Medium Optimization for Antitumor Agent Mycoepoxydiene by Marine Lignicolous Fungi Diaporthe sp.

从海洋木栖真菌HLY-2分离得到的真菌环氧二烯(Mycoepoxydiene)是新发现的高抗肿瘤活性化合物。通过正交设计,改良普通半海水PD培养基的配方,比较固体和液体两种发酵方法,得到了使该化合物产量大幅提高的最佳培养条件:在固体发酵条件下土豆250g/L,海水300mL/L,葡萄糖30g/L,乳糖50g/L,磷酸二氢钾0·65mmol/L,硫酸铵1g/L,产量高达543mg/L,比普通的PD培养基提高了43倍,也比液体发酵的最高产量提高了近15倍。同时还对固体发酵和液体发酵造成的产量差异进行了分析。并检验了发酵产物的抗肿瘤活性。Mycoepoxydiene is a novel antitumor agent extracted from marine lignicolous fungi HLY-2, which is Diaporthe phaseolorum by molecule identification. The medium optimization for mycoepoxydiene by orthogonal design and the comparison of submerged fermentation and solid state fermentation were studied. The rusult is that the maximal yield of the compound is 543mg/L, which is 43 times compared to the customary half-seawater PD medium and 15 times to the best submerged condition. This optimum culture medium included potato 250g/L, seawater 300mL/L, glucose 30g/L, lactose 50g/L, KH_ 2 PO_ 4 0.65mmol/L and (NH_ 4 )_ 2 SO_ 4 1g/L in the solid state condition. Differentiation analysis between submerged and solid state fermentation, and antitumor activity of these ferment products were also studied. The antitumor activity of products of the optimum medium approached the pure compound.国家自然科学基金资助项目(No.2003AA624010);; 福建省科技项目基金(No.2004N003);; 福建省自然科学基金(No.C0210001

Green Emission from a Strain-Modulated InGaN Active Layer

Strain-induced quantum dots (QDs) like island formations are demonstrated to effectively suppress pits/dislocation generation in high indium content (26.8%) InGaN active layers. In addition to the strain redistribution in the QD-like islands, strain modulation on the InGaN active layers by using the GaN island capping is employed to form an increased surface potential barrier around the dislocation cores, which inhibits the carrier transport to the surrounding dislocations. Cathodoluminescence shows distinct double-peak emissions at 503 nm and 444 nm, corresponding to the In-rich QD-like emission and the normal quantum well emission, respectively. The QD-like emission becomes dominated in photoluminescence due to the carrier localization effect of In-rich InGaN QDs at relatively low "carrier injection current". Accordingly, green emission may be enhanced by the following origins: (1) reduction in pits/dislocations density, (2) carrier localization and strain reduction in QDs, (3) strain modulation by GaN island capping, (4) enhanced light extraction with faceted GaN islands on the surface.National Natural Science Foundation of China [60876008, 61076091]; Program for New Century Excellent Talents in Fujian Province Universit

永磁式同步馬達直接驅動單軸機械臂系統之非線性控制

本文旨在對永磁式同步馬達直接驅動單軸機械臂系統設計非線性控制器以達到定 位控制之目的。 首先設計一漸近穩定之速度估測器， 接著利用 Integrator Backstepping 與非線性阻尼的技巧來設計一非線性控制律，然後將速度估測器與非線性控制律結合成一非 線性控制器，並利用遺傳演算法來搜尋及獲得最佳的控制器參數值。電腦模擬結果顯示此非 線性控制器具有良好的定位控制性能及強韌性。In this paper, a nonlinear controller is designed for a one-link robot system directly driven by a permanent magnet synchronous motor to achieve a desired position control. This nonlinear controller includes an asymptotic speed estimator and a nonlinear control law that is designed by using an integrator backstepping method and a nonlinear damping technique. Values of control parameters of this nonlinear controller are automatically searched and obtained by using a simply genetic algorithm with a fitness function that appropriately describes the control objective. Results of computer simulation demonstrate the effectiveness and the feasibility of the designed robust nonlinear controller

鲫耳石年轮的观察及其确证

对耳石边缘年轮形成周期进行了分析。结果表明，鲫耳石上1a形成1个年轮，年轮形成时期洪湖种群主要在4－6月，洞庭湖种群主要在3－5月。星耳石和微耳石一样，可用于鲫年龄测定，而且不经磨片即可直接读取年轮，完整星耳石和微耳石与微耳石磨片上的年轮读数的吻合率均在80％以上，误差不超过1龄。但相对而言，微耳石上年轮更易观察。文中对耳石形态和年轮特征进行了描述

