Growth and energy budget of F-2 'all-fish' growth hormone gene transgenic common carp

The growth and energy budget for F-2 'all-fish' growth hormone gene transgenic common carp Cyprinus carpio of two body sizes were investigated at 29.2 degrees C for 21 days. Specific growth rate, feed intake, feed efficiency, digestibility coefficients of dry matter and protein, gross energy intake (I-E), and the proportion of I-E utilized for heat production (H-E) were significantly higher in the transgenics than in the controls. The proportion of I-E directed to waste products [faecal energy (F-E) and excretory energy loss (Z(E) + U-E) where Z(E) is through the gills and U-E through the kidney], and the proportion of metabolizable energy (M-E) for recovered energy (R-E) were significantly lower in the transgenics than in the controls. The average energy budget equation of transgenic fish was as follows: 100 I-E = 19.3 F-E + 6.0 (Z(E) + U-E) + 45.2 H-E + 29.5 R-E or 100 M-E = 60.5 H-E + 39.5 R-E. The average energy budget equation of the controls was: 100 I-E = 25.2 F-E + 7.4 (Z(E) + U-E) + 35.5 H-E + 31.9 R-E or 100 M-E = 52.7 H-E + 47.3 R-E. These findings indicate that the high growth rate of 'all-fish' transgenic common carp relative to their non-transgenic counterparts was due to their increased feed intake, reduced lose of waste productions and improved feed efficiency. The benefit of the increased energy intake by transgenic fish, however, was diminished by their increased metabolism.

Fabrication of a 4x4 strictly nonblocking SOI switch matrix

A 4 x 4 strictly nonblocking thermo-optical switch matrix based on Mach-Zehnder (MZ) switching unit was designed and fabricated in silicon-on-insulator (SOI) wafer. The paired multi-mode interferometers (MMI) were used as power splitters and combiners in MZ structures. The device presents an average insertion loss of 17 dB and an average crosstalk of 16.5 dB. The power consumption needed for operation is reduced to 0.288 W by adding isolating trenches. The switching time of the device is about 15 mu s, which is much faster than that of silica-based switches. (C) 2005 Elsevier B.V. All rights reserved.

High-power AlGaInP laser diodes with current-injection-free region near the laser facet

A high-power AlGaInP laser diode with current-injection-free region near the facet is successfully fabricated by metaorganic chemical vapor deposition (MOCVD) using the (100) direction n-GaAs substrates with a misorientation of 15 deg toward the (011) direction. The maximum continuous wave output power is about 90 mW for the traditional structure. In comparison, the maximum output power is enhanced by about 67%, and achieves 150 mW for LDs with current-infection-free regions. The fundamental transverse-mode operation is obtained up to 70 mW. Output characteristics at high temperatures are also improved greatly for an LD with a current-injection-free region, and the highest operation temperature is 70 C at 50 mW without kink. The threshold current is about 33 mA, the operation current and the slope efficiency at 100 mW are 120 mA and 0.9 mW/mA, respectively. The lasing wavelength is 658.4 nm at room-temperature 50 mW. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

Fracture properties of PECVD silicon nitride thin films by long rectangular memrane bulge test

Bulge test combined with a refined load-deflection model for long rectangular membrane was applied to determine the mechanical and fracture properties of PECVD silicon nitride (SiNx) thin films. Plane-strain modulus E-ps prestress s(0), and fracture strength s(max) of SiNx thin films deposited both on bare Si substrate and on SiO2-topped Si substrate were extracted. The SiNx thin films on different substrates possess similar values of E-ps and s(0) but quite different values of s(max). The statistical analysis of fracture strengths were performed by Weibull distribution function and the fracture origins were further predicted.

掺Er3+玻璃上转换发光特性研究

采用高温熔制工艺制备了掺Er3+硅酸盐玻璃，应用Judd-Ofelt 理论计算了Er3+光谱参数， 发现玻璃中含有0.15 mol%Er2O3 时各参数取得最大值；分析了玻璃的吸收光谱随Er3+离子浓度的变 化关系；上转换光谱分析表明在522 nm、544 nm、658 nm 处有较强的绿光和红光，分别对应于 2H11/2→4I15/2、4 S3/2→4I15/2、4 F9/2→4I15/2 的跃迁，且522 nm 绿光强度和658nm 红光强度要远大于544 nm 绿光强度. 分析了上转换发光强度随泵浦功率和Er3+离子浓度的变化关系，揭示了上转换发光机制 主要是激发态吸收和能量转换，且均为双光子吸收过程.

