Peritoneal fluid accumulation in the femoral canal as a result of a post-traumatic femoral hydrocele in a mature Warmblood stallion

The following case report documents the clinical presentation, ultrasonographic appearance, surgical management and outcome of a horse with a traumatic tear extending from the superficial and deep inguinal rings, across the aponeurosis of the external abdominal oblique muscle and inguinal ligament, disrupting the femoral ring, vascular lacuna and peritoneum. This subsequently resulted in fluid accumulation within the femoral canal. This unusual injury and presentation gives rise to discussion of the aetiology and nomenclature that should be used to properly describe this injury.     

Changes to freshwater mussel assemblages after 25 years of impoundment and river habitat fragmentation

1. The Tennessee–Tombigbee Waterway is among the largest and most expensive environmental engineering projects of the 20^th century. The waterway accommodates barge navigation between the Tennessee River Drainage and Mobile River Basin through a series of locks, dams, canals, and dredged and diverted streams. These structures have altered riverine habitat and fragmented lotic habitats resulting in isolated freshwater mussel populations in patches of streams such as the East Fork Tombigbee River, where 42 species were known historically.
2. The first post‐waterway mussel surveys in 1987 and 1988 reported 31 taxa. During 2010 and 2011 surveys, 70 sites were sampled using both timed searches and quadrats and detected 29 extant mussel species. Between 1988 and 2010–2011 the relative abundance of nine mussel taxa decreased, whereas the abundance of 11 taxa increased. The populations of three federally listed species were detected at levels below the detection limits in 1988 as well as three non‐native unionids that appear to have colonized the East Fork Tombigbee River via the Tennessee–Tombigbee Waterway River.
3. Although mussel abundance and total species richness were relatively unchanged, assemblage composition shifted toward animals typical of smaller streams rather than large rivers. This shift suggests that present‐day East Fork Tombigbee River habitats favour smaller‐bodied, thinner shelled taxa that are laterally compressed and lack shell sculpture. These taxa are likely to be better adapted to hydrologically and hydraulically variable habitats than are thick‐shelled, large bodied, and sculptured mussels.
4. The results suggest that mussel assemblages are dynamic and may exhibit predictable responses to changes in hydrology, physical habitat conditions, and stream connectivity. However, examinations over broad (20+ yr) temporal scales are needed to observe these shifts. The data demonstrate the value of regular monitoring of diverse mussel assemblages and the importance of stream connectivity and flow modifications to this long‐lived group of benthic invertebrates.

     

抛物线形混凝土衬砌渠道标准化结构形式研究

通过实例比较了2种常用的抛物线形渠道水力最佳断面参数,得出二次抛物线渠道的水力性能优于半立方抛物线形渠道,并推导出了二次抛物线渠道实用经济断面的计算公式,提出了详细的计算步骤,给出了二次抛物线渠道实用经济断面水力计算表以供设计人员使用。同时,根据渠道工程实际应用情况和现行规范要求,提出了抛物线形混凝土衬砌渠道标准化结构形式,计算得出了常用抛物线形混凝土渠道结构尺寸、不同比降流量表,在实际工程应用中可根据设计渠道的具体情况进行选用。     

饥饿对褐菖鲉消化道指数及消化酶活力的影响

在水温(18±0.5)℃、盐度27.0±0.5条件下,测定了褐菖鲉不同饥饿时间(0、3、7、14、21 d)的比肝质量、比胃质量、比幽门质量、比肠长及各消化组织消化酶活力。试验结果表明,在饥饿过程中,褐菖鲉消化道组织萎缩,比肝质量、比胃质量、比幽门质量和比肠长呈显著下降趋势(P<0.01),其中比肝质量下降速率最大,饥饿21 d的比肝质量比对照组下降85.033%。饥饿期间,蛋白酶活力总体呈先升后降的趋势,差异显著(P<0.05)。淀粉酶活力的变化趋势亦为先升后降,饥饿1 d,前、中、后肠、幽门的淀粉酶活力呈不同程度上升,之后,除胃和幽门外,随着饥饿时间的延长,皆呈下降趋势,与对照组相比,差异显著(P<0.05);脂肪酶活力总体呈缓慢下降趋势,差异不显著(P>0.05)。     

保温型刚性护面渠道设计

在刚性面层下设置一道性能良好的保温层来防止基土冻结,可以从根本上解决冻胀破坏的问题。这种带保温层的刚性护面渠道称为保温型刚性护面渠道,根据热工原理,提出了保温型刚性护面渠道横断面设计在构造方面的要求,进一步推导出计算保温层厚度的有关公式,并给出算例,还指出了需要进一步研究和探讨的问题。     

梯形防渗渠道塑膜铺衬机的试验

借助均匀设计理论和软件对防渗渠道塑膜铺衬机进行了试验研究。提出了渠道塑膜铺衬效果的评价方法,分析了机器前进速度、展膜刷后倾角、展膜刷高度对铺膜效果的影响规律,并对设计参数进行了优化,证明主动同步放膜、展膜刷随动展膜的铺膜机构适于渠道空间铺膜作业。     

灌溉渠系流量最优调配的0-1规划模型

本文根据灌溉配水渠系的运行特点,提出在一定轮期和来水流量限制条件下实现下级配水渠最优组合及其配水时间最优排序的一种0-1规划模型,实例运算表明,这种方法可有效减少无效弃水和闸门调节次数,同时对渠道横断面的设计有参考意义。     

PVC管道或砌护渠道输水与开沟灌溉相结合的造林方法及效果

开沟灌溉造林与大田平灌相比，具有总体用水量少，局部给水量多的特点，能够显著地提高灌溉效率，提高造林成活率和林木生长量。同时，利用管道和砌护渠道输水，可防止渗漏，提高水的利用率。     

渠道密度与渠系水利用系数关系研

为了研究灌区渠道密度与渠系水利用系数之间的关系，首先从分析渠道水的渗漏情况入手,分析了渠系水利用系数与渗漏之间的关系,建立了在相同衬砌条件下渠道密度与渠系水利用系数之间的数学关系。然后提出有关渠道密度概念，这一概念的提出有利于灌区渠道分布合理性的进一步评价。渠道密度与渠系水利用系数两者之间关系式的确立，有助于从理论上评价渠道分布对渠系水利用系数的影响。     

引水渠道口门泥沙淤积计算

引水渠是一种常见的河道分流形式，由于主河道与引水渠之间往往有一定的夹角，水流从分汊前主河道流入引水渠时必然在一定的范围内发生一定程度的弯曲，其结果是有利于较多较粗的泥沙分入引水渠，导致渠道口门产生较为严重的淤积现象，而渠道口门淤积问题是决定引水工程是否成败的主要因素之一，通过一维非恒定流水沙沙数学模型，研究了不同水沙条件下引江济汉工程引水渠道口门泥沙淤积厚度变化规律，并分析了糙率对口门淤积厚度的影响情况，模型的计算结果与水流运动规律相吻合，可以为渠道引水防沙设计提供技术支持。