南美白对虾人工育苗高产技术

通过对南美白对虾育苗工艺技术与生产设施的改进,提高无节幼体投放密度为100万只-120万只／立方米,使平均单t位水体出苗量达30．2万尾／立方米。     

双斑东方鲀人工育苗技术的探讨

综述了福建省水产研究所双斑东方的人工育苗过程,认为:(1)双斑东方属一次产卵型鱼类,性腺退化明显,仔鱼有相互残杀的习性;(2)缩短亲鱼暂养时间,及时催产。通过人工调控,可实现雌雄亲鱼性腺同步化,有效提高受精率;(3)孵化前期加大充气量,孵化后期加大换水量,有利于孵化率的提高;(4)仔鱼培育后期,应及时投足轮虫和分养仔鱼,并逐渐加大充气量和藻液的密度,从而提高出苗率。     

GGR在桉树扦插育苗的应用试验

本试验通过应用不同浓度的GGR6号水溶液处理巨尾桉优良无性系的嫩枝插穗进行扦插育苗的试验,认为GGR处理显著促进插条生根,提高巨尾桉扦插育苗的成活率,其中以浓度100mg.kg-1处理2h的效果最为显著.     

不同温度下饥饿对南方鲶仔细影响的初步观察

对有同类相残习性的南方鲶仔鱼饥饿效应的观察表明：在生态适温范围内,随温度升高,饥饿致死速度加快，首次同类相残所需时间缩短，仔鱼50％死亡所需时间缩短．仔鱼50％死亡时，随温度升高．各组间吞食率由升高而降低．各组先后仅剩一尾仔鱼．所剩仔鱼缺食期的生长表明，在25－27℃时，仔鱼的生长速度最快．本文还对南方鲶仔鱼饥饿时的生态行为特点进行了描述．     

饥饿对鲢鱼形态性状的影响

为探索鱼类资源保护和养殖技术,在实验室条件下,利用测量外部形态特征等方法,研究了饥饿条件下鲢鱼的存活与形态性状的变化．实验结果表明,随着饥饿时间的延长,鲢鱼的体长、全长、体重、去内脏重、内脏重和肥满度下降;其相对体重损失率在饥饿到2周时最大．根据饥饿仔鱼形态学的变化,可以初步地评价鲢鱼早期发育阶段的营养水平,从而为人工育苗中正确指导投饵提供依据．     

罗氏沼虾亲虾越冬技术的探讨

罗氏沼虾亲虾越冬是育苗的关键，采用大水体高水位、设置隐蔽体、引入水葫芦、伴养鳙鱼、多种饵料组合、交叉投喂、偏低温越冬等技术举措，能提高亲虾越冬成活率、育苗孵化率．本实验亲虾越冬成活率为９８％．每尾抱卵亲虾孵出１．９３万尾状幼体．     

理清知识 形成技能——分数与百分数应用题综合训练设计

一、利用葱本题,沟通知识联系,掌泪解法。2.某养鱼池,养鲤鱼 1500万尾,养鲫鱼的尾数比 第一类应用题:鲤鱼多20%,养鲫鱼多少万尾? 1.某果园里,有梨树150棵,桃树30棵,桃树是梨 3·某养鱼池,养鲤鱼1500万尾,鲫鱼比养的鲤鱼 树的几分之几(或百分之几)?少20%,养鲫鱼多少万尾? 2.某果     

两个番石榴品种导管细胞形态观察

利用常规木材制片法,结合细胞图象分析系统及显微照相,对番石榴2个品种（土种、珍珠）茎次生木质部导管细胞结构进行了观察.结果表明：1、导管细胞均为具单穿孔板的孔纹导管;2、总体上可分为两端具尾、一端具尾和无尾3种类型的导管;3、土种、珍珠2个品种番石榴导管细胞平均长度分别为959.67±203.01μm、861.95±167.49μm,平均直径分别为210.54±64.72μm、192.59±57.97μm.番石榴不同品种导管细胞形态差异与其生长的差异具有一定的相关性.     

人工培育鲟鱼首次在我国繁殖成功万余活化石戏水

记者4月12日从北京市汇瀛水产良种开发中心了解到,由国家淡水渔业工程技术研究中心和市科委组织的攻关项目取得重大突破,我国首次人工培育繁殖鲟鱼成功,1.3万尾"水中活化石"半个月就长到2厘米左右,活泼可爱,高科技在京郊又出重大成果.     

