Regulation of gamete release in the economic brown seaweed Hizikia fusiforme (Phaeophyta)

Gamete release is an essential event in artificial seeding of the economic brown seaweed, Hizikia fusiforme. Mass egg release occurred in the dark, with few eggs being discharged in the light. Release of eggs was elicited with eight practical salinity units (one PSU = 1 g sea salts l(-1)) and was inhibited by salinity levels > 32 PSU. Egg release was optimal at 23 degrees C, and was decreased by 72% in agitated seawater compared to unstirred seawater. Inhibitors of photosynthesis and ions channels suppressed egg release, indicating that this process was physiologically associated with photosynthetic activity and ion transport.

Magnetointersubband oscillations of the two-dimensional electron gas in AlxGa1-xN/GaN heterostructures

Shubmkov-de Haas (SdH) measurements are performed over a temperature range of 1.5-20K in AL(0.22)Ga(0.78)N/GaN heterostructures with two subbands occupied. In addition to an intermodulation between two sets of SdH oscillations from the first and second subbands, a beating in oscillatory magnetoresistance at 12K is observed, due to the mixing of the first subband SdH oscillations and 'magnetointersubband' (MIS) oscillations. A phase shift of pi between the SdH and MIS oscillations is also clearly identified. Our experimental results, i.e. that the SdH oscillations dominate at low temperature and MIS oscillations dominate at high temperature, fully comply with the expected behaviour of MIS oscillations.

Determining of the delay time for a heating ventilating and air-conditioning plant using multi-weights neurons approach

This paper presents an multi weights neurons approach to determine the delay time for a Heating ventilating and air-conditioning (HVAC) plan to respond to control actions. The multi weights neurons is a fully connected four-layer network. An acceleration technique was used to improve the general delta rule for the learning process. Experimental data for heating and cooling modes were used with both the multi weights neurons and a traditional mathematical method to determine the delay time. The results show that multi weights neurons can be used effectively determining the delay time for HVAC systems.

农副产品的太阳能干燥

目前，我国农村能源的开发与利用发展迅速，利用太阳能干燥器干燥农副产品取得明显的效果，其优点为:节约燃料，降低产品成本;减少污染，提高产品质量;改善条件，提高生产率。按被干燥物料接受太阳能方式不同，可分为直接受热式和间接受热式，或称之为辐射式和对流式。我国习惯叫法又称之为温室型太阳能干燥器与集热型太阳能干燥器。对以上两种结合的，称之为组合式太阳能干燥器。有些太阳能干燥器除主要依靠太阳能外，加设了常规的辅助能源，以便阴雨天和夜间使用，国际上称它为混合式太阳能干燥器。

有机硅嵌段共聚物的合成表征及性能

以八甲基环四硅氧烷（D_4）为单体，α，ω-双（γ-氨丙基）四甲基二硅氧烷（DSX）为封端剂，在催化剂四甲基氢氧化铵硅醇盐的作用下，合成了五种不同分子量的α，ω-双（γ-氨丙基）聚二甲基硅氧烷预聚物（PSX）。预聚物分子量的测定结果表明，分子量的实验值接近理论值。以聚二甲基硅氧烷为软段，分别以聚芳酯（PAE）。聚酰亚胺（PI）为硬段合成了有机硅嵌段长短不同及含量不同的两类嵌段共聚物。1）PSX/PAE嵌段共聚分别采用界缩聚法和低温溶液法使酚酞、对苯二甲酰氯同端氨丙基聚硅氧烷预聚物合成了聚二甲基硅氧烷-聚对苯二甲酸酚酞酯嵌段共聚物。使用NMR对共聚物的组成分析以及测定共聚物粘度的结果表明，采用界面法不易得到有机硅含量较高、高产率、高分子量的共聚物，而低温溶液法却能给出高分子量、高产率及有机硅含量可控的嵌段共聚物。以IR、NMR对共聚物的结构、组成进行了表征，还以TEM观察了有机硅嵌段长短、含量的多少以及成膜溶剂对共聚物形态的影响。当共聚物中有机硅含量一定时，相分离程度随有机硅嵌段长度的减小而变小。在软硬段的组成比较大地偏离50/50时，共聚物中较多的组份形成连续相，且由于软硬段的溶解度参数相差较大，相容性不好而使共聚物在有机硅嵌段较短（(M-bar)_n = 915）的情况下发生相分离。TMA、DSC及动态力学试验表明，共聚物分别表现出软硬段的转变，且当软段的聚合度大于40时，出现聚二甲基硅氧烷的结晶和熔融转变。某些共聚物的力学强度接近或大于硬段聚芳酯，而断裂伸长率均大于聚芳酯。TGA分析指出，共聚物具有比较好的耐热性。对共聚物透气性的初步测试表明，嵌段共聚物的透气性主要表现出连续相聚合物的性质。2）PSX/PI嵌段共聚物由嵌段共聚物的IR谱表明环化反应完全，由NMR谱确定共聚物中有机硅的含量。由于PI与PSX的相容性很不好（Δδ = 11.7）。TEM观察结果表明共聚物在有机硅嵌段较短（(M-bar)_n = 915）时即发生相分离，且相分离的程度比聚芳酯要大。共聚物的DSC测试结果也证明了共聚物的两相结构，共聚物具有比较好的耐热性。此外，对有机硅嵌段较短的共聚物的透气性测试表明，共聚物在具有较好的透气性（P_(O_2)为10~(-9)cm~3(STP)cm/cm~2·sec·cmHg数量级）的同时，还呈现出比较好的氧氮分离能力（α_(H_2)~(O_2) > 2.5）。

