气调保鲜运输车通风系统阻力特性试验

针对液氮气调运输保鲜环境对运输厢体和通风系统的要求,设计了气调保鲜运输车通风系统试验装置。研究了通风风速、开孔隔板开孔率、堆栈方式、回风道长度等因素对气调保鲜运输车通风系统压力损失及能耗的影响,分析了通风系统的阻力特性。结果表明：通风系统的阻力特性可用Ramsin方程表述,通风系统的压差随风速的增大而增大;风速相同时,压差随开孔率的增大而减小;保鲜室内压差分布较均匀;满箱、留中间空隙和留两侧空隙等3种堆栈方式对压力损失的影响不明显;无回风道时压力损失比有回风道时小;气调保鲜运输车开孔隔板的开孔率大于3.89%时,通风系统的压力损失小且能耗较低。     

负压下血管灌流固定兔肺组织的SEM观察

负压下经血管灌流固定的兔肺组织在扫描电镜下可观察到肺泡Ⅰ型细胞表面有少量微绒毛,肺泡Ⅱ型细胞的周围与Ⅰ型细胞之间形成环状的凹陷。Ⅱ型细胞表面具有散在的微绒毛肺泡壁的毛细血管形成网状隆起,并可见到大小不同的肺泡孔。     

Influences of ultra‐violet (UV)‐blue light radiation on the growth of cotton. I. Effect on iron nutrition and iron stress response

Cool white fluorescent (CWF) light reduces Fe³⁺ to Fe²⁺ while low pressure sodium (LPS) light does not. Cotton plants grown under CWF light are green, while those yrown under LPS light develop a chlorosis very similar to the chlorosis that develops when the plants are deficient in iron (Fe). It could be that CWF light (which has ultra violet) makes iron more available for plant use by maintaining more Fe²⁺ in the plant. Two of the factors commonly induced by Fe‐stress in dicotyledonous plants‐‐hydroyen ions and reductants released by the roots‐‐were measured as indicators of the Fe‐deficiency stress response mechanism in M8 cotton.

The plants were grown under LPS and CWF light in nutrient solutions containing either NO₃‐N or NH₄‐N as the source of nitrogen, and also in a fertilized alkaline soil. Leaf chlorophyll concentration varied significantly in plants grown under the two light sources as follows: CWF+Fe > LPS+Fe > CWF‐Fe ≥ LPS‐Fe. The leaf nitrate and root Fe concentrations were significantly greater and leaf Fe was generally lower in plants grown under LPS than CWF light. Hydrogen ions were extruded by Fe‐deficiency stressed roots grown under either LPS or CWF light, but “reductants”; were extruded only by the plants grown under CWF light. In tests demonstrating the ability of light to reduce Fe³⁺ to Fe²⁺ in solutions, enough ultra violet penetrated the chlorotic leaf of LPS yrown plants to reduce some Fe³⁺ in a beaker below, but no reduction was evident through a yreen CWF grown leaf.

The chlorosis that developed in these cotton plants appeared to be induced by a response to the source of liyht and not by the fertilizer added. It seems possible that ultra violet liyht could affect the reduction of Fe³⁺ to Fe²⁺ in leaves and thus control the availability of this iron to biological systems requiring iron in the plant.     

Tissue distribution of glycinebetaine,proline and inorganic ions in barley at different times during the plant growth cycle.

The study of tissue distribution of glycinebetaine in barley grown hypoponically revealed that, during the vegetative growth period, young actively growing leaves accumulated higher levels than the mature lower leaves. Proline showed a complex pattern of leaf distribution. While K⁺ and Cl^‐ were uniformly distributed, the former being at a much higher concentration, levels of Na⁺ Ca²⁺ and Mg²⁺ were generally higher in the older leaves than the younger leaves. As the plants matured their leaves contained higher levels of divalent cations. The ear contents of glycinebetaine, proline, Ca²⁺ and Mg²⁺ increased with the ear maturity. The relative contribution of cations to the tissue osmotic pressure is discussed.     

