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1.
福建武夷山甜槠群落能量的研究   总被引:42,自引:0,他引:42  
在生物量、生产力研究基础上,对武夷山甜槠(Castanopsis eyrei(Cham p.ex Benth.) Tutch.)群落各组分的热值、群落能量现存量、能量年净固定量以及太阳能转化效率进行了研究。结果表明:(1)甜槠群落各组分样品的干重热值具有一定的差异,树皮热值最高,细根热值最低。(2)甜槠群落的能量现存量达780584.1 kJ·m - 2,其中地上部分为678913.8 kJ·m - 2,占总量的86.98% ;地下部分为101670.3 kJ·m - 2,占13.02% 。(3)甜槠群落的能量年净固定量(1992年)为26856.2 kJ·m - 2·a- 1,林地太阳光合有效辐射能的转化效率为1.296% 。  相似文献   

2.
几种红树植物木材热值和灰分含量的研究   总被引:46,自引:6,他引:40  
在夏季对海南东寨港红树林自然保护区一些红树植物木材的灰分含量的热值进行了测定,并研究了夏季不同纬度的秋茄(Kandelia candel)木材热值的变化。结果表明,红树植物木材的灰分含量较低,在2.43%-5.17%之间;干重热值在17.23-19.21kJ.g^-1之间,去灰分热值在17.70-20.10kJ.g^-1之间;嗜热窄布种无瓣海桑(Sonneratia apetala)木材的干重热值  相似文献   

3.
武夷山黄山松群落能量的研究   总被引:19,自引:2,他引:17  
在生物量,生产力研究的基础上,通过干重热值测定,对黄山松(Pinustaiwanensis)群落的能量现存量,能量净固定量及太阳能转化效率进行分析讨论,测定结果表明,(1)黄山松群各组分样品的干重热值具有一定的差异,树皮的干重热值最高,为22.14kJ/g,枯根的干重热最低,为16.27kJ/g。(2)黄山松群落的能量现存量为379832.3kJ/m^2,其中地上部分为275488.0kJ/m^2  相似文献   

4.
亚热带山地突脉青冈群落能量的研究   总被引:1,自引:0,他引:1  
对突脉青冈(Cyclobalanopsiselevaticostata)群落植物体各组分的热值、群落能量现存量、能量年净固定量和太阳能转化效率的研究结果表明:该群落植物体各组分样品的干重热值具有一定差异,树皮热值最高,细根热值最低。突脉青同群落的能量现存量852058kJm-2,其中地上部分741416kJm-2,占总量的87.01%;地下部分110642kJm-2,占12.99%。突脉青冈1996年群落能量净固定量为28273kJm-2,林地太阳光有效辐射能转化效率1.35%。  相似文献   

5.
福建九龙江口红树林生态系统研究的一个主要部分。通过对秋茄红树群落凋落物进行为期11a(1982~1992年)逐月连续测定。结果表明:凋落物产量年际波动在651.2~1108.6g/m2a,11a平均为862.9g/m2a,其中,叶占总量的63.3%,枝15.9%,果15.3%,花5.5%。不同年份凋落物量变化率(R)为1.7。1年中凋落物量以夏季>秋季>春季>冬季。凋落物能流量达12702~21664kJ/m2a,年际均值为16832kJ/m2a,其中春季3847,夏季6557,秋季4214,冬季2214(kJ/m2)。各组分能流量分别为:落叶10756,落枝2683,落花930,落果2453(kJ/m2a)。大量凋落物可为近海河口海洋生物提供可持续利用的有机物质和能量来源。  相似文献   

6.
深圳福田白骨壤群落Cr,Ni,Mn的累积及分布   总被引:17,自引:2,他引:15  
探讨了深圳福田自然保护区白骨壤红树林对Cr、Ni、Mn的吸收、累积及分布.结果表明,该林地土壤Cr、Ni、Mn含量从底层至表层逐步提高;表层(0~30cm深)3种元素含量分别为7.97、25.0和537μg·g-1,贮量分别为1099.86、3450.00和74106.00mg·m-2.白骨壤植物各部位Cr、Ni、Mn含量范围分别为0.28~0.75、0.43~7.65和25~1552μg·g-1;植物对表层土壤加权平均富集系数为Mn>Ni≈Cr.该群落Cr、Ni、Mn的现存累积量分别为6.06、20.76和1631.17mg·m-2,年净存留累积量分别为0.43、1.43和107.98mg·m-2;林地残留物相应元素储量分别为Cr78.00μg·m-2、Ni1536.33μg·m-2和Mn405.54mg·m-2.该林区3种不同类型群落叶层Cr、Ni现存累积量为白骨壤林>桐花树林>秋茄林,Mn为秋茄林>白骨壤林>桐花树林.  相似文献   

