Design of Double Layer Torsional Reticulated Shell Using Back- Propagation Neural Network

In this paper artificial neural networks are used for design of large span double layer torsional reticulated shell. The torsional reticulated shells with spans varying between 50.0 - 80.0m are considered, Back -propagation algorithm is employed for training efficient neural networks for evaluation of the maximum deflection, weight and design of double layer torsional reticulated shell. A special method is developed for data ordering to reduce the nonlinearity of data and to increase the speed of training. This approach also provides the necessary stability. It shows that it is feasible to design double layer reticulated shell with artificial neural networks.     

Determination of the Binding Constant Between Sodium Houttuyfonate and Human Serum Albumin by Capillary Electrophoresis

The objective function of minimum cost is established for double layer torsional reticulated shell, taking the rise-span ratio, grid size and shell thickness as design variables. Based on the exhaustion and 0.618 methods, the computing program LSD has been developed. For the double layer torsional reticulated shell with the span of 50 m to 80m, the optimal grid size and thickness have been obtained for systems of light roof materials with different spans. Empirical formulas are deduced from the results.     

Numerical Simulation for Dynamic Response of Large Space Cylindrical Reticulated Shell under Internal Explosion by Ritz POD Method

A numerical simulation test of the internal explosive loading on large space structure was carried out by employing algorithm ANSYS/LS DYNA.An appropriate model was established for calculating the dynamic responses of the large space cylindrical reticulated shell under inner blast loading based on the proof of correctness and reliability of the model and parameters selection.Combining the Ritz vibration mode superposition method with the Proper Orthogonal Decomposition (POD) method, the problems of spatiotemporal asynchrony of shock waveforms and pressure distributions on large space structure surface were solved and the calculation for dynamic response of large space structure was reduced and simplified.Furthermore, the numerical simulation of dynamic responses was carried out.And the influence of the ratio of rise to span and the explosive position on the dynamic responses of the structure was studied.It was found that the calculation model was suitable for the dynamic response analysis of the large space cylindrical reticulated shell under internal explosion and the cylindrical reticulated shells with bigger ratios of rise to span were stronger in the capacity of anti explosion.In general, the damages to the large space structure caused by eccentric blast shock waves were more serious than that caused by central explosion.And it was the most disadvantageous to the edge components of the structure.The more attention should be paid to the anti explosion capacity of the support areas and the edge components while designing the shells.     

A Simplified Thermoelastic Model for Composite Iaminated Shells

To effectively analyze the one way coupled thermoelastic problem for composite laminated shells, a simplified thermoelastic shell model based on the variational asymptotic method (VAM) was developed. The 3 D energy functional for composite laminated shell was established according to the Hamilton extended principle. Then the 3 D energy was asymptotic expanded into a series of 2 D approximation energies by taking advantage of the inherent small parameters. Finally, the approximate energy was converted to the form of Reissner Mindlin model, and the 3 D recovery relationships were deduced to accurately predict the 3 D field distribution along the thickness direction. The cylindrical bending example of a four layer composite laminated shells under the sinusoidal surface load and temperature field shows that the modeling speed is fast (equivalent single layer model, which can reduce two or three order calculations compared to the 3 D finite element method), and the nonlinear approximation ability is excellent (convergent to the exact solution).     

空间高度对球面网壳结构内爆炸响应的影响

基于修正后的Johnson-Cook材料模型,应用ANSYS/LS-DYNA建立K8型单层球面网壳计算模型,对内爆炸下不同空间高度的结构爆炸响应进行计算和分析。首先,分析结构内爆炸冲击波传播规律,验证模型参数选取的可行性;其次,讨论内爆炸作用下球面网壳的动力响应,对比分析不同本构模型对爆炸响应的影响;最后,定义下部支承结构所围体积占结构所围总体积的比值为空间高度系数,讨论空间高度系数对墙面未开洞和墙面开洞球面网壳动力响应的影响。结果表明,爆炸冲击波在球面网壳结构角部有汇聚效应,与反射冲击波共同作用,严重影响球面网壳结构的动力响应;对于墙面未开洞的球面网壳,爆炸响应受反射冲击波影响较大;对于墙面开洞的球面网壳,爆炸响应受空间高度系数影响较大。基于研究结果给出了球面网壳结构在内爆炸下防爆和抗爆设计的合理空间高度系数建议值。     

