大鸨越冬习性观察与研究

2006年12月10日,在吉林莫莫格自然保护区胡家窝棚核心区首次发现大鸨越冬种群,是该区越冬鸟类种类的新记录。通过观察与研究表明,大鸨在胡家窝棚停留91 d,为冬候鸟;越冬期间雌、雄鸟分为两个种群;越冬食物主要是植物种子,特别喜食绿豆、黄豆、玉米、昆虫的残骸等。该区域良好的冬季生态环境是大鸨在此越冬栖息的基础条件。     

大豆害虫黑毛蓟马研究进展

为了进一步开展大豆黑毛蓟马的研究,笔者总结了该害虫的分布与寄主、形态特征、危害特点、发生规律、生活习性、发生与生态因子的关系以及综合防控等方面的研究进展.黑毛蓟马主要危害大豆、菊、烟草等多种经济作物,在国内外均曾多次较大发生并致灾害,今后也存在一定成灾风险.建议在新的气候和种植制度下,继续开展黑毛蓟马的发生规律、基础生...     

大渡河软刺裸裂尻鱼（Schizopygopsis malacanthus）游泳能力研究

探究大渡河软刺裸裂尻鱼的游泳能力,为大渡河软刺裸裂尻鱼的人工繁殖、保护以及大渡河过鱼设施建设提供参考和基础数据支持。采用递增流速法,用自制Brett-type水槽对大渡河软刺裸裂尻鱼的感应流速、临界游泳速度、突进游泳速度进行测试。结果表明,在水温范围为11.9～14.1℃条件下,体长为15.0～21.5 cm,体重为34.8～152.9 g的大渡河软刺裸裂尻鱼的绝对感应流速为0.084～0.095 m/s,相对感应流速为0.321～0.588 BL/s,相对感应游泳速度随体长增大而减小;绝对临界游泳速度(U_crit)为0.61～1.31 m/s,相对临界游泳速度为4.16～5.08 BL/s,两者均随体长增大而增大;绝对突进游泳速度(U_burst)为1.02～1.40 m/s,与体长关系并不显著(P>0.05),相对突进游泳速度为5.73～8.36 BL/s,随体长增加而减小。视频回放发现,实验鱼突进游泳速度测试过程分为 3 个阶段：第 1 阶段游速为 0～0.4 m/s,占突进速度0～29%;第2阶段游速为0.40～0.84 m/s,...     

Atlantic coast feeding habits of striped bass: a synthesis supporting a coast-wide understanding of trophic biology

The recent increase in the Atlantic coast population of striped bass, Morone saxatilis (Walbaum), prompted managers to re‐evaluate their predatory impact. Published and unpublished diet data for striped bass on the Atlantic Coast of North America were examined for geographical, ontogenetic and seasonal patterns in the diet and to assess diet for this species. Diets of young‐of‐the‐year (YOY) striped bass were similar across the Upper Atlantic (UPATL), Chesapeake and Delaware Bays (CBDEL) and North Carolina (NCARO) areas of the Atlantic coast where either fish or mysid shrimp dominate the diet. For age one and older striped bass, cluster analysis partitioned diets based on predominance of either Atlantic menhaden, Brevoortia tyrannus (Latrobe), characteristic of striped bass from the CBDEL and NCARO regions, or non‐menhaden fishes or invertebrates, characteristic of fish from the UPATL, in the diet. The predominance of invertebrates in the diets of striped bass in the UPATL region can be attributed to the absence of several important species groups in Northern waters, particularly sciaenid fishes, and to the sporadic occurrences of Atlantic menhaden to UPATL waters. In all regions, across most seasons and in most size classes of striped bass, the clupeiod fishes; menhaden, anchovies (Anchoa spp.) and river herrings (Alosa spp,) and Atlantic herring, Clupea harengus L., dominated the diets of striped bass above the first year of life.     

培养大学生数学学习精神的对策

良好的学习精神是时代的需求,更是每个人成长的需求.本文阐述了数学学习精神的内容及其重要性,并且提出了培养数学学习精神有以下几种政策,培养坚持精神的对策,培养钻研精神的对策,培养求美精神的对策以及培养良好学习习惯的对策.     