半干旱区施氮和灌溉条件下覆膜对春玉米产量及氮素平衡的影响

以典型半干旱区干湿砂质新成土(Ust-Sandic Entisols)为供试土壤进行田间试验,研究地膜覆盖、施氮及补充灌水量对春玉米(Zea maysL.)产量、土壤矿质氮(NO3--N和NH4+-N)及氮素平衡的影响。结果表明,0—100 cm土体范围内,随着土层加深,播前和收获后土壤NO3--N含量呈降低趋势,NH4+-N有所增加,但变幅不大;总矿质氮量(NO3--N和NH4+-N)表现为下降。说明地膜覆盖和施氮并没有使NO3--N深层累积量增加,这可能与土壤本身供氮能力严重不足有关。与不施氮相比,施氮各处理氮肥表观损失量增加;与不覆膜相比,作物氮素累积量比不覆膜显著增加(P<0.05)。在低灌(80 mm)覆膜和高灌(160 mm)覆膜条件下,玉米的氮肥利用率均比不覆膜提高了18.8%,说明覆膜低灌在相同施氮条件下,可节约80 mm灌水。但低灌(80 mm)与高灌(160 mm)不覆膜间氮肥利用率差异不显著,表明在相同施氮条件下,覆膜可有效提高氮肥利用率,减少氮素损失。综合考虑子粒产量和氮肥利用率,"覆膜+补灌80 mm+施氮90 kg/hm2"可能为本试验条件下较优的栽培模式。

猕猴胚胎干细胞培养以及定向分化成神经细胞的研究

灵长类胚胎干细胞（Es）的研究不仅对理解生殖发育生物学的基础理论、而且对实现细胞替代治疗具有重要意义。当前灵长类ES细胞还有很多问题需要解决，如ES细胞培养体系的改进、ES细胞定向分化成高纯度特定组织细胞的可能性、有效性以及分化机制等问题。本文一方面概述了灵长类ES细胞相关领域的研究进展；另一方面，以称猴胚胎干细胞（rEs）为材料，在改善rES细胞的培养体系、提高其定向分化成神经前体细胞（NPs）和少突细胞的比率进行了研究。实验采用同源称猴细胞系作为饲养层培养rES细胞，并在此基础上利用肝生长因子（HGF）和GS诱导rES细胞定向分化成高纯度的NPs和少突细胞，并评价了NPs是否具有移植功能。主要结论如下：1）四种称猴细胞系（MOF、MESF、MFG和CMESF）可作为饲养层支持rES细胞的生长，保持ES自我更新的能力和分化的多能性。而且这几种称猴饲养层支持ES细胞生长的能力存在明显的差异，进一步的研究表明这些差异主要是由于基因表达种类以及表达量上的差异而导致的。2）采用HGF和GS作为诱导因子添加到NDCM液中，诱导rES细胞分化成可移植的NPs。实验结果如下：单独的HGF或GS仅能诱导ES细胞分化成65±8.3％和69±14％NPs，而HGF和GS的联合使用NPs的比率达到88.3±8.1％，进一步纯化后获得98±1.2％的NPs。获得的NPs能在体内、外分化成三个谱系神经细胞，并能整合到大鼠脑部，发生迁移和分化。25％的NPs细胞8周后仍保持存活状态，其中65-80％的细胞发生了不同程度的迁移，而且细胞在脑部的分化种类以及数目与细胞在体内所处的微环境具有重要的关系。亚克隆实验也进一步证明采用HGF＋GS获得的部分单个NPs具有神经干细胞的特性，也能在体内、外分化成三个谱系的神经细胞，而另外的却只能分化成其中的一、两种谱系的细胞。3）利用五步法，ES细胞能分化成75±6.8％的少突祖细胞和81土8．6％的成熟少突细胞。HGF通过抑制NPs的凋亡和缩短NPs的复制周期，共同促进NPs的增殖。HGF也能诱导HGF+G5获得的NPs分化成少突祖细胞和成熟少突细胞，并且促进少突细胞成熟。而且HGF促进NPs分化成少突细胞的能力受到GS的调控，单独HGF作用将导致ES细胞分化成神经元。本实验的结果为促进rES细胞相关领域的研究，以及ES细胞在神经系统疾病临床应用上提供信息，也为研究NPs和少突细胞的发育提供典型的细胞模型。

Characteristics of InAs epilayers for Hall effect devices grown on GaAs substrates by MBE

InAs thin films with good characteristics were grown on GaAs (0 0 1) substrates by molecular beam epitaxy. Cross-sectional transmission electron microscopy indicated that most of the threading dislocations formed by the interaction of misfit dislocations are annihilated above a small thickness. The high electron mobility and small temperature dependence of InAs epilayers are useful for magnetic sensors which is demonstrated by the properties of Hall effect devices.

