类单晶硅结构Si（C≡C―C6H4―C≡C）4新材料的力学与光学性质:第一性原理研究

基于单晶硅中Si的四面体成键特征及对其结构单元的替换修饰,我们设计了一种类单晶硅结构的新材料-C40H16Si2。通过广泛的第一性原理计算,研究了这类材料的电子性质、力学性质和光学性质。计算结果表明,这种新材料具有好的热力学稳定性和机械稳定性。该材料的禁带宽度为3.32 eV,价带底和导带顶都位于Gamma点,是直接带隙宽禁带半导体材料。该材料的维氏硬度和密度非常小,不到单晶硅的十分之一,是一类低密度的柔性多孔材料。此外,该材料在紫外光区有强的吸收,有望应用于蓝绿光发光二极管。中央高校基本科研业务费专项资金(20720150215);;国家自然科学基金(21373164,21673185)资助项目~

Effects of Pre-Diffuser on Performance of Dump Diffuser

研究了突扩扩压器中前置扩压器各参数与总压损失和静压恢复间的关系。采用实验与fluEnT计算结合的方法,通过水槽PIV实验得出扩压器内的流场信息,对照不同的湍流模型,得出最佳的计算方案。根据此计算方案计算不同的扩张角下前置扩压器性能的变化,得出各参数之间的规律。结果表明雷诺应力模型能够较好地预测扩压器内部流场;前置扩压器扩张角存在一个最佳值,大于最佳值前置扩压器会出现流动分离;结合理论分析和计算数据总结出计算前置扩压器总压损失系数和静压恢复系数的公式,利用此公式还可求出最佳的前置扩张角和前置扩压器长度,计算误差在5%左右。Diffuser is one key component of the gas turbine combustor following the compressor.Its primary function is to slow down the air flow delivered by the compressor in order to promote efficient combustion and avoid large total pressure losses.An experimental and computational study of cold flow in the dump diffusers was presented.The main aims were to evaluate the influence of pre-diffuser wall angle and pre-diffuser length on the performance of dump diffusers,and to identify the pressure loss mechanisms.PIV experiments were conducted in a simplified test model to help choose of congruent turbulence model.It was observed that apparent flow separation occurred on pre-diffuser wall when pre-diffuser wall angle amplified to certain degree.The pre-diffuser exit flow was distorted,indicating that the uniform exit conditions typically assumed in the diffuser design were violated.Skew distribution of the pre-diffuser outlet flow can result in strong transverse mixing for liquid,the total pressure loss of pre-diffuser increases significantly.The formula of the total pressure loss coefficient and the pressure recovery coefficient was developed.The optimal pre-diffuser length and pre-diffuser wall angle can be conveniently obtained by this equation,the calculation error was less than 5%.中央高校基本业务费(2013121019); 航空基金(20132268003

Performance Analysis of Three Kinds of Aero-Engine with Inter-Stage Turbine Burner

为探究级间燃烧室对各种航空发动机的性能影响,利用热力循环原理分别计算了在有无级间燃烧室的情况下涡喷、涡扇和涡轴发动机的性能结果并与实际型号做出对比。通过计算获得了上述三种发动机在加入级间燃烧室后的单位推力和耗油率随飞行马赫数等参数在一定范围内变化的曲线。结果表明加入级间燃烧室后对各种发动机的动力性能提升都在10%以上,个别涡轴发动机可达30%。同时若能将加入级间燃烧室后增加的质量控制在一定范围内,则对于各型发动机均可提高其推重比。In order to investigate the effects of the inter-stage turbine burner( ITB) on aero-engines,the thermodynamic cycle analysis was performed to demonstrate the performance of three kinds of aero-engines with the inter-stage turbine burners.The performance curves for different flight and operation conditions were obtained by calculation.Results show that specific thrust can be improved by at least 10%,and for one turboshaft engine the specific thrust even can be improved by 30%.Based on comparison between the real aero-engine performance and the calculation results,the errors are acceptable and the thrust-weight ratios show the potential capability of ITB application.国家自然科学基金(11002125;51106131); 中央高校基本科研业务费专项资金(2013121019

