Long-term variation in brown trout, Salmo trutta L., stocking success in a large lake: interplay between availability of suitable prey and size at release

Abstract –  Factors affecting long-term variation in brown trout, Salmo trutta L., stocking success were examined in a large lake, Lake Oulujärvi, in central Finland. Brown trout were stocked in spring (late May to early June) in 1974–1991 and in summer (late June to early July) in 1992–2001. The biomass of the vendace, Coregonus albula (L.), population (prey) at release time had the largest positive effect on stocking success within both periods: biomass of adult vendace in spring and both 0+ and adult vendace in summer. Increasing the size of stocked fish had a positive effect if the vendace available at release were only adults. The increasing trend of predator-catch-per-unit-effort (CPUE) [combined CPUE of northern pike Esox lucius L., burbot Lota lota (L.), and pike-perch Stizostedion lucioperca (L.)] through the study period and its negative effect on trout stocking success suggested an increasing effect of predation within the entire time series.     

供热发展的未来展望

本文分析了燃煤集中供热的优缺点,并对未来城市供热的发展趋势提出了一些独特看法。     

发芽糙米的开发及其技术运用

近年,由于日本人饮食习惯的急速的西方化,过去较少见的癌症、心脏病、糖尿病等疾病日益激增。以附加功能性于大米为目的,2001年开发出了采用浸泡式工艺的发芽糙米,发芽糙米所含GABA对高血压及糖尿病等生活习惯病具有预防效果。通过将富含发芽糙米的功能性成分之一的GABA附加于免淘洗米,开发出功能性免淘洗米(免淘洗GABA米)。利用功能性液化液,制成具有降压等作用的免淘洗功能性包膜米。同时,利用发芽糙米等为功能性原料可开发一系列深加工产品。     

Movements by wild brown trout in a boreal river: response to habitat and flow contrasts

Abstract  Radio transmitters were implanted in wild brown trout, Salmo trutta L., in the River Måna at low summer water flows ( n  = 18), higher flow in summer ( n  =   20), and variable, peaking flows in autumn ( n  =   20), and tracked two to four times day and night for 4–5 weeks. Individuals were caught and released in a 4-km uniformly channelised section, and in a 4-km natural diverse river section. Substantial individual variation in home range and total movement (924–85 818 m² and 295–7014 m) suggested flexibility to adapt to local environmental conditions. Fish were stationary most of the time (median movement 0 m), but some individuals undertook few and apparently sporadic longer movements, sometimes involving shifts in home range. No consistent diurnal pattern in movements was found. Trout in the uniform habitat section appeared to have larger home ranges and moved more than trout in the natural section. Differences were, however, not statistically significant in most comparisons, due to large individual variation. Similarly, larger home ranges and movements between trials related to higher flow were found, but differences were generally not significant. No consistent effects of sudden, extreme peaking flows on area use or movements by the brown trout were observed.     

海湾泥碱渣和粉煤灰作为园林种植基质的氮素生理类群及生化作用研究

海湾泥、碱渣和粉煤灰是天津滨海地区大量存在的固体废弃物,通过前期室内配比筛选、盆栽试验、田间试验表明其混合基质可以用于园林绿化,并在防护林建设中获得成功.以滨海盐土、客土绿地为对照,对通过脱盐、培肥、种植毛白杨、刺槐、洋白蜡、金银木、紫花苜蓿等园林植物后基质的氨化细菌、好气性自身固氮菌、硝化细菌、反硝化细菌、纤维素分解菌等土壤氮素生理类群的数量进行了研究,同时对呼吸作用、氨化作用强度以及二者与土壤微生物数量、理化性质进行了相关性分析.结果表明,基质的氮素生理类群数量高于或与客土绿地相当,明显高于滨海盐土.呼吸作用高于客土绿地和滨海盐土,氨化作用强度与客土绿地相当,说明混合基质的氮素转化、有机物质的矿化能力以及基质整体的代谢水平好于客土绿地.土壤呼吸作用强度与土壤盐分呈极显著负相关,与细菌数量呈显著正相关.氨化作用强度与全氮、全磷、有机质含量、细菌和真菌数量呈极显著正相关,与放线菌呈显著正相关,与速效钾、盐分呈显著负相关.     

复合高效配方药剂对甘蔗褐锈病防控效果评价

为了筛选防控甘蔗褐锈病的复合高效配方药剂及精准施药技术,选用代森锌、烯唑醇、代森锰锌、嘧菌脂、吡唑醚菌脂、苯甲嘧菌酯、百菌清、多菌灵进行田间药效试验.结果表明,(65％代森锌WP 1500 g+75％百菌清 WP 1500 g+磷酸二氢钾2400 g+增效剂300 mL)/hm2、(12.5％烯唑醇 WP 1500 g...     

野生稻与栽培稻的杂种后代对褐稻虱的抗性机制初探

为了开拓抗虫基因源,培育抗性稳定的水稻抗虫品种,采用感虫的栽培稻雄性不育株为母本,以高抗褐稻虱的野生稻为父本进行有性杂交。通过用改良的苗期群体筛选法,对其后代进行抗性鉴定,证实其抗性可以遗传,已成功地获得了抗褐稻虱的杂种后代。并根据飞虱在抗虫植株上的生存率、群体建立、蜜露量和稻株的受害级别等指标与感虫对照种TN1上的差异显著性作比较,综合评定杂种后代对褐稻虱的抗性机制。结果表明,测试的N482(A)/101392组合的F_5、F_6、F_7和H_4等几个后代对褐稻虱的抗性机制均为抗生性。     

不同地理种群灰飞虱生物学特性差异

为明确灰飞虱生物学特性的地理差异,对沈阳、济宁、郑州、南京和嘉兴5个地理种群灰飞虱的表观形态、发育历期、存活率、成虫寿命及生殖力等生物学特性进行了研究。结果表明,在25℃条件下,不同地理种群灰飞虱的雌雄比随纬度降低而增大,沈阳、济宁种群的体长显著长于其它种群个体,雌虫中长翅比率存在明显差异。若虫存活率差异显著,由低到高为:郑州济宁沈阳嘉兴南京。不同地理种群灰飞虱若虫期的发育起点温度均为11~12℃,差异不显著;沈阳和济宁种群的若虫发育历期和有效积温值均显著长于其它3个种群。不同温度下不同地理种群的成虫寿命差异显著,但均随温度升高而缩短。25℃条件下,不同地理种群单雌有效产卵量差异显著,由低到高为:嘉兴郑州济宁沈阳南京。     

催化热解调控热解产物的研究进展

综述了煤和生物质催化裂解技术对热解产物的影响作用,分析了不同催化剂对热解气体和煤焦油的催化效果,对热解产物催化裂解技术进行了分析,展望了未来煤催化裂解的研究重点。     

AN APPRONTMATE CALCULATING METHOD FOR WALL PLATES OF MAN'' S DRY GAS HOLDERS

The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision.