首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 593 毫秒
1.
采用实验研究和模型拟合的方法对HAU-M1光合产氢混合菌种的生长规律进行研究,得到混合菌种的生长周期具有非线性的规律且12~72 h菌种增长迅速.Logistic、Gompertz和Bertalanffy模型拟合HAU-M1光合产氢混合菌种的生长曲线,Logistic模型的拟合度最高为0.979 7,其次是Gompertz模型,且各模型拟合的拐点时龄均在HAU-M1的对数生长期,而拐点干质量以Logistic模型最高,为0.228 8 mg/m L,模型拟合值与实验测试值接近.Logistic模型和Gompertz模型可以较好地用于HAU-M1光合菌种生长规律的预测和分析,为保存、改良和开发利用混合菌种进行光合产氢提供可靠的科学依据.  相似文献   

2.
美姑山羊体尺体重相关分析及生长曲线模型拟合   总被引:1,自引:0,他引:1  
根据四川省凉山彝族自治州美姑县三岗种羊场的382只美姑山羊出生后各月龄的体重及体尺记载资料,采用SPSS19.0对公、母羊主要生长性状进行了显著性比较和相关性分析,对Gompertz、Bertalanffy和Logistic 3种生长拟合模型的体重增长曲线拟合度进行了比较分析,对美姑山羊生长曲线选择了较为适宜的拟合方程,旨在为合理利用美姑山羊种质资源和选种繁育提供依据。结果表明:(1)美姑山羊公羊3月龄体重、6月龄体重、8月龄体重、周岁体重都极显著高于母羊同时期体重;性别对山羊体重的影响很大。(2)相关性分析结果表明,在控制变量体高和体长,体重与胸围具有显著性差异;而控制体高和胸围或控制体长和胸围后,体重与体长或体高差异均不显著。R2为0.977,所以体重可以用胸围通过方程表示,回归方程:Y=1.114x-48.174,其中Y为体重(kg);x代表胸围(cm)。真实值与预测值差异在3.564 kg之内。(3)选用Gompertz、Bertalanffy和Logistic等3种非线性生长模型分别对美姑山羊公羊母羊生长进行拟合,公羊生长曲线最佳模型选择Logistic:W=53.94×(1+2.74e-0.106t)-1;母羊生长曲线最佳模型选择Gompertz:W=50.15×e~(-1.44exp(-0.023t))。  相似文献   

3.
南方拟生长模型研究   总被引:2,自引:1,他引:1  
2008年4月,在北江流域采集了187尾南方拟标本,采用鳞片作为年龄鉴定材料,对其生长模型进行了研究.鳞片上年轮主要为2种,疏密型和切割型年轮.鳞片的鳞径(R)与体长(L)的关系为L=3.7262R+1.4915,体长(L)与体质量(W)的关系为W=0.0318L2.7081.运用Von Bertalanfy生长模型(VBGF)、Logistic生长模型(LGF)、Gompertz生长模型(GGF)等3种生长模型拟合了南方拟的体长和体质量生长,根据各模型拟合残差平方和的大小,判断拟合效果.结果表明,Logistic生长模型对南方拟生长的拟合效果最好,其次是Gompertz生长模型,而Von Bertalanfy生长模型拟合的效果最差.另外,不同生长模型拟合的渐近体长是L∞(VBGF)L∞(GGF)L∞(LGF).  相似文献   

4.
为研究蚯蚓处理有机固体废弃物(污泥)的生长发育规律,本实验以35±2日龄的赤子爱胜蚓作为实验材料,利用污泥饲养,对7 d、14 d、21 d、28 d、35 d、42 d、49 d的体重和繁殖性状进行测定,得到了赤子爱胜蚓生长的相关参数,分析其生长速度,结果表明幼蚓在接种初期0-14 d生长较快,日增重大,性成熟即接种21 d以后,生长速度变得缓慢,生长中期即接种28~42 d蚯蚓生长平稳,末期生长速度缓慢.通过比较拟合度(R~2)发现MMF、Gompertz和Logistic等几种曲线模型拟合度达到0.94以上,其中Gompertz模型的拟合结果更接近实际测量值,拟合效果最佳.赤子爱胜蚓的Gompertz模拟方程为:Wt=0.3507e~(-0.2096e-0.1192t).  相似文献   

