一种入仓水分超标粮食的分拣系统

给出一种入仓粮食在线自动分拣方法及系统。该方法依托于水分在线检测技术,以挡板为分拣实现形式,通过判断当前粮食的水分含量是否满足入仓标准,自动切换挡板,不同水分含量的粮食可分别由入仓通道或分拣通道流出,以适合入仓水分含量标准为界,有效区分入仓粮食的水分含量标准。该系统能够快速、自动地避免水分超标粮食入仓,保证仓储粮食安全,同时分拣方法简单有效,并通过实践验证。     

甘蔗收获机喂入分流系统的设计与试验

甘蔗收获机普遍使用的双圆盘切割台系统在收获过程中存在明显"居中堵塞现象"。为了合理利用收获机物流通道空间,使喂入的甘蔗流主动分流居中并行且均匀输出,设计了一种新型的甘蔗收获机喂入分流系统,通过三维设计软件Pro/E建立了甘蔗喂入分流机构虚拟样机模型,并导入多体动力学仿真软件ADAMS,在不同的分流转速、分流辊上的橡胶管按不同的角度安装及选择不同的橡胶管与甘蔗的摩擦因数进行了虚拟仿真试验并在仿真的基础上进行了物理样机实验。仿真与样机实验表明:当此机构分流辊机构转速为300r/min、分流辊上偏置胶管的偏置角度为30°,且偏置胶管与甘蔗间的静摩擦因数f0=0.3 5、动摩擦因数f1=0.2 5时,在保证甘蔗进给速度的前提下,可以使甘蔗流分布较为理想。     

Sensitivity and specificity of fasting ammonia and serum bile acids in the diagnosis of portosystemic shunts in dogs and cats

Background: Portosystemic shunt (PSS) is the most common cause of hepatic encephalopathy in dogs and cats. Fasting ammonia and serum bile acids (SBA) are used to diagnose PSS, but their true sensitivity and specificity have not been fully evaluated, especially in cats. Objectives: The purpose of this study was to determine the diagnostic accuracy of fasting ammonia and SBA concentrations in the diagnosis of PSS in dogs and cats and to compare diagnostic accuracy between species. Methods: A retrospective analysis of data from 373 dogs and 85 cats presented to the clinic from 1996 to 2006 was carried out. Based on clinical, laboratory, and imaging findings, animals were grouped as having PSS, parenchymal hepatic disease, or extrahepatic disease. The sensitivity and specificity of ammonia and SBA concentrations for the diagnosis of PSS were calculated and receiver‐operating characteristic analysis was used to optimize cut‐offs. Results: Using the upper limit of laboratory reference intervals (ammonia, 59 μmol/L; SBA, 20 μmol/L), the sensitivity and specificity of ammonia was 85% and 86% in dogs, and 83% and 76% in cats, respectively. The sensitivity and specificity of SBA was 93% and 67% in dogs, and 100% and 71% in cats, respectively. Using optimal cut‐off points for ammonia (dogs, 57 μmol/L; cats, 94 μmol/L) the sensitivity and specificity was 91% and 84% in dogs and 83% and 86% in cats, respectively. Using optimal cut‐off points for SBA (dogs, 58 μmol/L; cats, 34 μmol/L) the sensitivity and specificity was 78% and 87% in dogs and 100% and 84% in cats. Conclusion: Increased fasting ammonia and SBA concentrations are accurate indicators of PSS. An improvement in diagnostic accuracy can be achieved by using defined optimal cut‐off points for the selective diagnosis of PSS.     

入料速度动态调节式马铃薯切条机设计与试验

针对目前马铃薯切条机切削质量差、切削薯条破损率高以及自动化程度低等问题,对马铃薯切条机结构进行改进设计。采用激光传感器和入料分流装置检测入料速度并对入料速度进行调控,提高入料均匀性与切削稳定性。通过对关键部件的分析确定了影响切条质量的关键因素与取值范围。以离心滚筒转速、推料叶片倾角和切片刀安装角为试验因素,以切条合格率和分切破损率为试验指标,进行三因素三水平响应面试验,利用Design-Expert 10.0.1软件对试验结果进行方差分析,通过响应面分析交互因素对试验指标的影响规律。运用软件优化得出试验因素的最优组合并进行验证试验,结果表明：当离心滚筒转速为224.6r/min、推料叶片倾角为19.4°、切片刀安装角为292°时,切条合格率为96.7%、分切破损率为2.0%。在此基础上进行入料速度控制调节试验,试验结果显示：切条合格率为96.2%,分切破损率为2.4%,产量达3.3t/h,切条合格率提高7%,分切破损率降低4%,切削效率提高28%,提高了马铃薯切条机流水线工作时的切削质量与效率。     

高通量小粒径种子流检测装置设计与试验

针对油菜播种过程中因农艺要求增大播量以及高速播种产生的排种频率过高而导致高通量种子流检测精度不足的问题,提出了一种将高通量种子流分流为多路低通量种子流并行检测的方法,设计了基于分流机制与薄面激光-硅光电池结合的高通量小粒径种子流检测装置。考虑高通量种子流分流均匀性与快速通过性,对分流结构进行设计,运用离散元仿真软件EDEM及台架试验对处于不同倾斜角度的分流结构分流均匀性进行分析,当分流结构倾角小于5°时,分流管排量一致性变异系数的仿真与试验结果分别不超过5.19%和8.58%。基于薄面激光照射范围与落种区域,确定了薄面激光发射模组角度、上导种管出种口内半径以及薄面激光距硅光电池距离三者之间的关系,并优选得到三参数最佳组合。对4路种子输入信号进行调理,经电容滤波、双级放大、半波整流、电压比较、单稳态触发处理,成为4路独立可供单片机捕捉的脉冲信号。高通量小粒径种子流检测装置台架试验表明：在排种频率61.68 Hz范围内,油菜种子检测准确率不低于96.1%。田间试验结果表明：在田间排种频率62.23 Hz范围内,检测准确率不低于95.7%,且试验过程中无堵塞现象发生,田间正常光照、机具振动对装置检测精度无影响。     

