bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two Novel Transition‐Metal Phosphite Compounds with 4‐, 6‐ and 12‐Membered Rings: Hydrothermal Syntheses, Crystal Structures and Magnetic Properties of Na2[M(HPO3)2] (M = Fe, Co)
Authors: Liu Wei , Chen Hao‐Hong , Yang Xin‐Xin , Zhao Jing‐Tai 
Published: March 2005

AbstractTwo transition‐metal phosphites, Na2[M(HPO3)2] (M = Fe, Co) with a new structure type have been synthesised under mild hydrothermal conditions and the solid‐state structures have been elucidated by single‐crystal X‐ray diffraction studies. The structures are of a new type with the following data: orthorhombic, Pnma, a = 12.169(4), b = 5.441(2) and c = 9.146(3) Å for the iron species 1 and a = 12.091(3), b = 5.400(4) and c = 9.115(2) Å for the cobalt compound 2, with Z = 4. The crystal structures of these compounds are isotypic and built up from a 3D open framework with 4‐, 6‐ and 12‐membered polyhedral rings of vertex‐linked MO6 and HPO3 building units. The inorganic frameworks contains 12‐membered ring channel systems in which the sodium ions are located. The topology of this structure type is remarkably similar to that of the aeschynite CaTa2O6 with much larger channels. Magnetic measurements of Na2[Co(HPO3)2] show different magnetic features in the low‐temperature (5–30 K) and high‐temperature ranges (100–320 K) suggesting the possible existence of a complex magnetic structure. Antiferromagnetic ordering can be observed as a broadened cusp in χ–1 at θ = 2.6 K. For Na2[Fe(HPO3)2], the magnetic behavior follows the Curie–Weiss law with μeff = 5.41 μB, fitted for 100–320 K. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Coordination Chemistry of the Ditopic Ligand 4‐[6‐(2‐Pyridyl)‐2‐pyridyl]‐6‐(2‐pyridyl)pyrimidine: Encapsulation of Nitrate by [2 × 2]Grid Complexes
Authors: Kovbasyuk Larisa , Pritzkow Hans , Krämer Roland 
Published: March 2005

AbstractWe describe herein the synthesis, physical properties and crystal structures of metal complexes with the new ligand 6‐(2‐pyridyl)‐4‐[6‐(2‐pyridyl)‐2‐pyridyl]pyrimidine (L). Reactions of L with NiII, CoII, FeII, ZnII and CuII nitrates in a 1:1 ratio leads to the self‐assembled tetranuclear [2 × 2] grid complexes 1–5 with encapsulated NO3– ions, as confirmed by the X‐ray crystal structures of [Ni4L4(DMSO)2(H2O)2](NO3)(ClO4)7·4 DMSO·6 H2O (1) and [Co4L4(DMF)4](NO3)(ClO4)7 (2). The mononuclear copper(I) complex [CuL(PPh3)2]‐ClO4·2 (CH3CN) (6) and the binuclear [Cu2L2(CN)(PPh3)2]‐ClO4 (7) were synthesized from L and [Cu(PPh3)3]Cl. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Complexation of Charged Porphyrins by Charged and Metal‐Chelated EDTA‐Tethered β‐Cyclodextrin Dimers: A Thermodynamic Study on the Influence of Tether Charge and Flexibility on Binding Affinity
Authors: Mulder Alart , Huskens Jurriaan , Reinhoudt David N. 
Published: March 2005

