金钱松雌球花的形态构造及大孢子和雌配子体的形成

金钱松雌球花着生于树冠上部5a以上短枝顶端。成熟雌球花中央为1球花轴,其上螺旋着生苞鳞和珠鳞,珠鳞上着生2倒生胚珠,胚珠单珠被,珠心喙较厚,珠被唇顶部和内侧壁表皮为乳头状细胞,珠被中具溶生树脂道,珠被和珠鳞表皮下数层细胞将发育成种子的种翅和硬壳。花芽中胚珠原基出现至雌配子体卵细胞形成需5个月。1月胚珠原基出现。3月形成大孢子母细胞期的幼胚珠。3月下旬～4月上旬大孢子母细胞减数分裂形成大孢子。4月中旬雌球花迅速增长为胚乳游离核期。5月胚乳细胞壁形成,颈卵器原始细胞出现并发育为颈细胞、腹沟细胞和卵细胞,雌配子体成熟。     

三唑类杀菌剂金环唑构效关系的研究

金环唑属三唑类杀菌剂 ,其同系物包括戊环唑、甲环唑、乙环唑、丙环唑和醚唑。除戊环唑外 ,这类化合物的分子既有顺、反异构 ,又有旋光异构。综合报道了金环唑同系物之间及其分子立体异构体之间的构效关系 ,介绍了金环唑顺、反异构体与立体异构体的制备方法 ,同时研究了丙环唑及其硝酸盐对 6种病原真菌的毒力以及 2 5 %乙环唑弥散剂、 2 5 %金环唑复合弥散剂的配制与药效     

金钱松小卷蛾生物学特性的研究

金钱松小卷蛾危害金钱松,在湖南省和浙江省莫干山1年1代,以卵越冬,以幼虫缀叶危害。4月上旬幼虫孵化,5月中旬化蛹,5月下旬至6月上旬为羽化期,有较强趋光性。雌雄性比3.5～4.0:1.0.     

Acute tolerance of juvenile Florida pompano, Trachinotus carolinus L., to ammonia and nitrite at various salinities

The acute tolerance of juvenile Florida pompano Trachinotus carolinus L. (mean weight±SE=8.1±0.5 g) to environmental unionized ammonia‐nitrogen (NH₃‐N) and nitrite‐nitrogen (NO₂‐N) at various salinities was determined via a series of static exposure trials. Median‐lethal concentrations (LC₅₀ values) of NH₃‐N and NO₂‐N at 24, 48, and 96 h of exposure were calculated at salinities of 6.3, 12.5 and 25.0 g L^?1 at 28 °C (pH=8.23–8.36). Tolerance of pompano to acute NH₃‐N exposure was not affected by salinity, with 24, 48 and 96 h LC₅₀ values ranging from 1.05 to 1.12, 1.00 to 1.08 and 0.95 to 1.01 mg NH₃‐N L^?1 respectively. Regarding NO₂‐N, tolerance of pompano to this environmental toxicant was compromised at reduced salinities. Median‐lethal concentrations of NO₂‐N to pompano at 24, 48 and 96 h of exposure ranged from 67.4 to 220.1, 56.9 to 140.7 and 16.7 to 34.2 mg NO₂‐N L^?1 respectively. The results of this study indicate that juvenile Florida pompano are relatively sensitive to acute NH₃‐N and NO₂‐N exposure, and in the case of the latter, especially at lower salinities.     

闽浙近海金色小沙丁鱼种群的初步研究

通过对闽南—台湾浅滩渔场,浙江近海渔场金色小沙丁鱼形态计数性状,量度性状特征差异的比较,并结合生物学、产卵场、洄游以及海洋环境条件等综合分析,研究结果表明闽浙近海的金色小沙丁鱼群体分别属于闽南—台湾浅滩地方种群和东海地方种群。本章还讨论了两个海域金色小沙丁鱼的分布。     

基于改进的ISODATA算法的大样本数据聚类方法研究

针对数量大、数据结构复杂、离散度大的样本数据的聚类分析,采用ISODATA算法实现.ISODATA算法是1种基于统计模式识别的非监督学习动态聚类方法,是大样本数据聚类分析常用的方法,但该算法需要预先确定初始聚类参数.本文提出了基于黄金分割法来度量聚类的有效性,该方法能动态计算聚类度量参数,以此实现大样本数据的有效聚类.实验证明:该方法能够合理、有效的进行数据聚类.     

