasses remain a scientific enigma. Unlike crystalline metals, characterized by short, medium, and long-range order, in metallic glasses short and medium-range order persist, though long-range order is absent. This fact has prompted research to develop structural descriptions of metallic glasses. Among these are cluster-based models that attribute amorphous structure to the existence of clusters that are incommensurate with crystalline periodicity. Not addressed, however, are the chemical factors stabilizing these clusters and promoting their interconnections. We have found that glass formers are characterized by a rich cluster chemistry that above the glass transformation temperature promotes exchange as well as static and vibronic sharing of atoms between clusters. The vibronic mechanism induces correlated motions between neighboring clusters and we hypothesize that the distance over which these motions are correlated mediates metallic glass stability and influences critical cooling rates.
Probing the electronic structure and Au–C chemical bonding in AuC2− and AuC2 using high-resolution photoelectron spectroscopy
Authors: León Iker , Yang Zheng , Wang Lai-Sheng
Published: February 2014

We report photoelectron spectroscopy (PES) and high-resolution PE imaging of AuC2− at a wide range of photon energies. The ground state of AuC2− is found to be linear (C∞v, 1Σ+) with a …8π44δ417σ29π418σ2 valence configuration. Detachments from all the five valence orbitals of the ground state of AuC2− are observed at 193 nm. High-resolution PE images are obtained in the energy range from 830 to 330 nm, revealing complicated vibronic structures from electron detachment of the 18σ, 9π, and 17σ orbitals. Detachment from the 18σ orbital results in the 2Σ+ ground state of neutral AuC2, which, however, is bent due to strong vibronic coupling with the nearby 2Π state from detachment of a 9π electron. The 2Σ+–2Π vibronic and spin-orbit coupling results in complicated vibronic structures for the 2Σ+ and 2Π3/2 states with extensive bending excitations. The electron affinity of AuC2 is measured accurately to be 3.2192(7) eV with a ground state bending frequency of 195(6) cm−1. The first excited state (2A′) of AuC2, corresponding to the 2Π3/2 state at the linear geometry, is only 0.0021 eV above the ground state (2A′) and has a bending frequency of 207(6) cm−1. The 2Π1/2 state, 0.2291 eV above the ground state, is linear with little geometry change relative to the anion ground state. The detachment of the 17σ orbital also results in complicated vibronic structures, suggesting again a bent state due to possible vibronic coupling with the lower 2Π state. The spectrum at 193 nm shows the presence of a minor species with less than 2% intensity relative to the ground state of AuC2−. High-resolution data of the minor species reveal several vibrational progressions in the Au–C stretching mode, which are assigned to be from the metastable 3Π2,1,0 spin-orbit excited states of AuC2− to the 2Π3/2,1/2 spin-orbit states of neutral AuC2. The spin-orbit splittings of the 3Π and 2Π states are accurately measured at the linear geometry. The current study provides a wealth of electronic structure information about AuC2− and AuC2, which are ideal systems to investigate the strong Σ–Π and spin-orbit vibronic couplings.
Electron gun jitter effects on beam bunching
Authors: Liu M. S. , Iqbal M.
Published: February 2014

For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps which eventually deteriorates both the beam performance and the injection rate to the storage ring.
Origin of radical coercivity reduction in fine Nd-Fe-B-type hydrogenation, disproportionation, desorption, recombination particles and its recovery
Authors: Kwon H. W. , Lee J. G. , Yu J. H.
Published: February 2014

Coercivity variation of fine Nd-Fe-B-type particles prepared by ball milling of HDDR (hydrogenation, disproportionation, desorption, recombination)-treated Nd-Fe-B-type material was investigated using a HDDR-treated Nd12.5Fe80.6B6.4Ga0.3Nb0.2 material, and it was compared with that of fine particles prepared by mechanical milling of sintered Nd10Pr2.5Fe80.4B6Ga1Cu0.1 magnet. Coercivity of the fine particles prepared from the HDDR-treated Nd-Fe-B-type material was radically reduced as particle size decreased. In order to determine the major cause for the radical coercivity reduction, surface oxidation, structural damage (micro-strain), and crystallographic change (lattice shrinkage due to residual hydrogen desorption) in the milled fine particles were examined. The major contributory factor for the observed radical coercivity reduction was surface oxidation. Chemical etching proved an effective means for the recovery of the reduced coercivity in the milled fine particles prepared from the HDDR-treated Nd-Fe-B-type material. In contrast to fine particles prepared from sintered Nd-Fe-B-type magnet, the fine particles prepared from the HDDR-treated material could have reasonably high coercivity even as a very fine powder.
Influence of writing and reading intertrack interferences in terms of bit aspect ratio in shingled magnetic recording
Authors: Nobuhara Hirofumi , Okamoto Yoshihiro , Yamashita Masato , Nakamura Yasuaki , Osawa Hisashi , Muraoka Hiroaki
Published: February 2014

