Shape optimization of axisymmetric solids with the finite cell method using a fixed grid

In this work, a design procedure extending the B-spline based finite cell method into shape optimization is developed for axisymmetric solids involving the centrifugal force effect. We first replace the traditional conforming mesh in the finite element method with structured cells that are fixed during the whole design process with a view to avoid the sophisticated re-meshing and eventual mesh distortion.Then, B-spline shape functions are further implemented to yield a high-order continuity field along the cell boundary in stress analysis. By means of the implicit description of the shape boundary, stress sensitivity is analytically derived with respect to shape design variables. Finally, we illustrate the efficiency and accuracy of the proposed protocol by several numerical test cases as well as a whole design procedure carried out on an aeronautic turbine disk.

Comparison of shape representation methods for dynamic cell analysis

To evaluate the performance of basic shape representation methods for the description of dynamic cellular morphology, several frequently-used shape descriptors are compared. The methods are examined by using 50 lymphocyte video clips including two kinds of lymphocyte cells. Our goal is to represent cell shape in each frame accurately, meanwhile precisely classify the two groups of cells based on the cellular morphological variations in the video clips. Experimental results illustrate that in general the region-based shape descriptors outperform the contour-based ones, since the contourbased methods are excessively sensitive and ignorant to cellular internal information. Due to their robustness to noise, the region-based shape descriptors are suitable for dynamic cell representation. Although region-based methods are more time-consuming, they analyze the entire cell area.

Effects of Storage Duration and Temperature of Human Plasma and Serum on Red Blood Cell Aggregation and Shape

Platelet-free plasma of human blood (sodium citrate and EDTA as an anticoagulant) and serum were stored at 4°C, room temperature (25°C) and at 37°C for 24 hours. RBC aggregation decreased after incubation of plasma and serum at 37°C for 4 hours. The RBC shape was changed at the same time: discocytes transformed to echinocytes. Storage of plasma and serum at 4°C and room temperature did not lead to significant alterations of RBC aggregation. The RBC shape did not change in influence of such plasma and serum. The most considerable decrease of RBC aggregation and change of their shapes were observed in the plasma and serum incubated at 37°C for 24 hours. Dilution of incubated plasma by fresh plasma led to consistent restoration of erythrocyte shape and their aggregation.

Influence of matrigel on the shape and dynamics of cancer cells

The interaction between extracellular matrices and cancer cells plays an important role in regulating cancer cell behaviors. In this article, we use matrigel to mimic extracellular matrices and investigate experimentally how matrigel influences the shape and dynamics of breast cancer cells(MDA-MB-231-GFP cells). We find that matrigel facilitates cancer cells' migration and shape deformation. The influences of the matrigel concentration are also reported.

Electrochemical Properties of Electrodes with Different Shapes and Diffusion Kinetic Analysis of Microbial Fuel Cells on Ocean Floor

Microbial fuel cell(MFC) on the ocean floor is a kind of novel energy-harvesting device that can be developed to drive small instruments to work continuously.The shape of electrode has a great effect on the performance of the MFC.In this paper,several shapes of electrode and cell structure were designed,and their performance in MFC were compared in pairs:Mesh(cell-1) vs.flat plate(cell-2),branch(cell-3) vs.cylinder(cell-4),and forest(cell-5) vs.disk(cell-6) FC.Our results showed that the maximum power densities were 16.50,14.20,19.30,15.00,14.64,and 9.95 mWm-2 for cell-1,2,3,4,5 and 6 respectively.And the corre-sponding diffusion-limited currents were 7.16,2.80,18.86,10.50,18.00,and 6.900 mA.The mesh and branch anodes showed higher power densities and much higher diffusion-limited currents than the flat plate and the cylinder anodes respectively due to the low diffusion hindrance with the former anodes.The forest cathode improved by 47% of the power density and by 161% of diffusion-limited current than the disk cathode due to the former's extended solid/liquid/gas three-phase boundary.These results indicated that the shape of electrode is a major parameter that determining the diffusion-limited current of an MFC,and the differences in the elec-trode shape lead to the differences in cell performance.These results would be useful for MFC structure design in practical applica-tions.

Shape formation of closed-cell aluminum foam in solid–liquid–gas coexisting state

The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid–liquid–gas coexisting state was realized through cell wall deformation and cell movement caused by primary α-Al grains that slid,rotated,deformed,and ripened within cell walls.During formation,characteristic parameters of closed-cell aluminum foam were almost unchanged.Under proper forming conditions,shaped products of closed-cell aluminum foam could be fabricated through mold pressing.