2种壳色梨形环棱螺贝壳7种金属元素质量分数比较分析

利用电感耦合等离子体质谱(ICP-MS)对梨形环棱螺(Bellamya purificata)青色和紫色贝壳的7种金属元素质量分数进行了比较分析。结果显示,紫色梨形环棱螺贝壳中铁(Fe)、质量分数显著高于青色贝壳。青色贝壳中钾(K)、镁(Mg)、锰(Mn)的含量显著高于紫色贝壳,钠(Na)、锶(Sr)、锌(Zn)元素含量在两种壳色贝壳中差异不显著。贝壳中Fe含量和K、Mg、Mn的含量呈显著负相关,与Sr、Zn含量的相关性不显著。K、Mg、Mn、Na的四种元素含量呈显著正相关。     

Spawning of two Pomatoschistus species (gobbidae) in relation to nest availability and depth: A field experiment

The spawning of two sympatric gobiid fishes, the sand goby Pomatoschistus minutus and the common goby Pomatoschistus microps was investigated in relation to nest availability and depth. In two field experiments, carried out in the northern Baltic proper during summer, empty shells of the mussel Mya arenaria were divided into three size groups and provided as spawning substrates. The shells were set out at different depths and at different densities.Spatial habitat partitioning by depth was found. The sand goby preferred the deeper bottoms (2.8 m) and the common goby spawned only in areas shallower than 1 m. The spawning of the two species was separated in time by about 6 weeks with an overlap at the beginning of July. Low water temperatures (∼10°C) in June probably delayed spawning in the common goby.The sand goby preferred the larger shells. The larger the shells, the larger was the number of eggs, i.e. the male potential reproductive success. The common goby preferred the smaller shells, and their potential reproductive success did not show a clear trend with increasing shell size.In both species, the mean number of shells used for spawning increased with increasing substrate density. The maximum nesting density was 21 nests per m² for the sand goby and 20 nests per m² for the common goby. The maximum total density for both species together was 23 nests per m².Interspecific competition for spawning substrates was minimized, as spawning was separated in time and each species preferred different sizes of shell. The intensity of spawning under the shells provided indicates that a lack of suitable substrates limits spawning by both species in this area. The larger sand goby is limited in particular by the lack of larger substrates, and is probably forced to spawn in shallow water when suitable shells do not occur in its preferred depth range.     

3-D Finite Element Analysis of Solidified Shell in Molds for Continuous Casting of Thin Slabs

A three-dimentional thermal elastoplastic contact FE analysis model of solidifiedshell in moulds for continuous casting of thin slabs is set up, based on the known geometry of theshell and the temperature distribution in the shell. We in turn obtain the stress and Strain distributions of the solidified shells formed in lSP and CSP moulds,the gap distributions between the Shellsand the mould walls,as well as the curves of cracking index [1] in the shells,which provides afoundation for the design and control of technical parameturs for continuous casting of thin slabs.     

花生壳研究现状与应用前景分析

花生是我国的主要油料作物和经济作物,花生壳作为其副产物占花生产量的30%左右,花生壳含有多种矿物质及功能成分,在农业生产、食品加工、功能性产品开发等方面有重要的应用价值。但是,目前由于研究技术受限及研究工艺落后,花生壳大部分仍用作饲料和肥料,附加值与利用率低。文章对花生壳的组成成分及其在农业、食品、医药、环保、化工及建筑方面的重要应用及关键技术进行综述及分析。认为深入开发花生壳是未来花生壳利用的重要方向,今后应以工艺优化及技术提升为主,将目前实验室阶段的研究成果形成大规模生产,真正实现循环农业和低碳经济。     

食品加工剩余物板栗壳的利用研究进展

为了更好地对食品加工剩余物板栗壳进行开发利用,促进节能减排,综述了国内外最近20年在板栗壳资源化利用方面的研究进展,发现现有研究涉及将板栗壳作为生物吸附剂用于重金属污水处理、作为基质用于食用菌栽培和作为原料用于活性炭制备,以及从中提取天然色素用于食品着色和纺织品印染等方面,但这些研究并不系统,今后还需对板栗壳色素进行安全性评价,补充其毒理学和代谢方面的数据。板栗壳对重金属的吸附量偏低,有待于进一步通过理化改性提高其吸附性能,提取过色素的板栗壳残渣可进一步作为原料用于制备活性炭,以达到循环利用。     

Clonal selection in 'Uzunmusa' hazelnut

Clonal selection was practised in ‘Uzunmusa’ hazelnut over the past 3 years (1999‐2001) to select the highest quality types. Based on an initial assessment of a total of 102 types, 45 were selected for further study. The best types were selection numbers (SN) 397 and 570. The two selected clones have very good characteristics and seem to be superior to the standard clone. The clones had a higher kernel percentage (62.72%), a higher number of nuts per cluster (5.5), thinner shells (0.75 mm) and heavier nuts (2.34 g). On the other hand, the clones seem to be very suitable for the nut industry because of their oil content and size. These types have very thin shells which are suitable for in‐shell market.     

