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101.
Effects of diet and body size on phosphorus utilization of Liza haematocheila T. & S. 总被引:1,自引:0,他引:1
A 21-d laboratory experiment was conducted to study, the phosphorus (P) utilization of two different diets by redlip mullet Liza haematocheila T. & S. Sand-filtered water in salinity 30 and temperatare 25℃ was used. Twenty-nine fish individuals were divided into three groups: 11 to group 1 (G1) fed on diet 1, 11 to group 2 (G2) fed on diet 2, and 7 to contrast group. Diet 1 was a commercial feed, more valuable in nutrition than diet 2 that similar to natural detritus. The results show the intake phosphorus (IP) of G1 was significantly higher than that of G2, and both increased linearly with body size at a certain amount of diet. The retention phosphorus (RP) in fish of G1 was lower than G2. The relationship between retention phosphorus and body size was positive and stronger in G2. Significant difference in faecal phosphorus (FP) was found between G1 and G2. Body size significantly impacted the excretion phosphorus (EP) in G1 but G2. The loss of intake phosphorus in G1 was 10.83-20.27 mg per g fish weight gain, higher than that in G2 for 6.63-9.56. Of the phosphorus, about 10% was allocated into growth, 50% in faeces, and the rest lost in excretion. The main part of phosphorus was lost in faeces but excretion. The phosphorus budget of the fish could be described as 100IP = 7.40RP + 47.39FP + 36.63EP (Diet 1) or 100IP = 11.93RP + 56.64FP + 21.76EP (Diet 2). 相似文献
102.
Analyzing raw material's structure and performance of bentonite from Panzhihua in Sichuan, the authors think that it is adequate for agglomerant of iron smelting. According to its composition and property we have researched the purification and modification of I/S bentonite under conditions of different dispersants and sodium agent. XRD test result reveals that the essential minerals of Panzhihua bentonite are I/S mixed-layer ones, and FTIR analysis shows that when adding 1 5% sodium pyrophosphate to the bentonite slurry during purification, the composition of quartz in bentonite decreases to less than 4% and I/S is more than 90%. The optimized modification technic conditions are Na2CO3 (4%) and CMC-Na (3%) as modified agents, the clay and water are 10 vs. 1, and the temperature is 75℃. It is 40 min for stirring time and reacting time is 4 h. Under the conditions we can get the modified I/S bentonite with colloid index more than 500 ml/15 g. 相似文献
103.
104.
黄河一级支流水土保持“3S”分析应用 总被引:2,自引:0,他引:2
改善黄河流域生态环境是推动西部大开发的有力保证。本文以黄河一级支流为单元,以秃尾河、皇甫川和窟野河为重点研究对象,介绍了如何利用GPS、RS和GIS相结合的技术,动态监测黄河流域水土流失情况,为黄河流域环境治理提供科学依据。 相似文献
105.
对雷州常见的3种滨珊瑚科珊瑚:澄黄滨珊瑚(Porites lutea)、灰黑滨珊瑚(Porites nigrescens)、普哥滨珊瑚(Porites pukoensis),共32个样本的12S rRNA基因序列进行了PCR扩增和测序,研究其系统发生关系。结果显示,所得的3种珊瑚的12S rRNA基因长度在728~908 bp之间,G+C含量在34.3%~39.2%之间,遗传距离在0.004~0.019之间。利用邻接(NJ)法、最大似然(ML)法和不加权对群分析(UPGMA)法构建的系统进化树显示:3种珊瑚被分成了2个支系,澄黄滨珊瑚和灰黑滨珊瑚聚合在一个分支上,而普格滨珊瑚在另一支,这一研究结果与传统形态学分类研究的结果存在一定差异。 相似文献
106.
Shuangtaizi estuarine wetland along the Bohai Sea coast,the biggest bulrush wetland in the world,has been listed in ‘The Record of Important International Wetland Conservation District’. Taking the year of 2 000 as an example,the minimum,the most suitable and the maximum ecological water requirement of Shuangtaizi estuarine wetland are calculated in this paper based on both ecological theory and Geological Information System technology. In addition,the remote sensing technique is adopted in the data acquisi... 相似文献
107.
Known only in phaeophyceae, phlorotannins (brown algal polyphenols) are natural products with potential uses in pharmacology.
This study yielded an extraction procedure to obtain high purity, high molecular weight phlorotannins fromSargassum kjellmanianum and revealed the characteristics of their infrared and flourescence spectra. The antioxidative activity of phlorotannins,
which was about 2.6 times as strong as that of 0.02% BHT (tert-butyl-4-hydroxytoluene), showed potential for preventing oil
rancidification.
Contribution No. 2918 from the Institute of Oceanology, Chinese Academy of Sciences. The project was supported by The State
Ninth-five Key Program of China. (No. 96-916-04-01). 相似文献
108.
Rui-Qing Mao Qin Zeng Purple Mountain Observatory Chinese Academy of Sciences Nanjing National Astronomical Observatories Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2004,4(5):440-454
The massive star forming region S 233 IR is observed in the molecular lines CO J = 2-1, 3-2, NH3 (1,1), (2,2) and the 870#m dust continuum. Four submillimeter continuum sources, labelled SMM 1-4, are revealed in the 870μm dust emission. The main core, SMM1, is found to be associated with a deeply embedded near infrared cluster in the northeast; while the weaker source SMM2 coincides with a more evolved cluster in the southwest. The best fit spectral energy distribution of SMM1 gives an emissivity of β = 1.6, and temperatures of 32 K and 92 K for the cold- and hot-dust components. An SMM1 core mass of 246 M⊙ and a total mass of 445 M⊙ are estimated from the 870μm dust continuum emission.SMM1 is found to have a temperature gradient decreasing from inside out, indicative of the presence of interior heating sources. The total outflow gas mass as traced by the CO J = 3-2 emission is estimated to be 35 M⊙. Low velocity outflows are also found in the NH3 (1,1) emission. The non-thermal dominant NH3 line width as well as the substantial core mass suggest that the SMM1 core is a “turbulent,massive dense core”, in the process of forming a group or a cluster of stars. The much higher star formation efficiency found in the southwest cluster supports the suggestion that this cluster is more evolved than the northeast one. Large near infrared photometric variations found in the source PCS-IR93, a previously found highly polarized nebulosity, indicate an underlying star showing the FU Orionis type of behavior. 相似文献
109.
在《中华人民共和国测绘成果管理规定》及其相关的管理规定中 ,对基础测绘成果保密等级的划分、调整和解密都作了详细的规定。但是在新形势下 ,现行保密法规的对象发生了变化 ,传统的保密管理方式已不适用 ,因此 ,应在保守国家核心机密的前提下 ,重新审定各种地理信息产品的密级 ,最大限度地扩大流通服务范围 ,使地理信息能更多更好地为国民经济建设服务 相似文献
110.
清河镇超单元花岗岩,位于华北地台与吉黑地槽拼接带内,同位素年龄值274±4Ma(单颗粒锆石Pb—Pb法),层于早二叠世。据同源岩浆演化理论,按照岩石谱系单位划分原则,将其划分为阎家堡子单元、籍家街单元、杨木林子单元和吴家沟4个单元。主要岩石类型为二长花岗岩,成因类型为S型花岗岩类,由于侵位过程中的同构造变形作用,局部形成糜棱岩化花岗岩和片麻状花岗岩,岩浆侵位为膨胀底劈—顶蚀脉动上侵。 相似文献