Unusual W-shaped Galvanic Cell Model of ISCC of α-brass in Neutral Mattsson's Solution

Intergranular stress corrosion cracking (ISCC) of α-brass in neutral Mattsson's solution was found to be controlled by an unusual 'W'-shaped galvanic cell whose cathode is the grain boundary oxide film (G.B.0. film) and surface film and the anode is fresh metal at the cracked tip on both sides of the G.B.0. film. Redox reactions involved in the cell have been proposed here. According to this mdel, initidtion of ISCC is caused by the rupturing of surface film along grain boundaries, thus forming a galvanic cell. Propagation of ISCC resulted from alternate advances of G.B.0. film and dissolution on both sides of G.B.0. film caused by the effect of electrochemical reaction. This work developed an effective approach to investigate the embrittlement process at the tip of the crack, by increasing the length of the embrittlement region through constant strain test and distinguishing the morphology and the nature of the corrosion products by optical microscopy and scanning electron microscopy (SEH).

Carrier transport via V-shaped pits in InGaN/GaN MQW solar cells

Carrier transport via the V-shaped pits （V-pits） in InGaN/GaN multiple-quantum-well （MQW） solar cells is numer- ically investigated. By simulations, it is found that the V-pits can act as effective escape paths for the photo-generated carriers. Due to the thin barrier thickness and low indium composition of the MQW on V-pit sidewall, the carriers entered the sidewall QWs can easily escape and contribute to the photocurrent. This forms a parallel escape route for the carries generated in the fiat quantum wells. As the barrier thickness of the fiat MQW increases, more carriers would transport via the V-pits. Furthermore, it is found that the V-pits may reduce the recombination losses of carriers due to their screening effect to the dislocations. These discoveries are not only helpful for understanding the carrier transport mechanism in the InGaN/GaN MQW, but also important in design of the structure of solar cells.

腹膜后伴有奇异形细胞的Castleman病1例

目的:探讨腹膜后伴有奇异形细胞的Castleman病临床特点、病理特征、鉴别诊断,减少误诊。方法:对我院收治的腹膜后伴有奇异形细胞的Castleman病1例的临床资料进行回顾性分析并文献复习。结果:患者因腹部胀满不适半年余就诊。行CT检查提示腹膜后巨大肿块,考虑脂肪肉瘤遂行腹膜后肿瘤切除术。术后病理检查示淋巴滤泡数量增多,套区增宽,生发中心萎缩,滤泡间可见大量的浆细胞及少量淋巴细胞的背景中可见散在奇异形大细胞;免疫组织化学染色示:CD3、CD5、CD38、CD20及CD21均(+),CyClinD1(-),Kappa、Lambda均示部分(+)。确诊为腹膜后Castleman病,术后恢复良好出院。随访9个月未见明显复发征象。结论:伴有奇异形细胞的Castleman病较为罕见,对奇异形细胞认识不足,易误诊为恶性肿瘤,导致过度治疗。其体征及影像学检查缺乏特异性,及时行组织病理学检查是避免误诊的关键。

330 kA铝电解槽异形阴极碳块对水平电流的影响

采用有限元仿真计算,对330 kA铝电解槽传统阴极碳块结构和异形阴极碳块结构的电场进行仿真模拟,主要对铝液中水平电流分布进行分析。研究发现,异形阴极碳块结构相对于传统阴极碳块结构能够在影响压降较小的前提下降低水平电流密度。模拟结果表明,在异形阴极碳块表面凸起中增加隔断并改变凸起角度,对降低铝液中水平电流效果明显,能够降低铝液中最大水平电流密度27.8%,平均水平电流密度34.3%,有效提升了铝电解槽电流效率。

GTEM Cell斧形过渡块侧边曲线方程的算法

为便于加工 ,以往的吉赫兹横电磁波传输室 (GTEMCell)过渡接头中斧形过渡块均采用近似设计 ,即侧边取直线。这样做的结果是传输损耗曲线在过渡段的分布不理想。基于修正的目的 。

Cell adhesion molecules regulate contractile ring-indepen- dent cytokinesis in Dictyostelium discoideum

在胞质分裂调查底层粘附的角色，我们建立了房间线缺乏 paxillin (PAXB ) 或 vinculin (七弦琴) ，和在 Dictyostelium discoideum 表示各自的 GFP 熔化蛋白质的那些。作为在哺乳动物的房间， GFP-PAXB 和 GFP 七弦琴在房间底部上形成了焦点的像粘附的建筑群。paxB？在暂停的房间通常，但是上种了底层，经常没能在沟的回归以后划分。paxB 的有效胞质分裂？在暂停的房间不因为砍帮助截去，，的力量他们也在静态的暂停文化通常划分了。双猛烈紧张缺乏 mhcA，它为肌浆球蛋白 II 编码，和 paxB 或七弦琴比各单个的大美人显示了更严重的 cytokinetic 缺点紧张。在有丝分裂的野类型的房间， GFP-PAXB 广泛地在基础膜上被散布，但是惊人地在有丝分裂的 mhcA 沿着极的边被压缩吗？房间。这些结果与我们 Dictyostelium 显示胞质分裂的二种形式的想法一致，是可收缩的戒指依赖者的并且粘附无关，并且可收缩的其它戒指无关并且粘附依赖者，并且后者要求 PAXB 和七弦琴。而且，那 paxB？房间没能面对底层粘附通常划分建议这个粘附分子可以起另外的发信号的作用。