新奇半导体低维结构的自组织生长

文章介绍了自组织生长半导体量子线、量子点和量子环的进展，同时介绍了这些低维半导体材料在光电子和通信等领域应用情况。此外，对这些材料的一些测试方法也进行了介绍．

大功率GaInP／AlGaInP半导体激光器

制备了大功率实折射率GaInP／AlGaInP压应变分别限制量子阱激光器．所用外延材料在15°偏角的GaAs衬底上由有机金属气相外延一次外延生长得到．制备的激光器具有双沟脊波导结构，条宽和腔长分别为3和900μm，前后端面分别蒸镀5％的增透膜和95％的高反膜．分析了室温连续激射时激光器的光电输出性能．阈值电流的典型值为32mA，光学灾变阈值为88mW，功率为80mW时的工作电流为110mA，斜率效率为1W／A，串联电阻为3Ω．基横模光输出功率可达60mW，60mW时的平行结和垂直结的远场发散角分别为10°和32°，激射波长为658．4nm．器件的内损耗为4．1cm^-1，内量子效率达80％，透明电流密度为648A／cm^2．

落叶松人工林养分循环与养分利用效率研究

通过对抚顺市温道林场20、53和69年生长白落叶松（Larix olgensis）人工林生物量和营养元素的积累与分配、养分利用效率和养分再吸收效率、养分生物循环的研究，探讨了长白落叶松生长发育不同阶段的养分生态学特征；对东北林业大学帽儿山实验林场17年生兴安落叶松（Larix gmelinii）人工林进行5年的施肥（NH4NO3，15 g•m-2•a-1），研究了施肥对人工林养分生物循环的影响。结果表明： （1）20、53和69年生单株落叶松生物量分别为33.14 kg•tree-1、311.42 kg•tree-1和408.46 kg•tree-1，随林龄的增长而增加。各器官生物量的分配格局为：树干>根>树枝>树皮>针叶。树干生物量的分配比例为50.16%~69.20%，随林龄的增长比例增大，而其他器官生物量的分配比例则逐渐减小。20、53和69年生单株落叶松净生产力分别为3.04 kg•tree-1•a-1、9.68 kg•tree-1•a-1和10.21 kg•tree-1•a-1，随林龄的增长而增大。针叶和树干的净生产力最大，分别占整株林木净生产力的40.07%~47.93%和27.32%~40.97%，并且随林龄的增长而增大。树枝、树皮和根的净生产力则表现出随林龄的增长呈抛物线状。 （2）20、53和69年生单株落叶松N、P、K、Ca、Mg等5种营养元素的总贮量分别为308.14 g•tree-1、2021.01 g•tree-1和2485.24 g•tree-1，随林龄的增长而增加。5种营养元素的贮量大小为：Ca>N>K>Mg>P。树干养分贮量的分配比例为19.74%~34.23%，随林龄的增长呈抛物线状。针叶、树枝和树皮的养分贮量占整株林木养分贮量的比例为35.16%~45.59%，建议在采伐木材时实施去皮、打枝等措施，留下针叶、树枝和树皮在林地中，让其自然分解以使营养元素重新归还利用，对于维持林地的养分平衡和长期生产力具有积极作用。 （3）20、53和69年生单株落叶松年吸收养分量分别为35.31 g•tree-1•a-1、97.83 g•tree-1•a-1和100.08 g•tree-1•a-1，随林龄的增长而增加。5种营养元素的年吸收量大小为：Ca>N>K>Mg>P。落叶松的养分利用效率随林龄的增长而增大，但生长到一定年龄阶段后，其养分利用效率逐渐趋于稳定。落叶松的最佳采伐年龄应为养分利用效率保持稳定时的年龄，此时采伐单位干材所带走的林地养分量较少。不同营养元素的利用效率不同，P的利用效率最高，Mg、K次之，N、Ca最低。不同器官的养分利用效率不同，树干的养分利用效率最高，其次是根、树枝、树皮，针叶最低。随着林龄的增长，树干和根的养分利用效率增大，而树枝和树皮的养分利用效率减小。 （4）落叶松叶片的N再吸收效率为50.76%~55.11%，随林龄的增长表现出增大的趋势；P和K再吸收效率分别为64.38%~68.85%和87.85%~90.62%，随林龄的增长表现出减小的趋势。从养分利用效率和养分再吸收效率综合判断，本研究区落叶松生长可能受土壤N、P、K供应的限制，3种营养元素的限制作用大小为：K>P>N。 （5）落叶松人工林养分的年吸收量、年存留量和年归还量分别为51.94~78.35 kg•hm-2•a-1、17.77~29.43 kg•hm-2•a-1和34.18~48.92 kg•hm-2•a-1，均随林龄的增长而减少，这与林分密度逐渐减小有关。5种营养元素的年吸收量和年存留量大小均为：Ca>N>K>Mg>P，年归还量大小为：Ca>N>Mg>K>P。落叶松人工林的养分循环速率为0.624~0.658，随林龄的增长而增大。5种营养元素的循环速率以Mg、N最快，Ca、P次之，K最慢。K的循环速率较低，可能与研究区土壤K含量较低而表现出的K再吸收效率较高有关。 （6）施肥导致落叶松叶片N再吸收效率显著降低，而凋落叶片的N浓度显著增加，从而使凋落叶片的C/N比由80.29降低到60.29。施肥林地凋落叶片C/N比的降低使其分解速率加快，有利于其养分归还土壤，从而加快了系统的养分循环速率，提高了系统的养分利用率。因此，在人工林经营中，施肥不仅能提高林地生产力，而且对于维持林地养分循环具有积极作用。