Methodologic Study of HPCE Fingerprints of Radix paeoniae Alba and Radix paeoniae Rubra

目的确定赤芍和白芍的高效毛细管电泳分析方法,建立赤芍和白芍的高效毛细管电泳法(HPCE)指纹图谱。方法HPCE工作条件:采用未涂层熔融石英毛细管(内径75μm,有效长度50 cm),分离电压为25 kV,柱温25℃,二极管阵列检测器(DAD)检测波长为220 nm,缓冲液为30 mmol/L硼砂(pH=9.0)溶液。按此条件对来自不同产地的7种赤芍样品和8种白芍样品进行了分析。结果建立了赤芍和白芍HPCE指纹图谱,采用中药指纹图谱相似度计算软件,以系统生成的对照指纹图谱为对照模板对不同样品的图谱进行相似度计算。结论该方法简捷、有效,可以用于赤芍和白芍药材的质量控制。Objective To set up a modern High Performance Capillary Electrophoresis analysis method for separating and detecting Radix paeoniae Alba and Radix paeoniae Rubra and establish their fingerprints.Methods Seven samples of Radix paeoniae Alba and eight samples of Radix paeoniae Rubra were carried out by HPCE under the following conditions: bared fused silica capillary(50 cm ×75 μm i.d.),30 mmol/L borate(pH = 9.0) as buffer,the run voltage is +25 kV,detection wavelength of UV at 220 nm,and column temperature of 25℃.Results The fingerprints were confirmed and compared by the software of the similarity evaluation system for chromatographic fingerprint.Conclusion The results showed that the method of HPCE fingerprint is reliable and accurate to control the quality of two Chinese traditional medicines.国家自然科学基金重点项目(No.20235020);; 青岛“2004将才计划”(No.04-3-JJ-11);; 青岛市崂山区科技计划项目(No.LS-05-KJZX-76

The Present Situation Investigation and Model Transformation of China Part-time Kinesiology Postgraduates

运用问卷调查法和访谈法,对我国21所高校630名在职体育硕士的培养状况进行调查分析。结果显示:我国在职体育硕士的普遍特征是高校教师、31~40岁、已婚、工龄4~10年,这些因素与报考态度、师资现状、课程设置、管理方式、学习反馈等方面存在着一定的相关性。深入剖析这些相关性的内在机理,提出从"在职"到"非全日制"不是取代而是补充,并对即将来临的体育专业硕士培养模式的转型提出建议:1)应用型——明晰培养方向;2)分类培养——提高培养效率;3)弹性学制——突破时空限制;4)质量评价——保证人才质量。630 part-time of China kinesiology postgraduates in 21 universities cultivation conditions are investigated by method of questionnaire and interview. Results show that the postgraduates' identities are teachers,31 ~ 40 years old,married,4 ~ 10 years employed,and these identities were related to teachers' situation,curriculum,management,and learning feedback. Further analyze the internal mechanism of the correlations which show that model transition from the "on-the-job"to the "part-time"one is "supplement"rather than "replacement",from this to propose the coming part-time kinesiology postgraduates model transition: 1) application-oriented——clear cultivating direction; 2) cultivating classification——improve efficiency; 3) flexible education system——breakthrough the limit of time and space; 4) quality evaluation——ensure the quality of talent.国家社会科学基金资助青年项目(122CTY023);; 教育部新世纪优秀人才资助项目(NCET-12-0617

Evaluation of DPPH Free Radical Scavenging Capability of Hippocampus japonicus Kaup. and Their HPLC Fingerprint

