Relationship between Compostion,Density and Refractive Index for Heavy Metal Fluoride Glasses

The density and the refractive index for various compositions of heavy metal fluoride(HMF) glasses,used to make low-loss optical wave-guides,have been measured by standard archimedes method and by using as Pulfrich refrctometer respectively.The density as a function of composition is calculated considering the effective volume of the ions contained in the glass to be invariant.The refractive index as a function of composition is also calcuated.based on the Lorenz-Lorentz equation,by computing the electronic polarizability of HMF glasses.All calculated results are in good agreement with the observed data.     

English in action: school based teacher development in Bangladesh

In the Least Economically Developed Countries (LEDCs), School Based Teacher Development (SBTD) is sometimes advocated as a potential mechanism for improving the classroom practices experienced by millions of children in a complete school system, as quickly as possible. Robust evidence is required for approaches to be implemented with some confidence by Government development agencies, such as the UK Department for International Development (DFID). SBTD has a long history stemming from ideas of school-based curriculum development, which underlay the ideas on teacher-as-researcher, and is typically advocated in the developed world based on a view of the teacher as a professional. How might such notions play out, and to what effect, in LEDC contexts? This article examines the issues at stake in introducing SBTD in LEDCs, by examining: the nature of the evidence for various forms of teacher development, the nature of SBTD in particular and the evidence for its effectiveness. The latter issues will be illustrated through examination of English in Action (EIA, www.eiabd.com), a large-scale SBTD programme for primary and secondary English language (EL) teachers serving government schools across Bangladesh.     

Anomalous Hysteresis Behavior in a Cobalt Fewrrite Ferrofluid

The magnetization of cobalt ferrite ferrofluid has been studied at low temperature in the presence of the carrier fluid.A prominent difference between slow and fast cooled.samples was observed.In particular the slow cooled samples display an anoamlous increses in magnetization on field reversal.The data is analyzed in terms of the possibilites of both cotherent and incoherent spin rotations.     

A look at superheroes: Some issues and guidelines

Most early childhood teachers are not alarmists about children and television. TV is a fact of life for American children and simply another aspect that teachers must deal with in the classroom.     

Implementation of a new PC based controller for a PUMA robot

This paper describes the replacement of a controller for a programmable universal machine for assembly (PUMA) 512 robot with a newly designed PC based (open architecture) controller employing a real-time direct control of six joints. The original structure of the PUMA robot is retained. The hardware of the new controller includes such in-house designed parts as pulse width modulation (PWM) amplifiers, digital and analog controllers, I/O cards, signal conditioner cards, and 16-bit A/D and D/A boards. An Intel Pentium IV industrial computer is used as the central controller. The control software is implemented using VC programming language. The trajectory tracking performance of all six joints is tested at varying velocities. Experimental results show that it is feasible to implement the suggested open architecture platform for PUMA 500 series robots through the software routines running on a PC. By assembling controller from off-the-shell hardware and software components, the benefits of reduced and improved robustness have been realized.     

Nd3+-Yb3+-Ho3+掺杂四氟化锆玻璃的Ho3+上转换特性研究

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｉｎｒｅｃｅｎｔｙｅａｒｓ ,ｈｉｇｈ ｐｏｗｅｒｌａｓｅｒｄｉｏｄｅｓｈａｖｅｂｅｅｎｅｍｐｌｏｙｅｄａｓｐｕｍｐｉｎｇｓｏｕｒｃｅｓｗｉｔｈａｖｉｅｗｔｏｄｅｖｅｌｏｐｃｏｍｐａｃｔｕｐ ｃｏｎｖｅｒｓｉｏｎｖｉｓｉｂｌｅ ｌａｓｅｒｓｙｓｔｅｍｓ .Ｔｈｅｆｒｅ ｑｕｅｎｃｙｃｏｎｖｅｒｓｉｏｎｏｆｉｎｆｒａｒｅｄｌｉｇｈｔｔｏｖｉｓｉｂｌｅｌｉｇｈｔｈａｓｂｅｅｎｅｘｔｅｎｓｉｖｅｌｙｉｎｖｅｓｔｉｇａｔｅｄｆｏｒｒａｒｅ ｅａｒｔｈｄｏｐｅｄｃｒｙｓｔａｌｓａｎｄｇ…     

高压水解处理氧化乐果废水研究

The effect of pressure on the hydrolysis rates and the degradation kinetics of environmentally persistent omethoate pesticide was studied. The results showed that the values of kobs increased and the values of activation volume (AV) decreased with increasing pressure. Among pH conditions (3.58, 6.01 and 8.5), pH 8.5 was found to be the unstable condition and its half-life was reduced from 263 min at 1 atm to 19.37 min at 10 atm. These results describe that high-pressure hydrolysis is a useful technique for the conversion of toxic organic phosphorus into inorganic phosphorus.     

