A manganese molybdenum phosphate with a tunnel: hydrothermal synthesis, structure and catalytic properties of (NH3CH2CH2NH3)(10-)H3O)(3)(H5O2)Na-2[MnMo12O24(OH)(6)(PO4)(4)(PO3OH)(4)]-[MnMo12O24(OH)(6)(PO4)(6)(PO3OH)(2)] center dot 9H(2)O

A manganese molybdenum phosphate, (NH3CH2CH2NH3)(10)(H3O)(3)(H5O)Na-2[MnMo12O24(OH)(6) (PO4)(4)(PO3OH)(4)][MnMo12O24 (OH)(6)(PO4)(6)(PO3OH)(2)]. 9H(2)O, has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. The structure of this compound may be considered to be two [Mo6O12(OH)(3)(PO4)(2)(HPO4)(2)](7-) units bonded together by a manganese atom, although several P-O groups are not protonated on account of coordination to a Na+ cation. One-dimensional tunnels were formed in the solid. A probe reaction of the oxidation of acetaldehyde with H2O2 using this compound as catalyst was carried out in a liquid-solid system, showing that the manganese molybdenum phosphate has high catalytic activity in the reaction.

Controllable atom localization via double-dark resonances in a tripod system

We propose an atom localization scheme for a tripod-type atom making use of the sharp absorption peak resulting from interacting double-dark resonances. It is demonstrated that the probability of finding the atom at a particular position, as well as the localization precision, can be dramatically enhanced. The probability can be doubled by adjusting the Rabi frequency of the control field to the maximum Rabi frequency of the standing-wave field. Moreover, much better spatial resolution can be achieved for smaller detunings of the control and the standing-wave fields. (c) 2006 Optical Society of America.

Core size scaling of helical-core optical fibres

The mode-area, scaling properties of helical-core optical fibres are numerically studied and the limit of core size for achievable single-mode operation is explored. By appropriate design, helical-core fibres can operate in a single mode with possible scaling up to 300 mu m in core diameter with numerical aperture 0.1.

Preparation and characterization of hybrid ZnO/ormosils films

Hybrid ZnO/ormosils Elms are prepared by the sol-gel method. A FT-IR spectrometer, 900 UV/VIS/NIR spectrophotometer, atomic force microscope, and ellipsometer are employed to investigate microstructure and optical properties of the films fired at different temperatures. The results show that the films with high transmittance and low surface roughness could be obtained at the heat-treatment temperature of 150 degrees C, the refractive index and thickness of the film are 1.413, 2.11 mu m, respectively. Higher temperatures (350 degrees C, 550 degrees C) change the Elm microstructure severely, and then decrease the transmittance of the films.

Transparent Ni2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence

We report on transparent Ni2+-doped MgO-Al2O3-SiO2 glass ceramics with broadband infrared luminescence. Ni2+-doped MgO-Al2O3-SiO2 glass is Prepared by using the conventional method. After heat treatment at high temperature, MgAl2O4 crystallites are precipitated, and their average size is about 4.3nm. No luminescence is detected in the as-prepared glass sample, while broadband infrared luminescence centred at around 1315nm with full width at half maximum (FWHM) of about 300nm is observed from the glass ceramics. The observed infrared emission could be attributed to the T-3(2g)(F-3) -> (3)A(2g)(F-3) transition of octahedral Ni2+ ions in the MgAl2O4 crystallites of the transparent glass ceramics. The product of the fluorescence lifetime and the stimulated emission cross section is about 1.6 X 10(-24) s cm(2).

