Effects of Dietary Protein and Lipid Levels on Growth Performance, Muscle Composition, Immunity Index and Biochemical Index of the Greenfin Horse-Faced Filefish (Thamnaconus septentrionalis) Juvenile

The effects of different dietary protein and lipid levels on juvenile greenfin horse-faced filefish(Thamnaconus septentrionalis)was experimentally evaluated in a 56-day study.Fish(initial weight 6.47±0.56 g)were fed with nine different diet combinations containing three varying levels of protein(37%,43%,49%)and lipids(4%,7%,10%)in triplicates,where the protein-to-energy(P/E)ratios of the diets varied in the range of 19.17-26.99mgkJ−1.Results showed that fish fed diets containing 49%protein and 10%lipid exhibited significantly lower feed intake than those fed other diets.The weight gain of fish fed diets with 43%protein was significantly higher than that of fish fed 37%or 49%protein diets.While no significant change in weight gain was observed when lipid content was increased from 4%to 7%,weight gain decreased significantly when lipid increased from 7%to 10%.The protein efficiency ratio and feed efficiency were highest when the fish were fed the diet with 49%protein and 7%lipids.Muscle crude lipid content was positively correlated with dietary protein level regardless of lipid level.The diet of 43%protein or 7%lipids significantly reduced the activity of alanine aminotransferase and aspartate aminotransferase in liver.The contents of aspartate aminotransferase,superoxide dismutase and malondialdehyde were significantly increased from 4%to 10%lipids in plasma.The plasma total cholesterol and triglyceride contents were positively correlated with dietary lipid level at the same protein level.Our comprehensive analysis concluded that a diet with 43%protein and 7%lipid,with a P/E ratio of 23.07mgkJ−1,significantly promote the growth performance,feed utilization and health of juvenile greenfin horse-faced filefish.

传统马面裙形制结构考释及其现代设计思辨

基于文化自信与传统文化振兴的背景下,马面裙代表着中国优秀的传统文化走进大众视野、走向国际舞台。文章纵向整理马面裙发展的历史脉络、横向梳理马面裙的款式差别,同时立足现代服装设计,对于马面裙从平面结构的对比到立体形态的差异进行拓展研究。采用实验法、比较研究法,将马面裙实物数据为基础样本,进行实物复原和形制特征记录。同时依据现代裙装结构制版方法,进行相同数据的多样本制作和横向的形制比对。采用概率逻辑分析,从平面结构的比对到立体形态的差异进行拓展分析。通过对比实验结果,就马面裙的结构复原、改良方案和创新视角展开设计思辨。

复合材料裙的优化设计及轴压性能研究

针对热压罐工艺成型的ϕ150 mm固体火箭发动机壳体复合材料裙,进行了轴压试验,并通过建立引入黏性行为及三维Hashin失效准则的渐进损伤模型开展有限元分析,对复合材料裙及含裙复合材料壳体的失效模式、失效位置及轴压载荷进行了准确预测,以验证有限元模型的可靠性。以此为基础,根据复合材料裙铺层原则,建立了基于随机正态算法的铺层优化模型,对复合材料裙的铺层顺序和铺层角度进行优化,得到了满足要求的最优铺层。基于最优铺层,分析了不同搭接角度与搭接长度对载荷规律的影响,确定了最优的搭接角度和长度,并通过轴压试验对结果进行验证。结果表明:当铺层为[90/0/45/0/90/90/-45/-45/45/0]时,复合材料裙在达到材料强度极限前发生屈曲失稳,满足设计需求;随着搭接角度增大,屈曲载荷逐渐增大,而载荷增量先增大后减小;随着搭接长度的增大,屈曲载荷逐渐增大,但增量呈下降趋势,最终确定最优搭接角度为3°,最优搭接长度为20 mm。含裙复合材料壳体轴压试验最终屈曲载荷为29.77 kN,与仿真结果相差6%,失效位置在复合材料裙裙尖处,与仿真结果一致。