A POWER FLOW IN INFINITE VISCOELASTIC CYLINDRICAL SHELLS

In this paper, a solution of propagation wave in an. unconstrained damping viscoelastic cylindrical shells of infinte length under forced vibration is derived by Fourier integral transform techniques. The power flow transmitted along it is analysed. The power flow in an elastic cylindrical shell and that in a viscoelastic shell are compared. The effects of vibration reduction in two viscoelastic shells with different thickness are compared. The results provide a reference for designer in structural vibration reduction.     

高品质陆地棉铃-叶系统干物质质量的发育遗传研究

 应用加性-显性发育遗传模型及条件与非条件的统计分析方法,对6个高品质陆地棉品种（系）及其30个F₁组合的伏桃与对位果枝叶的干物质质量进行了研究。非条件方差分析表明,果枝叶质量在棉铃体积增大期主要受加性效应控制,内部充实期主要受显性效应控制;铃壳质量在不同发育时期均以加性效应为主;铃重在前中期主要受显性效应控制,后期以加性效应为主。条件遗传分析表明,影响果枝叶质量的净遗传效应在铃龄38 d至45 d达到高峰;控制铃壳质量的基因表达分别在铃龄17 d至24 d和铃龄38 d至45 d出现两个高峰;影响铃重性状的基因分别在铃龄17 d至24 d和铃龄31 d至38 d出现两个表达活跃的高峰,此后基因的表达量急剧下降。遗传相关分析表明不同发育时期的铃壳质量均与最终铃重成极显著的加性正相关。     

紫石房蛤形态性状对体重的影响效果分析

选取73只紫石房蛤,测定其壳长、壳宽、壳高、活体重,计算相关系数,采用通径分析方法计算了以贝壳性状为自变量对活体重作依变量的通径系数、决定系数及相关指数,对各性状的影响大小进行剖分,明确影响紫石房蛤体重的主要外部形态性状。结果表明,所测各表型性状与体重之间的相关系数均达到显著水平（P<0.05）;壳高对体重的直接影响（0.589）最大,对体重的决定程度最高,是影响体重的主要因素;壳长和壳宽对体重的直接作用（0.139, 0.297）相对较小,主要是通过壳高的间接作用（0.4023,0.3787）影响体重。所选表型性状对体重的回归系数R2=0.828,表明所选性状是影响体重的主要性状。利用逐步回归分析方法建立以壳长、壳宽、壳高为自变量估计体重的多元回归方程为:y=-265.233+0.743x1+2.459x2+3.688x3。     

The availability and quality of the mussel prey (Mytilus edulis) of oystercatchers (Haematopus ostralegus)

Spatial variations in the availability and quality of the mussel Mytilus edulis food supply of Oystercatchers Haematopus ostralegus on the Exe estuary, England, are described. Oystercatchers open mussels by stabbing into gaping mussels (or prising open closed ones) or by hammering a hole in either the dorsal or ventral shells. Spatial variations in the food supply are considered at four scales. In decreasing order of size, these are (i) whole mussel beds, (ii) zones within a mussel bed, (iii) different places within one zone, and (iv) different places within one clump of mussels. The first two scales are clearly related to exposure time. Both between and within the 12 main mussel beds of the estuary, most upshore mussels are up to 10% less likely than downshore mussels to be hidden under mud. However, upshore mussels of a given length contain less flesh, have thicker ventral shells and, except on high-level beds subject to wave erosion, have thicker dorsal shells than downshore mussels. Mussels at the top of the shore also contain the highest infestations of the helminth parasite of Oystercatchers, Psilostomum brevicolle. At a particular shore level, mussels of a given length have less flesh and thicker shells, though only on the dorsal side, in areas of high mussel density. Within one clump, mussels of a given length with thick dorsal shells have more flesh than those with thin shells. In contrast, flesh content is slightly higher in mussels that are thin on the ventral side. Flesh content and shell thickness on both sides are unaffected by whether a mussel is visible at the edge of a clump or hidden inside. Simulations with a model of foraging Oystercatchers suggested that variations in mussel availability (visibility and shell thickness) and flesh content at all four scales could sometimes have an important influence on intake rate. Most published values of intake rates of Oystercatchers eating surface-dwelling mussels may be biassed (and often considerably over-estimated) by the erroneous assumption that prey of average flesh content are taken.     

Optimization Analysis of Single-layer Reticulated Dome

A structural optimization algorithm is performed for single-layer Kiewit reticulated dome by means of ANASYS. In the process of optimum design, the overall weight is taken as objective function; the stress constraints and stability constraints etc are considered. Meanwhile, the geometrical non-linearity is taken into account. Then the overall stability analysis for the optimized single-layer reticulated dome is operated. The results show that the optimization design is reliable.     

