Studies on hollownesss regulation and properties of crosslinked hollow phenolic fibers

The hollowness of crosslinked hollow phenolic fibers was regulated successfully from 9 % to 80 % by adjusting the curing temperature of the partially crosslinked fibers. The partially crosslinked fibers was studied in detail by mass gained, tensile strength, solvent dissolution, SEM, IR, and TG analysis, and the prepared hollow phenolic fibers with different degrees of hollowness were characterized with SEM, tensile strength, TG-DSC and TG-MS. The results show that the factor determining the hollowness is the crosslinked extent of the partially crosslinked fibers and the hollow fibers with different degrees of hollowness have similar crosslinkage, mechanical properties and thermal stability.     

Efficiency of methods applied for goat estrous synchronization in subtropical monsoonal climate zone of Southwest China

Two experiments were undertaken to select the efficient method applied for goat estrous synchronization. In experiment 1, a total of 120 does (Capra hircus) were divided into five groups with a randomized block design, and the does of treatment 1 were synchronized by intravaginal sponges impregnated with 30 mg Levonorgestrel inserted for 10 days. Does of treatments 2, 3, and 4 were treated with further injection of 25 IU follicle-stimulating hormone (FSH), 0.05 mg prostaglandin F2 alpha (PGF_2α), and 25 IU FSH + 0.05 mg PGF_2α at sponge withdrawal, respectively. The does in the control group (n = 40) without estrous synchronization treatment and natural estrous does were observed. In experiment 2, a total of 140 does in five goat farms in breeding and non-breeding seasons were treated with the selective efficient procedure. The results presented that all the employed treatments were capable of inducing and synchronizing estrous goats. According to estrous response and economy, the use of intravaginal sponges impregnated with 30 mg Levonorgestrel and 0.05 mg PGF_2α (treatment 3) is the first choice for estrous synchronization, and 95.0% of synchronized does demonstrated estrus, which was significantly higher than that of treatment 1 (P < 0.05) and control group (P < 0.01). The percentages of ovulating of treatments 3 and 4 were the same (95.0%), which were significantly higher than that of treatment 1 (P < 0.01). The ovulation rates among different groups were not significant (P > 0.05). When the selective procedure was applied to five goat farms, 85.7% (120/140) of does demonstrated estrus, and the kidding percentage, litter size, and prolificacy rate were 53.6%, 0.95, and 177%, respectively.     

Effects of additive iron on growth,tissue distribution,haematology and immunology of gilthead sea bream, <Emphasis Type="Italic">Sparus aurata</Emphasis>

The comparative effects of iron-supplemented levels on growth, tissue distribution, haematology and immunology of gilthead sea bream, Sparus aurata (2 g) were investigated, using four organic (50, 100, 200, 300 mg ORG/kg diet) and one inorganic iron source (200 INOR mg/kg diet). Fish were treated for 12 weeks with the experimental diets and maintained at a water temperature of 19–22°C. Growth (final weight and specific growth rate), tissue distribution (spleen, liver and muscle), haematological parameters (red blood cells, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration) and non-specific immune indexes (respiratory burst activity and antibacterial activity of serum) were analysed. No significant differences were found in growth and iron tissue distribution among the tested groups. Red blood cell counting was statistically higher in fish given 50 ORG, 100 ORG, 200 ORG and 200 INOR feeds. However, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration were not significantly affected by increasing dietary iron. Fish receiving the 100 ORG diet had the best performance with respect to the respiratory burst activity and significantly higher values for antibacterial activity of serum were obtained in fish fed with the 300 ORG diet. The present findings provided no clear evidence of the optimum iron concentration. However, there was adequate indication that iron supplementation enhanced the performance of gilthead sea bream, mainly from a haematological and immunological point of view.     

加强木材销售提高森工经济效益的对策研究

本文从正的、反两个方面分析了当前木材销售工作的市场形式。提出了加强木材销售,提高森工经济效益的对策     

小麦品种对麦红吸浆虫抗性的研究

种植抗虫品种是防治麦红吸浆虫的经济有效措施,研究小麦品种抗虫性是抗虫育种的重要基础。在50、60年代,国内对此进行了一些研究,但随着吸浆虫为害的逐步控制,此项研究也随之中断。近几年,吸浆虫的发生为害又有回升。为此,作者在前人工作的基础上,作了进一步的研究。     

青海高原有蹄类的分布特征

青海高原北接蒙新荒漠、南邻西南山地、东连黄土高原。平均海拔在4000米以上。低温、强风、空气稀薄、光辐射强、地势险峻、冬季严寒、夏季凉爽为其自然特征。受东南季风尾闾的影响,降水量由东向西递减,植被分布呈东西走向,依次为寒温性针叶林——温性草原——荒漠,显示出明显的东西向演替现象。受其影响,有蹄类动物的分布亦呈现相应的规律。     

杀虫剂对硃砂叶螨某些生物学特性的影响

溴氰菊酯、氧化乐果、杀虫脒和三氯杀螨醇对硃砂叶螨连续选择3代后,该螨对这些药剂的敏感度分别降低了6.23、1.16、1.23和2.24倍。而4种药剂12个轮换用药组合的敏感度则有不同程度的提高。组建雌性生命表表明,4种药剂对各螨态历期均有不同程度的缩短,Ro、γm、λ各值以溴氰菊酯最高,分别为23.191、0.213、1.139;氧化乐果LC₅₀处理组各数值亦略高于对照组,分别为21.548、0.204、1.226;杀虫脒、三氯杀螨醇处理组各数值略低于对照组。田间试验证实,连续用药3次的三氯杀螨醇、杀虫脒和氧化乐果的较高浓度处理区均能大大降低螨群数量,而溴氰菊酯处理区的螨群数量比对照区高出6.39和8.77倍,认为溴氢菊酯对叶螨的毒性低、刺激增殖、驱使分散和杀伤灭敌而诱使叶螨发生再猖獗。     

向日葵细菌性茎腐病的研究Ⅰ.症状及病原菌鉴定

 本文首次报道了向日葵细菌性茎腐病在我国的发生。对分离到的20个菌株经形态学特性、培养性状、生理生化和血清学反应测定,确定引起我国东北地区向日葵细菌性茎腐病的病原细菌有三种,即Erwinia carotovora subsp.carotovora Dye,E.carotovora subsp.atroseptica Dye和Pseudomonas caryophylli (Burkholder) Starr and Burkholder。