目的采用体外1,1-二苯基苦基苯肼(dPPH)抗氧化模型对海马提取物的抗氧化性质进行评价,并建立小海马HPlC特征指纹图谱,用于小海马药材的鉴别及质量评价。方法利用离线dPPH抗氧化评价体系对海马不同提取物进行评价,结果表明,海马水提物抗氧化能力最强,在此基础上又探明了海马水提物抗氧化能力随时间和浓度的变化规律,为海马抗氧化活性提供了科学依据。依据抗氧化活性实验结果,建立了海马水提物HPlC特征指纹图谱分析方法。结果海马水提物大部分化合物达到基线分离,方法的精密度、重现性、稳定性良好;建立小海马药材HPlC指纹图谱,采用中药指纹图谱相似度计算软件,对小海马进行真伪辨别和质量评价。结论表明该方法简捷、有效,是小海马药材鉴别及质量控制的有效方法。OBJECTIVE To evaluate the antioxidant activity of the extracts of Haima,and to establish the HPLC fingerprint of Haima for the discrimination and the quality evaluation of Haima.METHODS Antioxidant properties of Haima extracts with different solvent were assayed in terms of antioxidant activity by scavenging activities on 1,1-diphenyl-2-picrylhdrazyl(DPPH).The effect of time and concentration of Haima extract on the antioxidant activity was also studied.Secondly,a chromatographic fingerprint method was developed.RESULTS The antioxidant activity of water extract of Haima was higher than all the other extracts of Haima.The developed HPLC method was simple,accurate and reliable for the development of Haima fingerprint.Ten Haima samples collected from different medicine store were analyzed and the Haima HPLC fingerprint was established.The similarity of the HPLC chromatogram was performed for authentication and quality control of Haima.CONCLUSION The HPLC fingerprinting techniques have high potential in authentication or source-tracing types of applications.国家自然科学基金重点项目(20235020);青岛市共建生物医药研发测试中心资助项目(LS-05-KJZX-76

Redistribution of iron during directional solidification of metallurgical-grade silicon at low growth rate

研究冶金级硅低速定向凝固过程中杂质铁的再分布。采用ICP-MS检测铁的浓度,绘制铁在固相、液相、晶界和晶体生长方向上的浓度示意图。铁浓度在固、液相中具有明显差异。依据质量守恒定理,计算得出溶质边界层约为4 mm,铁的有效分凝系数约为2.98×10~(-4)。在低速凝固条件下,铁容易偏析聚集在晶界。在生长方向上,由于低速凝固,铁浓度在硅锭86%高度以下几乎恒定,不完全符合Scheil方程规律。讨论了对流对铁再分布的影响,对流"死区"对铁再分布具有重要影响。Redistribution of iron during directional solidification of metallurgical-grade silicon(MG-Si) was conducted at low growth rate. Concentrations of iron were examined by ICP-MS and figured in solid and liquid phases, at grain boundary and in growth direction. Concentrations are significantly different between solid and liquid phases. The thickness of the solute boundary layer is about 4 mm verified by mass balance law, and the effective distribution coefficient is 2.98×10~(-4). Iron element easily segregates at grain boundary at low growth rate. In growth direction, concentrations are almost constant until 86% ingot height, and they do not meet the Scheil equation completely, which is caused by the low growth rate. The effect of convection on the redistribution of iron was discussed in detail. Especially, the "dead zone" of convection plays an important role in the iron redistribution.Projects(51334004,51204143)supported by the National Natural Science Foundation of China;; Project(2006L2003)supported by the Scientific Technological Innovation Platform of Fujian Province,Chin

负偏置沉积法可控制备CuO多孔纳米结构薄膜

由于具有低成本、无毒、铜源丰富等优点,以及在气敏传感器、太阳能电池、光催化等领域的潜在应用前景,CuO薄膜引起了人们的广泛关注.采用射频平衡磁控溅射镀膜系统,在薄膜沉积过程中通过施加不同衬底负偏压可控制备了CuO多孔纳米结构薄膜.研究发现,所得CuO薄膜具有灵活可调的孔隙度和纳米构筑单元形貌特征,并且它们与衬底负偏压的大小密切相关;薄膜沿衬底法线方向呈柱状生长且具有显著的（111）择优取向;禁带宽度在2.0.35 eV之间可调.很明显地,传统的溅射离子轰击、再溅射理论并不适合用来解释上述负偏压效应,因此在此基础上提出了一种负偏置沉积过程中材料原子或分子在薄膜表面选择性优先沉积机制.国家自然科学基金(51501018,11574255)；江苏省自然科学基金(BK20150267,BK20141169)；江西省教育厅科技项目(GJJ161197)；江西省自然科学基金(20132BAB212005)资助

Controllable fabrication of Cu_2O porous nanostructured films by negative bias deposition method

