bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of salicylic acid on the germination and initial growth of coffee (Coffea arabica L. var. Costa Rica 95)
Authors: Gordillo Alder , Rodríguez Luis , Salas Miguel , Rosales María
Published: December 2020

The establishment of new coffee plantations requires vigorous and healthy seedlings that guarantee good growth and high yields; hence the importance of studying the effect of bio-stimulant substances in the early stages of the crop's ontogeny. In this sense, the combined effect of five concentrations of salicylic acid (0; 0.0125; 0.025; 0.05; 0.1 and 1 mM) and different times of imbibition of the seeds (1, 2, 3 and 4 h), on the germination and initial growth of coffee plants (Coffea arabica L.) variety Costa Rica 95 was studied. The experimental design was completely randomized with a bifactorial arrangement, with 24 treatments and 20 repetitions. The percentage and germination rate, height and diameter of the hypocotyl were evaluated. The results showed that the concentrations (0.0125; 0.025 and 0.05 mM) and imbibition times of the seeds of 3 and 4 h in salicylic acid promoted an early germination and a positive effect on the height and diameter of the hypocotyl. The findings show that salicylic acid applied in low concentrations can be used to accelerate the germination of coffee seeds and induce the initial growth of coffee plantlets, while it could be considered as a viable option for coffee producers, both for its easy application and the safety of the product.
Production of biodiesel by esterification and transesterification from waste cooking oils
Authors: Arenas Elsy , Urribarrí Aidin , Sánchez John , Rincón Marisela , Martínez Karina , González Eduardo , Aiello Cateryna
Published: December 2020

Large quantities of used vegetable oils (AVUs) are generated annually, as a result of food preparation, which can cause contamination of waters and soils, if they are not disposed of properly, but in turn have great potential in the production of biodiesel. In this work, the AVU collected from fast food establishments were subjected to an esterification pretreatment, varying the reaction conditions, molar ratio, catalyst concentration and time, to decrease the content of free fatty acids generated in the frying processes; after an alkaline transesterification. The initial acidity of the AVUs (10,08 ± 0,22 %) was found to drop below 1 % during esterification at 60 °C and 100 rpm, with RMAVU:MeOH of 1: 7 and HCl concentration of 0.3 % v/v, with a conversion of free fatty acids (FFA) to methyl esters of 94.48 and 98.61 % for reaction times of 4 and 6 hours, respectively. The previously esterified AVUs were subjected to a transesterification process with KOH as a catalyst in the presence of methanol, at 60 °C and 100 rpm, finding that the biodiesel produced was a mixture composed of the methyl esters of linoleic acids (57 %), palmitic (14 %), oleic (22 %), stearic (4 %) and elaidic (3 %). The highest concentration of methyl esters (93,797 ± 0.685 g.L-1) was obtained when using the esterified AVU during 6 hours of reaction. FTIR spectra confirmed the conversion of fatty acids to methyl esters, so this product could be used as a biofuel.
Kur’ân’da Hak Kelimesinin Anlam Biçimleri
Authors: ARVAS Hamdullah
Published: December 2020

Kur’ân-ı Kerim, hem İslâm dininin hem de İslâm düşüncesi alanında ortaya konulan ilmî çalışmaların temel kaynağıdır. Bu nedenle bir kelimenin Kur’ân’da nasıl istihdâm edildiği meselesi, vokabüleri yönünden Kur’ân’a bağlı olan İslâm ilimlerinin konu, yöntem ve hedeflerinin tespit edilmesi açısından son derece önemlidir. Bu anlamda geniş bir anlam yelpazesi ile Kur’an’da istihdam edilen kavramlardan biri de hak kelimesidir. Hak sahip olduğu anlam biçimleri ile bir tarafta Müslümanların din ve düşünce dünyalarını, niyet ve hareket tarzlarını etkilemiş öte yanda İslam düşüncesi ile irtibatlı ilimlerin anlama gelenekleri içinde farklı anlam boyutları kazanmıştır. Kelâm ilminde, eşyânın hakikati bağlamında felsefi-teolojik bir zeminde ele alınmıştır. İslâm Hukuku’nda normatif ilkelerin temel ve nesnel idesi olarak yer bulmuştur. Tasavvufta bâtınî alanı daha çok vurgulayan ezoterik bir anlam biçimiyle işlenmiştir. Belâgât ilimlerinde, lafız ve mana ilişkisi içerisinde incelenmiştir. Bu yüzden günümüzde hak kelimesinin anlam biçimlerini tespit etmek isteyen araştırmacılar için geniş bir literatür bulunmaktadır. Bununla birlikte Kur’ân’da geçen bir kelimenin anlamlarına hızlı bir şekilde ulaşmak isteyenler için Vücûh ve Nezâir kitapları temel başvuru kaynakları arasındadır. Fakat bu kitaplar Kur’ân’daki bütün kelimeleri kapsamadıkları gibi ele alınan kelimelerin bütün anlamlarını da içermemektedir. Bu bağlamda geniş bir literatür içinde kullanılmasına rağmen Vücûh ve Nezâir kitaplarında bütün anlamlarına yer verilmeyen sözcüklerden biri de hak kelimesidir. Bu tespitlerle gerekçelendirilmiş metnimizde ilk olarak Kur’ân’da hak kelimesinin anlam biçimleri hakkında bilgi verilmiştir. Daha sonra hak kelimesinin, vücûh ve nezâir kitaplarında yer almayan hikmet ve yasa anlamları Mâturîdî ve Zemâhşerî’nin görüşlerinden yola çıkarak tespit edilmiş ve kelimenin anlam biçimlerine eklenmiştir.
Kelam Eserlerinde Hadis Kullanımı: el-Cürcânî’nin Şerhu’l-Mevâkıf’ı Örneği
Authors: KALAÇ Rıdvan , ENGİN Hayrullah
Published: December 2020

