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101.
De Brabandere H Forsgard N Israelsson L Petterson J Rydin E Waldebäck M Sjöberg PJ 《Analytical chemistry》2008,80(17):6689-6697
The structures of organic phosphorous (P) compounds in aquatic sediments are to a large extent unknown although these compounds are considered to play an important role in regulating lake trophic status. To enhance identification of these compounds, a liquid chromatography (LC) method for their separation was developed. The stationary phase was porous graphitic carbon (PGC), and the mobile phases used in the gradient elution were compatible with both inductive coupled plasma atomic emission spectroscopy (ICP-AES) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). With LC-ICP-AES, eight different P containing peaks could be observed in the P chromatogram indicating that at least eight different P compounds were separated. With the setup of an information dependent acquisition (IDA) with ESI-MS/MS, the mass over charge ( m/ z) of compounds containing a phosphate group (H 2PO 3 (-), m/ z 97) could be measured and further fragmentation experiments gave additional information on the structure of almost 40 separated P compounds, several were verified to be nucleotides. ICP-AES was very suitable in the development of the LC method and allowed screening and quantification of P compounds. The presented LC-ESI-MS/MS technique was able to identify several sediment organic P compounds. 相似文献
102.
Bieschke Kathleen J.; Bell Debora; Davis Claytie III; Hatcher Robert; Peterson Roger; Rodolfa Emil R. 《Canadian Metallurgical Quarterly》2011,5(3):123
We are frustrated with the internship imbalance. Twenty years ago, those of us involved in academic training programs prepared students in our doctoral programs for the internship application process by meeting with them for an hour and giving them a few pointers. Now, the focus on securing an internship seems to pervade all aspects of doctoral education. We listen to students worry that they don’t have sufficient hours, assessment experience, or diverse practicum placements. As the Association of Psychology Postdoctoral and Internship Centers (APPIC) Match approaches, we meet with students more frequently, helping them to prepare their applications and carefully construct their list of internship sites. We devote time helping students to complete the APPIC Application for Psychology Internship (AAPI), prepare for interviews, and rank sites. Those of us who are involved in internship training programs spend extensive hours reviewing hundreds of applications in Phase I and Phase II of the APPIC Match. We respond to applicant concerns, questions, and anxiety. And all of us try to provide support and consolation, as well as some understanding about “what went wrong” to those students who aren’t matched. When we have a moment, we look beyond the students in front of us and worry about the future of our profession. How is it possible that we’ve gotten ourselves into this mess? Hatcher’s (this issue, pp. 126 –140) article (a manifesto, if you will) has the potential to point us in a new direction. Our hope is that each of you, like us, will view Hatcher’s article as the beginning of a paradigm shift in terms of how we characterize this problem and its potential solutions. His innovative and bold view of how the professional training community can work collaboratively to reorganize has the potential to effectively impact the internship imbalance and the quality of the profession as a whole. By likening the internship imbalance to a resource management issue similar to what has been encountered in regard to other resources such as crops and forests, Hatcher provides us with an opportunity to rise above our own positions to draw upon existing, evidence-based approaches to cooperative solutions that can benefit all involved. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
103.
Han X Bian J Eaker DR Kline TL Sidky EY Ritman EL Pan X 《IEEE transactions on medical imaging》2011,30(3):606-620
Micro-computed tomography (micro-CT) is an important tool in biomedical research and preclinical applications that can provide visual inspection of and quantitative information about imaged small animals and biological samples such as vasculature specimens. Currently, micro-CT imaging uses projection data acquired at a large number (300-1000) of views, which can limit system throughput and potentially degrade image quality due to radiation-induced deformation or damage to the small animal or specimen. In this work, we have investigated low-dose micro-CT and its application to specimen imaging from substantially reduced projection data by using a recently developed algorithm, referred to as the adaptive-steepest-descent-projection-onto-convex-sets (ASD-POCS) algorithm, which reconstructs an image through minimizing the image total-variation and enforcing data constraints. To validate and evaluate the performance of the ASD-POCS algorithm, we carried out quantitative evaluation studies in a number of tasks of practical interest in imaging of specimens of real animal organs. The results show that the ASD-POCS algorithm can yield images with quality comparable to that obtained with existing algorithms, while using one-sixth to one quarter of the 361-view data currently used in typical micro-CT specimen imaging. 相似文献
104.
Erika HodúlováMarián Palcut Emil Lechovi?Beáta Šimeková Koloman Ulrich 《Journal of Alloys and Compounds》2011,509(25):7052-7059
The effects of Bi and In additions on intermetallic phase formation in lead-free solder joints of Sn-3.7Ag-0.7Cu; Sn-1.0Ag-0.5Cu-1.0Bi and Sn-1.5Ag-0.7Cu-9.5In (composition given in weight %) with copper substrate are studied. Soldering of copper plate was conducted at 250 °C for 5 s. The joints were subsequently aged at temperatures of 130-170 °C for 2-16 days in a convection oven. The aged interfaces were analyzed by optical microscopy and energy dispersive X-ray spectroscopy (EDX) microanalysis. Two intermetallic layers are observed at the interface - Cu3Sn and Cu6Sn5. Cu6Sn5 is formed during soldering. Cu3Sn is formed during solid state ageing. Bi and In decrease the growth rate of Cu3Sn since they appear to inhibit tin diffusion through the grain boundaries. Furthermore, indium was found to produce a new phase - Cu6(Sn,In)5 instead of Cu6Sn5, with a higher rate constant. The mechanism of the Cu6(Sn,In)5 layer growth is discussed and the conclusions for the optimal solder chemical composition are presented. 相似文献
105.