AbstractComplex formation between charged porphyrin guests and charged or neutral β‐cyclodextrin (CD) host dimers linked by ethylenediamine‐N,N,N,N‐tetraacetate (EDTA) tethers was assessed by microcalorimetry. Two EDTA‐tethered CD dimers (1 and 2) were employed to obtain a series of structurally similar CD dimers with different tether charges and flexibilities through either (partial) protonation or metal chelation (with CaII or EuIII) of the EDTA tether. Both the tether charge and the flexibility of the CD dimers strongly influenced the binding properties, giving rise to binding constants differing by factors of up to 22. The effect of tether charge was elucidated by the complexation of tetraanionic meso‐tetrakis(4‐sulfonatophenyl)porphyrin (TSPP) by the different forms of CD dimer 1. Tether charge‐dependent complex (de)solvation gave rise to large systematic and counteracting changes in binding enthalpy and entropy, resulting in a binding affinity for the positively charged europium complex of the CD dimer five times larger than that of the negatively charged free li‐gand CD dimer. No marked differences in binding affinities were observed for the complexation of TSPP by CD dimer 2. Both restricted tether flexibility by metal chelation and repulsive electrostatic interactions resulted in diminished binding affinity of CD dimer 1 for the relatively large tetracationic p‐tert‐butylbenzyl‐functionalized p‐pyridylporphyrin (TBPyP). The europium complex of CD dimer 1 binds TBPyP less strongly than the corresponding negatively charged uncomplexed forms of the CD dimer, by a factor of up to 22. The tether of CD dimer 2 is too short to allow strong binding of TBPyP. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Natural recovery from accelerated forest ditch and stream bank erosion five years after harvesting of plantation forest on Plynlimon, mid‐Wales
Authors: Stott Tim 
Published: March 2005

AbstractErosion rates surveyed using 230 erosion pins on 24 occasions over eight years (1994–2001) on forested stream banks, tributaries and forest ditches in the 0·89 km2Nant Tanllwyth catchment, part of the Hafren Forest on Plynlimon, mid‐Wales, showed statistically significant increases of up to 40 mm a−1in mean erosion rates during the two‐year period in which environmentally sensitive plot‐scale timber harvesting operations took place (1996–97). In the four years following timber harvesting mean erosion rates at all sites recovered to levels that were lower than before the harvesting operations began. This is attributed to increased light levels, following canopy removal, allowing vegetation to colonize exposed banks. There was a statistically significant relationship (p< 0·05) between mean erosion rate in 2000–01 (four years after harvesting) and percentage vegetation cover at erosion monitoring sites in the clearfelled (south tributaries) area though the same relationship did not hold for sites on the mainstream banks or for sites on the north (mature forest) ditch sites. The implications of natural vegetation colonization for management of such streams are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Application of supplementary flow in comprehensive 2D liquid chromatography combining SEC and RPC
Authors: Winther Bjørn , Reubsaet J. Léon E. 
Published: March 2005

AbstractA comprehensive two‐dimensional HPLC system (SEC×RPC) was evaluated. Various model compounds with differing hydrophobicity (log D: –0.08 to 2.22) and size (MW: 194 to 66.0×103) were used. In order to reduce the run time of the second dimension, and thereby optimize the number of runs per unit volume from the first dimension, short RPC columns were used (7.5 mm). This column size demanded a low concentration of methanol in the mobile phase from the first dimension, in order to avoid severe band broadening and solute loss. Secondary interactions on SEC make a high methanol concentration in the mobile phase a necessity. Up to 40% methanol was required to diminish non‐ideal SEC behavior. These conditions were non‐compatible with trapping of hydrophilic compounds on RPC. The use of a supplementary flow (0.1% TFA) mixed after the first dimension led to better peak shape and trapping of hydrophilic compounds in the second dimension. This demanded flow adjustment in SEC, which in turn caused performance improvement and an increase in analysis time, making more RPC separations possible. These factors contributed to a larger peak capacity.
Reversible Superhydrophobicity to Superhydrophilicity Transition by Extending and Unloading an Elastic Polyamide Film
Authors: Zhang Jilin , Lu Xiaoying , Huang Weihuan , Han Yanchun 
Published: March 2005

AbstractSummary: Reversible switching between superhydrophobic and superhydrophilic wettability of a polyamide film with a triangular net‐like structure can be achieved by biaxially extending and unloading the elastic film. Both the change of the average side‐length of the triangular net‐like structure upon biaxial extension and unloading, and the surface tension of the water droplet, are believed to be responsible for the reversible switching between superhydrophobicity and superhydrophilicity.Change in structure and wettability of the triangular net‐like polyamide film upon extension and unloading.imageChange in structure and wettability of the triangular net‐like polyamide film upon extension and unloading.
A continuous‐time strategic capacity planning model
Authors: Huh Woonghee Tim , Roundy Robin O. 
Published: March 2005

