Material Growth and Device Fabrication of GaN-Based Blue-Violet Laser Diodes

Studies on first GaN-based blue-violet laser diodes(LDs) in China mainland are reported.High quality GaN materials as well as GaN-based quantum wells laser structures are grown by metal-organic chemical vapor deposition method.The X-ray double-crystal diffraction rocking curve measurements show the fullwidth half maximum of 180″ and 185″ for (0002) symmetric reflection and (10-12) skew reflection,respectively.A room temperature mobility of 850cm2/(V·s) is obtained for a 3μm thick GaN film.Gain guided and ridge geometry waveguide laser diodes are fabricated with cleaved facet mirrors at room temperature under pulse current injection.The lasing wavelength is 405.9nm.A threshold current density of 5kA/cm2 and an output light power over 100mW are obtained for ridge geometry waveguide laser diodes.     

水滑石类插层组装功能材料

水滑石类(LDHs)化合物是一类典型的阴离子型层状材料。LDHs的构筑单元和结构的可控性和多样性,为此类材料的应用研究提供了广阔前景。以LDHs的层状结构和可插层性为线索,介绍了LDHs的结构特征和制备化学,讨论了阴离子插层LDHs的组装原理和主-客体相互作用,对基于主体层板调控及主-客体相互作用的多种插层LDHs功能材料的制备和应用进行了综述,并对LDHs的结构创新和制备技术的研究方向进行了展望。     

云南水电基地在国家实施“西电东送”中的主力作用

云南水能资源丰富，总量大，人均占有量多；开发条件有利，外部环境优越；水库淹没损失较小，技术经济优越；电能质量高，送电稳定可靠；地理位置适中，电力市场前景广阔，电价具有较强的竞争力。云南水电建设已有一定基础，但目前开发程度低，开发潜力大，除满足云南本省国民经济发展和人民生活用电增长的需求外，在相当长时间内，具有较强的外送能力，在国家的西部大开发战略中，实施“西电东送”战略必将起到主力作用。     

直机翼静气动弹性特性研究

现代亚音速飞机的柔性较大,其静气动弹性对载荷分布有重要影响。为此,基于全机地面共振试验结果建立机翼的结构有限元模型,利用颤振风洞试验测量的弹性变形对基于偶极子格网法的定常气动力进行下洗修正,建立了直机翼的静气动弹性模型,分析了静气动弹性对直机翼飞行载荷分布的影响。结果表明:静气动弹性使直机翼存在"弹性加载"效应。直机翼结构设计时,应考虑静气动弹性引起的飞行载荷分布问题。     

海南锆钛砂矿产业海外发展SWOT分析及对策建议

为了降低投资风险,取得较好的经济效益,借助SWOT手段分析海南锆钛砂产业海外发展的影响因素,并提出对策建议。海南锆钛砂产业在海外发展具有产业基础优势、技术管理优势、市场优势以及华侨华人关系优势,有博鳌亚洲论坛、中非合作论坛等交流平台和国际矿业产业调整的机会,但也存在资金不足、人才短缺、抵御风险能力差的劣势,面临国际资本对锆钛砂产业的控制及锆英砂价格的不确定性等不利因素。因此,要发挥地矿行业的主渠道作用,利用矿业投资推动社会交往,积极融入当地社会,不断加强企业竞争力,坚持勘查－生产一体化和找矿与采矿相结合的发展道路。     

3D打印数字人像快速成型技术的研究与实现

自动获取人像数据并高精度重建是三维人脸识别的研究热点。针对三维重构缺少成熟算法与有效应用方法的问题,提出了一种基于二维数据的三维打印数字人像快速成型方法。该方法采用二维照相的方法获取人像的正视图、侧视图和俯视图,使用MAYA软件对人像数据进行网格化处理,生成OBJ文件导入PROE生成三维实体,并导入JDpaint实现数控仿真加工,最后将STL文档导入打印机打印出三维人像。实验证明,该方法实现了数据获取、网格划分、曲面重建和快速成型的整个工作流程。     

Potential of Leersia hexandra Swartz for phytoextraction of Cr from soil

Research on the phytoextraction of Cr from contaminated soils has been scarce, because very few plant species have been reported to accumulate Cr to high concentrations in their aerial parts. In this study, a Cr-hyperaccumulator, Leersia hexandra was investigated for its potential to remove Cr from the soil in a series of pot experiments. The results showed that L. hexandra had a high extraction capacity for chromium in soil, with the highest Cr concentration in shoot of 1844 mg/kg. Model calculation based on the negative linear relationship between the bioconcentration factors (BCF) and the concentrations of soil Cr indicated that phytoremediation using L. hexandra was feasible when soil was only moderately contaminated with Cr. Three sequential harvests did not significantly alter Cr accumulation and shoot biomass (p > 0.05), indicating that sequential harvest might be an available and convenient way to achieve the decontamination of Cr-contaminated soils by L. hexandra. On average, fertilization increased the shoot biomass by 45% and the total amount of extracted-Cr by 26%, suggesting that fertilization is able to enhance Cr phytoextraction of L. hexandra. Although EDTA increased the concentrations of Cr in shoots by 1.4 times, it also resulted in low plant biomass, thereby decreasing the amount of Cr accumulation.     