7.
 测定云南西双版纳热带季节雨林和哀牢山中山湿性常绿阔叶林优势种植物叶片及地表凋落物层的干重热值,分析并比较了两地群落类型热值的差异及其与地理条件的关系。植物叶片分为鲜叶和凋落叶,地表凋落物层分为新鲜凋落物层(L层)和腐叶层(F层)进行取样测量,所有样品在60℃烘干至恒重,样品热值采用Parr1261氧弹式热量计测量。结果表明:西双版纳的11种植物鲜叶和凋落叶干重热值的变化范围分别是14.595 3~19.863 9和14.046 7~19.884 0 kJ·g-1, L和F层的平均干重热值分别为17.419 6 和14.780 5 kJ·g-1;哀牢山的10种植物鲜叶和凋落叶干重热值的变化范围分别是17.805 1~21.525 3和17.893 4~21.436 7 kJ·g-1,L和F层的平均干重热值分别为19.208 4和17.494 7 kJ·g-1。两地植物鲜叶与凋落叶干重热值的大小顺序近似或一致,即植物鲜 叶干重热值越高,其凋落叶干重热值也越高;植物鲜叶与凋落叶干重热值的差值有正有负, 因物种而异;西双版纳凋落物L与F层之间的热值差值显著地大于哀牢山两层凋落物的热值差值,可能是由西双版纳凋落物的分解速率较快导致的;两地样品的平均干重热值的顺序为:鲜叶>凋落叶>L层>F层;将两地的相应样品对比发现,干重热值呈现为哀牢山>西双版纳,体现出高海拔>低海拔、高纬度>低纬度以及常绿阔叶林>热带季节雨林的特点。  相似文献   

8.
盐胁迫对VA菌根形成及接种VAM真菌对植物耐盐性的效应   总被引:52,自引:5,他引:47  
用盆栽法研究了不同土壤含盐量条件下接种不同VAM真菌菌株对棉花、玉米、大豆和甜瓜耐盐性的影响.结果表明,随着土壤中NaCl水平提高,真菌对棉花、玉米、大豆和甜瓜的侵染率下降,其生长量亦均呈递减趋势但对VAM真菌的依赖性则呈明显递增趋势.接种VAM真菌促进了棉花、玉米和大豆的生长,如在NaCl施入量为0~3g·kg-1时,接种M1菌株使棉花干重提高4.6~80.9%;在NaCl施入量为0~2.5g·kg-1时,接种M1菌株的玉米干重比对照增加20~109.6%;NaCl施入量为1g·kg-1时,接种M1和M2两菌株使大豆干重分别增加22.1%和10.2%.不同的VAM真菌菌株对同一植物的耐盐性以及同一种VAM真菌菌株对不同植物的耐盐性的影响程度不同.可以认为,VAM真菌与植物共生对植物在盐渍环境中的生存起着重要的作用;接种VAM真菌可以提高植物在盐渍土壤上的生产能力并减轻植物因盐害造成的产量损失.  相似文献   

9.
鹤山马占相思人工林的能量现存量及能量流动   总被引:6,自引:0,他引:6  
通过测定广东鹤山一个马占相思(Aeaeia mangiun)人工林的辐射能环境,优势种的净光合速率、呼吸速率和生产力,群落的生物量及热值,定量地刻划了太阳辐射能被马占相思群群吸收、固定、转化、损耗、积累和分配的生物能量学过程。全年抵达林冠上层的总太阳辐射能力4351.4MJ.m^-2.s^-1,能量量为14.8MJ.m^-2.s^-1,折合光能利用效率为0.34%,群落的能量正面量为193.9MJ  相似文献   

10.
林承超 《生态学报》1999,19(6):832-836
研究了福州鼓山次生的南亚热带季风常绿阔叶要及其林缘不同层次13种植物叶热值、灰分含是及营养成分。结果表明:群落的不同层次平均灰分含量从低到高依次是乔木层(6.8%),草本层(8.5%)、灌木层(10%);平均含灰分热值(GCV)从低到高低次是草本层(16.89KJ/g)、灌木层(17.75KJ/g)、乔木层(19.79KJ/g);平均不含灰分热值(AFCV)从低到高依次是草本层(18.55KJ/g  相似文献   

11.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

12.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

13.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

14.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

15.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

16.
17.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.  相似文献   

18.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

19.
We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.  相似文献   

20.
《Ibis》1894,36(3):447-460
  相似文献   

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