bluuebunny/crossref_metadata_2025_split huggingface dataset:
What makes the difference? An empirical comparison of critical aspects identified in phenomenographic and variation theory analyses
Authors: Holmqvist Mona , Selin Per 
Published: July 2019

AbstractThis study investigated differences and similarities in outcomes of analyses based on phenomenography and variation theory. We used the same data for both analyses to highlight the assumptions of each approach. Participants were 198 students (grades 7–9) who provided written answers to the question ‘What is learning?’. The phenomenographic analysis identified qualitatively different categories representing different ways participants’ conceptualised learning, separated by critical aspects that distinguished each category. This analysis found six categories, seeing learning as: extended skills, process, investment, feelings, object-knowledge, relationships, and feelings. The variation theory analysis identified aspects constituting the object of learning, with critical aspects being those not yet discerned by the learner. Aspects and features identified in this analysis were: learner (skills, abilities, pre-knowledge, attitudes), learning activities (brain, listen, repeat, practicing), learning source (teacher, school, learning materials, friends, Internet, places/persons outside school), content/object of learning (facts, information, activity), and outcomes (job, enhanced future, development, performance, widening knowledge). Aspects and features not yet discerned are critical, and must be made discernable for the learner to enhance their understanding. This use of critical aspects differs from phenomenography, in which critical aspects identified qualitatively different ways of seeing learning (i.e., categories of collective experiences). In variation theory, aspects (dimensions) and features (values of the dimension) relate to individuals’ understanding in specific contexts (e.g., a school class). A major difference between phenomenography and variation theory is the perspective of collective- and individual-expressed discernments. In phenomenography, a person may belong to several categories, whereas in variation theory, the aspects an individual has discerned reflect the way that person understands the phenomenon. This means the outcome of variation theory can be used to design and test the outcome of instruction, whereas the outcome of phenomenography provides information about general assumptions of how a phenomenon can be discerned.
C2-C5 components in mixtures of liquified hydrocarbons
Authors: Konopelko L A , Kustikov Y A , Kolobova A V , Meshkov A V , Efremova O V , Rozhnov M , Melnyk D , Kisel S , Levbarg O , Shpilnyi S , Yakubov S , Mironchik A M , Mokhnach M V , Ananyin V N 
Published: July 2019

This article presents the report on the supplementary comparison COOMET.QM-S4, "C2-C5 components in mixtures of liquified hydrocarbons". The objective of this comparison was assessment of the analytical capabilities of COOMET NMIs for measuring the composition of Liquid Petroleum Gas (LPG) mixtures when sampled in the liquid phase from Constant Pressure Cylinders (CPCs).
KEY WORDS FOR SEARCH
supplementary comparison, COOMET, Liquid Petroleum Gas, LPG, amount of substance fraction, constant pressure cylinders, ethane, propane, propene, i-butane, n-butane, 1-butene, i-pentane

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.
The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Image processing for quantitative measurement of e/m in the undergraduate laboratory
Authors: Gelir Ali , Kocaman Merve , Pekacar Ilgım 
Published: July 2019

Abstract
In conventional e/m experiments performed in undergraduate laboratories, generally a simple mechanical ruler is used to measure the radius of the circular trajectory of the electrons. But, the measurement error in this technique is mostly big and varies from one student to another. As an alternative to a mechanical ruler, we proposed a more accurate and a more precise technique for measuring the radius. This technique is based on image processing and it is well known that the image processing is one of the more powerful techniques for precise measurements in physical experiments.
ImageJ software was used for image processing and for taking photographs of the circular trajectory of the electrons in the e/m experiment. ImageJ is a java-based image processing program which was developed by the National Institute of Health of USA.
The photographs of the trajectory were taken by using a generic webcam connected to the computer and it was observed that the trajectory was not visible for a one shot photograph which is due to the low intensity of the light coming from the trajectory. By taking multiple photographs of the trajectory at the same time and adding these photographs to each other, the trajectory on the photograph became visible.
It was concluded that the accuracy of the measuring the radius of the circular trajectory could be increased by using the image processing and it was found that the relative error made in this measurement is about 0.5% which is 10 times smaller than the relative errors made in conventional measuring techniques performed by a simple mechanical ruler (around 5%). This result directly increases the precision and the accuracy of measuring the e/m ratio of the electrons in undergraduate physics laboratories.
Band structure of Ge1−xSnx alloy: a full-zone 30-band k · p model
Authors: Song Zhigang , Fan Weijun , Tan Chuan Seng , Wang Qijie , Nam Donguk , Zhang Dao Hua , Sun Greg 
Published: July 2019

