Effect of Fabrication Technology on the Performance and Structure of Stearic Acid/Attapulgite Composite Phase Change Materials

Two kinds of stearic acid (SA)/ attapulgite (ATTP) composite phase change materials (PCMs) were prepared for the latent heat thermal energy storage (LHTES) in buildings or other area by the methods of fusion and immersion, using SA as PCMs and ATTP supplied by Linze of Gansu province as supporting material. The structure, thermal properties, thermal reliability and heat storage or release performance of the composite PCMs were determined by scanning electron microscope (SEM), fourier transformation infrared (FTIR), differential scanning calorimetry (DSC) and thermal cycling test analysis technique. The results indicate that the preparation method has no effect on the structure and morphologies of the composites. Two kinds of composites have same structure due to the SA adsorbed in the surface of ATTP by physical reaction. The results also show that two form-stable composites PCMs have the optimal effect for preventing SA leak from the composite emerges when the maximum load proportion of SA in the composites were 38.64wt% and 29.13wt%. The latent heats and phase change temperature were measured as 68.71 J/g and 57.3℃ for the composite which was prepared by fusion method and 51.79 J/g and 55.2℃ for the composite fabricated by immersion method, respectively. The results of DSC, FTIR and thermal cycling test are all showing that two kinds of composites have good heat storage property but the composite prepared by fusion method has a better thermal and chemical stability.     

Study on constant current control of inductive power transfer with parameter identification

Aiminy at magnetic exciting current (resonant current) control, a constant current control method based on dynamic parameter identification is put forward. With energy conversion analysis, the energy storage, supply and dissipation functions of the system resonant network are constructed. The reflecting impedance identification functions are obtained by constructing the energy equilibrium relations in a period and among several periods. Furthermore, a constant current control strategy by regulating the system input voltage with Buck converter is presented. Combining the relations among system input voltage, the envelope of resonant current and the input of Buck converter, the constant current control law is proposed. The control law is verified with experiments. For the proposed method, in parameter identification, only the data of zero crossing point of resonant voltage and current are required, which reduces the complexity and costs of sampling system. Also, the constant current control law does not need complex computation and is easy to implement.     

Application of time-frequency distribution correlating and matching method in signal extraction

The time-frequency coupling relation between useful non-stationary components and noises bring great difficulties to the realization of de-noising for non-stationary signals,which can not be solved by classic de-noising method in time or frequency domain. The principles of short time Fourier transform(STFT),Wigner-Ville transform,Chirplet adaptive decomposition are analyzed,and then a novel de-noising method for non-stationary based on joint time-frequency distribution is proposed. In this method,the analyzed signal WVD is seen as the combination of auto-WVD and cross-term WVD. Firstly,STFT energy spectrum of the analyzed signal is used as template to cross-correlate with its corresponding WVD in order to obtain the satisfactory time-frequency distribution with high time-frequency resolution and without cross-term interferences. Secondly,the useful components are decomposed as Chirplet function using the two-dimension least square fitting method,and then are extracted out to reconstruct for noise suppression. Finally,the computer simulation results verify the effectiveness of this proposed method. Its application in gearbox fault diagnosis indicates that with the method the extracted cycle of the gearbox vibration impulses has a good consistency with the corresponding fault frequency.     

基于表达序列标签（EST）的基因克隆和基因表达分析研究进展

表达序列标签 (expressed sequence tag,EST)是在生物体特定时空表达基因的一段 c DNA序列。随着生物信息学的发展 ,EST已成为基因定位、基因克隆、基因表达分析的有力工具。文章对应用 EST克隆基因和分析基因表达的研究进展进行了综述 ,并讨论了利用 EST进行基因克隆和表达分析时应注意的问题和发展趋势     

不同叶龄移栽对水稻产量及品质的影响

通过叶龄移栽试验结果分析表明,水稻在3～8叶之间移栽,以4叶处理产量最高,达10374kg/hm2,比8叶期移栽增产11.0%,方差分析结果,3～6叶之间处理产量差异不显著,但均比8叶期移栽显著增产;根据稻米检验结果,垩白率、垩白度受移栽叶龄影响较大,适宜叶龄移栽能显著降低垩白率和垩白度.采取中苗移栽能使糙米率、精米率,整精米率及蛋白质的含量提高,直链淀粉降低,有利于产量的提高和稻米品质的改善.     