Electronic Structure and Magnetic Properties of NiCu Multilayers

【中文摘要】 用自旋极化的 LMTO超元胞方法计算了 Ni Cu多层膜的电子结构 ,通过对 Ni Cu多层膜的每一层的态密度的分析 ,表明 Ni的磁性随层数变化而明显变化 . 【英文摘要】 The electronic structure of NiCu multilayers were calculated using ab initio localspindensity of the Linear MuffinTin Orbital (LMTO) method. The selfconsistent calculations were made for superlattice parameters in order to obtain ground state properties of these multilayers. The analysis of the density of states at an equilibrium volume gives a good description of the electronic and magnetic properties.国家自然科学基金资助项目(69896260

用鳞片和耳石鉴定鲫年龄的比较研究

两观测者独立观测了分别采自洪湖的175尾和洞庭湖的168尾鲫样本的鲜片和耳石，结果显示鳞片适于鉴定年龄组成简单、生长较快的洞庭湖鲫种群的年龄，两观测者年轮读数的总吻合率可达90.5%，与耳石上年轮读数的吻合率也可高达91.7%；但用鳞片鉴定年龄结构复杂、生长缓慢的洪湖鲫种群年龄，两观测者总吻合率只有50.9%，各龄组吻合率随年龄上升而迅速下降。与耳石上年轮读数总吻合率也仅为56.6A%，存在比耳石低估高龄个体年龄的问题，用耳石鉴定鲫年龄具有易于识别、精确度高的优点，用之鉴定洪湖和洞庭湖鲫种群年龄，两观测者年轮读数的总吻合率都很高，分别为92.7%和97.0%，且随年龄上升，依然可保持较高的精确度，对洪湖鲫种群应用耳石为宜

用鳞片和耳石鉴定鲫年龄的比较研究

两观测者独立观测了分别采自洪湖的 1 75尾和洞庭湖的 1 6 8尾鲫样本的鳞片和耳石 ,结果显示鳞片适于鉴定年龄组成简单、生长较快的洞庭湖鲫种群的年龄 ,两观测者年轮读数的总吻合率可达 90 5% ,与耳石上年轮读数的吻合率也可高达 91 7% ;但用鳞片鉴定年龄结构复杂、生长缓慢的洪湖鲫种群年龄 ,两观测者总吻合率只有 50 9% ,各龄组吻合率随年龄上升而迅速下降 ,与耳石上年轮读数总吻合率也仅为 56 6 % ,存在比耳石低估高龄个体年龄的问题。用耳石鉴定鲫年龄具有易于识别、精确度高的优点 ,用

鲫耳石年轮的观察及其确证

对耳石边缘年轮形成周期进行了分析。结果表明 ,鲫耳石上 1a形成 1个年轮 ,年轮形成时期洪湖种群主要在 4～ 6月 ,洞庭湖种群主要在 3～ 5月。星耳石和微耳石一样 ,可用于鲫年龄鉴定 ,而且不经磨片即可直接读取年轮 ,完整星耳石和微耳石与微耳石磨片上的年轮读数的吻合率均在 80 %以上 ,误差不超过 1龄。但相对而言 ,微耳石上年轮更易观察。文中对耳石形态和年轮特征作了描

鲫耳石重量与年龄的关系及其在年龄鉴定中的作用

耳石重量在年龄组间重叠较少 ,大小相近的个体 ,年龄大的 ,即生长慢的耳石重量比年龄小的、即生长快的大 ,不同龄组之间耳石重量有显著差异 (P <0 .0 5 )。按年龄组以耳石重量与相应的体长作图 ,可初步判断观测年龄的可靠性 ,分析耳石重量频率分布能分离出体长相近、年龄不同的个体 ,其结果与耳石年轮观测的基本一致。耳石重量与年龄呈显著线性正相关 (P <0 .0 5 ) ,用耳石重量与年龄关系估算的年龄与从耳石上直接读取的年龄无显著差异 (P>0 .0 5 )。文中对耳石重量直接用于确定鱼类年龄的可

鲫耳石重量与年龄的关系及其在年龄鉴定中的作用

耳石重量在年龄组间重叠较少，大小相近的个体，年龄大的，即生长慢的耳石重量比年龄小的，即生长快的大，不同龄组之间耳石重量有显著差异（P＜0．05），按年龄组在耳石重量与相应的体长作图，可初步判断观测年龄的可靠性，分析耳石重量频率分布能分离出体长相近，年龄不同的个体，其结构与耳石年轮观测的基本一致，耳石重量与年龄呈显著线性正相关（P＜0．05），用耳石重量与年龄关系估算的年龄从耳石上直接读取的年龄无显著差异（P＞0．05），文中对耳石重量直接用于确定鱼类年龄的可能性作了分析和探讨