Daha ziyade kesin deliller ve özellikle belli bir dönemden sonra felsefenin argümanları üzerine temellendirilen kelam ilminde, sübut ve delalet bakımından bir takım problemler içeren hadisler de kullanılmıştır. Esasında teoride hadis ilmi açısından sağlam prensiplere sahip olan bu ilmin pratikteki durumunu anlamanın en iyi yolu usûlu’d-dine (kelam) ait eserlerin incelenmesidir. Bu anlamda durumu daha yakından görmek ve teori ile uygulamayı mukayese etmek amacıyla bu çalışmada el-Cürcânî’ye (ö. 816/1413) ait Şerhu’l-mevâkıf isimli eseri ele alınmıştır. Hicri IX. asrın dil ve fıkıh âlimlerinden olan Seyyid Şerif el-Cürcânî, aynı zamanda kelâm ilminin de bu asırdaki önemli simalarındandır. Öyle ki şerh olarak yazdığı birçok eseri asıl metinlermiş gibi kabul görmüştür. Bu eserlerinden bir tanesi de Adududdîn el-Îcî’ye (ö. 756/1355) ait olan el-Mevâkıf isimli esere yazdığı şerh’tir. Çalışmada el-Cürcânî’nin Şerhu’l-mevâkıf’ı özelinde mütekelliminin, ne tür rivâyetler kullandıkları ve hangi kaynaklardan beslendikleri; dolayısıyla rivâyet anlayışları, hadislere bakışları ve bu konuda bir usûllerinin olup olmadığı, mütevâtir rivâyetleri nasıl kullandıkları, mütevâtir olarak kullandıkları hadislerin mütevâtir kavramının tanımına ve şartlarına ne kadar uyduğu, eserlerinde isnad ve kaynak gösteriminin ne sıklıkta olduğu gibi hususlar sorgulanmaktadır.
Phương pháp thu nổ địa chấn 2D và xử lý số liệu sơ bộ trên tàu
Authors: Le Hong Lam
Published: December 2020

Trong công tác tìm kiếm thăm dò nói chung và tìm kiếm thăm dò dầu khí nói riêng, thăm dò địa chấn là phương pháp hàng đầu để cung cấp bức tranh địa chất của khu vực, bên cạnh các phương pháp thăm dò điện, từ, trọng lực… Bằng việc phát sóng đàn hồi vào môi trường và bố trí thu sóng phản xạ từ các ranh giới địa chấn ở các tầng trầm tích nằm dưới lòng đất, từ đó xác lập cấu trúc địa chất của vùng và xác định được các đối tượng quan tâm như tầng chứa dầu khí, đứt gãy… Phương pháp thăm dò địa chấn đã phát triển vượt bậc, từ thăm dò địa chấn 2D thu số liệu bằng băng giấy cho tới các phương pháp hiện đại như thăm dò 3D độ phân giải cao (broadband seismic) tới địa chấn 4D, 4C, thăm dò địa chấn đa thành phần bao gồm sóng dọc, sóng ngang…

Bài báo giới thiệu khái quát về phương pháp thăm dò địa chấn 2D trên biển. Từ việc thiết kế mạng lưới đến bố trí các thiết bị cần thiết trong quá trình thu nổ như súng hơi, cáp thu và các phương pháp xử lý cơ bản như lọc tần số, cộng điểm sâu chung, xử lý vận tốc được thực hiện trên tàu địa chấn trước khi đưa về trung tâm xử lý để giúp đánh giá chất lượng tài liệu địa chấn khi xử lý và minh giải số liệu.
AgroGripModeling software and algorithms for configuration optimization of robotic gripper
Authors:   D.Q. Vu St. Petersburg Federal Research Center of the Russian Academy of Sciences, Vu D.Q.
Published: December 2020

The paper discusses the scientific problem of optimization and control of robotic grippers, describes the algorithmic model and the AgroGripModeling software system for the design of agricultural grippers.
Present and projected distribution of Sorghum halepense (L.) Pers. in the Caucasus
Authors:   V.A. Chadaeva Tembotov Institute of ecology of mountain territories Russian Academy of Sciences, Chadaeva V.A. , Pshegusov R.Kh. ,   R.Kh. Pshegusov Tembotov Institute of ecology of mountain territories Russian Academy of Sciences
Published: December 2020

Sorghum halepensed (L.) Pers, an invasive species, grows in diverse phytocenoses from plains to low-mountain zones of the Caucasus. Predictive modeling showed that at present there are significant areas in the Central, Eastern Caucasus and North-West coast of the Black sea (up to the middle-mountain zones) which are potentially adequate and optimal for the species. The spatial distribution of S. halepense is determined by the minimum temperature of the coldest month (12.5-17^0 C) and the Thornthwaite aridity index (16-50). In accordance with the predicted trends of climatic changes by 2050, it is possible to expand the area of suitable and optimal habitats for the species in the mountains of the Western and Eastern Caucasus, Georgia and Armenia, on the Black Sea coast. Significant range expansion of the species is expected along low river valleys in high-mountains.
The nature and characteristics of the political consolidation of sub-ethnic groups in Western Circassia in the 40-50s XIX century
Authors:   A.D. Panes Adyghe Republican Institute for Humanitarian Studies named after T.M. Kerashev, Panes A.D.
Published: December 2020

The article examines the main trends in the development of political consolidation processes in Western Circassia in the 40-50s. XIX century. The internal and external factors of socio-political processes and the peculiarities of their development in different sub-ethnic groups of Western Adygs are shown. The author traces the influence of the geopolitical situation on the internal socio-economic situation.
A priori estimate for the solution of a nonlocal boundary value problem for the McKendrick - von Foerster equation of fractional order
Authors:   R.Z. Berezgova Institute of Applied Mathematics and Automation KBSC RAS, Berezgova R.Z.
Published: December 2020

In this paper, by the method of energy inequalities, an a priori estimate for the solution of the nonlocal boundary value problem is obtained for the generalized Mackendrick - von Foerster equation with the Caputo operator with respect to the time variable.
Conceptual and methodological bases for the protection of soils of the Kabardino-Balkarian Republic from water and wind erosion
Authors:   FSBEI HE Kabardino-Balkarian SAU, Shekihachev Yu.A.
Published: December 2020

The article analyzes the ecological state of soil resources of the Kabardino-Balkarian republic. The conceptual and methodological foundations of the protection of the republic’s soils from water and wind erosion, the basic principles of the formation of an adaptive ecological-landscape farming system, the implementation of which will allow the formation of ecologically balanced and highly productive adaptive soil-protective agricultural landscapes, have been formulated.
Insights into teachers’ views on sharing ways of knowing and ways of teaching between and beyond existing disciplines
Authors: Algers Anne , Bradley Linda
Published: December 2020