低钙胁迫对不同品种花生钙素吸收分配特性的影响

为了明确不同品种花生的钙营养需求特性,以10个花生品种为试材,通过砂培盆栽试验研究了低钙胁迫对不同品种花生产量、生物量、农艺性状及钙素吸收分配、利用特性的影响。结果表明,低钙胁迫对绝大部分品种的花生分枝数无明显影响,但明显提高单仁果数和植株生物量,显著降低荚果及籽粒产量。不同花生品种植株茎叶、根系和果壳钙含量均表现为正常供钙处理显著高于低钙胁迫,但不同钙浓度处理间籽粒的钙含量无显著差异;低钙胁迫可提高茎叶和根系等营养体的钙分配率,降低钙素在果壳和籽粒等生殖体的分配率,且与果壳相比籽粒钙分配率降低幅度较大。不同品种的钙生产效率和钙干物质生产效率差异较大,钙素利用效率差异则相对较小;低钙胁迫显著降低不同花生品种钙素利用效率,但对各品种钙生产效率和钙干物质生产效率的影响因品种不同而异。     

Effects of Spherical Joint Stiffness on Seismic Response of Single-Layer Cylindrical Reticulated Shell Changing with Peak Ground Acceleration

The previous studies find that the hollow spherical joint stiffness has a certain influence on seismic response of single-layer cylindrical reticulated shell. In order to analyze the rule of this influence with PGA (peak ground acceleration) changing, two types of finite element models are built. The two types of models have the same size except the spherical joint. The first type is a fine model built by shell element and its spherical joints and tubes are built by considering the real size; the other type is the common model which is built by beam element, and the spherical joints are neglected. Comparing with the seismic response of the two types of models when PGA changes, the results show the difference between the two types of model in node displacement-time curves is increased as PGA increases; when the PGA is larger than the collapse acceleration of structure, the influence of increasing joint wall thickness on improving the structural capacity of anti-stability is decreased as PGA increases.     

屋顶农业栽培基质配比的筛选及对生菜生长、品质的影响

本文通过屋顶栽培试验,在保持生长环境相同的条件下,对7种不同配比基质的理化性质及其对生菜生长情况和品质的影响进行了研究,同时运用灰色关联法对各基质的效果进行综合分析。从而为筛选合适的屋顶农业轻质基质提供理论依据。结果表明,各配比处理基质的容重为0.38~0.60g/cm3,总孔隙度为54.77%~74.17%,EC为242~1150 μs/cm,其中花生壳和蘑菇渣的加入可显著降低容重、增加孔隙度,牛粪和草炭对基质养分含量影响最显著；相对于CK,不同配比基质促进了生菜生长,其中T4、T5处理显著提高株高、叶长和干、鲜重；T5对提高生菜的可溶性糖和可溶性固形物含量最为明显。综合各项指标通过灰色关联法分析,T5(V(花生壳):V(牛粪):V(蛭石):V(珍珠岩):V(草炭)=2:2:2:2:2)处理适合屋顶农业中生菜的栽培,效果最好,可以作为屋顶农业中优良的轻质基质配方。     

控（缓）释性复合肥在旱地春播高粱上的应用效应及对土壤有效氮的影响

摘要：为了探索寻求旱地高粱最佳施肥途径,追求最大的水肥利用率,以尽量减少对环境的污染,本研究特设了两种类型的肥料、两种施肥方式的比较研究。并分析了不同处理下,土壤碱解氮的变化情况,运用随机区组设计的方法进行了比较试验。结果表明：不同类型的肥料在不同的施肥方式下结果是有明显差异的。1、缓释性复合肥SRCF与普通复合肥CCF相比,在总养分含量相同的条件下,产量提高27.69%~28.71%,氮素农学利用率提高40.24%~42.05%,表观利用率提高4.18%~5.26%,生理利用率提高34.58%~34.95%;2、春施肥SAF与秋施肥AAF相比,产量、氮素利用率等均差异不显著。3、0~60cm土层内的碱解氮含量,在苗期表现为普通复合肥CCF高于缓释性复合肥SRCF,而进入拔节期后,情况则相反。随着生育期的推进,土壤碱解氮逐渐降低,而春施肥SAF与秋施肥AAF两种方式相比,土壤碱解氮的高峰出现的土壤深层不同,前者,碱解氮高峰出现在0-20cm土层,后者,碱解氮高峰出现在20-40cm土层中。4、在苗期,0-60cm土层中碱解氮含量,两种类型的肥料差异很明显,拔节期后,差异不太明显。5、各时期0-100cm土层中,碱解氮主要存在于0-60cm土层中,60cm是养分最低点,60cm以下碱解氮又有所回升。