由于具有低成本、无毒、铜源丰富等优点,以及在气敏传感器、太阳能电池、光催化等领域的潜在应用前景,; Cu_2O薄膜引起了人们的广泛关注.采用射频平衡磁控溅射镀膜系统,在薄膜沉积过程中通过施加不同衬底负偏压可控制备了Cu_2O多孔纳米结构薄膜.研; 究发现,所得Cu_2O薄膜具有灵活可调的孔隙度和纳米构筑单元形貌特征,并且它们与衬底负偏压的大小密切相关;薄膜沿衬底法线方向呈柱状生长且具有显著; 的(111)择优取向;禁带宽度在2.0~2.35; eV之间可调.很明显地,传统的溅射离子轰击、再溅射理论并不适合用来解释上述负偏压效应,因此在此基础上提出了一种负偏置沉积过程中材料原子或分子在薄; 膜表面选择性优先沉积机制.As one of the most common two kinds of copper oxides, cuprous oxide; (Cu_2O) is an important p-type transition metal oxide semiconductor; material. Due to the advantages of low-cost, non-toxicity and abundant; copper sources and the potential applications in the fields of gas; sensors, solar cells and photocatalysts, thin films of Cu_2O have; attracted great interest of researchers. To enhance the performances of; the above Cu_2O-based surface-sensitive devices and materials, the; researchers tend to prepare Cu_2O thin films of porous or even; nanoporous structures. However, there is still no effective method; available for the controllable fabrication of Cu_2O porous; nanostructured films (or porous nanostructure-films, short for PNFs),; which owns not only the common features of porous thin films but also; the unique properties of nanosize building units. By using a; radiofrequency balanced magnetron sputtering (MS) deposition system, in; this paper, Cu_2O PNFs were prepared on clean glass slides by applying; different negative bias voltage during film deposition. After the; preparation, a field-emission scanning electron microscope (FESEM), a; grazing-incidence X-ray diffractometer (GIXRD) and an; ultraviolet-visible (UV-Vis) spectrophotometer were applied subsequently; for the detailed characterizations of surface morphology, texture and; optical property respectively. It was observed that the as-prepared; Cu_2O PNFs exhibited flexible porosities and nanosize building units,; which were greatly dependent on the substrate negative bias voltage. In; particular, when the substrate bias voltage was kept at -50 or -150 V,; the as-prepared Cu_2O PNFs both demonstrated intriguing triangular; pyramid-like nanostructures with distinct edges and corners on the; porous film surface. Further, the side view FESEM images and the; out-of-plane GIXRD spectra demonstrated a columnar growth of the Cu_2O; PNFs with a notable preferential orientation of (111). The optical; testing results showed that the band gap of the Cu_2O PNFs obtained at; different negative bias voltages was tunable between 2.0 and 2.35 eV,; which demonstrated a little red or blue shift relative to that of bulk; Cu_2O (2.17 eV). It is expected that the traditional ion bombardment and; re-sputtering theories are not suitable for the explanation of the above; bias voltage effects. This is because the traditional ion bombardment; and re-sputtering theories were proposed to account for the bias; deposition in an unbalanced magnetron sputtering (MS) system rather than; the present balanced MS system. Further, the experimentally observed; non-linearly changed density or porosity of the Cu_2O PNFs with the bias; voltage at relatively low values and the common even surface at; relatively high values confirmed this viewpoint. Based on the above; findings and analysis, a selectively preferential deposition of material; atoms or molecules on the film surface during the negative bias; deposition was proposed. That is, when the substrate is negatively; biased, the tipcharging effect of electrons would occur on the nanoscale; rough surface of the substrate or the depositing film. The resulting; electric field near the substrate or film surface is non-uniform and; could be regarded as an assembly of many electric fields of particle or; tip charges.国家自然科学基金; 江苏省自然科学基金; 江西省教育厅科技项目; 江西省自然科学基

1978～2008年中国湿地类型变化

分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978～2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978～2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978～1990年)降为831km2/a(2000～2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978～1990年)几乎全部(98%)转换为非湿地;在1990～2000年间减少的自然湿地约有86%转化为非湿地,而在2000～2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动