Since academic teachers belong to different disciplines and thus discourses, they have different ways of knowing and teaching. Recent societal challenges call for thinking beyond boundaries and re-visiting academic practices. The purpose of this study is to investigate how academic teachers view sharing of knowledge and teaching. The study is based on survey data from eight faculties and interviews of teachers from each of these faculties at the University of Gothenburg. The results show that professional development courses in higher education teaching and learning, as well as open practices, and collaboration between academic disciplines and society are practices, which Galison (1997) termed trading zones. These trading zones are sources of learning to theorize and to facilitate exchange among peers with the potential to develop knowledge, identity and moral commitments necessary to address societal challenges. Further, the results suggest that universities need to scaffold these sharing practices. The findings inform how academic teachers’ practices can be transformed into sharing between and beyond academic disciplines.
SMARTAJWEED Automatic Recognition of Arabic Quranic Recitation Rules
Authors: M. Alagrami Ali , M. Eljazzar Maged
Published: December 2020

Tajweed is a set of rules to read the Quran in a correct Pronunciation of the letters with all its Qualities, while Reciting the Quran. which means you have to give every letter in the Quran its due of characteristics and apply it to this particular letter in this specific situation while reading, which may differ in other times. These characteristics include melodic rules, like where to stop and for how long, when to merge two letters in pronunciation or when to stretch some, or even when to put more strength on some letters over other. Most of the papers focus mainly on the main recitation rules and the pronunciation but not (Ahkam AL Tajweed) which give different rhythm and different melody to the pronunciation with every different rule of (Tajweed). Which is also considered very important and essential in Reading the Quran as it can give different meanings to the words. In this paper we discuss in detail full system for automatic recognition of Quran Recitation Rules (Tajweed) by using support vector machine and threshold scoring system.
Bridging Africa’s Infrastructure Gap Through Strong Sino-Africa Cooperation
Authors: Adeniyi Adetunji
Published: December 2020

The objective of the paper was to review the socio-economic benefits of the budding Sino-Africa economic relationship with a view to arriving at an informed opinion on its desirability and potency or contribution in closing Africa’s infrastructure investment gap.The paper also discussed the issues that may militate against or strengthen the new-found relationship against the backdrop of criticisms from pro-West sentiments.The desirability of Sino-Africa economic cooperation was established, and recommendations advanced on the issues that will guarantee mutual benefits and sustainability.
Estructuras, dinámicas y configuraciones familiares en el proceso de reintegración en Colombia
Authors: Laverde Gallego Diana Janeth , Zapata García José Gabriel , Duran Alicia , Aponte Canencio Diego Mauricio , Giovanni Aguilar Irene , Granados-García Alejandro , Manrique López Juan Guillermo
Published: December 2020

Este documento presenta el análisis de las experiencias de algunas familias vinculadas al proceso de reintegración de excombatientes en Colombia, con el fin de profundizar en la influencia que el conflicto armado y los procesos de reintegración ha tenido en sus estructuras, configuraciones y dinámicas. En 2017 se desarrollaron 11 entrevistas y 10 grupos focales con antiguos combatientes en proceso de reintegración, así como a familiares y profesionales de la Agencia de Reincorporación y Normalización de Colombia (ARN), en las ciudades de Ibagué, Bogotá, Soacha y Villavicencio. La información se analizó utilizando metodología de análisis de contenido inductivo y deductivo con una aproximación direccionada. Los resultados ofrecen una profundización en lo referente a las estructuras familiares, sus dinámicas y configuraciones en el marco del conflicto armado y el proceso de reintegración. La familia son un sistema que puede generar factores de riesgo y protección en la reintegración, en ella se identificaron reproducciones transgeneracionales de las pautas de relación del conflicto, de estigma y vulneración, pero en ella coexisten el perdón, el retorno, el cuidado y la posibilidad de un país en paz. Es importante incorporar a las familias como elemento fundamental de las políticas públicas y los programas desarrollados en el marco del desarme, la desmovilización y la reincorporación de antiguos combatientes.
Evolution of Multistage Hydrothermal Fluids in the Luoboling Porphyry Cu-Mo Deposit, Zijinshan Ore Field, Fujian Province, China: Insights from LA-ICP-MS Analyses of Fluid Inclusions
Authors: Zhao Xiao-Yu , Zhong Hong , Hu Rui-Zhong , Mao Wei , Bai Zhong-Jie , Lan Ting-Guang , Xue Kai
Published: December 2020

The Luoboling Cu-Mo deposit, with 1.4 million tons (Mt) Cu and 0.11 Mt Mo, is the largest porphyry deposit in the Zijinshan district of southeast China. Mineralization at Luoboling is divided into premineralization, synmineralization, and late-mineralization stages. Consistent Cs/(Na + K) ratios in fluid inclusions suggest that the mineralizing fluids originated from a common source—the Luoboling granodiorite porphyry. The absence of initial supercritical fluid inclusions and abundant coexisting vapor and brine fluid inclusions imply that the fluids exsolved at low-pressure two-phase conditions, with temperatures of 250° to 600°C and salinities of 30 to 60 wt % NaCl equiv (brines) and <10 wt % NaCl equiv (vapors). The deposit formed at ~120 to 800 bar, corresponding to the depths of ~1.2 to 3.2 km (assuming a transition from lithostatic to hydrostatic load). Metals such as Mo (up to 77 ppm), Pb (up to 8,800 ppm), Zn (up to 13,000 ppm), and Ag (up to 130 ppm) migrated mainly in brines. Although vapor inclusions have high concentrations of Cu (up to 20,000 ppm), hypersaline fluid was the major medium for Cu transport and precipitation. The successive precipitation of Mo and Cu occurred when fluids cooled to ~500°C and ~350° to 450°C, respectively. The late-stage quartz-pyrite veins with phyllic alteration were formed by Cu-rich magmatic hydrothermal fluids. The Zijinshan epithermal Cu-Au deposit and the Luoboling porphyry Cu-Mo deposit originated from independent hydrothermal systems. Nonetheless, the increasing trends of Pb, Zn, and Ag concentrations in different stage inclusions from Luoboling imply potential for distal Pb-Zn-Ag mineralization.
Understanding outreach: the potential of qualitative longitudinal research to enrich the evidence base
Authors: Raven Neil
Published: December 2020

