水稻插秧机分插机构的运动学特性分析

运用数学解析方法,建立了曲柄摇杆分插机构和偏心行星齿轮分插机构的运动学模型,并对这两种机构进行了运动学特性分析和比较,为机构的设计、分析提供了理论依据     

杉木胶合木的初步研究

本文探讨了利用杉木小径材生产新型基材———胶合木的方法，并研究了主要工艺参数对产品性能的影响，为优化生产胶合木的工艺打下基础     

红色的跳动韵律——安徽含山县玉龙公园景观设计

玉龙公园设计以整体布局为前提,以地域文脉寻求公园特色,突出红色的跳动韵律整体性的基调。     

Retinal degeneration in nine Swedish Jämthund dogs

The Jämthund is the fourth most common breed in Sweden with approximately 1600 pups registered each year. Although it has been known that some adult dogs go blind, so they cannot hunt, the Jämthund dog has historically not been screened for hereditary eye diseases. This report describes nine Swedish Jämthund dogs with retinal degeneration. These dogs represent all Jämthund dogs diagnosed with progressive retinal atrophy (PRA) by the Swedish Eye Panel and registered with the Swedish Kennel Club from January 1998 to September 2008. The dogs were examined with indirect opthalmoscopy and slitlamp biomicroscopy. Additionally, electroretinograms (ERGs) following ECVO guidelines were performed in two dogs (one affected and one normal) and the eyes from three affected dogs were examined by light‐microscopy postmortem. Typical findings were bilateral symmetric generalized retinal degeneration with tapetal hyper‐reflectivity, attenuation of blood vessels and pigment clumping in the nontapetal fundus. These retinal findings progressed with time in two dogs after re‐examination. Visual impairment, especially under dim light conditions, was observed in the affected dogs. ERG from one affected dog showed profoundly reduced rod responses, whereas cone responses were better preserved. Microscopic changes in the eyes from three dogs were characterized by a severe diffuse predominantly outer retinal degeneration and atrophy. Re‐sequencing of the prcd‐gene for eight of the nine investigated dogs revealed that none of the individuals carried disease allele that has been associated with prcd‐PRA in other breeds. In conclusion, ophthalmoscopic, electroretinographic, and light‐microscopic alterations observed in nine Jämthund dogs were compatible with PRA. The prcd mutation was excluded as a cause of this retinopathy.     

Internal fracture fixation

Over the past decade, many improvements to small animal internal fracture fixation have been developed, including improved fixation techniques and a more diverse selection of implants. The understanding that appropriate fixation selection is based on a plethora of biologic, mechanical, and clinical factors has also emerged. Classically, the methods of internal fracture fixation have used pins, wires, screws, and plates to rigidly stabilize fractures that have been anatomically reduced with significant disruption to the biologic fracture environment. Newer methods attempt to minimize trauma to the soft tissues surrounding a fracture and promote biologic osteosynthesis using such implants as interlocking nails and plate-rod fixations. This review provides an overview of both the traditional and current principles of small animal internal fracture fixation.     

摇枝式油茶果采摘机设计与试验

针对油茶果机械化采摘漏采率高、损伤率大的问题,设计了一款摇枝式油茶果采摘机。根据摇枝式采摘工作原理,完成了关键部件的结构设计,计算分析了采摘头夹持油茶枝的夹持力,对油茶枝和油茶果振动过程进行力学分析,建立力学方程并求解。结果表明,夹持油茶枝时最大压力为2826N,振动对树枝产生的径向力约为57.5N、法向力约为78.2N,夹持和振动都不会对枝条造成损伤。为保证采摘机安全性,对横梁架进行了静力学分析,经计算其弯曲变形为0.0005mm,远小于最大许用弯曲挠度。设计了四因素三水平正交试验,结果表明,最佳作业参数组合为：采摘装置的采摘时间10s、电机输出频率35Hz、采摘头的振幅5cm及采摘爪的夹持位置（夹持油茶枝的夹持中心到油茶树冠层距离）10~20cm,此时油茶果采净率为95.2%,花苞损伤率为17.2%。对摇枝式油茶果采摘机进行了田间试验,对枝条的损伤基本符合采摘要求。     

套索驱动空心杆机器人结构及运动学分析

确定了套索驱动空心杆机器人传动系统,并用SolidWorks三维绘图软件对机器人进行结构设计,采用D-H法建立位姿矩阵,对该机器人进行运动学分析,并给出控制方案。该机器人结构简单轻便,可用于大型结构、设备的检测清理、灾后废墟中的搜救等需要在狭小空间内作业的场合。     

An assessment of catches and harvest of recreational shore angling in the north of Portugal

Abstract  Recreational shore angling in the Atlantic Ocean between Moledo and Aveiro (Portugal) was examined using roving creel surveys (March/September 2001). Cooperation was high (90% of 2310 anglers approached). At least 39 species of fish were caught at a rate of approximately 0.5 fish angler h⁻¹. An estimated 7319 kg of Dicentrarchus labrax (L.), with 45.6% below the minimum legal size, and 2040 kg of sea breams (genus Diplodus ), correspond to 5.75% and 1.19% of the commercial landings in the same geographical area, respectively. The results shed light on a number of issues relevant to integrated coastal management, including temporal and spatial distribution of fishing effort, species caught, sizes of fish, catch rates, and factors influencing catches and angler satisfaction. Whilst the results suggest that the catches of sea breams and sea bass by day-time recreational shore angling in northern Portugal are small compared with commercial fishing, other recreational activities, such as boat fishing and spear-fishing, must be assessed.     

Biochemical characterization and physiological role of cortical rods in black tiger shrimp, Penaeus monodon

Cortical rods (CRs), precursors of egg jelly investment in many penaeoid shrimp, are composed of different proportions of proteins and carbohydrates, the physiological role of which still requires extensive investigation. In this study, we demonstrated the biochemical properties of the CRs and their role in the induction of the acrosome reaction (AR). Profiles of the isolated CRs revealed a number of major protein bands ranging from 35 to 230 kDa. These CR proteins were extensively glycosylated and sulfated. Lectin-based carbohydrate analysis further revealed the highest reactivity of concanavalin A (Con A) among other lectins used. In addition, the selective interference of Con A binding with mannose but not glucose indicated that CR glycoproteins were of high-mannose type. Using immunoblotting with anti-CR antibody, we further demonstrated that part of egg water (EW, a natural AR inducer) was derived from miscible components of the CRs. Physiological tests of water-soluble CR (wsCR) revealed its high AR inducing competency comparable to that of EW, which was far superior to that of acid-urea treated CR (auCR). Furthermore, the wsCR-induced AR was selectively inhibited by Con A, suggesting the significance of the exposing mannose residues in regulating P. monodon sperm AR response.