5.
为预测凝固型酸奶中金黄色葡萄球菌的生长情况,将金黄色葡萄球菌接种到凝固型酸奶中,应用Gompertz模型、Logistic模型、Richards模型等模型对10℃、25℃、42℃下金黄色葡萄球菌的生长数据进行拟合,构建了凝固型酸奶中金黄色葡萄球菌预测模型。通过残差和拟合度等统计指标考察了4种模型的拟合能力,通过比较分析4种模型对凝固型酸奶中金黄色葡萄球菌生长数据的拟合情况,建立了不同温度下凝固型酸奶中金黄色葡萄球菌的一级生长预测模型。结果表明:10℃条件下Logistic模型拟合出最小的RSS、RSE、AIC值,而Gompertz模型在25℃和42℃条件下拟合出最小的RSS、RSE、AIC值。凝固型酸奶中金黄色葡萄球菌最适生长模型分别为:10℃为Logistic模型,25℃、42℃适合采用Gompertz模型。  相似文献   

6.
对安塔红鸡和新罗曼鸡正、反交后代生长曲线进行了分析和非线性曲线拟合研究.结果表明,两种后代在30日龄前生长曲线基本一致,之后正交后代生长曲线明显高于反交后代,且保持较长时间的快速生长状态.Logistic模型和Gompertz模型能很好地拟合正交后代的生长曲线(分别为0.9950和0.9970) 和反交后代的生长曲线(分别为0.9932 和0.9942),但Gompertz模型在拟合度和预测体重效果方面相对较好.拟合曲线模型中参数A代表极限体重,正交后代明显高于反交后代,其它参数接近或略有差异.  相似文献   

7.
武自宪 《甘肃科技》2010,26(10):149-152
为研究罗斯308肉鸡生长规律,测定和收集了会宁县家禽良种场鸡场饲养的罗斯308肉鸡1~6周龄的体重数据,分别应用Logistic、Gompertz、Richard模型拟合其生长规律。结果表明,3种模型R2和SE分别为:Logistic,0.997494571和53.6106531;Gompertz模型,0.998792045和37.2244479;Richards,0.998638663和48.3966658。3种模型估计的拐点日龄、拐点体重、极限体重和最大日增重分别为:Gompertz模型,34.29d、1722.0576g、4681.0241g和76.87g;Richard模型,分别为32.94d、1623.21g、4081.9379g和78.57g;Logistic模型,31.31d、1504.76g、3009.5106g和82.00g。Gompertz和Richards模型都比较适宜模拟罗斯308肉鸡的生长模式,Gompertz模型模拟效果最佳。  相似文献   

8.
不同性别的川南山地黄牛生长曲线分析   总被引:1,自引:0,他引:1  
试验测定了三峡库区不同性别的川南山地黄牛的体尺体质量,运用Logistic、Gompertz和Brody模型进行了生长曲线分析.结果表明:公牛各月龄的体尺体质量均高于母牛,3种模型都能很好地拟合公、母牛的体尺体质量生长曲线,除公牛的体直长用Gompertz模型、母牛的体高用Logistic模型拟合较好外,其余公、母牛的体尺体质量用Brody模型拟合较好.公牛的体高生长速度一直高于母牛;而体直长、胸围、管围、体质量在前期母牛快于公牛,而后期公牛更快.生长强度最高的为体质量,其次是胸围、体直长、最后是体高.公、母牛早期生长强度明显高于后期.  相似文献   

9.
以0~8月龄甘肃仔马鹿为研究对象,对其体重和体尺的变化进行了分析,并利用Logistic模型和Gompertz模型对其体重进行拟合.结果表明:0~1月龄仔马鹿体重变化最大,平均日增重达610 g,杂种仔马鹿体重从0~8月龄,一直高于纯种仔马鹿,表现出很强的杂种优势;在体尺变化方面,仔马鹿在0~1月龄各项体尺指标变化最快,此后逐渐平缓,杂种仔马鹿除尾长生长强度弱于纯种仔马鹿外,其他体尺指标都强于纯种仔马鹿;生长模型拟合表明,Logistic模型和Gompertz模型都能很好地拟合仔马鹿体重增长状况(R2>0.97),其中以Gompertz模型的拟合度较高(R2>0.98),为最优模型,可更好地描述甘肃仔马鹿体重的变化.  相似文献   

10.
采用SPSS软件Logistic曲线拟合、Logistic非线性拟合和Asymptotic渐进回归3种模型对淇河鲫早期生长规律进行研究.结果表明:Logistic曲线拟合度较低(R~2=0.885);非线性渐进回归模型拟合度最高(R~2=0.982).根据模型计算出的早期生长拐点为出生后第5周.淇河鲫早期生长与其他一些鱼类生长模式相似,但也具有自身独特的生长模式.探讨了淇河鲫早期生长模式的生物学意义,为淇河鲫科学养殖、增殖和资源保护提供理论参数.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号