Abstract
A full-zone 30-band k · p model is developed as an efficient and reliable tool to compute electronic band structure in Ge1−x
Sn
x
alloy. The model was first used to reproduce the electronic band structures in Ge and α-Sn obtained with empirical tight binding and ab initio methods. Input parameters for the 30-band k · p model are carefully calibrated against prior empirical predications and experimental data. Important material properties such as effective mass for electrons and holes, Luttinger parameters, and density of states are obtained for Ge1−x
Sn
x
alloy with the composition range 0 < x < 0.3. The 30-band k · p model that requires far less computing resources is a necessary capability for optimization of sophisticated devices made from Ge1−x
Sn
x
alloy with a large parameter space to explore.
Response surface methodology optimization for extraction of natural anthocyanins from Vietnamese Carissa carandas L. fruit
Authors: Pham Tri Nhut , Xuan Huynh Thi Ha , Tran Thien Hien , Vo Dai-Viet N. , Toan Tran Quoc , Lam Tri Duc , Le Xuan Tien , Vu-Quang Hieu 
Published: July 2019

Abstract
Anthocyanins are naturally occurring compounds that are responsible for a wide variety of colors in many plants, fruits and vegetables. In this study, the extraction of natural anthocyanins from Vietnamese Carissa carandas L. beverage was optimized using response surface methodology (RSM). We applied a Box–Behnken design consisting of three levels and three factors. Examined factors are extraction temperature (ranging from 40 to 60°C), liquid to solid ratio (ranging from 2:1 to 4:1), extraction time (ranging from 30 to 60 min). Using 60% ethanol as solvent for the process, we determined the maximum yields of anthocyanin was 273.786 mg/L. This yield corresponds to extraction conditions of 3:1 (v/w) liquid to solid ratio, temperature of 48.10 °C with a 44.08 min extraction time. The experimental results also fit well with the proposed response model of anthocyanin yield (R2 = 0.9992). Therefore, this study suggested optimization of different extraction methods for the defatted fruit parts.
Chemical Constituents of the Aerial Parts of Scoparia dulcis and Anti-cancer, Anti-inflammatory Activities
Authors: Thanh Tin Nguyen Ngoc , Thanh Truc Nguyen Dang , Thu Hang Hoang Thi , Nhat Trinh Pham Thi , Lam Tri Duc , Dung Le Tien 
Published: July 2019

Abstract
In Vietnam, the medicinal plant Scoparia dulcis is used for the treatment of bronchitis, gastric disorders, antidiabetes, hypertension, hepatitis etc. In this paper, experiments was designed to evaluate in vitro anticancer and anti-inflammatory activities and isolate phytochemicals from methanol extracts of Scoparia dulcis whole plants. The chemical investigation of methanol fraction of Scoparia dulcis led to the isolation of benzoxazinone (1), phenylethanoid (2), flavone (3), and lignan (4) glycosides. The bioactivity results indicated that crude ethanol and ethyl acetate extracts had potent cytotoxic activity toward the HepG2 cancer cell with IC50 of 47.03 μg/mL and 36.04 μg/mL, respectively. Interestingly, crude ethanol and ethyl acetate extracts had the NO inhibitory activity, with inhibition of 56.9 % or 74.7 % at 30 μg/mL and 97.3% or 82.9 % at 100 μg/mL, respectively. In addition, the hexane extract at concentrations of 100 μg/ml demonstrated anti-inflammatory activity through the inhibition of nitric oxide production of 76.7%.
Experimental study on hydraulic expansion of tube-fin heat exchanger
Authors: Han Junjie , Yang Lianfa , Huang Jinjie , Jiang Jingyu , He Yulin 
Published: July 2019