Recent calls from the Office for Students, the regulatory body for the English higher education sector, have challenged those engaged in widening university access to ‘strengthen’ the outreach evidence base. Whilst focus groups have proved capable of revealing much about
the learner experience and the effectiveness of outreach interventions, the established way in which they have been applied – in capturing views and perceptions at one particular point in time – limits what can be discovered. Adopting a longitudinal approach in the application
of this research instrument – by returning to the same group of participants at regular intervals over a number of months – affords a chance to monitor changes in ideas and intentions, and distinguish the important from the fleeting. As the findings from three recent studies that
have deployed this approach show, it can also generate richer, more detailed insights than would otherwise be possible.
Towards Zero Solid Waste in Jordanian Universities: The Case of Al-Ahliyya Amman University
Authors: Al-Shatnawi Zahra , Alnusairat Saba , Kakani Anan
Published: December 2020

This paper investigates solid-waste management performance potential within Al-Ahliyya Amman University (AAU), Jordan, in the context of environmental benefits and the UI green metric rating system waste category indicators. First, a field survey was conducted to characterise and quantify solid waste generated in AAU. Second, a checklist of the solid-waste management practices in university campuses was developed, based on the UI green metric rating system. Finally, the environmental impact of implementing solid-waste management in AAU campus was measured using the zero waste index (ZWI). The findings show that 491 tonnes of mixed waste are produced each year on campus, of which compostable waste, recyclables, and non-recyclables account for around 21%, 47%, and 32%, respectively. Using the ZWI to measure the performance of waste management practices, the study found a score of 0.75 for non-recyclable paper and plastic prevention; paper, plastic, and metal recycling; and organic composting. Paper recycling was found to have the greatest impact on virgin material substitution, and metal recycling has the highest potential for energy, water, and greenhouse-gas savings. Waste management projects in Jordanian universities should include reduction, in addition to paper and metal recycling in phase 1; and plastic recycling and composting should be applied in phase 2. Since not all waste management practices have the same environmental impact, the study recommends redistributing the UI green metric waste indicators points in accordance with environmental impact.
Movie Aspects Identification Model for Aspect Based Sentiment Analysis
Authors: Mir Jibran , Mahmood Azhar
Published: December 2020

Aspect Based Sentiment Analysis techniques have been applied in several application domains. From the last two decades, these techniques have been developed mostly for product and service application domains. However, very few aspect-based sentiment techniques have been proposed for the movie application domain. Moreover, these techniques only mine specific aspects (Script, Director, and Actor) of a movie application domain, nevertheless, the movie application domain is more complex than the product and service application domain. Since, it contains NER (Named Entity Recognition) problem and it cannot be ignored, since there is an opinion often associated with it. Consequently, in this paper MAIM (Movie Aspect Identification Model) is proposed that can extract not only movie specific aspects, also identifies NEs (Named Entities) such as Person Name and Movie Title. The three main contributions are 1) the identification of infrequent aspects, 2) the identification of NE (named entity) in movie application domain, 3) identifying N-gram opinion words as an entity. MAIM incorporates the BiLSTM-CRF hybrid technique and is implemented on the movie application domain having precision 89.9%, recall 88.9% and f1-measure 89.4%. The experimental results show that MAIM performs better than baseline models CRF and LSTM-CRF.
Kalman Filter based Newton Extremum Seeking Control for Maximum Gases Production Rates of Anaerobic Digestion Process
Authors: Wang Haoping , Hu Maobo , Tian Yang , Simeonov Ivan , Kabaivanova Lyudmila , Christov Nicolai
Published: December 2020

This paper proposes a Kalman filter (KF) based Newton extremum seeking control (NESC) to maximize production rates of hydrogen and methane in anaerobic digestion process. The Kalman filtering algorithm is used to obtain more accurate gradient and Hessian estimates which makes possible to increase the convergence speed to the extremum and to eliminate input and output steady-state oscillations. The simulation examples demonstrate the performances of the proposed approach.
A STUDY ON THE BEHAVIOR OF THE ALIGNMENT FOR L3 VACANCY STATE IN Au BY IMPACT IONISATION
Authors: XIA ZONG-HUANG  , MA HONG-JI  , FU SHENG-CHUN  ,   北京大学技术物理系
Published: December 2020

In low projectile energy region, the alignment of L3 vacancy state in Au and the projectile energy dependence of alignment were measured for several kinds of ions and Au collision systems by a simple method. Using the plane-wave Born approximation (PWBA) and taking into account the coulomb deflection effect, the alignment was calculated. It is shown that the present calculated results are closer to the experimental data. The alignment behavior of L3 vacancy state in Au is furtherly discussed.
STUDY OF HARD-DESTRUCTIVE MECHANISM OF THE CHARGE-COUPLED DEVICES BY A LASER
Authors: NI XIAO-WU  , LU JIAN  , HE AN-ZHI  ,   南京理工大学应用物理系
Published: December 2020

Theoretical and experimental study has been made for the process of hard-des-truction produced by a laser acting upon the surface of charge-coupled devices (CCD) having the MOS structere. It is suggested that the thermal action of laser and the mechanical action of laser plasma shock wave are the main causes for destruction of the structure of the CCD. Optical breakdown threshold, visible damage threshold, thermal melting threshold of semiconductor materials of the CCD device by YAG laser and laser energy threshold caused the whole device to faiture are obtained.
STUDY OF EFFECTS OF LOW-ENERGY BOMBARDMENTS OF Si(001)-2×1 BY MOLECULAR DYNAMICS SIMULATION
Authors: JIA ZHENG-MING  , YANG GEN-QING  , CHENG ZHAO-NIAN  , LIU XIANG-HUAI  , ZOU SHI-CHANG  ,   中国科学院上海冶金研究所离子束开放研究实验室
Published: December 2020

Molecular dynamics simulations were performed for 1-100eV particle bombardments of Si(001)-2×1 surface. The two dimensional pair correlation functions were obtained to investigate the arrangement of surface atoms after such bombardments. The results show that 10eV and 100eV bombardments had the some effects on the behaviour of surface atoms. On one hand, 10eV and 100eV bombardments improved the mobility of surface atoms and produced more dimers. On the other hand, they increased the disordering of surface atom's arrangement and made the surface tend to be amorphous.
A STUDY ON THERMAL PROPERTIES FOR ZrO2 COATINGS BY ARC PHOTOTHERMAL TECHNIQUE AND FINITE-DIFFERENCE THERMAL FLOW MODEL
Authors: DU YING-LEI  , WU BAI-MEI  ,   (1)中国科学技术大学基础物理中心; (2)中国科学技术大学物理系
Published: December 2020