In this paper, we investigate the influence of the writing and reading intertrack interferences (ITIs) in terms of bit aspect ratio (BAR) in shingled magnetic recording by computer simulation using a read/write model which consists of a writing process based on Stoner–Wohlfarth switching asteroid by a one-side shielded isosceles triangular write head and a reading process by an around shielded read head for a discrete Voronoi medium model. The results show that BAR should be 3 to reduce the influence of writing and reading ITIs, media noise, and additive white Gaussian noise in an assumed areal density of 4.61Tbpsi.
Measurement of the microwave effective permittivity in tensile-strained polyvinylidene difluoride trifluoroethylene filled with graphene
Authors: Adohi B. J. P. , Laur V. , Haidar B. , Brosseau C.
Published: February 2014

We report an interesting effect in the form of a rise (up to 13%) in the permittivity of graphene (GE) filled polyvinylidene difluoride trifluoroethylene (P(VDF-TrFE)) subjected to a small uniaxial deformation (up to 7% in the principal direction). Our findings differ from GE-PVDF homopolymer samples that show a decrease of permittivity upon elongation. We argue that the VDF content which controls the spontaneous polarization has a profound effect on the charge storage through the addition of interface density by the GE phase.
Quasi-continuum photoluminescence: Unusual broad spectral and temporal characteristics found in defective surfaces of silica and other materials
Authors: Laurence Ted A. , Bude Jeff D. , Shen Nan , Steele William A. , Ly Sonny
Published: February 2014

We previously reported a novel photoluminescence (PL) with a distribution of fast decay times in fused silica surface flaws that is correlated with damage propensity by high fluence lasers. The source of the PL was not attributable to any known silica point defect. Due to its broad spectral and temporal features, we here give this PL the name quasi-continuum PL (QC-PL) and describe the features of QC-PL in more detail. The primary features of QC-PL include broad excitation and emission spectra, a broad distribution of PL lifetimes from 20 ps to 5 ns, continuous shifts in PL lifetime distributions with respect to emission wavelength, and a propensity to photo-bleach and photo-brighten. We found similar PL characteristics in surface flaws of other optical materials, including CaF2, DKDP, and quartz. Based on the commonality of the features in different optical materials and the proximity of QC-PL to surfaces, we suggest that these properties arise from interactions associated with high densities of defects, rather than a distribution over a large number of types of defects and is likely found in a wide variety of structures from nano-scale composites to bulk structures as well as in both broad and narrow band materials from dielectrics to semiconductors.
Silicon nanocrystals with high boron and phosphorus concentration hydrophilic shell—Raman scattering and X-ray photoelectron spectroscopic studies
Authors: Fujii Minoru , Sugimoto Hiroshi , Hasegawa Masataka , Imakita Kenji
Published: February 2014

Boron (B) and phosphorus (P) codoped silicon (Si) nanocrystals, which exhibit very wide range tunable luminescence due to the donor to acceptor transitions and can be dispersed in polar liquids without organic ligands, are studied by Raman scattering and X-ray photoelectron spectroscopies. Codoped Si nanocrystals exhibit a Raman spectrum significantly different from those of intrinsic ones. First, the Raman peak energy is almost insensitive to the size and is very close to that of bulk Si crystal in the diameter range of 2.7 to 14 nm. Second, the peak is much broader than that of intrinsic ones. Furthermore, an additional broad peak, the intensity of which is about 20% of the main peak, appears around 650 cm−1. The peak can be assigned to local vibrational modes of substitutional B and B-P pairs, B clusters, B-interstitial clusters, etc. in Si crystal. The Raman and X-ray photoelectron spectroscopic studies suggest that a crystalline shell heavily doped with these species is formed at the surface of a codoped Si nanocrystal and it induces the specific properties, i.e., hydrophilicity, high-stability in water, high resistance to hydrofluoric acid, etc.
Control of optical properties in cyanine dye thin film fabricated by a layer-by-layer method
Authors: Kojima Osamu , Fujii Ryoji , Kita Takashi , Shim YongGu
Published: February 2014