AbstractCapacity planning decisions affect a significant portion of future revenue. In the semiconductor industry, they need to be made in the presence of both highly volatile demand and long capacity installation lead‐times. In contrast to traditional discrete‐time models, we present a continuous‐time stochastic programming model for multiple resource types and product families. We show how this approach can solve capacity planning problems of reasonable size and complexity with provable efficiency. This is achieved by an application of the divide‐and‐conquer algorithm, convexity, submodularity, and the open‐pit mining problem. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.
Oxygen transport as a solid‐state structure probe for polymeric materials: A review
Authors: Hiltner A. , Liu R. Y. F. , Hu Y. S. , Baer E. 
Published: March 2005

AbstractIn the quest to elucidate the solid‐state structures of polymers, insight into the amorphous phase is particularly elusive. Although the permeability of small molecules is often measured as an important performance property, numerous researchers have found that a deeper analysis of the transport characteristics provides insight into polymer morphology, especially if used in combination with more usual characterization techniques. The transport of small gas molecules senses the permeable amorphous structure and probes the nature of the free volume. In recent years, our interest in the gas barrier of polyesters has resulted in an unusual opportunity to investigate the nature of the free volume in the polymer glassy state. This effort has been aided by access to aromatic polyesters with designed variations in their chemical structure. This review focuses on oxygen transport, supplemented with other methods of physical analysis, as a probe of the excess‐hole free volume. The review addresses the profound effects of orientation and crystallization on the free volume of the glassy state. The discussion also presents a simple odel for the gas permeability of the isotropic glass based on lattice concepts and tests more sophisticated models for the gas permeability of semicrystalline polymers. The final section addresses other opportunities for fruitful applications of oxygen transport as a solid‐state structure probe. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1047–1063, 2005
Biotic and abiotic processes on granite weathering landforms in a cryotic environment, Northern Victoria Land, Antarctica
Authors: Guglielmin Mauro , Cannone Nicoletta , Strini Andrea , Lewkowicz Antoni G. 
Published: March 2005

AbstractA multidisciplinary study was carried out to understand the interactions between biotic and abiotic processes in granite weathering in ice‐free areas of Northern Victoria Land, Antarctica. Examples of tafoni, pits and grooves were analyzed, focusing on their morphometry, infills, weathering rind types and vegetation patterns. Surface and subsurface temperatures and incoming radiation were measured to characterize microclimatic conditions. In addition, microscopic, SEM and X‐ray diffraction analyses of granite were carried out. These analyses indicate that, under present conditions, mechanical weathering is the main process active in the formation of tafoni, which post‐date pits and grooves. In these forms, granular disintegration is mainly induced by chasmoendolithic lichens, salt and thermal stress associated with the dilatation coefficients of different granite‐forming minerals. The overall morphology of pits and grooves indicates that they originate from water erosion. In the former, mechanical weathering prevails, caused by epilithic lichens, by freeze–thaw events, and by salt, while only the first two processes are active in the grooves. The intensity of these processes is less effective than in tafoni and on the outer surfaces, suggesting that pits and grooves are inherited features, possibly generated in the same way as landforms occurring on granite in the humid tropics. Copyright © 2005 John Wiley & Sons, Ltd.
Frequency and magnitude of active‐layer detachment failures in discontinuous and continuous permafrost, northern Canada
Authors: Lewkowicz Antoni G. , Harris Charles 
Published: March 2005

AbstractActive‐layer detachment failures triggered weeks to months after forest fire in the central Mackenzie Valley (65°N, discontinuous permafrost zone) are compared to others generated almost immediately by summer meteorological conditions on the Fosheim Peninsula, Ellesmere Island (80°N, continuous permafrost zone). Preferred long‐axis orientations in both zones vary in relation to valley geometry and ground ice distribution: differential insolation plays no direct role in detachment failure distribution. Rates of geomorphic work over periods of one to two centuries are of the same order of magnitude. Threshold meteorological conditions for initiating failures on the Fosheim Peninsula can be incorporated into a surface heating index, but pre‐conditioning of the active layer remains important because rapid thaw does not always initiate activity. Slope pre‐conditioning does not occur at the fire‐affected sites because the failure zone is within formerly perennially frozen ground. Long‐term rates of unit vertical transport at the most active site on the Fosheim Peninsula are similar to those due to debris flow and slushflow in a nearby mountain range. The frequency of potential triggering events at the Ellesmere Island sites is expected to increase if summer climate warms, providing low percentage cloud cover is maintained during periods of high air temperatures. Copyright © 2005 John Wiley & Sons, Ltd.
Dissociation of dislocations and the mobility of partial dislocations in elemental semiconductors
Authors: Vanderschaeve G. , Caillard D. 
Published: March 2005