钢筒仓环板环梁稳定承载力的中外规范比较

钢筒仓在仓壁、仓裙及漏斗相交处容易发生平面外屈曲破坏,通常在相交处设置一道环梁来抵抗破坏,相交处环梁稳定对钢筒仓安全运行起着至关重要的作用。环梁通常分T型环梁与环板环梁2种。环板环梁宽度、环板环梁厚度是环板环梁的2个主要参数,为进一步研究其对环板环梁稳定承载力的影响,以某项目钢筒仓环板环梁为例,分别依据中国规范、欧洲规范的计算方法,深入研究环板环梁宽度、环板环梁厚度与环板环梁稳定承载力的关系,比较分析中国规范与欧洲规范计算值之间的差异,提出合理化建议,为类似工程提供参考。

Response of Skirted Suction Caissons to Monotonic Lateral Loading in Saturated Medium Sand

Monotonic lateral load model tests were carried out on steel skirted suction caissons embedded in the saturated medium sand to study the bearing capacity. A three-dimensional continuum finite element model was developed with Z_SOIL software. The numerical model was calibrated against experimental results. Soil deformation and earth pressures on skirted caissons were investigated by using the finite element model to extend the model tests. It shows that the ＂skirted＂ structure can significantly increase the lateral capacity and limit the deflection, especially suitable for offshore wind turbines, compared with regular suction caissons without the ＂skirted＂ at the same load level. In addition, appropriate determination of rotation centers plays a crucial role in calculating the lateral capacity by using the analytical method. It was also found that the rotation center is related to dimensions of skirted suction caissons and loading process, i.e. the rotation center moves upwards with the increase of the ＂skirted＂ width and length; moreover, the rotation center moves downwards with the increase of loading and keeps constant when all the sand along the caisson＇s wall yields. It is so complex that we cannot simply determine its position like the regular suction caisson commonly with a specified position to the length ratio of the caisson.

Influence of deformation load on forging process of aluminium piston skirt

Based on the rigid-plastic theory, the finite element method (FEM) equation which incorporates the influence of impact load and volume force is presented. The hammer forging theory for simulation is also given. On the basis of technological analyses, the piston skirt forging processes of LD11 aluminium alloy are simulated under both mechanical pressure forging and hammer forging conditions. By comparison with the metal flow, fibre flow lines, distributions of strain and temperature of the two forging methods, practical forging was carried out and the product quality was controlled. The deformation pattern of the piston skirt forging process was determined by comparing the simulation results with the practical forging results.

Purification and Identification of Antioxidant Peptides from the Scallop Skirts of Mimachlamys Nobilis

The processes of scallop meats can produce a large amount of by-products like scallop skirts,which are rich in nutrients. This work aimed to obtain the information about antioxidant peptides derived from scallop skirts of Mimachlamys nobilis. The hydro-lysates obtained by trypsin exhibited the highest antioxidant activity( 75.6%,79.5% and 76.7% using DPPH,hydroxyl and superoxide anion radical scavenging activity assays,respectively). The antioxidant peptides( MNAP) were separated and purified using UF membranes,GFC processes and RP-HPLC,and the antioxidant activity of MNAP was identified to be 85.7% using DPPH radical scavenging activity assay. The peptides( MNAP) were composed of two peptides with their molecular weights2 855.6 Da and 3 007.2 Da using MALDI-TOF-MS,respectively. The results suggested that the scallop skirts of Mimachlamys nobilis could be explored as a source of antioxidant peptides.

3D FEA simulation of 4A11 piston skirt isothermal forging process

To eliminate the defects during piston skirt isothermal forming process,simulations under different process parameters such as the deformation temperature and friction factor were analyzed with the rigid-plastic FEA.Deformation pattern,metal flow and influence of process parameters were concluded.The prediction load value with a relative error of 4.98% is more accurate to the testing one than that from the empirical formula whose relative error is up to 50.8%.Finally,based on the simulation results,an improved process at 300 ℃ and 0.005-0.05 s-1 was verified without any defects by the physical try-out.

Research on Effect of Oil Film Inertia on Piston Skirt by Iteration Method

The influence of oil film inertia on piston skirt lubrication in a high speedengine is investigated by an iteration method that alternately solves the Navier-Stocks equationsand the Reynolds equa-tion by finite element method and difference method. The Reynolds lubricationequation including oil film inertia is developed, in which the inertia coefficient is introduced toinvestigate the effect of oil film inertia. The iteration procedure and finite formulation ofsolving the new Reynolds lubrication equation are given to analyze the effect of oil film on pistonskirt in this kind of engine. The calculation results show that the oil film inertia has someeffects on the friction force, pressure force and load capacity of oil film and its effect isobvious for the last. The Reynolds lubrication equation proposed can be also used to analyze thelubrication performance of the piston skirt in low or medium speed engine and some other lubricationproblems generally excluding oil film inertia with the inertia coefficient being set at zero.