Chitosan-whey protein isolate composite films for encapsulation and stabilization of fish oil containing ultra pure omega-3 fatty acids

Chitosan (1.5%, w/v)-whey protein isolate (WPI, 5% w/v) composite films were developed for encapsulating and stabilizing fish oil (FO) containing 93.7% eicosapentaenoic acid (EPA). Chitosan-WPI film-forming solutions (FFS) were incorporated with 1.5% or 2% FO (w/v), 2% (w/v) glycerol, Tween 80 (3 times weight of FO), and 0.5% (w/v) oregano or rosemary essential oil (EO), and cast for films at room conditions. Dried films were stored at 2 °C for 30 d for evaluating encapsulation efficiency (EE), lipid stability, and film functionality. Total oil contents in films from FFS incorporating 1.5% or 2% FO were 28.1% to 32.5% and 33.4% to 37.3%, respectively, and free oil contents were 13.5% to 14.7% and 15.5% to 16.3%, respectively. EE, moisture content, and water activity of the films were 47.8% to 66%, 18.7% to 24.9%, and 0.42% to 0.50%, respectively, without significant difference among differently formulated films. Increasing FO concentration from 1.5% to 2% in FFS decreased tensile strength of the films from 0.57-0.73 to 0.34-0.44 MPa, but not the film elongation. Addition of oregano EO in FFS retarded lipid oxidation of the fish oil encapsulated in the films, in which a 43% to 53% reduction in thiobarbituric acid-reactive substances value and 39% to 51% reduction in peroxide value were achieved. Chitosan-WPI composite films with incorporation of oregano essential oil could be applied as a simple and economic means for encapsulating and stabilizing fish oil for fortifying omega-3 fatty acids in various applications.     

Quantum dots with phenylboronic acid tags for specific labeling of sialic acids on living cells

Sialic acids with a nine-carbon backbone are commonly found at the terminal position of the glycans structures on cell membranes. The unique distribution and ubiquitous existence of sialic acid on the cell membrane make them important mediators in various biological and pathological processes. We report a new class of imaging probes based on semiconductor quantum dots with small molecular phenylboronic acid tags for highly specific and efficient labeling of sialic acid on living cells. Our results have shown that the use of these probes enables one-step labeling and continuous tracking of the cell surface sialic acid moieties without any pretreatment of living cells. The one-step procedure with fast binding kinetics and the biocompatibility of these probes make it an ideal noninvasive technology for living cell imaging. We also find that the labeled sialic acids undergo quick internalization shortly after surface binding via endocytosis and eventually distribute in the perinuclear region. This distribution pattern is consistent with the notion that sialylated glycoproteins are populated on cell membranes and recycled through the vesicular exocytotic and endocytic pathways. The superior photostability and brightness of quantum dots enable quantitative analysis of the diffusion dynamics of sialic acids, which has been a significant challenge for glycan imaging.     

Photocatalytically Patterned TiO(2) Arrays for On-Plate Selective Enrichment of Phosphopeptides and Direct MALDI MS Analysis

We report the development of photocatalytically patterned TiO(2) arrays for selective on-plate enrichment and direct matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of phosphopeptides. A thin TiO(2) nanofilm with controlled porosity is prepared on gold-covered glass slides by a layer-by-layer (LbL) deposition/calcination process. The highly porous and rough nanostructure offers high surface area for selective binding of phosphorylated species. The patterned arrays are generated using an octadecyltrichlorosilane (OTS) coating in combination of UV irradiation with a photomask, followed by NaOH etching. The resulting hydrophilic TiO(2) spots are thus surrounded by a hydrophobic OTS layer, which can facilitate the enrichment of low-abundance components by confining a large volume sample into a small area. The TiO(2) arrays exhibit high specificity toward phosphopeptides in complex samples including phosphoprotein digests and human serum, and the detection can be made in the fmole range. Additional advantages of the arrays include excellent stability, reusability/reproducibility, and low cost. This method has been successfully applied to the analysis of phosphopeptides in nonfat milk. The patterned TiO(2) arrays provide an attractive interface for performing on-plate reactions, including selective capture of target species for MALDI-MS analysis, and can serve as a versatile lab-on-a-chip platform for high throughput analysis in phosphoproteome research.