我国主要森林生态系统碳循环研究

作者广泛收集了近二十年来我国森林生物量生产力、土壤剖面有机质含量、凋落物现存量、年凋落量、凋落物分解等方面的研究资料，以及国内外土壤呼吸的相关资料，把森林作为一个自然的生态系统，从生物自身循环的角度系统地研究了我国森林在全球变化中的地位和作用提供了基础数据。主要得到以下几个方面的研究结果： 1、基于上述资料，采用林业部规划院1989-1993年的最新统计的我国不同森林类型的面积（不包括经济林和竹林，台湾省未计入），估算了我国森林生态系统总碳贮量。森林生态系统有机碳库包括植被、土壤和凋落物层三个分室，我国主要森林生态系统的碳贮量为281.16 * 10~8吨，其中植被碳库为62.00 * 10~8吨，占总碳库的22.2%;土壤碳库为210.23 * 10~8吨，占总碳库的74.6%;凋落物层的碳贮量为8.92 * 10~8吨，占总量的3.2%。我国森林生态系统碳贮量由大到小的顺序是：落叶阔叶林、暖性针叶林、常绿和常绿落叶阔叶林、云冷杉林、落叶松林、硬叶常绿阔叶林、温性针叶林、针叶和针阔混交林、阔叶红松林、热带林、樟子松林，前5类森林碳贮量占总贮量的87%，是我国森林主要的碳库。 2、分析了我国森林生态系统各个分室的碳密度特点。我国森林生态系统的平均碳密度是258.83t/ha，基本趋势是随纬度的增加而增加。其中植被的平均碳密度是57.07t/ha，随纬度的增加而减小;土壤碳密度约是植被碳密度3.4倍，其区域特点与植被碳密度呈相反趋势，随纬度升高而增加，作者根据所选117个样本建立了土壤有机碳密度与水热因子的模拟方程;凋落物层平均碳密度是8.21t/ha，随水热因子的改善而减小。这些结果为研制森林生态系统仿真模型提供了基础。 3、分析了我国森林生态系统的主要碳平衡通量，对中国森林生态系统的碳源与碳汇作初步评价，为减缓我国二氧化碳排放提供理论基础。结果表明我国森林生态系统在与大气的气体交换中表现为碳汇，年通量为4.80 * 10~8吨C/年。基本规律是随纬度的升高，即从热带向寒带，碳汇功能下降，这取决于系统碳收支的各个通量之间的动态平衡;阔叶林的固碳能力大于针叶林。 4、初步评价了我国森林生态系统在碳循环中的作用。我国生物物质燃烧、化石燃料燃烧、人口呼吸每所释放的总碳量为9.87 * 10~8吨/年，而我国森林生态系统可以吸收其中的48.7%。

藏猴替代父母行为

在23周龄内,婴猴有10.5%的时间受到替代父母, 主要是成年雄性的照料, 此行为可能用以补偿母亲在恶劣觅食条件下对子女的高投入。其中,7.3%的时间与成年雄性在一起, 1.9%与非母亲成年雌性, 1.3%与少年猴在一起。雄性较雌性更经常地照料、探查、拦回、排斥婴猴;他们一般只与雄性婴猴玩耍。

尼罗罗非鱼在淡水和海水中的生长及对蛋白质需求的比较

以酪蛋白为蛋白源,配制蛋白质含量为19 80%～40 50%的6种精饲料,采用室内循环水养殖系统,在饱食投喂和(27±1)℃水温条件下对吉富品系尼罗罗非鱼幼鱼进行8周的饲养实验,比较其在淡水和海水中的生长及蛋白质需求。结果显示:尼罗罗非鱼在淡水和海水中生长良好,存活率分别为100%和87%～100%;随着饲料蛋白质含量增加,实验鱼的平均终重、增重率和日增重率呈线性增加,饲料系数呈线性下降,蛋白质效率也呈下降趋势。在相同的饲料蛋白水平下,上述指标在淡水鱼和海水鱼之间均无显著差异蛋白质适宜需要量为28%～32

A taxonomic study of Oconnorella (Enchytraeidae, Oligochaeta) from Changbaishan Mountain, China

We describe three enchytraeid species, including two new species, from Mt. Changbaishan, Jilin Province, northeastern China. Oconnorella cheni sp. nov. is characterized by a simple spermatheca; absence of the oesophageal appendages and seminal vesicle; and nephridia from 6/7, with a distinct funnel and the efferent duct arising from the anterior part of the postseptale. Oconnorella globula sp. nov. is distinguished by a spermatheca with two diverticula; lack of oesophageal appendages and seminal vesicle; and nephridia from 6/7, with distinct funnel and the efferent duct arising from the mid-ventral or posteroventral part of the postseptale. We redescribe Oconnorella changbaishanensis (Xie et al., 2000) from type and live specimens, and amend some characters that cannot be investigated clearly from mounted specimens. We revise the generic diagnosis of Oconnorella.

A traveling-wave electroabsorption modulator with a large optical cavity and intrastep quantum wells

This paper reports a novel traveling-wave electroabsorption modulator (TWEAM) with a large optical cavity waveguide and an intrastep quantum well structure designed to achieve a high bandwidth, high saturation power and better fiber-matched optical profile, which is good for high coupling efficiency. The optical mode characteristic shows a great improvement in matching the circular mode of the fiber and the saturation power of 21 dBm, and a 3 dB bandwidth of 23 GHz was achieved for the fabricated TWEAM.