We report the fabrication of cyanine dye molecule thin films by a layer-by-layer (LBL) method. In the LBL thin film, the photoluminescence properties can be controlled by the separation between the donor and acceptor dye molecule layers. While the distance dependence of the energy-transfer rate changes around 2 nm, which is comparable with the lengths of the molecules, the energy-transfer rate as evaluated from the photoluminescence decay time shows a maximum value of approximately 15 ns−1. The thin films fabricated by the LBL method will be therefore applicable for ultrafast optical switches with higher repetition rate.
Textured PrCo5 nanoflakes with large coercivity prepared by low power surfactant-assisted ball milling
Authors: Zuo Wen-Liang , Liu Rong-Ming , Zheng Xin-Qi , Wu Rong-Rong , Hu Feng-Xia , Sun Ji-Rong , Shen Bao-Gen
Published: February 2014

The effect of the milling time on the structure, morphology, coercivity, and remanence ratio of textured PrCo5 nanoflakes produced by low power surfactant-assisted ball milling (SABM) was investigated. The X-ray powder diffraction (XRD) patterns indicate that the SABM PrCo5 samples are all CaCu5-type hexagonal structure. The average grain size is smaller than 10 nm when the SABM time is equal to or longer than 5.5 h. The thickness of nanoflakes is mainly in the range of 50−100 nm while the length is 0.5−5 μm when the SABM time reaches 8 h. For the field-aligned PrCo5 nanoflakes, the out-of-plane texture is indicated from the increasing (0 0 l) peaks in the XRD patterns, and the easy magnetization direction is perpendicular to the flake surface. The strong texture of PrCo5 nanoflakes leads to a large coercivity Hc (7.8 kOe) and obvious anisotropic magnetic behaviors for the aligned samples.
Physical properties of bifunctional BST/LSMO nanocomposites
Authors: Beltran-Huarac Juan , Martinez Ricardo , Morell Gerardo
Published: February 2014

We report the fabrication of bifunctional nanocomposites consisting of ferroelectric Ba0.7Sr0.3TiO3 (BST) and ferromagnetic La0.67Sr0.33MnO3 (LSMO) at different concentrations via a high-temperature solid state route. The structural, dielectric, electrical, magnetodielectric (MD), magnetoelectric (ME) and magnetic properties of BST/LSMO nanocomposites were systematically investigated over a wide range of temperatures and frequencies. The X-Ray Diffraction analyses reveal the nanocrystalline nature of the heterostructures, wherein both perovskite phases co-exist. No parasitic phases were observed. The study of the dielectric properties shows that the nanocomposites exhibit relaxor ferroelectric character, with ferroelectric-paraelectric phase transition temperatures around 287–292 K that do not follow the Curie-Weiss law. The electrical measurements indicate that ac conductivities of the nanocomposites follow the Jonscher's universal power law, with activation energies of 0.42–0.63 eV based on Arrhenius-type behavior at high temperatures. The nanocomposites exhibit well-defined ferromagnetic hysteresis loops at room temperature (RT). The MD and ME measurements at RT indicate that BST/LSMO exhibits a nonlinear ME effect at low frequencies, with a threshold near 0.5 T. The magnetocapacitance (MCp) measurements evidence a quadratic dependence on magnetic field, further confirming the multiferroic nature of BST/LSMO. The order of MCp was found to be ∼7% per Tesla. The analysis of the MCp measurements indicates that one of the BST/LSMO compositions studied can be considered as a new multiferroic compound.
Quantum confinement of zero-dimensional hybrid organic-inorganic polaritons at room temperature
Authors: Nguyen H. S. , Han Z. , Abdel-Baki K. , Lafosse X. , Amo A. , Lauret J.-S. , Deleporte E. , Bouchoule S. , Bloch J.
Published: February 2014

We report on the quantum confinement of zero-dimensional polaritons in perovskite-based microcavity at room temperature. Photoluminescence of discrete polaritonic states is observed for polaritons localized in symmetric sphere-like defects which are spontaneously nucleated on the top dielectric Bragg mirror. The linewidth of these confined states is found much sharper (almost one order of magnitude) than that of photonic modes in the perovskite planar microcavity. Our results show the possibility to study organic-inorganic cavity polaritons in confined microstructure and suggest a fabrication method to realize integrated polaritonic devices operating at room temperature.
Acceptor levels in ZnMgO:N probed by deep level optical spectroscopy
Authors: Kurtz A. , Hierro A. , Muñoz E. , Mohanta S. K. , Nakamura A. , Temmyo J.
Published: February 2014

