Survey of large circular and octagonal tanks operated at Norwegian commercial smolt and post-smolt sites

A survey was conducted to determine the geometry, operating parameters, and other key features of large circular or octagonal culture tanks used to produce Atlantic salmon smolt and post-smolt at six major Norwegian Atlantic salmon production companies. A total of 55 large tanks were reported at seven land-based hatchery locations, i.e., averaging 7.9 (range of 4–12) large tanks per land-based site. In addition, one 21,000 m³ floating fiberglass tank in sea was reported. Culture volume ranged from 500 to 1300 m³ for each land-based tank. Most tanks were circular, but one site used octagonal tanks. Land-based tank diameters ranged from 14.5 to 20 m diameter, whereas the floating tank was 40 m diameter. Maximum tank depths ranged from 3.5 to 4.5 m at land-based facilities, which produced diameter-to-average-depth ratios of 3.6:1 to 5.5:1 m:m. The floating tank was much deeper at 20 m, with a diameter-to-average-depth ratio of only 2.4:1 m:m. All land-based tanks had floors sloping at 4.0–6.5% toward the tank center and various pipe configurations that penetrated the culture tank water volume at tank center. These pipes and sloping floors were used to reduce labor when removing dead fish and harvesting fish.Maximum flow ranged from 3 to 19 m³/min per land-based tank, with 400 m³/min at the floating tank, but tank flow was adjustable at most facilities. Land-based tanks were flushed at a mean hydraulic retention time (HRT) of 35–170 min. Maximum feed load on each land-based tank ranged from 525 to 850 kg/day, but the floating tank reached 3700 kg/day. Almost half of the large tanks reported in this survey were installed or renovated since 2013, including the three tank systems with the highest flow rate per tank (greater than 17.6 m³/min). These more recent tanks were operated at more rapid tank HRT’s, i.e., from 34.8 to 52.5 min, than the 67–170 min HRT typical of the large tanks built before 2013. In addition, flow per unit of feed load in land-based tanks that began operating before 2010 were lower (19–30 m³ flow/kg feed) than in tanks that began operating later (33–40 m³ flow/kg feed). In comparison, the floating tank operates at a maximum daily tank flow to feed load of 160 m³ flow/kg feed, which is the least intensive of all tanks surveyed. Survey results suggest that the recently built tanks have been designed to operate at a reduced metabolic loading per unit of flow, a tendency that would improve water quality throughout the culture tank, all else equal. This trend is possible due to the ever increasing application of water recirculating systems.     

深化图书馆改革是增强文化活力的重要基石———初论图书馆事业在新时期国家发展中的战略地位

建设社会主义文化强国，关键是增强全民族的文化活力。为增强文化活力，就要深化文化体制改革，解放和发展文化生产力，发扬学术民主，艺术民主，为人民提供广阔文化舞台，让一切文化创造源泉充分涌流。而全面深化图书馆改革就属于深化文化体制改革这一战略规划的重要组成部分．具有不容忽视的战略地位，它必将为增强中华民族的文化活力、建设文化强国做出自身应有的贡献。     

大球盖菇菌丝生长适宜氮源研究

研究了不同氮源对犬球盖菇菌丝生长的影响，结果表明大球盖菇菌丝生长最适氮源是尿素，其适宜浓度是0．026％；蛋白胨次之，其适宜浓度是0．1％；硫酸铵最差。大球盖菇菌丝生长对氮源浓度极敏感，低浓度氮促进菌丝生长，高浓度氮显著抑制菌丝生长。     

沙松造林技术的研究

对沙松造林技术的研究结果表明，最适宜沙松生长的条件是：造林密度为６６００株／ｈｍ＾２；山下部，阴坡半阴坡；整地方式为边整边造。     

不同Xenorhabdus spp菌株培养物游离氨基酸的含量分析

本文测定了在加入六个 Xenorhabdus luminescens 菌株和 X.nematophilus A24菌株后,一种豆粉鸡蛋线虫培养基游离氨基酸含量的变化.Xenorhabdus luminesces 菌株和 X.nematophilus A24菌株培养物中游离氨基酸的含量差别明显,后者未测出谷氨酸,苯丙氨酸极微;而这两种氨基酸在 X.luminescens 菌株中都占很大比例,Xenorhabdus luminescens不同的菌株培养物中游离氨基酸的含量变化很大,这可能反映出各菌株含氮代谢的差别.但这些变化与线虫对细菌的营养专化性未见直接的相关.     

菌根性食用菌栽培研究进展

对目前菌根性食用菌栽培研究的进展进行了综述。重点介绍了菌根性食用菌与共生植物的相互作用,几种主要菌根性食用菌的培养条件、接种方法和栽培方法,以及种植园管理技术的研究现状。     

黑杨派新无性系造林试验

用9个黑杨派新无性系在泰安市进行造林试验,其中I107,中林46,W1－13,I108等4个无性系的生长量较大,造林成活率较高。     

早熟禾品种耐寒变异植株无性系的建立

对草地早熟禾的小矮人品种耐寒变异植株无性系的建立进行了研究,并成功地诱导出小矮人嫩叶的愈伤组织,分化出丛生不定芽.诱导愈伤组织的理想培养基是MS BA 0.1mg/L 2,4-D 1 mg/L;由愈伤组织分化出苗的理想培养基是1/2 MS BA 0.1 mg/L 2,4-D 0.1 mg/L;试管苗极易移栽成活,耐寒变异性状保持不变.     

勺状亚侧耳菌丝培养特性的研究

研究了C源、N源、pH、温度和料水比及不同培养基对勺状亚侧耳(Hohenbuehelia petaloides)Hp.831菌丝生长的影响。试验结果表明,该菌丝生长的最适温度、pH、C源、N源和含水量分别为25～30℃、6～7、羧甲基纤维素钠、蛋白胨和60%～70%;马铃薯和松针的热水提取液可促进该菌菌丝生长;该菌菌丝在配方7培养料上长势最好,菌丝生长动态符合logistic方程:Y=109.6/(1 60.1131e-0.1894x)(y=菌丝生长长度mm,x=培养时间d)。     

牛肝菌胞外多糖发酵培养基的优化

以美味牛肝菌为研究对象,对其多糖发酵主要影响因子和发酵培养基优化进行研究.通过对单因子培养基优化处理试验结果的分析比较,选择出3个对牛肝菌多糖发酵影响较大的因子进行了正交试验,结果表明:美味牛肝菌最适培养基为20.0g葡萄糖 7.0g酵母粉 3.0g黄豆粉 1.0gKH2PO4 0.5g MgSO4·7H2O 0.5 gMnSO4·H2O.