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1.
初步研究了气液双升式动物细胞反应器微载体培养 Bowes细胞和悬浮培养 M4G3杂交瘤细胞的生长条件 ,在不加入消泡剂和保护剂的情况下 ,批式培养 Bowes细胞的最大密度为 2 .6×1 0 6/ml,批式培养 M4G3细胞的最大密度为 1 .5× 1 0 6/ml。基于细胞生长的密度效应 ,建立了动物细胞生长动力学模型 :   μ=0   t相似文献   

2.
基于杉木胸径生长方程D=Dmt((K+t)本文进一步提高林分断面积的动态方程:G=Gm「t/(K+T)^2」,新方程表达形式简单,基本参数生物意义确切,应用精确度高,能够反映杉木林分断面积随林分年龄增长的变化规律。  相似文献   

3.
基于杉木胸径( D)生长方程 D= Dm t/( K+ t),本文进一步提出林分断面积( G)的动态方程: G= Gm [t/( K+ t)]2 .新方程表达形式简单,基本参数(断面积极值 Gm 和生长特征系数 K)生物意义确切,应用精确度高,能够反映杉木林分断面积随林分年龄增长的变化规律  相似文献   

4.
2012年7月和2013年6月从大渡河支流脚木足河采集黄石爬(鱼兆)(Euchiloglanis kishinouyei)383尾,以脊椎骨作为主要年龄鉴定材料,对其年龄结构和生长特性进行了研究.黄石爬(鱼兆)体长92~190 mm,其中110 ~ 140mm个体占渔获物总量的74.41%;体重14.70 ~ 119.80 g,其中20~60 g个体占渔获物总量的84.86%;由3~ 13龄11个年龄组组成,5~8龄鱼占渔获物总量的84.07%;种群雌雄性比为1∶1.06.体长(L)与脊椎骨半径(Ro)回归方程为L=67.038+ 50.783Ro(n=325,R2=0.758,P< 0.01).雌雄个体体长和体重生长无显著差异,据体长(L,单位mm)与体重(W,单位g)关系式W=3×10-5L2.9279(n=383,R2=0.807 1,P<0.01),黄石爬(鱼兆)为等速生长类型.据体长、体重生长方程Lt=208.42[1-e-0.089(t+1.20)]、Wt=184.82[1-e-0.089(t+1.20)]2.9279,体长和体重生长速度方程分别为dL/dt=18.549 4 e0089(t+ 1.20)和dW/dt=48.161 0 e-0.089(t+1.20)[1-e-0.089(t+ 1.20)] 1.9279,体长和体重生长加速度方程分别为d2L/dt2=-1.650 9 e-0.089(t+1.20)和d2W/dt2=4.286 3 e-0.089(t+1.20)[1-e-0.089(t+1.20)]0.9279[2.927 9 e-0.089(t+1.20)-1],黄石爬(鱼兆)属于生长缓慢,生命周期较长的鱼类.生长拐点年龄为10.87,落后于性成熟年龄(♀6龄,♂5龄),属于性成熟后生长仍然较快的类型.产卵群体主要以补充群体(5、6龄)和低龄剩余群体(7、8龄)为主,资源已经受到严重破坏,需加大保护力度.  相似文献   