Effect of conspecific and heterospecific urine odors on the foraging behavior of the golden spiny mouse

The common spiny mouse (Acomys cahirinus) inhibits the foraging activity of the golden spiny mouse (A. russatus). These two sympatric species of spiny mice, which are considered habitat competitors, occur in extreme arid environments. To test this theory of competition, the influence of urinary odors of both conspecific and heterospecific mice on the foraging behavior of A. russatus was studied under controlled laboratory conditions. Twenty adult males, born in captivity and unfamiliar to the odors of the donor mice, were tested in 3 experimental conditions choosing between 2 seed patches that were scented with urine of either heterospecifics (A. cahirinus), conspecifics (A. russatus) or controls (odors of the tested individual). Of the 20 males, 12 were also tested with urine of unfamiliar gerbils, bushy‐tailed jird, considered as competitors in the field. Both conspecific and heterospecific urine samples from Acomys significantly reduced foraging behavior of A. russatus when compared to the control odor. The inhibitory effect of the Acomys urine does not result from the novelty of chemical stimuli of the urine because no effect was shown with unfamiliar gerbil urine. The findings are in accordance with the general theory that A. cahirinus dominates the foraging activity of A. russatus. We hypothesize that chemical cues in the urine of Acomys spp. might induce a negative effect on the foraging behavior of A. russatus.     

16种植物对福寿螺的趋避效果研究

于实验室内通过自制的八边形分室趋避试验装置观察研究了16种植物对福寿螺(Ampullaria gigas Spix)的趋避效果。结果表明:福寿螺具有沿壁爬行的偏好性,沿壁爬行的福寿螺数量平均为非沿壁爬行福寿螺数的3.77倍。同时发现,在所选的16种植物中,白千层(Melaleuca leucadendra L.)、扶桑(Hibiscus rosa-sinensis L.)2种植物对福寿螺有较大的吸引作用;金叶假连翘(Duranta repens cv.Dwarf Yellow)、木麻黄(Casuarina equisetifolia L.)、红龙草(Alternanthera dentata cv.Ruliginosa)、鸭脚木〔Schefflera octophylla(Lour.)Harms〕、剑麻(Agave Sisalana Perrine)5种植物对福寿螺有一定的驱赶作用。     

Effect of replacing fish meal with soybean meal and of DL‐methionine or lysine supplementation in pelleted diets on growth and nutrient utilization of juvenile golden pompano (Trachinotus ovatus)

The experiment was conducted to determine the effect of dietary DL‐methionine addition in fish meal reduction diet for juvenile golden pompano (Trachinotus ovatus). The trial comprises the following of 11 diet treatments. (i) D1 diet as the standard was formulated with fish meal as the main protein source. (ii) D2–D5 diets were formulated to replace fish meal with soybean meal at 60, 120, 180 and 300 g kg^?1, respectively, and the amino acid profiles (including methionine and lysine) of D2–D5 were referred to the amino acid profile of D1. (iii) D6‐D9 diets were the same as D2–D5, respectively, but without methionine supplementation. (iv) D10 and D11 diets were the same as D3 and D5 diets, respectively, but without lysine supplementation. Each diet was randomly fed to groups of 20 fish (initial average weight about 18 g) per net cage (1.0 × 1.0 × 1.5 m) in triplicate and the feeding experiment lasted for 56 days. Weight gain (WG, %) and final body weight (FBW, g) of fish fed D3 diet were significantly higher than those of fish fed D8 and D9 diets (P < 0.05), but without significant differences with fish fed other diets (P > 0.05). Feed conversion ratio (FCR) of D3, D4 and D5 diet treatments were significantly lower than that of D11 diet treatment (P < 0.05), but without significant difference with other diet treatments (P > 0.05). Whole‐body protein contents of fish fed D3–D5 were significantly higher than those of fish fed D7–D9 (P < 0.05), but without significant differences with fish fed other diets (P > 0.05). In conclusion, the replacement of fish meal by soybean meal could reach 300 g kg^?1 without detrimental but profitable effect on growth and survival when enough methionine and lysine were supplemented in the diet; moreover, lysine is not the first‐limiting amino acid relative to methionine for juvenile T. ovatus from the present growth and proximate composition results.