Jiří Vondráček Emil PelikánOndřej Konár Jana ČermákováKryštof Eben Marek MalýMarek Brabec 《Applied Energy》2008
In this paper we present a statistical approach to natural gas consumption estimation of individual residential and small commercial customers. The approach is based on nonlinear regression principles. Parameters are estimated using mainly two real data sets – ordinary (approximately annual) meter readings of almost all customers and additional (approximately monthly) meter readings designed and operated within the frame of cooperation between the Institute of Computer Science of the Czech Academy of Sciences (ICS) and the West Bohemian Gas Distribution Company, a part of the RWE Group (WBG). The model was tested on various data sets. It has broad applicability in many areas of gas industry. 相似文献
106.
Keilin W. Gregory; Thorn Beverly E.; Rodolfa Emil R.; Constantine Madonna G.; Kaslow Nadine J. 《Canadian Metallurgical Quarterly》2000,31(3):288
Over the past several years, students, academic program faculty, and internship training directors have become increasingly concerned about the inequity between the demand for predoctoral internship slots and the limited supply of those placements. This article presents data from the 1999 Association of Psychology Postdoctoral and Internship Centers' (APPIC) Match, along with the results of 2 studies conducted by the authors. Results indicate that the number of internship positions available in the U.S. and Canada may be nearly balanced with the number of first-time internship applicants and that the current imbalance may result, in large part, from a carryover of unplaced applicants from previous selection processes. Furthermore, approximately ? of unmatched applicants are able to find internship positions subsequent to the conclusion of the matching process, although many of these positions are in non-American Psychological Association-accredited and non-APPIC-member programs. Implications of these findings for the profession and for student applicants are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Emil Gizdarski 《Journal of Electronic Testing》2000,16(4):381-387
In this paper we present an efficient test concept for detection of delay faults in memory address decoders based on the march test tactic. The proposed Transition Sequence Generator (TSG) generates an optimal transition sequence for sensitization of the delay faults in address decoders by Hayes's transformation on a reflected Gray code. It can be used for parallel Built-In Self-Testing (BIST) of high-density RAMs. We also present an efficient Design For Test (DFT) approach for immediate detection of the effects of the delay faults in the address decoders which does not change memory access time. It requires extra logic to be attached to the outputs of the address decoders. This DFT approach can be used to increase memory testability for both on-line and off-line testing of single- and multi-port RAMs. 相似文献
108.
109.
Enrico Soldati Francesca Rossi Jerome Vicente Daphne Guenoun Martine Pithioux Stefano Iotti Emil Malucelli David Bendahan 《International journal of molecular sciences》2021,22(5)
Bone microarchitecture has been shown to provide useful information regarding the evaluation of skeleton quality with an added value to areal bone mineral density, which can be used for the diagnosis of several bone diseases. Bone mineral density estimated from dual-energy X-ray absorptiometry (DXA) has shown to be a limited tool to identify patients’ risk stratification and therapy delivery. Magnetic resonance imaging (MRI) has been proposed as another technique to assess bone quality and fracture risk by evaluating the bone structure and microarchitecture. To date, MRI is the only completely non-invasive and non-ionizing imaging modality that can assess both cortical and trabecular bone in vivo. In this review article, we reported a survey regarding the clinically relevant information MRI could provide for the assessment of the inner trabecular morphology of different bone segments. The last section will be devoted to the upcoming MRI applications (MR spectroscopy and chemical shift encoding MRI, solid state MRI and quantitative susceptibility mapping), which could provide additional biomarkers for the assessment of bone microarchitecture. 相似文献
110.
Markus Wolf Daniel Emil Mack Olivier Guillon Robert Vaßen 《Journal of the American Ceramic Society》2020,103(12):7056-7071
Rare earth silicate environmental barrier coatings (EBCs) are state of the art for protecting SiC ceramic matrix composites (CMCs) against corrosive media. The interaction of four pure rare earth silicate EBC materials Yb2SiO5, Yb2Si2O7, Y2SiO5, Y2Si2O7 and three ytterbium silicate mixtures with molten calcium-magnesium-aluminosilicate (CMAS) were studied at high temperature (1400°C). The samples were characterized by SEM and XRD in order to evaluate the recession of the different materials after a reaction time of 8 hours. Additionally, the coefficient of thermal expansion (CTE) was determined to evaluate the suitability of Yb silicate mixtures as EBC materials for SiC CMCs. Results show that monosilicates exhibit a lower recession in contact with CMAS than their disilicate counterparts. The recession of the ytterbium silicates is far lower than the recession of the yttrium silicates under CMAS attack. Investigation of the ytterbium silicate mixtures exposes their superior resistance to CMAS, which is even higher than the resistance of the pure monosilicate. Also their decreased CTE suggests they will display better performance than the pure monosilicate. 相似文献