西双版纳白背桐群落生物量研究

对云南西双版纳热带次生演替初期的白背桐群落生物量进行了测定.结果表明,10龄群落总生物量为57.819 t·hm-2,其中乔木层为51.019 t·hm-2(占群落生物量的88.24%),灌木层5.644 t·hm-2(占9.76%),层间植物1.013 t·hm-2(占1.75%),草本层0.143 t·hm-2(占0.25%).与其5龄群落相比,10龄群落乔木层、灌木层和层间植物的生物量分别增长了105.04%、122.73%和93.32%,草本层生物量降低83.53%.在演替过程中群落乔木层生物量主要集中于少数优势树种,白背桐、木姜子、榕树的生物量合计26.170 t·hm-2(占乔木层生物量的51.29%).群落乔木层生物量主要以小径级树木的生物量为主,其器官生物量积累的大小顺序依次为干＞枝＞根＞叶.     

西双版纳热带湿性季节雨林生物量及其分配规律研究

 本文采用标准木回归分析法(乔木层、木质藤本)和样方收获法(灌木层、草本层)研究了西双版纳湿性季节雨林生物量及其分配规律。群落总生物量为360.909t·hm-2,其在各层的分配为：乔木层352.563t·hm-2(占群落生物量的97.69％)、灌木层4.737t·hm-2(占1.31％)、木质藤本3.108t·hm-2(占0.86％)、草本层0.501t·hm-2(占0.14％)。群落生物量绝大部分集中于乔木层。乔木层生物量的器官分配为：干241.270t·hm-2(占乔木层生物量的68.43％)、根69.614t·hm-2(占19.75％)、枝37.287t·hm-2(占10.57％)、叶4.392t·hm-2(占1.25％);乔木层生物量的径级分配主要集中于中等径级,胸径在20～80cm间的6个径级,生物量达255.460t·hm-2(占72.46％);生物量在乔木层中垂直分配为：Ⅰ亚层219.365t·hm-2(62.22％)、Ⅱ亚层107.743t·hm-2(30.56％)、Ⅲ亚层25.455t·hm-2(7.22％);生物量大于乔木层生物量0.5％的树种共计26种,其中大于5％的有番龙眼(Pometia tomentosa)(19.67％)、云南玉蕊(Barringtonia macrostachya)(5.44％)、千果榄仁(Terminalia myriocarpa)(5.27％),生物量种类分配反映出优势种明显的特点。乔木层叶面积指数为5.724。     

湖南会同红栲-青冈-刨花楠群落生物生产力的研究

用回归分析方法 ,对我国亚热带湖南会同红栲 青冈 刨花楠群落的生物生产力进行了研究 ,结果表明 ,林分总生物量为 45 1.0 2t·hm-2 ,其中乔木层、灌木层和藤本生物量分别为 42 6 .76、17.76和 1.80t·hm-2 ,枯枝落叶层现存量为 4.70t·hm-2 ,乔木层净生产量和平均生产量分别为 34.46t·hm-2 ·年 -1、13 .32t·hm-2 ·年 -1.     

西双版纳原始热带湿性季节雨林生物量及净初级生产

应用生物量回归模型和生产力方程,研究了西双版纳原始热带湿性季节雨林生物量及净初级生产量（NPP）。雨林总生物量为692．590t·hm-2,总生物量分配为：乔木层占98．66％、灌木层占0．76％、木质藤本层占0．50％、草本层占0．09％,生物量主要集中于乔木层。雨林年平均NPP为25．764t·hm-2·a－1,其中各层次的NPP分别为（t·hm-2·a－1）：乔木层23．972（占总NPP的93．04％）、灌木层0．749（占2．91％）、木质藤本层0．431（占1．67％）和草本层0．612（占2．38％）。乔木层NPP分配为（t·hm－2·a-1）：凋落量11．566、叶虫食量0．694和生物量增量11．712。结果表明：西双版纳虽地处热带北缘,当地原始热带湿性季节雨林同样具有典型热带雨林一样高的生物量和NPP。     

