Selected schedules of reinforcement in the black-tailed prairie dog (Cynomys ludovicianus)

Wild black-tailed prairie dogs were run on FR, FI, VR, and VI schedules for Noyes pellet reinforcement. Cumulative barpress responses, postreinforcement pause lengths, and responses per second were recorded. The highest response rates occurred in the VR schedules, with the lowest response rates coming in the FI schedules. Fixed-ratio schedules had the longest postreinforcement pauses, VI schedules had the shortest. At the upper levels of the fixed-ratio schedules (FR 90–100), the animals ceased to respond consistently. Generally, data from prairie dogs were consistent with data reported in studies from other mammalian species.     

美国犹他大学化学实验室管理及借鉴

以美国犹他大学化学实验室为主要研究对象,介绍了美国高校环境、安全与健康管理体系(简称EHS)的组成、管理模式、网站内容等信息,并详细介绍了EHS在犹他大学化学实验室安全管理中的应用,然后结合目前我国高校安全管理存在的主要问题,提出了高校安全管理机构、网络、安全培训、药品管理及废弃物管理等方面建设的具体措施,为高校化学实验室安全管理建设提出了参考思路。     

西藏自治区民族师范学生的化学学习现状调查及思考

设计问卷对拉萨师范高等专科学校理科专业和科学教育专业3个年级的部分学生进行调查,对西藏自治区民族师范学生的化学基础、实验能力和学生对大学化学教学的希望等问题进行深入的分析,不仅可以了解西藏自治区中学化学教学和实验教学的情况,形成对西藏自治区民族师范学生总体化学能力的认识,而且为西藏自治区民族师范学生的化学教学内容和教学方法改革提供实践和理论的依据。     

Responses of water snakes (Natrix r. rhombifera) and garter snakes (Thamnophis sirtalis) to chemical cues

In a series of simultaneous two-choice preference tests, water snakes (Natrix r. rhombifera) displayed a significant preference for a clean area of a test chamber vs an area soiled by a conspecific. No differential responsiveness was found for a clean area as compared to an area soiled by either a sympatric species of garter snake (Thamnophis sirtalis) or by the individual water snake Ss. A similar series of tests with individual garter snakes (Thamnophis radix) revealed significant preferences for areas soiled either by the Ss themselves or by conspecifics as compared to clean areas. No preferences were found for a clean area of the test chamber vs an area soiled by a sympatric water snake (Natrix r. r.). The possible role of chemical cues in the mediation of dispersion and social responsiveness was discussed.     

化工专业毕业设计存在的问题及应对措施

分析了当前化工专业毕业设计存在的问题,并从学生、教师和教学管理角度提出了解决措施。     

英语学习动机与教学方法及相互关系的调查分析

本文通过问卷形式,调查了广州市某高中学生学习英语的动机与其喜爱的教学方法之间的关系情况。本项研究采用SPSS(statistics package for social science 10.0)进行数据处理,运用因子分析提取了10个动机因子和7个喜爱的教学方法因子;方差分析结果表明动机在性别上有显著差异;相关分析显示多数动机和学生喜爱的教学方法之间相关显著。     

Adult-like odor preferences and aversions in three-year-old children

Previous studies of young children have failed to demonstrate adult-like odor preferences in children less than 5 years old. To test whether these results may have been due to inappropriate methods or to stimulus sets that were too limited in range to capture discriminations, a forced-choice procedure embedded in a simple game was used to contrast 3-year-olds' (n = 16) and adults' (n = 17) hedonic reactions to 9 odorants. Subjects indicated liking an odor by pointing to one puppet and disliking an odor by pointing to another puppet. Analyses revealed essentially the same pattern of preferences in both groups. In general, the odorant was a much better predictor of its hedonic quality than was the age of the subject. However, children and adults did differ in their ratings of some odors, and response patterns indicated that children may be more sensitive than adults to some odorants (e.g., the steroid androstenone). These data indicate that the predominant view that adult-like odor preferences and aversions do not exist until between 5 and 7 years of age must be reevaluated.     