The thermal conductivity and thermal diffusivity of ZrO2 coatings were studied using arc-photothermal evaluation technique in which the sample was heated at front surface and detected at back surface, and finite-difference thermal flow model was applied. The values of thermal conductivity and thermal diffusivity of ZrO2 are ｋ＝０．００６９Ｊ／ｃｍ·Ｋ·ｓ and α＝０．００２８ｃｍ2／ｓ, respectively. It is shown that, first, the finite-difference thermal flow model is an available and useful method for the multilayer coating system, and, second, the arc photothermal evaluation technique has low cost of equipment, and more simple and convenient measurement.
ELECTRON CORRELATION EFFECT ON C60 EXCITON POLARON
Authors: HUANG QING-PENG  , FU RONG-TANG  , SUN XIN  , FU ROU-LI  ,   (1)复旦大学李政道综合物理实验室; (2)复旦大学物理系; (3)中国科学院上海技术物理研究所红外物理国家重点实验室
Published: December 2020

Exciton polaron states in C60 molecular are theoretically studied in the tight-binding approach supplemented by the extended Hubbard interaction. The binding energies of the lowest singlet and triplet excitons depend sensitively upon the electron correlation. Then the exciton polaron is formed due to the electron-lattice coupling. Relevent experiments in photo-luminescence spectrum of Cso can be explained qualitatively by the present model with moderate interaction strength Ｕ～５．０ｅＶ，Ｖ～２．０ｅＶ.
MECHANISM OF CONDUCTION IN BaSn1-xSbxO3-δ AND Ba1-yLaySnO3-δ
Authors: HUANG TONG-KAI  , TETSURO NAKAMURA  ,   (1)东京工业大学工业材料研究所; (2)上海大学物理系
Published: December 2020

The temperature dependence of resistivity and magnetic susceptibility was measured for both BaSn1-xSbxO3-δ and Ba1-yLaySnO3-δ systems below room temperature. The results show that the mechanism of conduction is the variable range hopping for both systems at lower temperature. Whereas the two types of mechanism of conduction at higher temperature, are considered the nearest-neighbor hopping (Ba1-yLaySnO3-δ)and as the excitation of electrons to the conduction band (BaSn1-xSbxO3-δ)
ION SIZE EFFECT OF Tc-PLATEAU IN R1-xPrxBa2Cu3O7-δ
Authors: CAO XIAO-WEN  , Y. J. TANG  , J. C. HO  ,   中国科学院等离子体物理研究所
Published: December 2020

Dependence of superconducting Tc upon Pr-substitution concentration x was studied systematically in Ｒ1-xＰｒxＢａ2Ｃｕ3Ｏ7-δ system with R=Nd, Dy, Tm, Yb and Lu. It was found that there is a Tc-plateau in the range of low x as R３＋ radius ｒi≤ｒi(Dy). The Pr-concentration width corresponded by Tc-plateau exhibits a R３＋ ion size effect. We suggest that the ion size effect of Tc-plateau might result from the change of local state of Pr 4f electron. A critical R３＋ radius, ｒic, is suggested and superconductivity disappears as ｒi＞ｒic.
A STUDY ON DISSOCIATION KINETICS OF SiH4+CH4 PLASMA INDUCED BY PULSED INFRARED LASER
Authors: YU WEI  , LI XIAO-WEI  , HAN LI  , ZHANG LIAN-SHUI  , FU GUANG-SHENG  ,   河北大学物理系
Published: December 2020

The time-resolve optical emission spectroscopy is used to study silane and methane laser plasma. The results show that the different fragments' characteristic lines has the same appearance time but different temporal behaviours when the reactant breaks down. Based on the experimental results of dissociation processes it is suggested that the producing of Si and C atoms is the main dissociation channels of the reaction.
RELATIVISTICALLY STOCHASTIC ACCELERATION OF ELECTRONS IN PLASMA DRIVEN BY A STANDING WAVE
Authors: ZHOU XIAO-BING  , WANG ZHI-JUN  , SHENG GUANG-ZHAO  ,   核工业西南物理研究院,成都610041
Published: December 2020

The possibility and conditions of stochastic acceleration of an electron in plasma by a standing wave is discussed and numerically calculated. The analytical results show that the stochasticity of the motion of the electron is due to overlap of the two resonances imbedded in the interaction between the electron and the standing wave. The threshold of stochastic acceleration is evaluated analytically and numerically. The energy of stochastic acceleration of the electron is also calculated numerically with the trajectories of the electron being traced by using Poincare's surface-of-sectiun plot technique.
COMPUTER DEPTH PROFILING ANALYSIS METHOD FOR X-RAY DIFFRACTION POLYCRYSTALLINE PATTERNS
Authors: LUO JIAN  , TAO KUN  ,   清华大学材料科学研究所,北京100084
Published: December 2020

A new method to extract X-ray polycrystalline diffraction patterns diffracted from different depth in real scale is pnesented. In this method the X-ray polycrystalline diffraction data of surface layer are collected at different incident angles, and then the X-ray diffraction patters diffracted from thin sheets at different depth are extracted directly by some special mathematical method. So the depth profiles of peak intensity, peak position and line profile can be obtained quantitatively and nondestrnctively. The algorithm was deduced in theory, and the feasibility of this method was primarily tested with a Ni/Mo film sample with prefered orientation. This method has the prospective application in the area of the thin films and its reactions, interface and surface processing studies.
A LOOP-CLUSTER UPATING MONTE CARLO STUDY FOR THE TWO-DIMENSIONAL QHAF ON THE HEXAGONAL LATTICES
Authors: YIN HE-PING  , JI DA-REN  , WANG ZHI-GANG  ,   浙江近代物理中心,浙江大学物理系,杭州310027
Published: December 2020

A new type of cluster algorithm is developed to simulate the two-dimensional spin one half quantum Heisenberg antiferromagnet (QHAF) on a hexagonal lattice. The numerical results show that the method can be applied to study efficiently the QHAF systems at lowertemperatures, with large Trotter number, on the general bipartite lattices.
MEASUREMENT OF THE MASS ATTENUATION COEFFICIENTS FOR SiH4 ANDSi
Authors: WANG DA-CUN  , LUO PING-AN  , YANG HUA  , WANG ZHI-DONG  ,   (1)北京师范大学低能核物理研究所,北京100875北京市辐射中心,北京100875; (2)中国科学院科技政策与管理科学研究所,北京100080
Published: December 2020