鼎湖山马尾松林生态系统碳素分配和贮量的研究

鼎湖山马尾松林中 ,马尾松各器官碳含量平均为 5 4.46%,灌木层植物 48.1 0 %,草本层植物40 .2 1 %,地表现存凋落物层 5 4.40 %,以上各组分总平均为 49.2 9%。土壤碳密度为 7.3 7kg· m- 2 (深 1 0 0cm)。生态系统各组分碳贮量分别为 :乔木层 68.876t·hm- 2 ,林下植物层 6.0 3 0 t· hm- 2 ,凋落物层 5 .892 t·hm- 2 ,土壤层 73 .70 5 t· hm- 2。根据研究结果 ,还对广东省马尾松林的现有碳贮量和碳吸存潜力进行了估算和讨论。     

西双版纳热带次生林生物量的初步研究

 本文采用“空间代替时间”和维量分析的方法研究了西双版纳热带次生林4块不同年龄林分的生物量,并详细分析了热带次生林在演替初期阶段生物量的变化趋势。结果表明：林分总生物量随林龄而增加,5年生林分的总生物量为41.932t·hm-2,10年生林分的总生物量为52.116t·hm-2,14年生林分的总生物量为88.284t·hm-2,22年生林分的总生物量为113.743t·hm-2。林分生物量的层次分配比例以乔木层所占的比例最大,占4/5以上,随林龄而增加;灌木层增长到14年生林分后又下降,草本层随林龄而递减,层间植物则上升。生物量的器官分配比例以干材所占的比例最大,占1/2以上,随林龄而递增;而枝、根和叶的生物量分配比例则随林龄而下降。并建立了4个林分主要优势种及乔木层器官生物量的回归模型。     

秦岭南坡锐齿栎林的生态环境及其营养积累

秦岭锐齿栎林 (含 0～ 6 0cm土层 )营养元素总储量达 182 .6 4 5～ 394 .70 1t·hm-2 ,植被占 0 .5 9%～2 .13% ;林分生物量为 131.713～ 5 0 3.82 2t·hm-2 ,乔木层占 92 .1%～ 99.2 % ;凋落物层现存量和营养元素积累量分别为 2 .897～ 33.999t·hm-2 和 10 4 .339～ 1136 .5 36kg·hm-2 .在一定范围内 ,林分生物量和营养元素积累量随密度的增加而增大 ;立地、林分条件相似的林分 ,生物量和营养元素积累量与林龄呈正相关 .林分针叶树占的比例越大 ,营养元素积累量越小 ,而且对生物量的影响远小于对营养元素积累量的影响 .在同一地区 ,立地、林分状况相似 ,林型不同 ,生物量及营养元素积累量差别不大 ,树种组成和林型不同林分的生物量和营养元素积累量均不同 .不同地区 ,生态和林分条件相似的林分的生物量和营养元素积累量也有差异 ;林型、结构相似林分生物量和营养元素积累量南坡 >北坡 ,中段 东段≈西段 .林分对营养元素利用率与海拔呈负相关 ,且南坡 >北坡 ,中段 >东西段 ,中段 >西段 >东段 .     

西双版纳热带季节雨林生态系统氮的生物地球化学循环研究

 用小流域集水区和物质平衡方法,于1999年对西双版纳热带季节雨林生态系统的氮素循环进行了初步研究。西双版纳季节雨林生态系统的氮库总储量为6 481.2 kg·hm-2,其中活体生物量、凋落物层和土壤（0～30 cm）中的氮储量分别为970.9、37.7、5 481.2 kg·hm-2。土壤中的氮占生态系统氮总储量的84.4%,活体生物量占15.0%,凋落物层仅占0.6%。结果表明季节雨林的氮主要分布在土壤中,而在生物量中只占很少部分。大气降水、林内穿透水、树干流及地表径流的氮含量分别为0.565、0.828、0.983和1.042 mg·dm-3,氮通量则分别为8.89、10.97、3.57、5.95 kg·hm-2·a-1。大气降水输入氮8.89 kg·hm-2·a-1,径流输出氮5.95 kg·hm-2·a-1, 收支平衡（输入—输出）为2.94 kg·hm-2·a-1。氮的生物循环：吸收为149.86 kg·hm-2·a-1,存留为69.30 kg·hm-2·a-1,归还为80.56 kg·hm-2·a-1,循环系数为0.54。结果表明未受干扰的季节雨林生态系统处于氮积累的状态,有利于该生态系统的稳定与持续发展。     