Abstract
The tube-fin heat exchanger is the core equipment in the whole air-conditioning system, the thermal resistance of copper tube and fin contact accounts for 10%-20% of the total thermal resistance of the heat exchanger, and the thermal contact with the fin increases. Therefore, reducing the contact gap of the heat exchanger is extremely important to improve the overall heat exchange efficiency. In this paper, for the high-efficiency heat exchanger composed of seamless internal thread copper pipe, the heat exchange tube and the fin are expanded by hydraulic expansion and the liquid pressure range, reasonable pressure holding time and pull-off force are guaranteed by a large number of experiments. In this paper, the heat transfer tube and the fins are expanded by hydraulic expansion, and the relationship between the liquid pressure range, the reasonable pressure holding time and the pull-off force and the dwell time is measured through a large number of experiments. Finally, the effect of different liquid pressure expansion joints on the contact gap was further observed by a microscope.
Structural and Electrochemical Properties of Layered-Layered-Spinel Composite Cathode Materials LixMn4/6Ni1/6Co1/6O(1.75+0.5x) (1.1 ≤ x ≤ 1.3) for Lithium-Ion Batteries
Authors: Zhenye Zhu 
Published: July 2019

Abstract
The cathode materials LixMn4/6Ni1/6Co1/6O(1.75+0.5x) (x=1 1, 1.2, 1.3) with different content of lithium have been synthesized by two step temperature co-precipitation in this paper. X-ray diffraction patterns confirm that there are spinel structure and layer structure in prepared composite. SEM images show that the same diameters of the assembled microspheres are at about 4 μm in LixMn4/6Nii/6Coi/6O(1.75+0.5x) composite. The measurement of electrochemical properties indicates that, with content of lithium varying from 1.1 to 1.3, content of spinel component declines, which induce to the increase of discharge capacity and decrease of capacity retention. Li1.1Mn4/6Ni1/6Co1/6O2.30 composite delivers best rate capability, because there is more spinel component in Li1.1Mn4/6Ni1/6Co1/6O2.30.
Vibration characteristic analysis and control of hospital ship
Authors: Shan Yanhe , Miao Xuhong , Li Chengshun , Liu Zhigang 
Published: July 2019

Abstract
Aiming at the problem of high requirement of hospital ship for hull vibration, this paper takes a hospital ship as an example to analyse its vibration characteristic. The three-dimensional finite element model of hospital ship is established. Take the pulsating force of propeller as the exciting force, the vibration response of the whole ship is calculated by acoustic-structure coupling method. Refer to related standard of ISO6954-2000(E), the numerical result shows that the vibration of some region of stern is over standard. An optimization scheme is proposed for the area whose vibration over standard, the result suggests that the whole ship vibration meets the standard after optimization design. This research provides a reference for design and construction of hospital ship.
Transformer Selection Calculation for the design of Flyback Switching Power Supply
Authors: Ni Hao , Wu Aixia , Zhang Xin , Ruan Ruolin , Hu Yonghong , Zhang Wei 
Published: July 2019

Abstract
Pulse-width modulating (PWM) is one of the most popular methods to design the switching power supply. The framework to design a novel flyback switching power supply with a PWM integrated circuit is described in this paper. In order to meet the design demand, the significant step of transformer selection calculation is discussed in details. Ap method is used in the transformer calculation. Then some other parameters of the transformer, such as the transformer ratio, Primary current of transformer, the primary inductance of transformer, the transformer turn and air gap and the wire diameter of the winding, are computed step by step. With the selected transformer, the proposed switching power supply has simpler circuit and higher accuracy. Different input voltage ranges and output voltages required by different electric appliances can be well satisfied.
Study on Basic Properties of Inorganic Isolation Partitioned Polystyrene Insulation Board
Authors: Zhang Jusong , Chen Ruge , Wang Xin 
Published: July 2019