美国黑莓鲈繁殖生物学的初步研究

对美国黑莓鲈（Ｐｏｍｏｘｉｓｎｉｇｒｏｍａｃｕｆａｔｕｓ）的繁殖生物学进行了初步研究．结果显示在池塘自然繁殖条件下,当平均水温上升至１６℃,黑莓鲈开始筑巢产卵．鱼卵一般筑在岸边水草根部或较硬的泥底上,水深１５～４０ｃｍ,鱼巢平坦,范围在２０ｃｍ×３０ｃｍ左右,每巢产卵数千粒．产卵后雄鱼有守巢行为．在池塘中投入２０ｃｍ×４０ｃｍ的人工鱼巢黑莓鲈也可在其上产卵．在水泥池中,通过注射ＨＣＧ可进行人工催产,鱼卵产在人工鱼巢上,但无守巢行为．黑莓鲈卵小,卵径平均０８８ｍｍ,卵具油球,卵间隙小．水温１９℃时需４８ｈ以上受精卵方可孵出仔鱼．在人工观察条件下,仔鱼孵出６ｄ后离巢起水,８ｄ后卵黄囊、油球消失,１０ｄ后开始摄食,初摄食物为轮虫     

草甘膦对3种滩涂动物的急性毒性及安全评价

采用静水法和半静水法检测不同浓度下除草剂草甘膦对缢蛏、可口革囊星虫和大弹涂鱼的急性毒性,并根据·化学农药环境安全评价试验准则·中农药的毒性分级,评价了草甘膦对三种滩涂生物的安全性．结果显示：草甘膦对于缢蛏、可口革囊星虫和大弹涂鱼的96 h LC50分别为233．60,1267．00,1068．00 mg·L－1,均属于低毒;安全浓度分别为23．36,126．70,106．80 mg·L－1,毒性顺序为缢蛏＞大弹涂鱼＞可口革囊星虫．     

Students’ imaginings of spaces of learning in Outdoor and Environmental Education

In this article, I interrogate students’ stories about the spaces and places in a tertiary Outdoor and Environmental Education course that support and shape their environmental ethics. Drawing on a longitudinal qualitative study, I explore the ways in which particular sites of learning (outdoor, practical learning) are privileged and how particular stories of outdoor spaces get reproduced. I employ the work of poststructuralist geography scholar Doreen Massey in my analysis to highlight the intersections between space, relations of power and identity. This analysis also underscores the simultaneity of multiple and conflicting stories around Outdoor Education’s outdoor (practical) and indoor (theoretical) learning spaces. I conclude by drawing on Elizabeth Ellsworth’s work on anomalous places of learning to explore some of the spaces in-between the indoor/outdoor binary as a way of interrupting and re-imagining places and spaces of learning in Outdoor Education.     

Effect of early experience and age on initial responsiveness ofTilapia mossambica fry to a maternal model

Fry of the maternal mouth brooding fishTilapia mossambica were tested for the effects of (1) rearing and (2) increasing age on initial responsiveness to a gray disk covered with small black pits that served as a maternal model. In the first experiment, the eggs were removed from their mother’s mouth shortly after spawning, hatched, and the fry raised in groups, singly in complete visual isolation, or by the mother (control) until testing. When free swimming, the fry were tested individually for responsiveness to the model. High levels of responsiveness were exhibited by all fry regardless of rearing experience, indicating that responsiveness to the mother’s mouth is fully developed at birth and needs no previous social experience for its expression. In the second experiment, naive group-reared fry were tested individually for initial responsiveness to the model at 13, 16, 20, or 26 days postspawning. It was found that naive fry were strongly attracted to the model at 13 and 16 days of age but were neutral or actively avoiding it at 26 days of age. This decline is almost identical to the decline in responsiveness of normally reared fry toward their actual mother.     

基于DSP控制的多联空调内外机通讯的研究

采用DSP芯片控制室外机的多联空调机组,室内机往往采用单片机控制.通过对其内外机通讯系统的硬件和软件进行分析和研究,设计了一套控制方案.通过实验验证,通讯正确率可以达到98%以上,系统可以实时对用户要求做出反馈.     