热带、亚热带玉米自交系与温带自交系遗传关系研究

以 9个热带、亚热带玉米自交系和 5个代表中国温带主要杂优群的自交系为材料 ,利用SSR分子标记技术和NC -Ⅱ遗传设计的田间试验方法 ,研究了它们之间的遗传关系。结果表明 ,温热杂交组合掖 478×CML31 0、Mo1 7×CML1 0、黄早 4×CML1 0 7、旅 9×CML31 0、自330×CML31 2产量特殊配合力较高 ;根据SSR标记遗传多态性结果将供试自交系分为 6个杂优类群 :第 1类群包括CML1 0、CML2 65 ,第 2类群包括CML2 7、CML96、CML2 95、Mo1 7,第3类群包括CML32 3、黄早 4 ,第 4类群包括CML31 0、CML31 2、自 330、丹 340 ,第 5类群包括CML1 0 7,第 6类群包括掖 478;SSR标记的分类结果与产量配合力及系谱分析结果基本一致     

玉米新品种丹玉33号的选育及其特征特性

玉米杂交种丹玉33号（原代号丹123）是丹东农业科学院1996年组配的中熟单交种，1998-2001年参加辽宁省中熟组区域试验及生产试验。该品种高产，抗病，适于辽宁，吉林等地种植。2001年12月通过辽宁省农作物品种审定委员会审定。     

遮阳网的小气候效应及其对蔬菜生长的影响

在遮阳网覆盖与露地条件下 ,进行不同蔬菜种类的分期播种对比试验 .采用平行观测法 ,较系统地进行小气候和蔬菜生长状况观测 .结合统计分析 ,得到以下主要结论 :( 1)在晴至少云与多云天气条件下 ,遮阳网覆盖能显著降低气温及地温 ,且 0 cm及 10 cm地温降幅大于气温 ;( 2 )在阴雨天气条件下 ,遮阳网覆盖无降温效果 ;( 3)因水气难以散失 ,雨后覆盖遮阳网 ,会造成高温、高湿的小气候条件 ,并会助长病害的蔓延 ;( 4 )无论何种天气条件 ,遮阳网覆盖均会显著削弱太阳辐射 ;( 5)在蔬菜栽培上 ,苗期覆盖遮阳网 ,有减轻病害、保全苗的效果 ;( 6)全生育期覆盖 ,应视品种的耐阴性选用遮光率合适的遮阳网 ,并注意适时揭、盖 ,否则会因光照不足而造成严重减产     

吉首沙田柚少核机理研究Ⅰ.吉首沙田柚少核原因及其果实品质初探

为充分利用开发无核或少核品种，以吉首少核沙田柚为试材，经自然授粉、花粉隔离和人工杂交授粉等处理，研究了其少核原因，并对吉首少核沙田柚的果实品质进行了测定。结果表明：吉首少核沙田柚单果平均种子数2-32粒；初步认为其少核可能是由于多数幼胚中途停止发育所致；少核沙田柚果皮变薄，可食率增加。     

甘蓝新品种秦甘70的选育及其抗病优质性评价

秦甘 70是利用具有抗病优质和配合力高的两个自交不亲和系 HS2 10 3- 6 - 9和 FT6 32 8- 1- 5配育成的杂交一代 ,为中早熟甘蓝新品种 ,定植到叶球收获 70 d左右。植株综合经济性状优良 ,中心柱 6 .5 cm,紧实度0 .5 7,帮叶比 2 6 .5 % ;叶质脆甜 ,富含营养物质 ,鲜重含粗蛋白 11.81g/ kg,粗纤维 4 .113g/ kg,可溶糖 32 .5 g/ kg,VB1 2 .118g/ kg;抗 Tu MV,Br和 CMV3种病害 ;产量 6 4 32 0 .0 kg/ hm2 ,比对照中甘八号增产 15 .1%。