Abstract
In order to ensure the safety of the inorganic isolation partitioned polystyrene insulation board in applying, this paper studied its heat retention,flame retardancy, water absorption, fatigue performance, and microscopic analysis.The test results showed that the apparent density of the board is about 120kg/m3 would meet the demands of great flame retardancy and good thermal insulation; the volume water absorption rate is curve growing in the early stage, it drops slightly and keeping stable after reach the maximum, the maximum is less than 8%; after 1500 times 12.1KN/m2 impact on the board, the internal inorganic material is destroyed basically and remain unchanged in the substrate level; x-ray diffraction analysis result showed that there were Mg(OH)2 and hydrated magnesium sulfate in the solidified inorganic material.
Study of Mechanical Property and Cellular structure Based on the Controllable Crosslinking Polyethylene Foaming Materials
Authors: Xia Bihua , Xu Wenqiang , Wang Ke , Huang Qigu , Liang Wenbin , Sun Xiaojie 
Published: July 2019

AbstractIn this paper, the controllable crosslinking polyethylene foaming materials were established though adding foaming agent additives zinc stearate firstly. Then, the density, expansion ratio, cellular structure, gel content and compression strength of crosslinking polyethylene foaming materials were studied by changing zinc stearate content. Furtherly, those properties were researched after added nucleating agent. Experimental results showed that zinc stearate could facilitate foaming reaction and broad foaming window. Density, compression strength and gel content was decreased with zinc stearate content increased, and the expansion ratio increased with zinc stearate content increased. In addition, the compression strength was improved and cellular structure became uniform after adding nucleating agent. Generally, this material not only has the controllable property, but also has the higher mechanical property and more uniform structure.
Establishment of Constitutive Equation of Hot Deformation of Ti-6Al-4V-0.1B alloy with Widmannstätten structure
Authors: Yu Y , You Z P , Hu H L , Yu W J 
Published: July 2019

Abstract
In order to study the hot deformation behavior of the Ti-6Al-4V-0.1B alloy with Widmannstätten structure and obtain its constitutive equation,the Ti-6Al-4V-0.1B alloy cylindrical specimens with size of Φ8 × 12mm were prepared for the hot compression test on the Gleeble-1500 simulation machine,the deformation temperature from 850 to 980°Cand strain rates of 0.01 to 1s-1.The true stress-strain data and curves were obtained from the hot compression test.The results show that the true stress-strain curves of Ti-6Al-4V-0.1B alloy with Widmannstätten structure have the characteristics of flow stress softening and the flow stress is sensitive to temperature and strain rate.At the same temperature, flow stress increase with the strain rate.At the same strain rate, flow stress decrease with the temperature.Through regression analysis of true stress and strain data by Arrhenius hyperbolic sine function, the activation energy Q is calculated, 890.49kJ/mol.Under the range of the experimental deformation temperatures and strain rates, the constitutive equation is σ=11.36ln{(Z/e88.47)1/4.4107+[(Z/e88.47)2/4.4107+1]1/2}.
An Uncommon Case of Double-Hit Mantle Cell Lymphoma That Demonstrates a Transformation Process
Authors: Zhou Jihao , Hu Lina , Zuo Min , Zhou Yaying , Li Guoqiang , Zhang Xinyou 
Published: July 2019

Abstract

Objectives
Mantle cell lymphoma (MCL) is a mature B-cell lymphoma characterized by CCND1/IGH rearrangement. We reported a case of MCL harboring both CCND1/IGH and MYC/IGH rearrangements that also presented with an aggressive clinical course.

Methods
Biopsy specimens were evaluated by morphological staining, immunohistochemistry, flow cytometry, conventional cytogenetics, fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS).