AbstractFrom a theoretical analysis of the energy of dissociated dislocations moving in a periodic Peierls potential, it is shown that metastable dissociation configurations are expected, the range of which is asymmetrically distributed with respect to the equilibrium dissociation distance. In the course of this investigation, we have reexamined the literature data on the dissociation of dislocations in high‐stress deformed silicon. It is concluded that the experimental results can be interpreted in a consistent way without the assumption of different mobilities for leading or trailing partials. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improvement of crystalline quality of GaPN layers grown by RF‐plasma MBE with ion collector
Authors: Utsumi A. , Furukawa Y. , Yonezu H. , Yoshizumi Y. , Morita Y. , Wakahara A. 
Published: March 2005

AbstractThe effects on structural crystalline quality and luminescence properties of deflecting nitrogen (N) ions away from the substrate were investigated for GaPN layers grown on GaP substrates by RF‐plasma MBE. The GaPN layers were grown with and without use of an ion collector for N ions deflection. The Pendellösung fringes in the X‐ray diffraction spectrum were more distinct in samples grown with than without the ion collector. This result indicates that the structural and/or interface quality were improved by preventing ion‐induced damage. The sample grown with the ion collector indicated higher crystalline quality by the more linear excitation power dependence of photoluminescence intensity. On the other hand, the sample grown without the ion collector appears to contain a high concentration of non‐radiative recombination centers related to the ion‐induced damage. The ion‐induced damage cannot be completely healed by rapid thermal annealing. To summarize, eliminating ion exposure during growth improves the crystalline quality and radiative recombination properties of the GaPN layer. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Demonstration of a GaN‐spacer high electron mobility transistor with low alloy scattering
Authors: Palacios T. , Shen L. , Keller S. , Chakraborty A. , Heikman S. , Buttari D. , DenBaars S. P. , Mishra U. K. 
Published: March 2005

AbstractA new kind of high electron mobility transistor (HEMT) based on a GaN‐spacer is reported. To confine the two‐dimensional electron gas in this AlGaN‐free HEMT, a GaN/ultrathin AlN/GaN pseudo‐hetero‐junction has been used. The effective conduction band discontinuity is given by the AlN polarization‐induced electric field. This new transistor shows a superior general performance than the standard HEMT due to a decrease in the alloy and real space transfer scattering, as well as lower ohmic contact resistance. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prognostic Impact of CK‐20‐positive Cells in Peripheral Venous Blood of Patients with Gastrointestinal Carcinoma
Authors: Friederichs Jan , Gertler Ralf , Rosenberg Robert , Nahrig Jörg , Führer Katrin , Holzmann Bernhard , Dittler Hans‐Joachim , Dahm Michael , Thorban Stefan , Nekarda Hjalmar , Siewer Jörg Rüdiger 
Published: March 2005

AbstractDespite curative tumor resection, about 30%–50% of patients with locally advanced gastrointestinal (GI) carcinoma develop tumor recurrence which may be caused by pre‐ or intraoperative tumor cell dissemination. We examined the combination of optimized density gradient centrifugation with a CK‐20 reverse transcriptase‐polymerase chain reaction to detect and quantify circulating tumor cells in peripheral blood. Peripheral venous blood (20 ml) of patients with GI carcinomas was collected during primary tumor staging before and after the endoscopy procedure. CK‐20 expression in peripheral venous blood was found in 22 of 82 patients (26.8%) with a nonsignificant difference between the upper GI tract (23.9%) and the lower GI tract (30.5%). The correlation with clinical outcome (24‐month‐survival) revealed a significantly worse prognosis (p < 0.05) of CK‐20–positive patients with carcinoma of the upper GI tract and a trend toward a worse prognosis for patients with carcinoma of the lower GI tract. Quantification of CK‐20 expression in peripheral blood showed a significantly higher circulating CK‐20 copy number (median: 2816) in patients with metastatic tumors than in those with non‐metastatic tumors (median: 983) (p < 0.05). For a subset of 42 primarily operated patients, we correlated the detection rate with UICC (International Union Against Cancer) staging categories. In contrast to the upper GI tract, the detection rate of patients with carcinoma of the lower GI tract showed a trend toward tumor size (pT) and a significant correlation with the presence of distant metastases (pM) (p < 0.01) and the postoperative residual tumor status (R) (p < 0.01). The endoscopy procedure did not lead to an increased detection of CK‐20 expression.
Hepatic Resection for Metastatic Breast Cancer: Prognostic Analysis of 34 Patients
Authors: Sakamoto Yoshihiro , Yamamoto Junji , Yoshimoto Masataka , Kasumi Fujio , Kosuge Tomoo , Kokudo Norihiro , Makuuchi Masatoshi 
Published: March 2005

