摘要：为了提高热设计的设计效率,基于热传导、流体换热、流体力学理论,对典型强迫风冷散热系统进行精确建模,对精确模型进行简化方法的研究.使用该简化热模型,可以对强迫风冷散热系统进行快速、准确的设计.采用该简化热模型设计的380 V/50 kVar SiC-MOSFET静止无功补偿器(SVG)的工业化样机,散热器表面温升误差为4.1℃(满载条件),满足工程化设计的要求.

摘要：Taking advantage of the new standard HTML5,we designed an online tool called a browser/server-based glaucoma image database builder(BGIDB)for the demarcation of the optic disk and cup’s ellipse-like *** B-spline interpolation algorithm is used,and a specially designed algorithm is proposed for classifying the disease grade according to the disc damage likelihood scale criterion,which is correlated strongly with the glaucoma process by *** tool exhibits the best performance with a low overlapping error of 4.34%for the optic disk demarcation and 8.31%for the optic cup *** also has preferable time-consuming as compared to other tools and is a cross-platform *** tool has already been utilized in building the ophthalmic image database in the cooperation of Center for Ophthalmic Imaging Research and The Second Xiangya Hospital.

摘要：Camelid single-domain antibody fragments(nanobodies)are an emerging force in therapeutic biopharmaceuticals and clinical diagnostic reagents in recent *** all nanobodies available to date have been obtained by animal immunization,a bottleneck restricting the large-scale application of *** this study,we developed three kinds of gene designatedregion pan-editing(GDP)technologies to introduce multiple mutations in complementarity-determining regions(CDRs)of nanobodies in *** the integration of G-quadruplex fragments in CDRs,which induces the spontaneous multiple mutations in CDRs;however,these mutant sequences are highly similar,resulting in a lack of sequences diversity in the *** also used CDR-targeting traditional gRNA-guided base-editors,which effectively diversify the *** most importantly,we developed the self-assembling gRNAs,which are generated by reprogrammed tracrRNA hijacking of endogenous mRNAs as *** base-editors guided by self-assembling gRNAs,we can realize the iteratively diversify the *** we believe the last GDP technology is highly promising in immunization-free nanobody library construction,and the full development of this novel nanobody discovery platform can realize the synthetic evolution of nanobodies in vitro.

摘要：针对多级推力固体火箭发动机轴对称喷管的特点,以CFD流场仿真为基础,通过运用合理的模型简化、动态网格、并行仿真等技术和优化策略,建立了合适的喷管流场仿真模型和型面优化模型,实现了基于CFD仿真的喷管型面优化方法,解决了计算规模过大、计算不稳定的问题,能够高效和稳定地对喷管型面进行优化设计计算,同时通过对不同工作段流场的分析和综合计算,实现对喷管的高精度性能预估。计算实例验证了此方法的有效性。此方法的应用,为进一步挖掘喷管潜能、提高喷管设计水平提供了切实可行的途径。

摘要：浮动核电厂的安全性与反应堆供电系统的优劣紧密相连,为提高浮动核电厂的安全系数,需对反应堆供电系统进行分析。本文结合反应堆供电系统设计的要点,分析浮动核电厂反应堆供电系统的配置,对比了2种方案下的辅助电力系统和核应急电力系统。结果表明,优化后的方案2在可靠性和安全性方面都较方案1更优,且方案2也更为经济。本文提出的优化方案可为后续核动力船舶反应堆供电系统的设计提供参考和借鉴。

摘要：Gradation equation is one way to describe the gradation of coarse-grained soil conveniently,exactly and *** the gradation equation,the influence of gradation on the mechanical behaviors of coarse-grained soil can be expressed quantitatively.A new gradation equation with a parameter is *** basic properties and applicability of the new equation are *** results show that the proposed equation has the applicability to express coarse-grained soil gradation(CSG),and the range of the parameter β is found to be 00.5,the gradation curve is sigmoidal,otherwise the gradation curve is *** well graded gradations,the parameter has the value of 0.13<β<*** CSGs used in domestic and foreign earth-rockfill dams are probed,and the value of the parameterbfalls in the range of 0.18 to *** investigation of the range of β is of value to guide the design for CSG of earth-rockfill dam.