Influence of Oil Film Inertia on Piston Skirt Lubrication in High Speed Engine

By an iteration method, the influence of oil film inertia on piston skirt lubrication in a high speed engine is investigated. By alternately solving the Navier-Stocks equations and the Reynolds equation, the new iteration method can trace the variations of velocity field and pressure field with time. Based on this, the mixed-lubrication model suitable for the piston skirt of high engines is proposed. By introducing the inertia coefficient, the new lubrication model includes the inertia term in oil film. The model can be also used to solve for the lubrication performances of a piston skirt in low or medium speed engines and for lubrication problem in general excluding the inertia term of oil film , when the inertia coefficient is put equal to zero. The calculation results show that the influence of oil film inertia on the friction force increases with the ratio of the piston skirt's length to its diameter, the inertia coefficient and the eccentricities of the lower and the upper piston skirt, with other conditions kept constant, while the influence of it on the load capacity of oil film is small.

The Surface Skirt in Gaseous Scanning Electron Microscope (GSEM)

In this work, a novel parameter called the surface skirt (Ss) is introduced. The electron beam scattering by gaseous environment is the fundamental parameter limiting the performance of the Gaseous Scanning Electron Microscopy (GSEM). The result is the enlargement of the primary beam characterized by the radius skirt Rs. The scattering phenomena require a much closer re-examination. In fact, depending on the localization of EDX detector and the particles shape to analyze, the collected signal after the beam skirt will be different and Rs also will be different. So, except for homogeneous materials, Rs can not describe the scattering behavior. In this study, the surface skirt Ss instead of the radius skirt is introduced. Unlike Rs, the results show that Ss is a linear function versus pressure. This may help to use Ss in different scattering regimes and for a best interpretation of the consequences of electron scattering beam by gaseous environment. For demonstration, two gases environment: helium and water vapor are given but the results are valid whatever the environment used.

Optimal Skirt Spacing for Subsea Skirted Foundation Considering Floating Stability

A hydraulics model is built in Moses to find the optimal internal skirt spacing for the maximum floating stability of the skirted foundation. The results show that the increase in the internal skirts’ number can help improve the floating stability of the skirted foundation. However, with the increase in the internal skirts’ number, the improvement of floating stability becomes more and more weak. In this study, an optimal number of four are found for the internal skirt spacing. Moreover, to testify the feasibility of internal skirt spacing, a practical project is modeled, which indicates that the optimal internal skirt spacing can satisfy the requirements of towing. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

Mixed Lubrication Analysis and Experiment Validation of Internal Combustion Piston Skirt

A mixed lubrication model was established for piston skirt lubrication. The mathematical model developed in this paper incorporates governing equations of motion with average Reynolds equation. This model considers the surfaceroughness and profile. The corresponding computer program can be used to calculate oscillatory motion of piston during the entire trajectory, which has the excellent convergence.In addition, a set of equipment, which adopt the laser induced fluorescent method, was developed to measure the oil film thickness between the piston and the bore.

Dynamic Behaviors of a Moored Floating Structure with Flexible Skirts

A numerical model was developed by using the dual boundary element method to investigate the dynamic behavior of a moored floating structure with a pair of vertical and flexible skirts attached at its bottom in the linear wave field. Theoretical conception is based on potential theory with linear external forces. The motions of the structure were assumed to be small and linear. The flexible skirts mounted beneath the structure were assumed uniform flexural rigidity and the thickness of the skirts was negligible. Comparison between the present model and Gesraha＇s solution was made to verify the results for a moored floating structure with or without rigid skirts. The influence of the skirt rigidity on the moored floating structure, moored lines and waves is investigated in this study. The results show that, the natural frequencies of structure＇s oscillation, moored force, wave reflection and transmission tend to the region of short-period waves when the flexible rigidity gradually decreases. Positive correlation exists between the aft mooring force and the pitch motion of the floating structure.