With X-rays produced by protons exciting elemental and compound targets the mass attenuation coefficients have been systematicaJly measured for SiH4 in the range of X-ray energy 1.486-15.165keV, for Si in 8.041-29.109keV. Not only the validity of Bragg's additivity law in the gaseous compound was verifed by experiment, but also the mass attenuation coefficients of Si in the energy range 1.4-6 keV were obtained. The photoelectric cross sections have been obtained by subtracting thermal diffuse scattering and Compton scattering cross section from the measured total cross sections and compared with the theoretical results.
HOT ELECTRON THERMOELECTRIC POWER UNDER A MICROWAVE FIELD
Authors: LIU MEI  , LIU WEI  , CAO SHU  , XING DIN-YU  ,   (1)东南大学物理系,南京210018; (2)南京大学物理系,南京210008
Published: December 2020

Gradient of temperature and chemical potential can be produced in a semiconductor sample by applying a localized microwave field. The nonequilibrium statistical opertor method is generalized and applied to study the transport coefficients of a hot-electro
ELECTRONIC STRUCTURES AND OPTICAL PROPERTIES OF SUPERLATTICES (Si_2)_4/(GaAs)_4 GROWN ON Si(00l)
Authors: XU ZHI-ZHONG  ,   复旦大学物理系,上海200433
Published: December 2020

With using the atomic geometrical structures and band-offset extracted from the results of computations by Peressi et al with first principle pseudopotential method, the electronic band structures and the optical oscillator strengths for the superlatti-ce
CRITICAL BEHAVIORS IN A WEDGESHAPED Pt-FILM PERCOLATION SYSTEM
Authors: YE GAO-XIANG  , GE HONG-LIANHG  , XU YU-QING  , JIAO ZHEN-KUAN  , ZHANG QI-RUI  ,   (1)杭州大学物理系,杭州310028; (2)浙江大学物理系,杭州310027
Published: December 2020

This paper reports the preparation of a wedgeshaped Pt-film percolation system and its critical behaviors. A strange R-I characteristic and power-law behaviors are observed. The general scaling law still holds in this anisotropic percolation system. We be
A DIATOMIC MOLECULE MULTIPHOTON DISSOCIATION IN INTENSE FIELDS
Authors: DING SHI-LIANG  , MA JIE  , GUAN DA-REN  ,   (1)山东大学理论化学研究室; (2)山东师范大学物理系
Published: December 2020

This work deals with the multiphoton dissociation of diatomic molecule in intense IR laser field, the interaction between field and molecules is approximated to that between field and the dipoles. The Ｓｃｈｒ?ｄｉｎｇｅｒ equation is solved by using Close-Coupling method and Floquet theory. Numerical results for molecule HF are given.
MEASUREMENT OF EXCITATION CROSS SECTIONS OF TARGET ATOM Na BY HIGHLY CHARGED ION N4+ IMPACT
Authors: WANG YOU-DE  , YANG ZHI-HU  , MA XIN-WEN  , LIU HUI-PING  , ZHAO MENG-CHUN  , ZHOU SI-XIN  , LIU ZHAN-WEN  , ZHANG WEN  , ZHANG XUE-ZHEN  , GUO XIAO-HONG  , PAN GUANG-YAN  , YANG FENG  , LI DA-WAN  ,   (1)中国科学院近代物理研究所; (2)中国科学院物理研究所
Published: December 2020

The emission cross sections and excitation cross sections have been measured in collisions between N4+ ion and Na atoms. The experimental results show that the excitation cross sections of NaI(3p-3s) are vety large, about １０-15ｃｍ2 . The data of cross sections have been given in this paper and reasons for the large excitation cross sections of NaI(3p-3s) have been discussed qualitatively.
DARK SPATIAL OPTICAL SOLITON AND SOLITON-INDUCED ELEXIBLE WAVEGUIDE IN C60 SOLUTION
Authors: LI CHUN-FEI  , HONG TAO  ,   哈尔滨工业大学物理系
Published: December 2020

The phenomena of dark spatial optical soliton and soliton-induced flexible optical wave-guide have been observed, which are induced by thermal self-defocusing effect of Ar+ laser beam in C60-toluene solution. The numerical simulations of the formation process of dark spatial soliton using the nonlinear Schr?dinger equation are consistent with the experimental results.
STUDY OF DOUBLE-BARRIER SUPERLATTICE BY SYNCHROTRON RADIATION AND DOUBLE-CRYSTAL X-RAY DIFFRACTION
Authors: WANG YU-TIAN  , ZHUANG YAN  , JIANG DE-SHENG  , YANG XIAO-PING  , JIANG XIAO-MING  , WU JIA-YANG  , XIU LI-SONG  , ZHENG WEN-LI  ,   (1)中国科学院半导体研究所,国家光电子工艺中心; (2)中国科学院高能物理研究所
Published: December 2020

A AlAs/GaAs/AlAs/AlGaAs double-barrier superlattice grown on GaAs substrate by MBE has been studied by combining double-crystal X-ray diffraction and synchrotron radiation. This combination provides a comprehensive structural analysis. During simulated by X-ray dynamical diffraction theory, we find the intensity of satellite peaks which situated near-by the modulated wave point of one layer are very sensitive to the variation of the layer's structural parameters. Accoding to these, the accurate layer thickness can be get with an error less than 0.1nm. The modulated phenomenon is investigated by X-ray kinematical diffraction theory.
THE ELECTRONIC STRUCTURE AND SUPERCONDUCTIVITY FOR （Ｂａ1-xＫx）ＢｉＯ３
Authors: SHEN YAO-WEN  , ZHANG ZHI-PENG  , CHEN LONG-HAI  , HUANG MEI-CHUN  ,   厦门大学物理系
Published: December 2020