Perceptions of Chinese students in an Australian university: are we meeting their needs?

This short-term longitudinal study sought to identify the issues faced by a group of international Chinese students undertaking study in an Australian university. While the focus was on educational issues, socio-cultural and personal factors were also examined in an attempt to identify the sorts of strategies students used in settling into a new socio-cultural and educational context. Interviews conducted at the beginning and end of the first semester of study indicate a range of issues that are supported by previous studies. What has not previously been highlighted, however, is the emphasis on speaking and listening skills which students reported they needed to improve. Lack of proficiency in these areas was seen by students as hampering their active participation in class, leading to lack of confidence in approaching Australian students, and resulting in their inability to benefit from the “Australian experience”. Many existing academic support structures in Australian universities tend to emphasize support with written and study skills. While this is important because of the direct impact on assessment, it is perhaps now opportune to place some emphasis on developing strategies and programmes that will support the development of students' speaking and listening skills, with a focus on intercultural communication.     

Evidence of sub-optimal sleep in adolescent Middle Eastern academy soccer players which is exacerbated by sleep intermission proximal to dawn†

The purpose was to assess sleep patterns, quantity and quality in adolescent (16.2?±?1.2 yr) Middle Eastern academy soccer players (n?=?20) and the influence of an intermission upon these characteristics. On a 17-day training camp (located one time zone west of home) including three discrete matches, sleep was assessed pre- (PRE) and post-match (POST) via wrist actigraphy. Retrospective actigraphy analysis identified sleep characteristics, including if players experienced a sleep intermission (YES) or not (NO) proximal to dawn, and bedtime (hh:mm), get-up time (hh:mm), time in bed (h), sleep duration (h) and sleep efficiency (%). Within YES two bouts were identified (BOUT1 and BOUT2). No differences were seen between PRE and POST, nor between BOUT1 and BOUT2 (p?>?.05). Overall players did not meet National Sleep Foundation (NSF) guidelines (7:04?±?1:16?h vs. recommended 8–10?h for 14–17 yr). Sleep duration was significantly reduced (～ ?13% or ?1:06) in YES compared to NO (6:33?±?1:05 vs. 7:29?±?1:17, p?<?.01). Despite players in YES waking earlier due to an intermission, they did not compensate for this with a later wake time, rising significantly earlier compared to NO (09:40?±?00:38 vs. 10:13?±?00:40, p?<?.05). These players on average do not obtain sufficient sleep durations relative to NSF guidelines, with decrements increased by an intermission proximal to dawn. High inter- and intra-individual variance in the players sleep characteristics indicates the need for individualized sleep education strategies and interventions to promote appropriate sleep.     

闪烁氟化玻璃的应用研究

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｈｅａｖｙｍｅｔａｌｆｌｕｏｒｉｄｅｓｇｌａｓｓｅｓａｒｅｏｆｐｒｉｍａｒｙｉｎｔｅｒ ｅｓｔｆｏｒｉｍｐｏｒｔａｎｔａｐｐｌｉｃａｔｉｏｎｓｉｎｔｈｅｏｐｔｉｃａｌｃｏｍｍｕｎｉ ｃａｔｉｏｎｆｉｅｌｄ ,ｄｕｅｔｏｔｈｅｉｒｔｒａｎｓｐａｒｅｎｃｙｔｏｌｉｇｈｔｓｒａｎｇ ｉｎｇｆｒｏｍＵＶｔｏｉｎｆｒａｒｅｄｒｅｇｉｏｎｓ.Ｍｏｒｅｏｖｅｒ ,ｔｈｅｉｒｍｅ ｃｈａｎｉｃａｌｓｔｒｅｎｇｔｈｍａｋｅｓｔｈｅｍｇｏｏｄｃａｎｄｉｄａｔｅｓｆｏｒｗｉｎ ｄｏｗｓ,ｌａｓｅｒｈ…