单光子源低密度长波长InAs／GaAs量子点的制备

通过优化分子束外延生长条件，得到室温发光在1300nm低密度的自组织InAs／GaAs量子点。使用极低的InAs生长速率（0．001单层／秒）可以把量子点的密度降低到4×10~6cm~(-2)。这些结果使得InAs／GaAs量子点可以作为单光子源应用在未来的光纤基量子密码、量子通信中。

1.55μm Fabry-Perot Thermo-Optical Tunable Filter with amorphous-Si as Cavity

A 1.55μm Fabry-Perot (F-P) thermo-optical tunable filter is fabricated. The cavity is made of amorphous silicon (a-Si) layer grown by electron-beam evaporation technique. Due to the excellent thermo-optical property of a-Si, the refractive index of the F-P cavity will be changed by heating; the transmittance resonant peak will therefore shift substantially. The measured tuning range is 12nm, FWHM (full-width-at-half-maximum) of the transmission peak is 9nm, and heating efficiency is 0.1K/mW. The large FWHM is mainly due to the non-ideal coating deposition and mirror undulation. Possible improvements to increase the efficiency of heating are suggested.

Effect of rapid thermal annealing on the Raman spectrum of Si0.33Ge0.67/Si (100) alloy

The effect of thermal annealing on the Raman spectrum of Si0.33Ge0.67 alloy grown on Si (100) by molecular beam epitaxy is investigated in the temperature range of 550-800 degrees C. For annealing below 700 degrees C, interdiffusion at the interface is negligible and the residual strain plays the dominant role in the Raman shift. The strain-shift coefficients for Si-Ge and Ge-Ge phonon modes are determined to be 915 +/- 215 cm(-1) and 732 +/- 117 cm(-1), respectively. For higher temperature annealing, interdiffusion is significant and strongly affects the Raman shift and the spectral shape.

三维风沙运动的CFD-DEM数值模拟

采用计算流体力学(Computational Fluid Dynamics,CFD)和颗粒离散元(Discrete Element Method,DEM)耦合的方法模拟三维风沙运动,并且将三维模拟结果和二维模拟结果以及实验结果进行了对比.计算结果表明:沙粒水平速度随着高度按幂函数规律增加,沙床表面附近沙粒撞击和起跳速度的概率分布均可用对数正态函数描述,沙粒撞击和起跳角度的概率分布均可用指数函数描述,沙粒水平速度,展向速度和垂直速度在不同高度处的概率分布可分别用对数正态分布,正态分布和正态分布表示.与二维计算结果的分析对比表明:二维计算得到的颗粒速度的分布规律和三维计算结果类似,但二维计算的颗粒表观密度明显偏大,由此导致输沙量计算偏大.和实验结果的对比表明:三维计算得到的颗粒速度概率分布与实验基本保持一致

