北京地区太阳能、空气源热泵、发电余热联合沼气工程增温系统研究

为了解决北京地区大中型沼气工程增温问题,文章结合北京地区气候特点,构建了一套太阳能、空气源热泵、发电余热联合沼气增温系统,阐述了系统设计的原理,计算和分析了发酵罐的热负荷、太阳能集热器集热量、空气源热泵供热量、沼气发电余热量和系统的经济性。结果表明:3种联合增温系统的作用下料液的温度能够一直维持在(37℃±1℃)范围内,在中温厌氧发酵范围内产气也达到最佳,取得了良好的试验效果。沼气工程全年月平均热量损失为7325.0 MJ,太阳能、空气源热泵、发电余热联合沼气增温系统月平均产热量为7464.1 MJ,可以完全满足工程的热量需要,保证整个系统稳定运行。同时也具有良好的经济效益性,对今后在北京的大中型沼气工程中具有一定的的参考意义。     

Bilirubin excretion and bile flow in fed and fasted Brazilian squirrel monkeys (Saimiri sciureus)

Fasted Brazilian squirrel monkeys (BrSMs) exhibited slightly higher serum bilirubin levels (0.30±0.05 mg/dl) than others in the fed state (0.13±0.01). The mean liver weight was 50% lower following a 22 h fast. The rate of bile flow was unaffected by fasting and averaged 13.8 l/min/kg and 47.5 l/min/100g liver in six BrSMs. No significant difference in mean bilirubin excretion/min was observed on a body weight basis following fasting. When the mean rate of bilirubin excretion was calculated as a function of liver weight, a two-fold higher rate was present in fasted monkeys, but only at the p=0.06 level of statistical significance. From data collected in this and earlier studies, it would appear that BrSMs represent the best animals studied to date to serve as experimental controls in comparative studies with Bovilian squirrel monkeys which exhibit a Gilbert-like syndrome.     

液相色谱-串联质谱法检测猪肉中20种违禁药物残留的研究

建立了猪肉中违禁药物（糖皮质激素、性激素、β2-肾上腺素受体激动剂、玉米赤霉烯酮4类）同时测定的高效液相色谱-串联质谱方法。试样经盐酸水解,乙酸乙酯提取,低温冷冻去除脂类,亲水亲脂平衡固相萃取柱净化。采用C18反相色谱柱分离,以乙腈+水为流动相梯度洗脱,分别在电喷雾离子源正、负离子模式下以多反应监测模式（MRM）分段扫描同时检测,基质匹配内标法定量。结果表明,20种违禁药物在相应的浓度范围内线性良好,相关系数均大于0.99;该方法在猪肉中的检测限（LOD,S/N=3）和定量限（LOQ,S/N=10）分别为0.5、1.0 μg/kg。在0.5~10 μg/kg添加浓度水平下,平均回收率为63.9%~117%,批内变异系数1.9%~9.1%,批间变异系数4.9%~13.1%。该方法简单、快速、准确,适用于猪肉中多类违禁药物的残留检测。     

EFFECTS OF ACEPROMAZINE ON THREE-PHASE 99mTc-MDP BONE IMAGING IN 11 HORSES

Horses undergoing skeletal scintigraphy can have decreased radiopharmaceutical bone uptake in the limbs. This reduces the diagnostic value of the scan. The aim of the present study was to measure the changes in count density caused by vasodilatation and increased blood flow associated with intravenous injection of acepromazine during bone scintigraphy in normal horses. A three-phase bone scan was performed twice in 11 adult horses to study the effects of acepromazine on the count density of the resultant scintigrams. With acepromazine, there was a statistically significant mean difference of 12 s for initial blood flow and 21 s for peak flow. The time to initial blood flow and time to peak flow occurred earlier for the scans in which acepromazine was used. There were no significant differences in the bone to soft tissue ratios during the soft tissue and bone phases of the scan between procedures. Intravenous administration of acepromazine increases peripheral blood flow causing an earlier onset of the vascular phase during the three-phase bone scan. Acepromazine did not increase the count density of the bone phase scintigrams. As expected, the vasodilatation and increased blood flow associated with intravenous injection of acepromazine affected the count density of the vascular phase of the bone scan.     

Transcatheter closure of patent ductus arteriosus in 11 dogs and one cat after incomplete or aborted surgical ligation

ObjectiveTo describe the characteristics and outcomes of transcatheter patent ductus arteriosus (PDA) occlusion after incomplete or aborted surgical ligation in dogs and cats.AnimalsTwelve client-owned animals (11 dogs and one cat).Materials and methodsThis retrospective study describes data from animals with aborted or incomplete surgical PDA ligation that subsequently underwent transcatheter closure using endovascular methods. Patient demographics, reason for incomplete or aborted surgery, complications, and method of transcatheter occlusion were recorded. Data are presented as mean ± standard deviation or median (interquartile range), where appropriate.ResultsFor all cases, median age at surgery was 12.2 months (4.9–15.1 months) and at catheterization was 15.4 months (8.9–21.9 months), with 79 days (29–209 days) between surgical and interventional procedures. Median weight at catheterization was 4.5 kg (2.5–12.6 kg). Reasons for failed surgical ligation included hemorrhage during ductal dissection in seven dogs, residual flow in four dogs, and inability to identify the ductus in one cat. Transcatheter closure was successfully performed using a canine duct occluder in eight dogs, transarterial coil embolization in two dogs, and transvenous coil embolization in one dog and one cat. Metallic hemoclips partially obscured angiographic findings in three cases with prior surgical hemorrhage but did not prevent transcatheter closure. In all cases, ductal flow was successfully attenuated, with no or trace residual shunting on angiography and complete occlusion the following day on echocardiography.ConclusionsWhen surgery is unsuccessful, either owing to hemorrhage or residual flow, transcatheter closure of PDA is feasible, even in small patients.     

高级别动物生物安全实验室气密性的探讨

高级别动物生物安全实验室气密性是保证实验室空气洁净度、室内实验人员和室外环境安全的重要手段。我国现行规范对高级别动物生物实验室各区域气密性有严格的规定。从实验室装修、围护结构设备安装以及气密性检测方面对实验室气密性进行了讨论,以期为我国高级别动物生物安全实验室的建设提供参考。     

旋壳转速对腔内液体流动特性的效应

为研究旋壳转速对腔内液体流动特性的影响,以试验旋喷泵为研究对象,在高度验证叶轮与旋壳同步旋转试验与模拟结果准确性的基础上,对叶轮转速相同、旋壳转速不同的5个模型采用RNG k-ε湍流模型进行数值计算,分析腔内液体流动特性的变化情况,研究泵的性能.结果表明:旋壳转速增大,液体圆周速度和旋转系数均增大,圆周速度曲线沿径向逐渐形成同心圆,腔内液体做非刚性旋转.腔内液体径向压力梯度增大,压力低于624 kPa时,旋壳转速越高,压力越小;压力高于624 kPa时,旋壳转速越高,压力越大.集流管迎流区涡分布在进口附近,尾迹区涡集中在扩散段结尾处,整体呈增大趋势.旋壳转速增大,泵的扬程升高,但效率降低,通过改变集流管进口直径发现集流管并非效率降低的主要原因,而是由圆盘摩擦损失的增大导致的,圆盘摩擦损失随旋壳转速增加呈3次幂函数式增大,文中最优进口直径为13 mm.     

桐乡市秋种春养推广与应用

由于大气污染的日趋严重 ,桐乡市从 1994年起试行秋种春养 ,至 1999年饲养量占春期蚕种总量的 6 4.4 % ,取得了单产、茧丝质量和经济效益提高的较好效果