Learning in the outdoor environment: a missed opportunity?

In 2001, the Welsh Assembly Government announced proposals for a Foundation Phase for children aged three to seven years. The Foundation Phase framework promotes a play‐based approach to children's learning in both indoor and outdoor contexts and places children's well‐being and their personal and social development at its core. While the framework is currently being piloted across Wales, full implementation will not take place until 2010; for many schools, then, this is a time of transition. This paper discusses the findings of a research project that aimed to document the current use of the outdoors by a group of early years teachers working in South Wales. Drawing on data from interviews and observations conducted in four schools, it is suggested that the teachers missed many of the opportunities afforded by the outdoor environment to enhance children's learning. The paper considers the reasons why this might be the case and comments on the distinction, apparent in two schools, between what was seen as ‘normal’ and ‘special’ outdoor activity.     

Elementary Science Indoors and Out: Teachers, Time, and Testing

In this article, we present the results from a mixed-methods research study aimed to document indoor and outdoor fifth grade science experiences in one school in the USA in the context of accountability and standardized testing. We used quantitative measures to explore students’ science knowledge, environmental attitudes, and outdoor comfort levels, and via qualitative measures, we examined views on science education and environmental issues from multiple sources, including the school’s principal, teachers, and students. Students’ science knowledge in each of the four objectives specified for grade 5 significantly improved during the school year. Qualitative data collected through interviews and observations found limited impressions of outdoor science. Findings revealed that, despite best intentions and a school culture that supported outdoor learning, it was very difficult in practice for teachers to supplement their classroom science instruction with outdoor activities. They felt constrained by time and heavy content demands and decided that the most efficient way of delivering science instruction was through traditional methods. Researchers discuss potentials and obstacles for the science community to consider in supporting teachers and preparing elementary school teachers to provide students with authentic experiential learning opportunities. We further confront teachers’ and students’ perceptions that science is always best and most efficiently learned inside the classroom through traditional text-driven instruction.     

EM菌对罗非鱼土池水环境的影响

采用生产取样与室内分析相结合的方法,以养猪-养鱼的生态模式进行了施用EM菌对罗非鱼水环境综合影响的研究。通过试验组和对照组进行的试验,得出以下结论：（1）施用EM菌,在7～10d内可以很好的调控罗非鱼养殖水体中的BOD、COD、pH值、DO、氨-硝态氮等主要指标,使罗非鱼水环境达到良好的生长水质标准;（2）施用EM菌后,试验组的鱼体重比对照组增长了2％-17．1％;（3）试验组鱼种色泽油润,身体柔软光滑,大小整齐,池塘水清亮无臭味。     

基于教育心理学研究新进展的教与学——针对教学环境的研究的启示

教学环境对于学生的学业成就和智力发展有着至关重要的影响。教学环境可分为教育环境与学习环境。本文将从教育心理学针对教学环境的新进展入手,探讨教育环境、教学环境对学生学业成就、学业自我概念的影响,以针对课堂情感氛围和Marsh的I＼E模型与大鱼小池效应的组合模型为重点,探讨其对于教与学的启示。     

An indoor air aerosol model for outdoor contaminant transmission into occupied rooms

The paper presents a simple model for outdoor air contaminant transmission into occupied rooms. In the model, several factors such as filtration, ventilation, deposition, re-emission, outdoor concentration and indoor sources are included. The model results show that the air exchange rate plays an important role in the transmission of outdoor contaminants into the indoor environment. The model shows that increasing the value of the filtration efficiency decreases the mass concentration of indoor particles. In addition, if outdoor aerosol particles have a periodic behaviour, indoor aerosol particles also behave periodically but smoother. Indoor sources are found to be able to increase indoor concentrations greatly and continuously.     

山区池塘培育瓯江倒刺鲃鱼种试验

通过到山塘培育瓯江倒刺鲃鱼种试验,结果表明:1亩鱼塘和3.5亩山塘,经过8个月的鱼苗培育鱼种试验,获利12 290元,每公顷收入为40 967元,投入产出比为1:1.89,经济和生态效益显著。在试验中提出了养殖过程中的有关注意问题,为山塘培育倒刺鲃规模养殖提供了实践和理论的参考。