5.
养殖美洲鲥的生长特性   总被引:8,自引:0,他引:8  
通过对各周年生长阶段的养殖美洲鲥(Alosa sapidissima)体长、体重的测量与分析,研究了工厂化养殖美洲鲥的周年生长特性。养殖美洲鲥雌雄鱼的体长与体重关系均呈幂函数增长相关,其方程分别为,雌:W=0.8062×10~(-5) L~(3.1113)(n=122,R~2=0.997 5,P0.01);雄:W=1.0047×10~(-5) L~(3.0574)(n=125,R~2=0.997 5,P0.01),b均接近于3,呈等速生长;雌雄鱼生长均可分快速生长期(0~+龄)、稳定生长期(1~+龄)、生长衰老期(2~+龄)三个时期,雌鱼生长快于雄鱼。拟合出von Bertallanffy生长方程,雌:Lt=467.92(1﹣e~(-0.5748(t+0.1710))),Wt=1637.72(1﹣e~(-0.5748(t+0.1710)))~(3.1113);雄:Lt=389.21(1﹣e~(-0.7374(t+0.1975))),Wt=834.08(1﹣e~(-0.7374(t+0.7189)))~(3.0574)。雌雄鱼体重生长拐点分别位于1.517 8 a和1.224 7 a,属性成熟拐点,拐点前生长较快;拐点后,特别是性成熟后(2龄),2~+龄鱼的生长速度明显降低;同时,2龄鱼繁殖季节过后会出现大量死亡。建议商业化工厂化养殖美洲鲥以2龄前上市为宜。  相似文献   

6.
用Logistic方程[y=K/(1+eA+Bt)]来表示切花月季花枝生长量与生长时间的关系,并得出花枝生长最快的时期是现蕾期。以100 mg/L GA3溶液喷施生长期花枝,可改变其原有生长规律,快速生长期延长,生长速度明显加快,从而使其长度比对照增加22.5%~63.1%,其中以现蕾时处理效果最优。  相似文献   

7.
本文报道闽南—台湾浅滩渔场羽鳃鲐的生长特性和死亡参数,并讨论了捕捞规格问题。其纯体重 W 和总体重 W’与叉长的相关式分别为 W=2.5687×10~(-7)L~(3.7545),W’=1.003×10~(-6)L~(3.5140);叉长生长方程 L_t=346.5[1-e~(-0.2209(t+1.2263))]~(0.5700),体重生长方程 W_t=881.1[1-e~(-0.2209(t+1.2263))]~(2.1399);1988—1989年种群存活率为0.2808,瞬时总死亡率为1.2600,瞬时自然死亡率和瞬时捕捞死亡率分别为0.5863和0.6738;最佳最小捕捞叉长为170.3mm,最佳最小捕捞纯体重和总体重分别为63.9g 和71.0g.  相似文献   

8.
2010年4~11月,在沱江的资中-隆昌段采集宽体华鳅(Sinibotia reevesae)573尾,研究了其年龄结构和生长特性。结果表明,微耳石厚度适中,易于磨片,且磨片后轮纹清晰,能准确反映宽体华鳅的年龄情况。收集到的沱江宽体华鳅体长主要分布在80~100 mm,占总数的67.54%;体重主要分布在8~20 g,占总数的69.11%;年龄由2~6龄组成,以3~4龄为主,占85.91%;种群雌雄性比为1︰1.11。体长(L,单位mm)和体重(W,单位g)关系,雌雄群体间无明显差异(P0.05),其表达式为W=5×10﹣6L3.286 8(n=573,R2=0.820 2),为近等速生长类型。von Bertalanffy生长方程为Lt=128.72[1﹣e﹣0.197 4(t+1.66)]和Wt=42.95[1﹣e﹣0.197 4(t+1.66)]3.286 8。体长生长速度和加速度方程为d L/dt=25.413 3 e﹣0.197 4(t+1.66)和d2L/dt 2=﹣5.015 8 e﹣0.197 4(t+1.66),体重生长速度和加速度方程为d W/dt=27.866 6 e﹣0.197 4(t+1.66)[1﹣e﹣0.197 4(t+1.66)]2.286 8和d2W/dt2=5.500 9 e﹣0.197 4(t+1.66)[1﹣e﹣0.197 4(t+1.66)]1.286 8×[3.286 8 e﹣0.197 4(t+1.66)﹣1]。生长拐点年龄为4.37,此时的体长和体重分别为89.46 mm和12.99 g。分析显示,沱江资中-隆昌段宽体华鳅自然种群资源未遭到严重破坏,但合理开发水电资源和选择合适的渔具、渔法是进行其资源保护的最有效措施。  相似文献   