Electronic structure for BKB has been calculated by using LMTO-ASA-Supercell method based on the X-ray absorption fine structure (XAFS) spectroscopy measurements. Measurements show that Bi posseses two valence states Ｂｉ３＋ and Ｂｉ5＋ and their Bi—Ｏ bond lengths are diffferent, the difference decreases with the increase of K concentration. Calculations are performed on five samples namely Ｂａ4Ｂｉ4Ｏ12（４０４），（Ｂａ３Ｋ）Ｂｉ4Ｏ12（３１４），（ＢａＫ）Ｂｉ2Ｏ6（１１２），（ＢａＫ３）Ｂｉ4Ｏ12（１３４），Ｋ2Ｂｉ2Ｏ6（０２２）.Results from the calculations show that （404）and (314)are semiconductors with gaps of 1.6eV and 1.5eV, respectively. Other samples are metals. Total energy analysis shows that (314) is not stable, so that the extreme value of x is 0.5. The BKB electronic structures at x=0.1 to 0.5 are calculated by combining the probability with sample's Bernoull's distribution. Superconducting transition temperature Tc of BKB is suddenly changed when x approximates to 0.25. The experimental data are close to the prediction values of percolation theory.
CHARACTERISTICS IN MAGNETOCALORIC EFFECT AND MAGNETIC ENTROPY OF NANOMETER BINARY GADOLINIUM ALLOYS
Authors: SHAO YUAN-ZHI  , XIONG ZHENG-YE  , ZHANG JIE-LI  , ZHANG JIN-XIU  ,   中山大学物理系
Published: December 2020

Investigations on magnetocaloric effect and magnetic entropy,Curie temperature and specific heat of nanometer binary gadolinium alloys such as Gd-Y,Gd-Tb and Gd-Zn have been carried out under the conditions of a low magnetic-field intensity(1T) and a temperature range within 233～313K. Both Curie temperature and specific heat of the prepared nanometer alloys,compared with the bulk materials,show obvious decrease and increase respectively. The nanometer alloy Gd-Y demonstrates an enhanced magnetocaloric effect and magnetic entropy over the same bulk material, which is of importance on researching and developing new materials for magnetic refrigeration. Adiscussion concerning the influence of nanometer structure on magnetic and heat properties mentioned above is given in detail.
A STUDY OF THE RAMAN SCATTERING OF Ge NANOCRYSTALLITES EMBEDDED IN ＳｉＯ２ THIN FILMS
Authors: YUE LAN-PING  , HE YI-ZHEN  ,   (1)中国科学院固体物理研究所; (2)中国科学院固体物理研究所;中国科学技术大学结构分析开放研究实验室
Published: December 2020

Raman scattering of Ge nanocrystallites from 4 to 16nm is size, embedded in ＳｉＯ２ thin films has been studied. The Ge-ＳｉＯ２ samples were prepared by ion-beam sputtering and a post-annealing technique. A red shift and broadening of the Raman peak observed with decreasing the size of Ge particles are in good agreement with the calculated results based on the phonon confinement theory. Effects of the surface and interface of the Ge-nanocrystallites on Raman spectra have also been investigated.
STUDY OF BORON-DOPED DIAMOND FILMS BY HOT FILAMENT CVD
Authors: LIAO KE-JUN  , WANG WAN-LU  , ZHANG ZHEN-GANG  , WU BIN  ,   兰州大学物理系
Published: December 2020

The properties of boron-doped diamond films prepared by hot filament CVD were studied with Raman spectra and X-ray microanalysis. It was found that the content of the graphitic type （Ｓｐ2)bonding in the CVD diamond was reduced at low boron concentrations, and the widening and shift of the characteristic diamond Ｓｐ3 Raman peak appeared in the diamond with increasing boron concentrations. This can be interpreted in terms of the lattice strain and Fano interaction caused by boron doping.
PHOTOIONIZATION STUDIES OF DIBROMOMETHANE USING SYNCHROTRON RADIATION: A STUDY OF VIBRATIONAL AUTOIONIZATION STATES FOR CH2Br2 IN 10-12eV
Authors: LI QUAN-XIN  , RAN QIN  , CHEN CONG-XIANG  , SHENG LIU-SI  , YU SHU-QIN  , ZHANG YUN-WU  , MA XING-XIAO  ,   (1)中国科学技术大学国家同步辐射实验室; (2)中国科学技术大学化学物理系
Published: December 2020

The vibrational autoionization stucture of dibromomethane has been investigated in the supersonic beam conditions using ＶＵＶ synchrotron radiation. Based on photoionization efficiency curve of ＣＨ2Ｂｒ2+ in １０５—１２３ｎｍ we have found that the adiabatic ionization potential(IP) of the dibromomethane is １０.２３±０.０１ｅＶ．The thresholds at １０.７８±０.０１ｅＶ，１１.２０±０.０１ｅＶ and １１.２７±０.０１ｅＶ ware identified as the electronically excited states of ＣＨ2Ｂｒ2+,i.e., Ａ（2Ａ2），Ｂ（2Ｂ1） and Ｃ（2Ａ1） states. The discrete peaks with some autoionization features superposed on a step-like structure in the PIE curve of the parent ion were observed in the range of １１５.０１—１２１.１５ｎｍ. The average step width was about ７１６.８±４０.０ｃｍ-1，which was in good agreement with the value of the vibrational frequency of the Ｂｒ-Ｃ-Ｂｒ antisymmetrically stretching motion （ｖ9） of the parent ion ＣＨ2Ｂｒ2+（Ｘ2Ｂ2) which was measured by infrared absorption method. All strong peaks ware assigned to the autoionization, ｎｓ，ｎｐ and ｎｄ Ｒｙｄｂｅｒｇ states converging to various vibrationally excited states of the ground state of ＣＨ2Ｂｒ2+. In addition, the vibrational modes and autoionization structure occurring in the ground electronic state of the daughter ion ＣＨ2Ｂｒ+（Ｘ）were also assigned.
EVEN AND ODD GENERALIZED COHERENT STATES IN THE NON HARMONIC OSCILLATOR POTENTIAL
Authors: XU ZI-WEN  ,   北京机械工业学院基础部
Published: December 2020

In this paper,the conception of even and odd coherent states is generalized to the nonharmonic oscillator potential. It is found that squeezing exists alternatively in the even and odd coherent states with the increase of the mean energy, and the squeezing of the quantum fluctuation of the natural coordinate in the time evolution has a period of π／２.
THE DYNAMICALLY MECHANICAL PROPERTIES OF Zn-22%Al ALLOYS IN EUTECTOID DECOMPOSITION
Authors: LIU JUN-MIN  , ZHANG JIN-XIU  ,   中山大学物理系
Published: December 2020