马面裙的定义与结构特征来源探析

马面裙是中国传统服饰中较为经典的款式之一。为了从结构特征的角度解决马面裙来源不明晰、定义冗杂的问题,采用词频分析法整理归纳马面裙的3个结构特征,同时通过比例分析法对宋代褶裥裙及二片式旋裙的形制进行分析,并结合宋代相关裙型形制特点,重新定义马面裙的形制特征。研究表明,马面裙源于宋代,其形制为前后有马面状搭叠裙门的二片式结构,侧面有多个褶裥的中式裙装。

汽车侧裙板数值成型分析及模具设计

汽车侧裙板长度约为1 m,宽度约为0.1 m,卡扣、加强筋、嵌件孔等复杂结构较多,属于大型细长复杂塑件。大型细长复杂塑件成型难度较大,需要采用数值仿真与模具设计相结合的方法,仿真、设计和验证交叉进行、相互渗透。根据产品的特点拟定了3种进浇方案,仿真结果表明,方案Ⅲ(9点进浇)翘曲变形量最小,其值为4.51 mm。通过验证方案Ⅲ的缩水性、填充时间、填充等值线、填充末端时间差及压力差等参数可知,方案Ⅲ填充均匀、末端压力一致、产品无缩水,表面无质量缺陷,为可行方案。根据方案Ⅲ进行模具设计,包括浇注系统、成型零部件、推出机构、冷却系统等。模具设计完毕后对冷却系统进行验证,结果表明,凸凹模的模温温差小于10℃,模温趋于一致,无翘曲变形风险。基于方案Ⅲ的模具设计可作为最终方案,为模具制造和生产提供方向。

“重回汉唐”马面裙流行趋势分析

本研究旨在探讨传统服饰马面裙在现代时尚中的复兴与流行趋势,为进一步研究时尚设计的动态变化提供有价值的参考。通过收集“重回汉唐”品牌过去三年共六个季节的99张马面裙图片,采用定性观察法,观察并分析每款马面裙的类型、图案题材、装饰工艺和裙长的变化。研究采用编码后数据统计,通过表格和趋势图形式直观呈现研究期间马面裙流行趋势的细节。结果表明,马面裙的现代流行展现了历史尊重与创新融合的设计趋势,预示着在个性化和文化认同需求的推动下,传统与现代结合的风格有望在全球范围内继续流行。

深厚软土深基坑被动区土体加固机制

周边环境复杂地区的软土深基坑对变形控制的要求极高,目前基坑支护主要遵循“强桩强撑”的设计思路,针对坑底以下存在深厚软土地层的情况,对基坑内侧被动区软土进行加固,能改善土体物理力学性能,有效约束基坑开挖变形。建立4种深厚软土地层基坑开挖模型,通过将离心模型试验的实际监测结果与Plaxis3D岩土有限元软件建立的等比例三维数值模型模拟结果相互验证,研究支护桩端在软土中的深基坑变形破坏模式和被动区加固效果。结果表明:在被动区软土未加固的情况下,支护桩端在软土中的基坑发生整体失稳破坏,支护桩进入硬土后的嵌固作用对基坑变形控制非常有利,在被动区设置裙边矩形加固,基坑变形显著减小;随着加固体深度、宽度的增加,基坑各项变形值均呈减小趋势,到一定值后变化不明显,加固深度、加固宽度的有效范围分别为0.4H~0.6H、0.6H~1.0H;加固体尺寸变化对地表沉降的影响最大,其次为支护桩水平位移、基底隆起。

明宁靖王夫人吴氏墓出土团窠双龙戏珠纹暗花缎褶裙形制考

对明代吴氏墓出土团窠双龙戏珠纹暗花缎褶裙形制进行研究推考,探讨明代命妇褶裙形制特征。运用实验考古学、文献图像查阅、个案分析与多元类比相结合的方法,对该裙的出土背景、面料、形制、裙片拼缝方式、褶裥制式及数量、裙与上衣组配方式等方面进行深入分析。结果表明:团窠双龙戏珠纹暗花缎褶裙为两片一腰样式的侧褶裙,裙片共用七幅料拼缝,裙两侧捏“四对四”抱合对褶,为明代较为典型的褶裙制式,具有明显的传承性;该裙与墓中出土短上衣组配,体现了弘治年间江南地区命妇着装的礼仪性与时尚性,代表了明中期命妇典型的生活着装配伍。