AbstractLiver metastasis of breast cancer is considered a generalized disease, and surgical treatment is rarely discussed. Thirty‐four patients who underwent 35 hepatectomies for liver metastases of breast cancer between 1985 and 2003 were analyzed. The median interval between the breast surgery and relapse in the liver was 1.9 years (0–20 years). The liver was the first site of recurrence in 25 patients. Fifteen clinicopathologic factors were evaluated using univariate and multivariate analyses to predict survival after hepatic resection. No patients died because of the surgery. The median survival was 36 months (1 month to 20 years). The overall and disease‐free 5‐year survival rates after hepatectomy for breast metastases were 21% and 16%, respectively. Four patients survived more than 5 years. The presence of extrahepatic recurrence prior to hepatectomy was the only significant prognostic factor according to the analyses, and the 5‐year survival rate of patients without extrahepatic disease was 31%. No patient who had hilar lymph node metastasis survived more than 5 years. In the absence of extrahepatic recurrence, surgical resection of liver metastasis from breast cancer can offer an acceptable prognosis and should not be avoided in selected patients.
Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods
Authors: Stransky Christoph , Gudmundsdóttir Sif , Sigurdsson Thorsteinn , Lemvig Svend , Nedreaas Kjell , Saborido-Rey Fran 
Published: March 2005

Abstract
Age determination of Atlantic redfish (Sebastes spp.) has proven difficult and has led to inconsistent age and growth estimates in the past. Using otoliths of the two major commercial species, golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella), a series of exchange schemes was carried out to assess bias and precision of age readings between four readers and between two preparation methods. Considerable bias between readers and moderate precision were observed for the S. marinus readings, especially for ages >20 years, with coefficients of variation (CV) of 7.7–12.0% and average percent error (APE) of 5.4–8.5%. Agreement between readers increased from 17–28% to 45–61% when allowing deviations of ±1 year, and to 80–92% with ±3 years tolerance. The age of S. marinus determined from broken and burnt otoliths was estimated to be slightly lower than when the age of the same individuals was determined from thin-sectioned otoliths. The bias and precision estimates obtained from the S. mentella material were generally poorer than for S. marinus (CV 8.2–19.1%, APE 5.8–13.5%), but similar to reported values for other long-lived fish species. Better than 50% agreement was only achieved with ±3 years tolerance. Growth rates differed significantly between species, confirming slower growth for S. mentella. For S. marinus, only one reader comparison revealed significantly different growth functions, whereas almost all S. mentella reader pairs showed significant differences in growth curves. Section and break-and-burn readings of S. marinus did not differ significantly. Average ages of around 9–10 years were determined for juvenile S. mentella 24–30 cm long, which were likely to have migrated from East Greenland into the Irminger Sea, based on earlier observations. As some of the error in the age determinations presented could be attributed to interpretation differences between readers, further intercalibration of redfish ageing is urgently needed in order to provide consistent input data for stock assessment.
Development and validation of a measurement instrument for studying supply chain management practices
Authors: Li Suhong , Rao S. Subba , Ragu‐Nathan T.S. , Ragu‐Nathan Bhanu 
Published: March 2005

AbstractIt is widely argued that competition is no longer between organizations, but among supply chains. Effective supply chain management (SCM) has become a potentially valuable way of securing competitive advantage and improving organizational performance. This research conceptualizes, develops, and validates six dimensions of SCM practices (strategic supplier partnership, customer relationship, information sharing, information quality, internal lean practices, and postponement). Data for the study were collected from 196 organizations and the measurement scales were tested and validated using structural equation modeling. It is hoped that this study will provide a parsimonious measurement instrument to assess the performance of the overall supply chain.