不同结荚习性大豆品种综合生产力灰色关联度分析

[目的]综合评估不同结荚习性大豆(Glycine max)品种(系)的综合生产力表现,为大豆育种工作提供参考。[方法]用灰色关联度分析法对4个有限结荚习性大豆品种(铁99009-7、辽200045-2、铁00052-1、铁00027-5)和4个亚有限结荚习性大豆品种(铁97118-2、阜05-148、辽02品-4-3-1、铁丰33号)的主要农艺性状、光合速率、叶绿素含量和品质进行分析。[结果]等权关联度大小顺序依次为铁99009-7>铁00052-1>铁00027-5>阜05-148>辽02品-4-3-1>铁丰33号>辽000045-2>铁97118-2;加权关联度大小顺序依次为铁99009-7>铁00027-5>铁00052-1>辽000045-2>阜05-148>辽02品-4-3-1>铁丰33号>铁97118-2。所以有限结荚大豆品种铁99009-7综合表现最好,有限结荚大豆品种铁00052-1和铁00027-5次之,亚有限品种铁97118-2表现最差,其他品种居中。[结论]有限结荚习性品种综合表现优于亚有限结荚习性品种。     

黄菖蒲花部特征及繁育习性研究

该研究旨在通过定点观察与人工授粉等方法,为黄菖蒲生殖生物学与杂交育种提供理论依据。对引种多年的黄菖蒲(Iris pseudacorus L.)的花器官特征、开花动态、花粉形态及活力、柱头可授性、繁育习性与访花昆虫进行了观察与研究,结果表明,黄菖蒲在南京地区为4月下—5月上开花,雌雄异熟;花粉活力与柱头可授性均为开花当天最强,随后下降;雌雄异位,开花过程中柱头向下弯曲,雄蕊始终短于柱头;花粉/胚珠比380.4,杂交指数为5。黄菖蒲的繁育习性为异交为主,部分自交亲和,需要传粉者,自然状态下存在花粉限制,不存在无融合生殖现象,黑纹食蚜蝇为潜在传粉者。     

暹罗斗鱼的品系与色彩

对暹罗斗鱼(Betta splendens)的生活习性、形态特征及分类地位等进行简要概述,并对经过了100多年人工改良所产生的暹罗斗鱼不同品系进行了详细介绍。根据用途可把暹罗斗鱼分为两大类:观赏型和搏击型斗鱼,其中观赏型斗鱼7种;根据鳞片的色层叠加顺序,暹罗斗鱼的颜色分为彩虹层颜色、金属层颜色和拓展层颜色,其中彩虹层颜色约15种,金属层颜色约7种,现阶段拓展层的终极表现形式为风靡的龙鳞;根据鳍膜的变化,又有蝶翼色和芥子色之分;根据鳞片的覆盖方式,定义了面具和黑头。详细了解暹罗斗鱼的品种分类特征,对于维持其品系的稳定性研究及其品种改良具有深远的意义。     

High-intensity light of full-spectrum LED promotes survival rate but not development of the larval swimming crab Portunus trituberculatus

In this study, a 25-day experiment was performed to evaluate the survival and development of Portunus trituberculatus larvae under different light intensities (0, 61.55, 93.57, 124.31, 195.31, 248.51, and 310.95 μmol m⁻² s^-1). The newly hatched larvae were cultured in 1-L beakers at a density of 100 individuals/L, with four replicates per treatment. Full-spectrum light-emitting diode (LED) strip lamps were used as the light source. The larvae were fed with Artemia nauplii until all the larvae metamorphosed to young crabs or died, and survival and development of the larvae were recorded. The results showed that P. trituberculatus zoeae were not able to complete the entire larval cycle in the absence of light. In the dark treatment, the survival rate of the larvae decreased sharply in Z3 and reached 0.8 % in Z4, and all the larvae failed to develop to the megalopa stage. In the light treatment, no significant differences were observed in the survival rates of the Z1, Z2, and Z3 larvae under different light intensities (P > 0.05). However, the highest survival rates were detected for Z4 larvae and megalopae at 195.31 and 124.31 μmol m⁻² s^-1, respectively, indicating a decline in the light requirement. Although the Z2 and Z4 larvae were found to develop faster at a light intensity of 195.31 μmol m⁻² s^-1 (P < 0.05), no significant differences were found among the treatments at the end of the experiment (P> 0.05). In conclusion, the results show that P. trituberculatus needs more lighting than other crab species, and the light requirement declines as the zoeal and megalopal larvae develop into young crabs.     

科学饮茶有利于青少年健康成长

本文针对青少年大量饮用碳酸饮料的现状,阐述了科学饮茶有利于青少年身体健康、修身养性、培养高尚的道德情操,提出了青少年如何科学合理饮茶、泡好茶,并希望茶产业推出更多适合青少年口味、绿色而又时尚的茶饮品。