Relationship between cognitive preferences and achievement in chemistry

In this report the relationships between cognitive preferences and patterns of achievement in chemistry for grade 12 students in Australia are investigated. The results of the study are consistent with the following two general propostions:

• 1 Students who develop the cognitive preferences consistent with those implied or stressed by the Higher School Certificate chemistry course tend to perform better on an end-of-course achievement examination than do students whose cognitive preferences are not consis tent with these implied preferences.
• 2 Higher cognitive preference for a particular preference is positively correlated with performance on the sorts of cognitive tasks implied in that preference.

     

Learner preferences and prior knowledge in learner-controlled computer-based instruction

This study examined the effects of prior knowledge, learner preference for control, and type of control (learner or program) on the achievement of middle-school students in a computer-based instructional program on adding and subtracting integers. Students were blocked by preference-for-control scores and randomly assigned to either a learner-control or program-control version of instruction. A significant three-way interaction (prior knowledge × preference scores × type of control) revealed that students with high prior knowledge achieved better on the posttest when their preference for control was matched with the type of control they received, whereas students with low prior knowledge achieved better when their preference was mismatched. A significant three-way interaction on attitude reflected the same pattern found in the interaction for achievement scores. The overall results indicate that matching learner preference to the type of program they receive is an effective strategy for high-prior-knowledge students but not for those with low prior knowledge.

模拟分析SiH_4和N_2O产生等离子体加强化学沉积制备SiO_2薄膜

通过等离子体粒子模拟实验(PIC),成功模拟了硅烷(SiH4)和笑气(N2O)的等离子体加强化学沉积(PECVD)制备SiO2薄膜的过程。模拟实验过程分析了电离后各种离子的动能、以及鞘层的空间和能量分布。分析这些物理参量,对比SiH4和N2O的等离子体加强化学沉积实验中的化学反应式,模拟实验结果从动能、能量空间分布的角度都能合理地解释等离子体加强化学沉积制备SiO2薄膜的实验过程,通过这些粒子模拟实验(PIC),从理论上合理地解释了使用SiH4和N2O形成SiO2薄膜的一些形成机制。     

英国大学的科研组织管理模式和运行机制探究——以Bristol大学化学系为例

英国大学有着百年的人文和科学积淀,研究实力雄厚,大学科研组织管理具有严谨而又富有人性化的特点。以英国布里斯托大学(University of Bristol)为例,介绍化学实验室在风险评估、科研组织、大型设备培训和预约、实验室的管理和创新平台等方面的管理模式和运行机制,给我国高校科研实验室的建设与管理提供一些启发。从安全培训、设备共享模式、科研组织管理和协同创新中心建设等方面提出了几点建议。     

Gender differences in use and preferences of agricultural information sources in Pakistan

Purpose: Rural advisory services ensure agricultural information is disseminated to rural populations, yet they are less accessible to women. This research provides insight on gender differences in information access by investigating frequency of use and preference of agricultural information sources by gender in a rural setting, differentiated according to literacy and age. Design/Methodology/approach: This study interviewed 401 male/female individuals in farm households in Jhang and Bahawalpur district of Punjab, Pakistan in 2016. Findings: Men and women farmers’ use and preferences in accessing information sources are extremely different. Women hardly use sources for agricultural information, and value interpersonal communication from informal sources. In contrast, men use and value official agencies more. Radio, surprisingly, was very rarely used, contradicting previous findings of research elsewhere. Age and literacy affect differences between women more than it does between men, particularly for convenient locations to access information. Practical implications The study identified and refined major gender differences regarding use and preference for agricultural information in relation to age and literacy, and helps to articulate options to improve gender equality of access to agricultural information in Pakistan. Theoretical implications: The focus and outcomes regarding gender intersecting with age and literacy in agricultural information access imply the need for more refined socio-economic models, discerning and interrelating gender and other social dimensions beyond the standard of male-headed households. Originality/value: This paper adds to the growing body of evidence on information access according to gender, highlighting the need to investigate deeper socio-cultural issues around age and literacy.     

化工仿真在高校化工课程教学中的应用

概述了化工仿真技术及其在化工课程教学、化工实习、科学研究中的作用,讨论了将其引入教学环节中的意义,表明把化工仿真引入高校化工课程教学已迫在眉睫.