Results
Morphological and immunohistochemical staining of gallbladder samples demonstrated blastoid variant MCL. However, in the bone marrow sample, FISH indicated rearrangements in CCND1/IGH and MYC/IGH. Flow cytometry identified two groups of malignant lymphocytes. We sorted these two groups of cells. NGS then revealed that both cell types carried CCND1/IGH rearrangements and TP53 mutations. Furthermore, the CD19+/CD10+ cells carried additional MYC/IGH rearrangement and NOTCH2 mutation.

Conclusions
The rearrangement of MYC and a mutation in NOTCH2 probably induced the transformation of MCL cells in this patient. This uncommon double-hit MCL case clearly demonstrates a transformation process.
Identification of expression signatures for non-small-cell lung carcinoma subtype classification
Authors: Su Ran , Zhang Jiahang , Liu Xiaofeng , Wei Leyi 
Published: July 2019

Abstract

Motivation
Non-small-cell lung carcinoma (NSCLC) mainly consists of two subtypes: lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). It has been reported that the genetic and epigenetic profiles vary strikingly between LUAD and LUSC in the process of tumorigenesis and development. Efficient and precise treatment can be made if subtypes can be identified correctly. Identification of discriminative expression signatures has been explored recently to aid the classification of NSCLC subtypes.

Results
In this study, we designed a classification model integrating both mRNA and long non-coding RNA (lncRNA) expression data to effectively classify the subtypes of NSCLC. A gene selection algorithm, named WGRFE, was proposed to identify the most discriminative gene signatures within the recursive feature elimination (RFE) framework. GeneRank scores considering both expression level and correlation, together with the importance generated by classifiers were all taken into account to improve the selection performance. Moreover, a module-based initial filtering of the genes was performed to reduce the computation cost of RFE. We validated the proposed algorithm on The Cancer Genome Atlas (TCGA) dataset. The results demonstrate that the developed approach identified a small number of expression signatures for accurate subtype classification and particularly, we here for the first time show the potential role of LncRNA in building computational NSCLC subtype classification models.

Availability and implementation
The R implementation for the proposed approach is available at https://github.com/RanSuLab/NSCLC-subtype-classification.
Bootstrapping spectral statistics in high dimensions
Authors: Lopes Miles E , Blandino Andrew , Aue Alexander 
Published: July 2019

Summary
Statistics derived from the eigenvalues of sample covariance matrices are called spectral statistics, and they play a central role in multivariate testing. Although bootstrap methods are an established approach to approximating the laws of spectral statistics in low-dimensional problems, such methods are relatively unexplored in the high-dimensional setting. The aim of this article is to focus on linear spectral statistics as a class of prototypes for developing a new bootstrap in high dimensions, a method we refer to as the spectral bootstrap. In essence, the proposed method originates from the parametric bootstrap and is motivated by the fact that in high dimensions it is difficult to obtain a nonparametric approximation to the full data-generating distribution. From a practical standpoint, the method is easy to use and allows the user to circumvent the difficulties of complex asymptotic formulas for linear spectral statistics. In addition to proving the consistency of the proposed method, we present encouraging empirical results in a variety of settings. Lastly, and perhaps most interestingly, we show through simulations that the method can be applied successfully to statistics outside the class of linear spectral statistics, such as the largest sample eigenvalue and others.
Simultaneous control of all false discovery proportions in large-scale multiple hypothesis testing
Authors: Goeman Jelle J , Meijer Rosa J , Krebs Thijmen J P , Solari Aldo 
Published: July 2019

SummaryClosed testing procedures are classically used for familywise error rate control, but they can also be used to obtain simultaneous confidence bounds for the false discovery proportion in all subsets of the hypotheses, allowing for inference robust to post hoc selection of subsets. In this paper we investigate the special case of closed testing with Simes local tests. We construct a novel fast and exact shortcut and use it to investigate the power of this approach when the number of hypotheses goes to infinity. We show that if a minimal level of signal is present, the average power to detect false hypotheses at any desired false discovery proportion does not vanish. Additionally, we show that the confidence bounds for false discovery proportion are consistent estimators for the true false discovery proportion for every nonvanishing subset. We also show close connections between Simes-based closed testing and the procedure of Benjamini and Hochberg.