ULTRASONOGRAPHIC DIAGNOSIS OF CONGENITAL PORTOSYSTEMIC SHUNTS IN DOGS: RESULTS OF A PROSPECTIVE STUDY

The aims of this study were to determine if accurate diagnosis of congenital portosystemic shunt was possible using two dimensional, grey-scale ultrasonography, duplex-Doppler, and color-flow Doppler ultrasonography in combination, and to determine if dogs with congenital portosystemic shunts have increased or variable mean portal blood flow velocity. Eighty-two dogs with clinical and/or clinicopathologic signs compatible with portosystemic shunting were examined prospectively. Diagnosis of congenital portosystemic shunt was subsequently confirmed in 38 of these dogs using operative mesenteric portography: 14(37%) dogs had an intrahepatic shunt and 24(63%) had an extrahepatic shunt. Ultrasonography had a sensitivity of 95%, specificity of 98%, and accuracy of 94%. Ultrasonographic signs in dogs with congenital portosystemic shunts included small liver, reduced visibility of intrahepatic portal vessels, and anomalous blood vessel draining into the caudal vena cava. Correct determination of intra - versus extrahepatic shunt was made ultrasonographically in 35/38 (92%) dogs. Increased and/or variable portal blood flow velocity was present in 21/30 (70%) dogs with congenital portosystemic shunts. In one dog with an intrahepatic shunt the ultrasonographic diagnosis was based partly on finding increased mean portal blood flow velocity because the shunting vessel was not visible. Detection of the shunting vessel and placement of duplex-Doppler sample volumes were facilitated by use of color-flow Doppler. Two-dimensional, grey-scale ultrasonography alone is sufficient to detect most intrahepatic and extrahepatic shunts; sensitivity is increased by additional use of duplex-Doppler and color-flow Doppler. Increased and/or variable portal blood flow velocity occurs in the majority of dogs with congenital portosystemic shunts.     

Cardiopulmonary effects of thoracoscopy in anesthetized normal dogs

Objective To evaluate the effect of an open‐chest condition on oxygen delivery in anesthetized dogs. Study design Prospective, controlled experimental study. Animals Eight clinically normal adult Walker Hound dogs weighing 25.6–29.2 kg. Methods Eight anesthetized dogs underwent an open‐chest operation after the insertion of thoracoscopy cannulae in the lateral chest walls . A Swan Ganz catheter was used to both measure hemodynamic parameters and obtain mixed venous blood samples for blood gas analysis. A dorsal pedal catheter was placed to both measure arterial blood pressure and obtain blood samples for blood gas analysis. Oxygen delivery index and oxygen extraction ratio were calculated. A randomized block anova for repeated measures was used to evaluate the effect of the treatment on hemodynamic and pulmonary parameters. Results Creation of an open chest did not significantly affect oxygen delivery index (DO₂I; p = 0.545). It induced a significant decrease in arterial oxygen partial pressure (PaO₂; p = 0.018) and arterial oxygen content (CaO₂; p = 0.025). It induced a significant increase in shunt fraction (p = 0.023), physiologic dead space (p = 0.015), and alveolar‐arterial oxygen difference (p = 0.019). Arterial partial pressure of carbon dioxide (PaCO₂; p = 0.766) and arterial hemoglobin oxygen saturation (SaO₂; p = 0.178) were not significantly affected. Diastolic (DPAP; p = 0.050) and mean (MPAP; p = 0.033) pulmonary arterial pressures were significantly increased by opening the chest. Other hemodynamic parameters were not significantly affected. Conclusions Opening the thoracic cavity is not detrimental to hemodynamic function and oxygen delivery in normal dogs, although impaired gas exchange does occur. Clinical relevance Close monitoring of patients is recommended during open‐chest thoracoscopy as adverse effects on gas exchange can contribute to hypoxemia.     

Portal Vein Thrombosis in Cats: 6 Cases (2001–2006)

Background: Portal vein thrombosis (PVT) in cats is sparsely reported.
Purpose of Study: To evaluate the clinical signs and diseases associated with PVT in cats.
Animals: 6 client-owned cats.
Methods: Medical records for cats with a portal vein thrombus diagnosed on abdominal ultrasound or at necropsy were reviewed. Signalment, historical data, underlying disorders, clinical findings, clinicopathologic and histopathologic data, diagnostic imaging findings, treatment, and outcome were recorded.
Results: All 6 cats identified with PVT also had hepatic disease. Evidence of a congenital portosystemic shunt was present in 3/6 cats. Two cats had primary or metastatic hepatic neoplasia. One cat had acute cholangitis, acute pancreatitis, and locally extensive acute centrilobular hepatic necrosis. Two cats were suspected to have acute thrombi and 4 cats had chronic thrombi.
Conclusion and Clinical Significance: PVT might be an important concurrent finding in cats with hepatic disease.