摘要：由于PCR影响因素多 ,获得理想扩增结果比较困难 ,有必要寻找一种简单有效的方法建立最佳扩增体系 .针对Mg2 +浓度、二甲基亚砜 (DMSO)浓度、变性时间、延伸时间、循环次数等因素进行 4因素 6水平和6因素 10水平均匀设计实验优化apoE基因 2 4 4bp片段的PCR扩增条件 .采用纯化模板和简易模板 ,只需 6～10次实验即可获得特异性、高产率扩增结果 .研究表明 ,将均匀设计用于PCR条件优化以及有关的样品处理、试剂选择等研究方面可以避免盲目性 。

摘要：为解决可控饱和电抗器(MCR)在每相分别补偿时,其输出电流含有大量谐波的问题,提出一种可有效抑制谐波电流的多磁阀可控电抗器优化设计方法.该MCR的铁芯由多种磁阀串联组成,每种磁阀具有不同的长度和导磁面积,在工作过程中,各个磁阀因磁饱和程度不同而输出大小和相位各不同的谐波电流,可减小电抗器输出电流谐波.根据该装置的结构特点,建立其磁化曲线数学模型及谐波输出数学模型,通过遗传算法优化计算得到当磁阀取不同值时的最优结构参数;对所提出的电抗器结构进行三维电磁有限元仿真计算以修正设计参数,并根据提出的理论进行了仿真实验.结果表明:经过优化设计后,MCR的输出谐波含量最大值被抑制在输出电流的2.8%以下,和理论分析一致,证明该方法是可行的.

摘要：文章对电流连续工作模式(CCM)下LCC谐振变换器的工作模态进行了分析,在此基础上采用基波近似法对LCC谐振拓扑进行了简化,推导出LCC谐振变换器的基波纯阻性和基波容性等效电路,建立了与开关频率、负载及变换器增益有关的数学模型.结合模型,提出了宽范围输入输出电压LCC谐振拓扑的设计方法,基于此方法结合一套电源设计指标设计了一组谐振参数.通过仿真验证了所设计的LCC谐振变换器在宽范围输入输出电压条件下可实现全负载范围的软开关,满足设计指标,证明了模型和设计方法具有较高精准度和良好应用价值.

摘要：Anthocyanins have high antioxidant activities, and engineering of anthocyanin biosynthesis in staple crops, such as rice （Oryza sativa L.）, could provide health-promoting foods for improving human health. However, engineering metabolic pathways for biofortification remains difficult, and previous attempts to engineer anthocyanin production in rice endosperm failed because of the sophisticated genetic regulatory network of its biosynthetic pathway. In this study, we developed a high-efficiency vector system for transgene stacking and used it to engineer anthocyanin biosynthesis in rice endosperm. We made a construct containing eight anthocyanin-related genes （two regulatory genes from maize and six structural genes from Coleus） driven by the endosperm-specific promoters,plus a selectable marker and a gene for marker excision. Transformation of rice with this construct generated a novel biofortified germplasm ＂Purple Endosperm Rice＂ （called ＂Zijingmi＂ in Chinese）, which has high anthocyanin contents and antioxidant activity in the endosperm. This anthocyanin production results from expression of the transgenes and the resulting activation （or enhancement） of expression of 13 endogenous anthocyanin biosynthesis genes that are silenced or expressed at low levels in wild-type rice endosperm. This study provides an efficient, versatile toolkit for transgene stacking and demonstrates its use for successful engineering of a sophisticated biological pathway, suggesting the potential utility of this toolkit for synthetic biology and improvement of agronomic traits in plants.