The mechanical properties of Zn-22% Al alloys were measured with the low-frequency forced vibration mode. It was observed that a typical transformation internal friction peak was associated with eutectoid decomposition. A relaxation peak in the complex elastic modulus M2-T curves with an activation energy of 100±1.2kJ/mol was observed at the low-temperature side of the eutectoid decomposition peak. It was deduced that the relaxation process was related to the diffusion process of Al atom along the α／β phase boundary and α／α crystal boundary.
A THEORETICAL STUDY ON THE SURFACE ELECTRONIC STRUCTURES OF Si NANO-CLUSTERS
Authors: YE LING  ,   复旦大学物理系
Published: December 2020

The electronic structures of H,O and OH chemisorbed on Si nano-clusters were calculated with local density functional formalism. Atomic force calculations were used to reach at an optimized chemisorption site for the adsorbates. Different models were used. For all H adsorbed clusters, wider energy gaps are opened up compared with that of bulk Si, and quantum size effect is obviously shown. When a shell of the adsorbed H atoms is replaced by oxygen atoms, oxygen induced tail states appear in the gap. Both occupied and unoccupied states exist, and the gap is reduced from that in all H-terminated cases. For O atoms replaced by OH, the tail states become all occupied, but the gap widths do not differ much. No quantum size effects are observable for both O and OH adsorption.
ELECTRIC BREAKDOWN OF PERCOLATION SYSTEM OF 2D METAL FILM ON FULLERENE UNDERLAYER
Authors: WU KE  , WU JUN-QIAO  , WANG ZHI-JUN  , ZHANG JIN-LONG  , LI CHUAN-YI  , YIN DAO-LE  , GU ZHEN-NAN  , ZHOU XI-HUANG  , JIN ZHAO-XIA  ,   (1)北京大学化学系; (2)北京大学物理系
Published: December 2020

Fullerene （Ｃ６０ and Ｃ7０）films were epitaxially grown on fresh (001) mica fcc closely-packed plane parallel to the substrate surface. Metal-overlayers were deposited onto these fullerene films in an ultra-hight-vacuum(UHV) chamber and in situ resistance measurements were performed. With increasing current, we observed reversible resistance variation and irreversible breakdown. Nera the percolation threshold we find power law scaling behavior Ｉb～Ｒ－α,where Ｉb is breakdown current and R the sample resistance. The exponent α is much smaller than the values given by previous experiments and prediction of conventional Ｎｏｄｅｓ-Ｌｉｎｋｓ-Ｂｌｏｂｓ(NLB) model. Possible explanation of these phenomena based on metal-fullerene interfacial interactions is discussed.
NUMERICAL SIMULATIONS OF LARGE SCALE EQUATORIAL SPREAD F
Authors: HUANG CHAO-SONG  , M.C.KELLEY  ,   (1)Schol of Electrical Enginering,Cornel University,Ithaca,NY14850,USA; (2)中国科学院武汉物理研究所
Published: December 2020

We have performed numerical simulations of nonlinear evolution of plasma interchange instability in equatorial spread F(ESF) under different conditions. It is shown that the interchange instability resulting from one-or two-dimensional initial density perturbations can grow into plasma bubbles but cannot evolve into the plumelike structures on the west wall of a plasma bubble .The production of plasma bubbles initiated by gravity waves takes a much shorter time than that resulting from two-dimensional density perturbations. When both a gravity wave and a smaller scale initial density perturbation are used,it is found that the large scale gravity wave determines the outer scale of ESF irregularities and the smaller scale perturbation results in the plumelike structures preferentially located on the west wall. The numerical results show a good agreement with observations.
THE MAGNETIC PROPERTIES OF THE GROUND STATE OF Ru13 CLUSTER
Authors: DENG KAI-MING  , XIAO CHUAN-YUN  , YANG JIN-LONG  , LONG QI-WEI  ,   (1)华中师范大学物理系; (2)南京理工大学应用物理系; (3)中国科学技术大学基础物理中心; (4)中国科学院国际材料物理中心
Published: December 2020

The electronic structures of 13-atom Ru clusters with three possible high-symmetry geometries have been studied using the discrete-variational local-spin-density-functional method. The results indicata that all clusters with different symmetry at their equilibrium configuration have two magnetie solutions, and the low-spin solutions of the clusters are energetically more stable than the high-spin solutions of the clusters for each kind of symmetry. The ground state is the ＩhRu13 cluster, and has the magnetic moment of ４μB, or ０.３１μB per atom, which is in good agreement with the upper limit of experimental observation, ０.２９μB per atom. The reason for the contradiction of the magnetic moments between previous theory and experiment is that multiple magnetic solutions exist for the Kohn-Sham equations. The calculated results are compared and discussed with those of the previous theory. The real geometry of the Ru13 cluster is suggested to be a distorted icosahedron.
PHASE TRANSITION OF A PERIODICALLY DILUTED ISING MAGNET
Authors: GAO HONG  , WANG XUAN-ZHANG  , Lü SHU-CHEN  ,   哈尔滨师范大学物理系
Published: December 2020

Applying the effective-field theory with correlations, we study the phase transition of a periodically diluted Ising system in the presence or absence of a transverse field. We focus on the dependence of the critical temperature of the system on the modulation amplitude and transverse field. The interesting result is: the inhomogeneity of the concentration of magnetic atoms can cause an increase in the critical temperature of the system. However, as the modulation amplitude is increased, the bulk magnetic order of the system may change to a partial magnetic order.
TWO-PHASE RANDOM MAGNETIC ANISOTROPY MODEL FOR NANOSTRUCTURED SOFT MAGNETIC ALLOYS
Authors: JI SONG  , YANG GUO-BIN  , WANG RUN  ,   (1)北京科技大学材料科学与工程系; (2)中国兵器工业总公司第五二研究所宁波分所
Published: December 2020

Following the random magnetic anisotropy model proposed by Alben for amorphous ferromagnets and taking into consideration the two-phase microstructure of nanostructured soft magnetic alloys, we propose a two-phase random magnetic anisotropy model for nanostructured soft magnetic alloys. We obtain the relationship of the effective magnetic anisotropy density with the microstructure parameters and magnetic parameters of ferromagnetic phases in the alloy, and also the dependence of the magnetic propertics on the effective magnetic anisotropy density. The experimental results of X-ray diffraction and magnetic measurements of Ｆｅ７３.５Ｃｕ１.０Ｎｂ３.０Ｓｉ１３.５Ｂ９.０ nanostructured soft magnetic alloys give favourable support to the above theoretical research.