阳极支撑型锥管串接式直接碳固体氧化物燃料电池组的制备及性能

针对阳极支撑型直接碳固体氧化物燃料电池(DC-SOFC)的浓差极化阻抗大的问题,本研究采用改进后的凝胶注模法制备了阳极支撑型锥管状固体氧化物燃料电池(SOFC)。通过适当增加溶剂的含量,改善了浆料的流动性,提高了成品的质量;通过增大造孔剂的含量,提高了阳极的孔隙率,减小了气体的扩散阻力。改进后的SOFC以氢气为燃料,在800℃运行时,开路电压为1.05 V,电化学阻抗谱的极化阻抗更小,电池的最大功率密度为0.67 W×cm^(–2)(阴极有效面积为2.2 cm^(2)),明显优于改进前的SOFC。改进后的SOFC直接采用担载质量分数5%K的活性炭为燃料,在800℃运行时,开路电压为1.030 V,接近理论电压,最大功率密度达0.74 W×cm^(–2),以400 mA进行恒流放电,碳燃料的有效利用率为31%,高于改进前电池的碳燃料的有效利用率17%。将改进后的4个锥管状单电池串联成电池组,直接采用担载质量分数5%K催化剂的活性炭为燃料,在800℃运行时,最大功率达8.0 W,高于改进前的4节DC-SOFC电池组(4.1 W),该电池组碳燃料的有效利用率为15%,峰值功率密度可达0.91 W×cm^(–2),超过了文献报道的最高值。

花瓣形钢管混凝土柱轴压受力机理和承载力研究

花瓣形钢管混凝土柱具有造型美观的优点,为具体研究其受力机理和承载力,定义了其截面组成,提出了截面偏移比和截面对称系数以反映花瓣形截面性质,提出在花瓣柱中设置十字形加劲肋以增强其组合效应。基于某工程中墩柱和有限元模型,研究了花瓣形钢管混凝土短柱在轴压荷载作用下的受力机理,分析了加劲肋厚度、混凝土强度、钢材强度、加劲肋开孔直径和间距等参数对轴压性能的影响,研究了加劲肋厚度与钢管壁厚的匹配关系。根据理论分析和大量有限元参数分析结果,建议了加劲肋厚度与钢管壁厚之比和钢管名义径厚比的取值范围,提出了花瓣形钢管混凝土短柱的轴压承载力计算式。

Sequence Pair-Based Scatter Search Approach for Cell Formation and Layout Considering Unequal Machine Dimensions and Cell Input and Output Locations

In the purpose of dealing with the inconsistency of the machine dimensions in cell formation and layout problems,comprehensively taking into account such factors as alternative process routings, lot splitting, cell input and output( I / O)locations,an integrated cell formation and layout model considering unequal machine dimensions is established which aims at minimizing intra-cell material handling cost,inter-cell material handling cost and cell expansion cost. A sequence pair-based scatter search algorithm is proposed which simultaneously adopts the roulette wheel selection operator as a subsets combination method to improve the quality of new solutions and the dynamic reference sets updating method to accelerate the convergence rate. Through the comparison of the results achieved by the proposed algorithm, Lingo and simulated annealing under different problem scales,the correctness of the model and the effectiveness of the algorithm are verified.

水稻籽粒伸长突变体lgdp的鉴定与基因定位

水稻粒形与产量和营养品质密切相关,挖掘水稻粒形发育相关基因并解析其分子机制,对提高水稻产量、改善籽粒营养品质具有重要意义。利用甲基磺酸乙酯(ethyl methanesulfonate,EMS)处理籼稻品种西大1B,获得了1个水稻粒形突变体,命名为long grain and degenerated palea(lgdp)。lgdp表现出外稃伸长,从而导致籽粒长度增加的特征,进一步扫描电镜分析发现,lgdp籽粒变长主要原因是其外稃细胞数目极显著增加。遗传分析表明该性状受1对隐性基因调控;利用lgdp与ZH11杂交构建的F2分离群体,通过BSA法将目标基因定位在3号染色体分子标记ZLN43和ZLN-1之间,物理距离大约810 kb。通过转录测序和PCR分析初步确认LGDP候选基因编码一个MADS-box基因。qPCR分析表明,LGDP可能通过负向调控GW7/GL7、GS3、TGW6等水稻粒长正向调控因子的表达,从而影响了颖壳细胞数目的增殖,进而影响籽粒长度。本研究结果为应用LGDP基因改良水稻粒形提供了新的资源。