酿酒酵母和运动发酵单胞菌木薯乙醇发酵条件研究

本文结合我国燃料乙醇发展的方针政策，以酿酒酵母和运动发酵单胞菌为菌种研究其在非粮能源作物木薯中乙醇发酵的情况，为木薯原料更好地应用于生产中提供了理论依据。 酿酒酵母木薯高浓度乙醇发酵的研究。实验采用的木薯干淀粉含量约70-75%。以酿酒酵母为菌种进行高浓度乙醇发酵的工艺条件研究，最佳条件为：木薯干粉碎细度为35目，料水比1：2，α-淀粉酶用量0.09 KNU/g淀粉，蒸煮温度85 ℃，蒸煮时间15 min。采用30 ℃同步糖化发酵工艺，糖化酶用量为3.4 AGU/g淀粉，发酵时间30 h。在10 L发酵罐中，乙醇质量比达127.88 g/kg，发酵效率为88.28%，发酵强度4.263 g/kg/h，100 L中试研究中乙醇浓度为127.75 g/kg，发酵强度4.258 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析，证明葡萄糖、果糖等单糖已完全被菌体利用，剩余糖为二糖，三糖等不可发酵的低聚糖。 运动发酵单胞菌快速乙醇发酵的研究。对实验室保藏的8株运动发酵单胞菌进行比较，选择发酵速度最快的Zymomonas mobilis232B进行研究。该菌在纯葡萄糖中的最佳发酵条件为：葡萄糖浓度18%，起始pH 6-7，发酵温度30 ℃，发酵时间18 h，乙醇浓度88 g/kg。在以木薯为底物同步糖化快速乙醇发酵中，采用Full Factorial设计和最速上升实验确定了培养基成分中的2个显著性因子及其最适浓度：酵母粉4 g/kg，硫酸铵0.8 g/kg。在最适培养基条件下，对木薯料水比和糖化酶用量进行了优化，得到Z.mobilis232B木薯乙醇发酵最佳料水比1：3，糖化酶浓度4 AGU/g淀粉，乙醇发酵4.915 g/kg/h。利用高效液相色谱对发酵液中残糖进行了分析，剩余糖为二糖，三糖等，但成分较酵母发酵后复杂。 According to the fuel ethanol development plans and policies in our country, the ethanol production from cassava by Saccharomyces cerevisiae and Zymomonas mobilis was studied. It provided theoretical basis for ethanol fermentation by cassava in industry. Part 1 is the study of VHG (very high gravity) ethanol fermentation by Saccharomyces cerevisiae. The content of starch in cassava was 70-75%. Compared with the performances under different experimental conditions, the following optimal conditions for VHG fermentation were obtained: Granule size of dry cassava 35 mashes, hydromodulus of cassava to water at 1:2, α-amylase enzyme dosage 0.09 KNU/g starch, cooking temperature 85 ℃ for 15 min, using the SSF process (simultaneous saccharification and fermentation) and the amount of glucoamylase 3.4 AGU/g starch. Accordingly, the final ethanol concentration was up to 127.88 g/kg; the ethanol yield reached 88.28%, and ethanol productivity was 4.263 g/kg/h after 30 h. When the fermentation scale expanded to 100 L, the final ethanol concentration was 127.75 g/kg, and the ethanol productivity was 4.258 g/kg/h in 30 h. The residual sugar was analyzed by high performance liquid chromatography, and proved that there was no glucose and fructose. The residual reducing sugar was some unfermentable oligosaccharide Part 2 is the study of the rapid ethanol production by Zymomonas mobilis. Compare with other seven stains, Zymomonas mobilis 232B was selected for research. The optimum condition in glucose medium was as follow: glucose concentration 18%, initial pH 6-7, and fermentation temperature 30 ℃. The ethanol concentration was 88g/kg in 18 h. After that, rapid ethanol production from cassava in SSF by Zymomonas mobilis 232B was studied. Through a series of experiments aided by Full Factorial Design and steepest ascent search, the optimal concentration yeast extract and ammonium sulfate were determined: 4 g/kg and 0.8 g/kg, each. Under optimum medium conditions, the optimal hydromodulus of cassava to water and glucoamylase dosages were obtained: hydromodulus of cassava to water at 1:3 and glucoamylase dosages 4 AGU/g starch. The ethanol production reached 4.915 g/kg/h. The residual sugar was analyzed by HPLC, and proved that the residual reducing sugar was some unfermentable oligosaccharide，but the components were more complex than that fermentation by Saccharomyces cerevisiae.

微波辐射对菘蓝种子生理及幼苗发育的影响

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