胡椒调味油加工工艺条件的研究

以胡椒粉和大豆色拉油为主要原料制备风味独特的食用调味油,采用正交试验分析胡椒原料粒度、浸提温度以及质量比对胡椒调味油产品品质的影响,确定最佳工艺条件:以40目胡椒粉为原料,浸提温度为130℃,质量比(胡椒:大豆色拉油)为1:6(g/g).     

流量可调燃气发生器压力闭环模糊控制算法

为了改进流量可调燃气发生器的调节精度,引入燃气发生器压力闭环控制,针对流量可调燃气发生器压力闭环控制特点,在压力闭环中引入了模糊积分控制,此控制算法响应速度快,超调量较小,不同工况及长时间工作下系统仍然有较好的动态特性。      

青县气象站气压·气温平行观测数据对比分析

利用2009年1月～2010年12月青县自动气象站和人工观测的气压、气温资料,进行统计对比分析并探讨两者差值的形成原因。结果表明,自动站与人工观测值月平均气压差值为-0.7～0.1 hPa,月平均最高气压差值为-0.5～0.4 hPa,月平均最低气压差值为-0.7～0.2 hPa,月极端最高气压差值为-0.3～0.6 hPa,月极端最低气压差值为-1.1～0.1 hPa;月平均气温差值为-0.2～0℃,月平均最高气温差值为-0.4～0℃,月平均最低气温差值为-0.1～0.2℃,月极端最高气温差值为-0.3～0.3℃,月极端最低气温差值为-0.3～0.3℃。气象要素对比观测差值产生的原因主要有:观测仪器和观测原理的差异、数据采集时间与方法不同、感应器安装位置及所处环境不同以及人工干预与观测误差等主观因素。     

压强、固化时间与赋形剂对舔块饲料质量参数和舔食量的影响

通过 3个试验研究了 3种压强、固化时间及赋形剂的添加水平对尿素 糖蜜 矿物质舔块质量参数和舔食量的影响。结果表明 ,随着压强的增加 ,舔块硬度和密度呈二次曲线规律提高 (P <0 .0 0 1) ,而厚度膨胀度和肉牛舔食量呈二次曲线规律降低 (P <0 .0 0 1) ,其曲线的拐点约在 2 0Mpa压强。固化时间对舔块硬度、密度和膨胀度均有显著影响 (P <0 .0 5 )。糖蜜、氧化钙添加水平 ,导致舔块硬度和密度明显增加 (P <0 .0 5 )。本试验结论 :糖蜜、氧化钙、氧化镁和钠型的适宜添加水平为 12 %、5 %、2 %～ 4 %和 5 %～ 10 %。     

萜烯树指及其在压敏胶粘剂中的应用

本文对萜烯树脂生产和研究的基本情况及在压敏胶中的应用作了综述性报道     

Stenosis hemodynamics: from physical principles to clinical indices

Clinical evaluation of patients with aortic stenosis entails hemodynamic determinations and interpretations that depend on complex blood flow patterns. Although pressure gradient and Doppler velocity are intrinsically adjusted for a wide range of species and body size, they are highly flow-dependent indices that can vary among patients with physically identical stenosis areas and within individuals between determinations. Other indices, such as the Gorlin area, are adjusted for flow. All stenosis indices derived from hemodynamic measurements, however, must exhibit some degree of flow dependence because of fundamental aspects of fluid dynamics that affect the blood velocity profile. The Gorlin effective orifice area is an index that sacrifices adjustment for body size. This hinders comparisons over a range of patient species, breed, and size because it may be problematic to determine what effective orifice area is appropriate for a given individual. One potential solution is to compare the effective area of an individual's normal tract, if one exists, to the tract in question as a ratio, the effective orifice area ratio (EOAR). The EOAR can be estimated from the ratio of flow velocity integrals (FVIs) of the 2 outflow tracts. Clinical data and experience are lacking, but theoretical advantages of the index include intrinsic adjustment for both body size and flow rate. Aortic stenosis is a complex, multifactorial disease, and selection of an optimal hemodynamic severity index may not result in adequate prognostic criteria for segregation of patient risk and treatment groups.