Guayule seedling response to nitrogen fertilizers

Slow growth and high seedling mortality limit direct seeding establishment of guayule (Parthenium argentatum G.). This study was conducted to assess seedling growth enhancement by the addition of different rates and forms of N fertilizers and Ca salts. Experiments were conducted in a greenhouse with cultivar 593 under both surface and subirrigated conditions using water low in salts (salinity of 0.8 dSm^–1, SAR of 5.0 and 10 mg Ca L^–1). Under surface-irrigated conditions, seedling height and fresh plant weight increased with N application to the irrigation water to 70 mg L^–1. The best seedling growth was observed when (NH₄)₂SO₄ was added in combination with CaCl₂ or CaSO₄. Progressively less growth was observed by addition of (NH₄)₂SO₄ alone, CO(NH₂)₂ plus CaSO₄, CO(NH₂)₂ alone and Ca(NO₃)₂. When seedlings were subirrigated, however, the best growth was observed with Ca(NO₃)₂. Intermediate growth was obtained with (NH₄)₂SO₄ plus CaSO₄ and lowest growth rates with (NH₄)₂SO₄ alone. These differential responses may be explained by the differences in leaching and volatile characteristics of the N forms. Growth enhancement from N and Ca additions increased with time with significant increases 45 days after seeding. Nitrogen application with Ca may be effective amendment in promoting subsequent growth of direct seeded guayule.     

Exploring teachers' perceptions on different CSCL script editing tools

Despite the apparent maturity of the learning design field, and the variety of tooling available to support it, adoption among the teacher community (one of its alleged main targets) is still low. There is a lack of research on teachers' perception and use of different technological learning design tools, as existing evaluations are often restricted to a single tool. In order to explore whether there are common factors hampering teacher adoption, and which tool features might appeal to different teachers, more studies involving multiple authoring tools are needed. This paper provides a first step in this direction, describing a mixed methods study performed around a professional development workshop with 18 university teachers from multiple disciplines. This workshop exposed teachers to two different authoring tools (WebCollage and EDIT2), as they learned to create computer-supported collaborative learning (CSCL) designs and implement them. The findings of our interpretive study (which included questionnaires, observations, or group discussion recordings) support the idea that there is no single tool or set of features that are globally perceived as better, although our evidence also highlights certain factors as important for participant teachers – amongst others, the integration of learning designs with the ICT platforms for enactment, as well as with other tools that they already use in their everyday practice.     

Polymer/surfactant interaction—Its relevance to detergent systems

The field of polymer/surfactant interaction is reviewed in this work. Results from two investigative methods,viz., dialysis and surface tension, are discussed, illustrating the main behavioral patterns and outlining the principles of the interactions. Next, aspects of the interaction phenomena that appear to have relevance to detergent formulation are presented. These include solution rheology, solubility control and surface conditioning. Lastly, the importance of surface activity of the polymer itself is stressed, culminating in a discussion of the properties of hydrophobically modified water-soluble polymers (“polymeric surfactants”), both alone and in the presence of conventional surfactants. Based on the Samuel Rosen Memorial Award lecture, given at the AOCS Annual Meeting, Anaheim, CA, April 1993.     

网络课程设计中学习者学习动力的调查与建议

网络教育中有关学习者学习动力的研究日益受到重视,通过对现有网络课程设计中学习者学习动力设计状况的调查可发现其中存在的问题,分析这些问题与不足并针对性地提出改进建议,以期对网络课程的完善提供有益参考。     

A social interaction system based on cloud computing for mobile video telephony

As the use of smartphones become popular,people heavily depend on smartphone applications to deal with their social activities.For this reason,traditional message texting between mobile applications does not fulfill the versatile requirements of social networking.Many mobile applications use multimodality to deliver multimedia messages including sticker,voice and photo message,video call,and snap movie to enhance the communicative capability.However,without face-to-face interaction,people may fail to detect the other side’s non-verbal social behavior such as fine-grain facial expressions,body movements,or hand gesture.During social interaction,non-verbal behavior conveys information about the involved individuals and help the speakers express their social emotion in an implicit way.It is so important for real-world face-to-face interaction but is often blocked on the mobile telephony.To cope with this problem,we propose an afective computing model to assist the representation of social emotion and then help the progress of social interaction on the mobile telephony.In this model,for the purpose of real-time afective analysis,we delegate the computing loading to the cloud side service and enhance the system’s scalability and availability.The result of this experiment approves the feasibility of our system design for the applications of social intelligent.Also,the system provides a research framework of the social intelligent system on the mobile telephony.     

高职学生学习主动性意识的缺失与重塑

分析高职学生的特点和学习主动性意识缺失的症状,从学生的学习自觉自信、教师的课堂教学反思、学校的学生评价机制等方面,对高职学生学习主动性意识的重塑策略进行探讨,并提出相应的对策。     

Potential pedagogical benefits and drawbacks of multimedia use in the English language classroom equipped with interactive whiteboard technology

This paper analyses the process of multimedia integration in English language classrooms equipped with interactive whiteboard (IWB) technology, and offers insights into the theoretical underpinnings of multimedia use in language learning from the perspective of cognitive learning theory. The data discussed here are drawn from a study carried out as part of a PhD research programme at Lancaster University (UK). The study was conducted within an interpretative research paradigm, and data were collected and analysed according to a qualitative approach. In the first part, the paper discusses some perceived pedagogical benefits of adopting a multimedia-oriented approach in the IWB-based classroom. Secondly, it discusses a variety of potential problems related to the use of multimedia resources in the language classroom in question. Finally, the paper draws upon the literature on multimedia learning to address the potential pedagogical implications of these research findings.     

Influence of ions on the critical behavior of a binary mixture near the consolute point

The lower critical point of stratification of a 3-methylpyridine (MP)+heavy water (D₂O) mixture in the presence of Na⁺ and CI^– ions has been studied by the Toepler shadow method. Addition of 0.3% ions lowered the critical temperature and reduced the equilibration time and the gradient of the refractive index (compressibillity). The analysis of the form of the near-critical isotherm demonstrated the ionic mixture to be described by the index = 3.05 ± 0.15. which corresponds to the classical mean-field theory. The results obtained provide evidence that even small admixtures of charged particles result in a substantial suppression of fluctuations near the critical point by the long-range Coulomb interaction.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

Linking employees’ e-learning system use to their overall job outcomes: An empirical study based on the IS success model

e-Learning systems are increasingly being adopted by modern enterprises, because of their cost-down effect. However, the extant literature provides little insight into their beneficial consequences. It is expected that a transfer of acquired knowledge, skills and/or work attitudes to jobs will occur through e-learning systems use. This makes e-learning systems a useful tool for improving job outcomes, although this is not well documented. The IS success model, which captures both the human and technological elements of information systems, provides a theoretical basis for linking system use to system task. The current study then examines the relation between e-learning systems use and overall job outcomes based on the model. The data collected from one hundred and ninety-three e-learning system users were analyzed with partial least square (PLS). The results indicate that e-learning systems are perceived as useful and satisfying by employees, and employees’ e-learning systems use is significantly associated with overall job outcomes. In practice, these results provide a basis for establishing a link between an organization’s investment in e-learning and human capital management. They also lend empirical support to the IS success model.     

谈智能科学多媒体辅助教学设计

在多媒体辅助教学中,教学设计直接影响教学效果。认知心理学的发展,尤其是R.E.Mayer提出的多媒体教学理论给我们提供了一个研究教学设计规则的依据。描述同多媒体教学相关的认知心理学的几个基本理论,在此基础上提出一些关于提高多媒体辅助教学效果的教学设计方法。