SMARCA4融合相关肉瘤的临床病理学及分子遗传学特征

目的探讨SMARCA4融合相关肉瘤的临床病理学及分子遗传学特征。方法回顾性分析2例SMARCA4融合相关肉瘤的临床病理学及免疫表型特征,采用二代测序技术分析分子遗传学特征。结果2例男童年龄分别为7岁(例1)及12岁(例2),病变部位为右侧睾丸及右侧腘窝,临床表现为右侧睾丸及右侧腘窝的无痛性占位,肿瘤最大径4.5~7.0 cm。镜检:低倍镜下2例瘤细胞均呈弥漫片状及交织束状排列,瘤细胞疏密不等,呈圆细胞样、上皮样及梭形,肿瘤性间质为黏液性及胶原样基质,均可见凝固性坏死,核分裂象均易见。例1以黏液样间质为主;例2以胶原化背景为主。免疫表型:2例具有肌源性分化,表达desmin和SMA;部分表达CD99;SMARCA2、SMARCA4(BRG1)、SMARCAB1(INI-1)、ARID1A、H3K27ME3表达均无缺失,Ki-67增殖指数分别为60%、20%。2例随访时间8~22个月,例1未见复发及转移,例2复发,出现可疑肺转移。2例均检测到SMARCA4融合,分别为SMARCA4-DOCK6融合及SMARCA4-VEZF1融合。结论SMARCA4融合相关肉瘤是一种罕见的恶性软组织肿瘤,分子特点为SMARCA4融合。

基于影像组学的脑脊液细胞分类方法

目的:基于影像组学构建出更为高效、准确的脑脊液细胞判别模型。方法:回顾性收集3331张脑脊液细胞显微图像,其中吞噬细胞167张、单核细胞332张、淋巴细胞1081张、中性粒细胞1751张。首先在显微图像上分割出细胞核、细胞核凸包区域和细胞核凸包区域的部分细胞质,然后设计3种细胞核形状特征,即圆度、凸度、坚固性。针对细胞核、凸包区域和凸包区域的部分细胞质设计48种颜色特征。基于细胞核凸包区域提取4 676种纹理特征。结果:共提取了4 727个影像组学特征,在经过ANOVA和LASSO特征选择之后,保留了519个特征,且形状特征和颜色特征都得到了较高比例的保留(100.0%, 66.7%)。特征选择之后,利用SMOTE数据增强和SVM分类器在测试集上进行预测,各项评价指标Accuracy、Sensitivity、Specificity、Precision、F1_score、AUC高达0.953、0.948、0.990、0.961、0.955、0.996。结论:本文提出的新的细胞显微图像特征提取方案和分类模型对细胞分类问题非常有效,且避免了细胞质分割的难题,无需分割细胞,只需分割细胞核和细胞核凸包区域就可以得到较好的分类结果。

传统村落“胞-链-形”结构的GIS识别与提取

以衡阳市中田村为研究区,应用“胞-链-形”方法,结合环境特征,从景观基因胞、景观基因链、景观基因形3个不同层次,数字化识别提取了中田村的空间结构,分析了中田村内部各组成部分的空间结构特征和空间关系,总结了中田村空间结构的形态特征。结果表明:①“胞-链-形”分析方法对于中田村空间结构的识别提取具有一定的适用性;②识别提取的“胞”有民居、祠堂、月光塘、广场、山体等,“链”主要是道路和巷道,“形”是中田村的整体结构形态;③中田村的空间结构形态是典型的组团式空间结构形态。该研究成果有利于深化对传统村落空间结构的认识,为传统村落空间结构的识别提取提供一定的科学依据。

装配工况下PEMFC不同双极板截面接触行为研究

为进一步探究双极板几何形状对层间接触行为的影响,以金属双极板为对象,搭建了双极板压缩试验台,同时建立了双极板压缩试验有限元模型,根据压敏纸采集到的试验结果验证了模型的有效性.然后,分别搭建了梯形、矩形和波浪形三种常见截面形状的双极板有限元模型,并搭建了相应的双极板压缩试验有限元模型.通过仿真分析研究在不同装配载荷作用下双极板截面形状对层间接触行为的影响.结果表明:装配载荷大小和双极板截面形状对双极板与气体扩散层(Gas Diffusion Layer, GDL)之间的接触行为有显著影响;在不同装配载荷作用下,三种双极板肋下的GDL表面接触应力幅值均在0.5~2 MPa之间,均符合装配要求;在同等条件下,双极板肋宽度是决定双极板与GDL之间整体平均接触应力幅值和GDL平均侵入面积的主要因素;在三种双极板中,矩形双极板下的接触行为对装配载荷的变化更为敏感,并且矩形双极板下平均接触应力分布均匀性最差.