鼎湖山南亚热带森林细根生产力与周转

 报道了鼎湖山季风常绿阔叶林和针阔叶混交林群落0～40cm土层中细根(≤2mm和2～5mm)的现存量、死亡量、生产力和周转率,并比较了用“连续钻取土芯法”和“埋无根土柱法”来估算表层土(0～20cm)细根生产力的差异。结果表明：在0～40cm土层中,季风常绿阔叶林≤2mm和2～5mm细根现存量分别为6.59t·hm-2和4.81t·hm-2,死根比率各为29.9％和22.9％;针阔叶混交林≤2mm和2～5mm细根现存量分别为5.35t·hm-2和4.24t·hm-2,死根比率各为34.4％和24.0％。细根现存量的季节性变化不显著。季风常绿阔叶林细根年分解量、年死亡量和年净生产力分别为0.90,1.59,2.65t·hm-2·a-1 (≤2mm)和0.41,0.63,1.25t·hm-2·a-1(2～5mm),针阔叶混交林的相应数值各为0.80,1.4l,2.42t·hm-2·a-1(≤2mm)和0.37,0.62,1.21t·hm-2·a-1(2～5mm)。季风常绿阔叶林细根年周转率为0.57 (≤2mm)和0.34次·a-1(2～5mm),针阔叶混交林分别为0.69(≤2mm)和0.38次·a-1(2～5mm)。     

贡嘎山森林生物量和生产力的研究

对贡嘎山苞槲柯、香桦林,铁杉、槭、桦杉,峨眉冷杉林Ⅰ,峨眉冷杉林Ⅱ和鳞皮冷杉林的生物量和生产力进行了研究。它们的生物量分别是220．082t·hm-2、568．008t·hm－2、544．519t·hm-2、282．558t·hm-2和279．819t·hm－2;它们的生产力分别是9．962t·hm-2·a-1、10．067t·hm－2·a－1、12．936t·hm-2·a-1、4．692t·hm-2·a-1和1．389t·hm-2·a－1。通过对贡嘎山森林生物量和生产力与生态因素的相关分析表明,年降水量是制约森林生物量和生产力的主导因子。     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

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.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

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.     

Crystal structure, detonation performance, and thermal stability of a new polynitro cage compound: 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptacyclo [5.5.1.13, 11. 15, 9] pentadecane

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.     

Reference values for the concentrations of As,Cd, Co,Cr, Cu,Fe, I,Hg, Mn,Mo, Ni,Pb, Se,and Zn in selected human tissues and body fluids

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.     

Relations of the Al,B, Ba,Br, Ca,Cl, Cu,Fe, K,Li, Mg,Mn, Na,P, S,Si, Sr,and Zn mass fractions to morphometric parameters in pediatric and nonhyperplastic young adult prostate glands

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.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

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.     

Monovalent Cation Permeation through the Connexin40 Gap Junction Channel : Cs,Rb, K,Na, Li,TEA, TMA,TBA, and Effects of Anions Br,Cl, F,Acetate, Aspartate,Glutamate, and NO3

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 (γ_j 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 γ_j 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.     

Caprine blood groups. 2. The C,G, H,I, J,K, L,N, and Q systems

Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera. The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents and shown to be controlled by three alleles,C ¹²,C ²⁵, andC ⁻. A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled by six codominant alleles (G ^10.19.20,G ^10.19,G ^10.20,G ¹⁰,G ¹⁹,G ²⁰) and a recessive allele (G ⁻). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively. This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, New South Wales 2031, Australia.