9.
以杉木林为研究对象,在12个县市选取浙江省2009年CFI体系的95个杉木林样地,根据样地平均木,在样地外围相似地段确定解析木共计95株,联立树高曲线方程和生物量模型,同时使用已公开发表的20个杉木生物量模型进行估算,由单株累加获得CFI系统样地的生物量,计算样地生物量与蓄积之比即BEF,建立BEF与林分蓄积之间的关系.根据2009年浙江省CFI体系数据,推算全省杉木林BEF为0.7453t/m3,杉木林总生物量为3721.54万t,不确定性为5.739%;使用IPCC(1996)的碳密度缺省值(0.50)计,生长1 m3杉木吸收CO2 1.3663 t.  相似文献   

10.
巨须裂腹鱼年龄与生长的初步研究   总被引:2,自引:0,他引:2  
巨须裂腹鱼(Schizothorax macropogon)是雅鲁藏布江的重要经济鱼类.作者利用2004~2006年在雅鲁藏布江水系收集的293尾样本,以背鳍条磨片作为主要鉴定年龄的材料,对西藏雅鲁藏布江巨须裂腹鱼种群进行了年龄结构和生长特性的研究.结果表明,巨须裂腹鱼的雅鲁藏布江种群由2~14龄和16龄共14个龄组组成.其中优势龄组为4~6龄(占74.85%).群体总性比为(♀:♂)=1:0.881.体长与体重的关系方程分别为:W♀=0.023L2.904(♀),W♂=0.018L2.962(♂),属于匀速生长类型.用von aertalanffy方程描述的生长方程分别为♀:Lt=65.676[1-e-0.053(t+3.305],Wt=4520.633[1-e-0.053(t+30305)]2.904;♂:Lt=49.622[1-e-0.074(t+4.017)],Wt=2034.481[1-e-0.074(t+4.017)]2.962.雌、雄个体生长的拐点年龄分别为16.6龄和10.7龄,对应的体长及体重分别为43.06 cm、1326.75 g(♀)和32.86 cm、600.31 g(♂).  相似文献   

11.
森林景观是森林公园的主体,是森林公园开展生态旅游的物质基础.本文将森林公园的森林景观划分为三大功能:美化功能、生态功能和保健功能,并总结了三大功能的评价方法,最后提出相关建议.认为对森林景观的三大功能进行综合评价,能更合理地利用森林公园资源,有利于森林公园的生态旅游开发和可持续发展.  相似文献   

12.
Forest alliance     
  相似文献   

13.
路南石林     
云南省的路南石林,是以岩柱高大雄伟、姿态多娇、分布广阔而闻名世界的喀斯特地貌,为我国首批公布的国家重点风景名胜区和国家地质公园。 石林,因成千上万根的石灰岩岩柱拔地而生得名,号称天下第一奇观,它们当中那些拟人拟物的形象更是千姿百态、栩栩如生,当地的撒尼族人民就曾流传很多的民间故事,差不多每块石头都有一段神话般的传说。然而,人们已经不满足于这些神话传说了,常常刨根问底,想知道大自然是如何锻造出这样的奇观。  相似文献   

14.
15.
Forest canopies     
《Plant Ecology》1996,127(2):225-225
  相似文献   

16.
17.
The Forest Health Monitoring (FHM) and Forest Inventory and Analyses (FIA) programs are integrated biological monitoring systems that use nationally standardized methods to evaluate and report on the health and sustainability of forest ecosystems in the United States. Many of the anticipated changes in forest ecosystems from climate change were also issues addressed in sections of FHM's National Technical Report 1991 to 1998. The integrated FHM and FIA monitoring systems are currently establishing baseline conditions (status and change) in most States for many of the expected effects, and are projected to have full implementation for all States and Territories in 2003. These monitoring systems utilize a broad suite of indicators of key ecosystem components and processes that are responsive to many biotic and abiotic stressors, including those anticipated from climate change. These programs will contribute essential information for many decades for many of the anticipated changes in forest ecosystem from increasing carbon dioxide concentrations, changing climatic scenarios, and extreme weather events that are probable in the next 30 to 100 years.  相似文献   