A combination of deep level optical spectroscopy and lighted capacitance voltage profiling has been used to analyze the effect of N into the energy levels close to the valence band of Zn0.9Mg0.1O. Three energy levels at EV + 0.47 eV, EV + 0.35 eV, and EV + 0.16 eV are observed in all films with concentrations in the range of 1015–1018 cm−3. The two shallowest traps at EV + 0.35 eV and EV + 0.16 eV have very large concentrations that scale with the N exposure and are thus potential acceptor levels. In order to correctly quantify the deep level concentrations, a metal-insulator-semiconductor model has been invoked, explaining well the resulting capacitance-voltage curves.
Dependence of reactive metal layer on resistive switching in a bi-layer structure Ta/HfOx filament type resistive random access memory
Authors: Lee Daeseok , Woo Jiyong , Park Sangsu , Cha Euijun , Lee Sangheon , Hwang Hyunsang
Published: February 2014

The dependence of reactive metal layer on resistive switching characteristics is investigated in a bi-layer structural Ta/HfOx filament type resistive random access memory (ReRAM). By increasing the oxygen absorption rate of the reactive metal layer, formation of an induced resistive switching region that led to significant changes in the resistive switching characteristics of the ReRAM was observed. Electrical and physical analyses showed that the induced TaOx-resistive switching region can result in self-compliance behavior, uniform resistive switching, and a gradual set process, which can be utilized for low power and analog operations.
Growth mechanisms study of microcrystalline silicon deposited by SiH4/H2 plasma using tailored voltage waveforms
Authors: Bruneau B. , Wang J. , Dornstetter J.-C. , Johnson E. V.
Published: February 2014

The use of Tailored Voltage Waveforms is a technique wherein one uses non-sinusoidal waveforms with a period equivalent to RF frequencies to excite a plasma. It has been shown to be an effective technique to decouple maximum Ion Bombardment Energy (IBE) from the ion flux at the surface of the electrodes. In this paper, we use it for the first time as a way to scan through the IBE in order to study the growth mechanism of hydrogenated microcrystalline silicon using a SiH4/H2 chemistry. We find that at critical energies, a stepwise increase in the amorphous to microcrystalline transition thickness is observed, as detected by Real Time Spectroscopic Ellipsometry. The same energy thresholds (30 eV and 70 eV) are found to be very influential on the final surface morphology of the samples, as observed by Atomic Force Microscopy. These thresholds correspond to SiHx+ bulk displacement (30 eV) and Hx+ (70 eV) surface displacement energies. A model is therefore proposed to account for the impact of these ions on the morphology of μc-Si:H growth.
Local work function measurements of plasma-fluorinated epitaxial graphene
Authors: Sherpa Sonam D. , Kunc Jan , Hu Yike , Levitin Galit , de Heer Walt A. , Berger Claire , Hess Dennis W.
Published: February 2014

Plasma-fluorination is an attractive route toward the work function engineering of graphene. The effect of surface topography of epitaxial graphene grown on silicon carbide on the increase in work function after plasma-fluorination was investigated using scanning Kelvin probe microscopy. Results of these studies demonstrate the ability of plasma-treatments to functionalize epitaxial graphene without significant surface roughening. For few-layer epitaxial graphene on the Si-face, work function distribution corresponds to its surface topography. A bimodal distribution is observed before and after fluorination and the separation between the two modes widens after the fluorination. For multi-layer epitaxial graphene on the C-face, no correlation is observed between the work function distribution and the surface topography. After fluorination, the work function is fairly uniform except in few peeled off areas that show a stronger work function contrast.
Investigation of coercivity mechanism in hot deformed Nd-Fe-B permanent magnets by small-angle neutron scattering
Authors: Yano M. , Ono K. , Harada M. , Manabe A. , Shoji T. , Kato A. , Kohlbrecher J.
Published: February 2014

The magnetic reversal behaviors of single domain sized Nd-Fe-B permanent magnets, with and without isolation between the Nd2Fe14B grains, was clarified using small-angle neutron scattering (SANS). The SANS patterns obtained arose from changes in the magnetic domains and were analyzed using the Teubner–Stray model, a phenomenological correlation length model, to quantify the periodicity and morphology of the magnetic domains. The results indicated that the magnetic reversal evolved with the magnetic domains that had similar sized grains. The grain isolation enabled us to realize the reversals of single domains.