18.
Forest Rehabilitation and Its Implication for Forest Transition Theory   总被引:1,自引:0,他引:1  
Forest transition theory bases its predictions of forest recovery in temperate regions primarily on macro-economic factors. In tropical countries, it is important to understand additional complex processes underlying forest recovery. Forest rehabilitation—meaning efforts to restore tree cover—is an important contributor to forest recovery in many tropical regions. Forest rehabilitation itself is subject to multiple factors that influence its scale, effectiveness and outcomes. This paper reviews forest rehabilitation in six countries—Brazil, China, Indonesia, Peru, Philippines and Vietnam. The cases reviewed suggest that globally, forest rehabilitation efforts can be understood in four time periods, or eras, each with distinct approaches to forest rehabilitation and outcomes. Various factors that influence forest rehabilitation outcomes evolved during these eras. Current outcomes of forest rehabilitation can only be adequately predicted if the historical processes influencing forest rehabilitation are understood. The paper suggests that forest transition in the tropics needs to be analyzed not only in terms of macro-economic factors, but also in terms of the factors that influence forest rehabilitation outcomes as well as other processes that affect forest cover increase.  相似文献   

19.
温带次生林破碎化对白眉姬鹟繁殖的影响   总被引:1,自引:0,他引:1  
曹长雷  高玮 《四川动物》2008,27(2):183-188
于2005~2006年鸟类繁殖季节,通过悬挂人工巢箱,探讨了次生林破碎化对白眉姬鹟Ficedula zanthopygia繁殖的影响.结果 表明:次生林破碎化对白眉姬鹟繁殖产生很大的影响,斑块面积、形状指数、隔离度均在不同程度上影响着白眉姬鹟的繁殖参数,破碎化指数不同的斑块间白眉姬鹟的窝卵数、孵化率和出飞率差异均不显著(P>0.05);卵重变异很大,差异显著(P<0.05);卵体积变动更大,差异达到极显著水平(P<0.01).回归分析表明,斑块破碎化指数与白眉姬鹟繁殖参数间均存在一元二次方程关系:当窝卵数达到最大值时,卵质量降低,出雏率达到最低,雏鸟存活率反而增大,出飞率达到最大,从而提高繁殖功效;当窝卵数达到最小值时,卵质量最高,出雏率增大,出飞率也相应的增高,从而使繁殖功效增大.白眉姬鹟存在一个最优窝卵数,验证了Lack的窝卵数假说.另外,白眉姬鹟通过对自身繁殖参数的调节来适应生境破碎化,尽量提高自身的繁殖功效,从而弥补自身种群.  相似文献   

20.
The quantity of litter-fall and the standing crop of H sublayer in the forest floor of evergreen broad-leaved forest were higher than that of Pinus yunnanensis forest. The quantity of the forest floor changed with the quantity of litter-fall, and thera was a dynamic equilibrium between the litter-fall and forest floor. The content of nutrient elements of the forest floor was higher than that of litter-fall in both types. The order of nutrient element content in the forest floor differed from that in litter-fall. In the evergreen broad-leaved forest, the order was N > Ca > Si>K>Mg>Al>P>Fe>Mn>Zn>Cu,and in Pinus yunnanensis forest it was Ca>N>Si>K>Al>Mg >Fe>P>Mn>Zn>Cu. But the order of nutrient element content in the forest floor had changed: in evergreen broad-leaved forest it was Si > N > Al > Ca > Fe > K>Mg>P>Mn>Zn>Cu, the Pinus yunnanensis forest it was Si > AI>N>Ca>Fe>K>M>P>Mn>Zn>Cu. With increase in the intensity of litter decomposition Ash, Si and Al had obviously increased, N, Fe, P and K had also increased in varying degrees, but there was some reduction in Ca, Zn and Mg. The ratio of carbon and nitrogen in litter decreased' with increase in litter decomposition.  相似文献   

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