压力高度

Based on the analysis of meeting a demand of the UAV engine and the characteristic of the diaphragm carburettor of altitude supply fuel,we design a altitude control device to regulate the displacement of the needle valve by pressure difference.

在分析无人机发动机使用要求以及膜片式化油器高度供油特性的基础上，设计了一种通过压力差来调节针阀升程的高度调节器，有效地改善了高度变化对化油器空燃比的影响，提高了发动机的高度性能。

After analyzing the soil stress, flexure moment data of central section of the sheet, and the flections data of two kinds of holding sheet models which are different on span, the paper gets the horizontal and vertical soil stress distribution rules and compares the result of the exam with calculating result of classic soil stress theory.

通过对两种跨度的挡板模型的土压力、挡板跨中弯矩、挡板跨中挠度值的分析总结，得到了挡板后土压力沿高度及水平方向的分布规律，并在土压力分布形式及数值大小与经典理论作了比较。

Based on the principle of variation of earth pressures on the culverts under different conditions, including topography, span of culvert, density of fill and the type of structure, and the property of arching action above the culvert, a nonlinear earth pressure theory for culverts beneath high fill is presented, the theory suggests the earth pressure on the culverts beneath high fill can be calculated with the formula σ=ξγH〓 as the fill up to higher height.

把这种方法与其它地下洞室的土压力计算理论进行的对比分析结果表明，非线性土压力理论考虑了填土达到一定高度时在涵洞上方产生的拱效应以及土拱的不稳定性特点，其计算的土压力明显低于不考虑拱效应的低填方涵洞土压力计算值，但高于具有稳定土拱效应的地下洞室土压力理论得到的土压力。

The fruits of research in the thesis as follow:(1) The principle of variation of earth pressures on the culverts beneath the high fills are investigated in the thesis.

论文通过模型试验和数值模拟计算，研究了狭窄沟谷地形、宽坦沟谷地形、岸坡设涵和坡脚设涵四种边界条件下的高填方涵洞土压力随填土高度变化的规律，研究结果表明，在各种边界条件下，高填方涵洞涵顶土压力变化规律相似，当填土达到一定高度后，仍有部分土压力传递到涵顶上，使高填方涵洞的土压力不随填土高度成线性增加，土压力呈非线性变化，高填方涵洞的土压力明显低于理论土压力σ=γH计算值。

The test results show the principle of variation of pressures on culverts beneath high fill is similar, it is that, even if the embankment is filled up to a higher height, the earth pressures can still partly transfer to the top of culvert, as a result the pressures on the culvert increase nonlinearly with the variation of height of fill and further the pressures are obviously lower than theoretical value by σ=γH.

模型试验和数值模拟计算结果表明，当填土达到一定高度后，高填方涵洞上方将产生明显的拱效应，但由于涵洞填土为破碎的岩土，其拱效应与岩石中开挖洞室上方的拱效应不同，高填方涵洞上方填土产生的"土拱"效应具有不稳定的特点，表现为随着填土高度的增加仍有部分土压力传递到涵洞上，涵顶土压力随填土高度成非线性增加。

Experimental results indicate that for the polystyrene particle with a larger size, Umf changes with p-0.3, and for the sand particle with a smaller size, Umf changes with p-0.21. An empirical equation about Umf is proposed based on the experimental data: Umf=μdp ρg｛［(34.15)2+0.05916×dp3 ρggμ2］12-34.15｝ It is found that the bed expansion height increases with the increasing of gas velocity, and increases with pressure for fixed value of UUmf, when the pressure exceeds 0.7MPa, the influence of pressure on the bed expansion height is weakened.

研究结果表明，大粒径聚苯乙烯颗粒的Umf与p-0.3成比例，小粒径石英砂的Umf与p-0.21成比例，并根据实验值拟合出压力下最小流化速度公式为： Umf=μdp ρg｛［(34.15)2+0.05916×dp3 ρggμ2］12-34.15｝床层膨胀高度随气速的增大而不断增高，在相同UUmf下床层膨胀高度随压力的增大而增高，在大于0.7MPa时，压力对膨胀高度的影响减弱。

It is found that for the same volumetric flow rate, the pressure drop in the shell side of the curved baffle heat exchanger is remarkably lower than that of the traditional one. And the pressure drop percentage deceases even more for a smaller curvature radius of the curved baffle and height of the baffle cut.

结果发现：在流量一定的情况下，曲面弓形折流板换热器的壳程压力降明显低于普通弓形折流板换热器的壳程压力降，而且随着曲面折流板曲率半径和折流板圆缺口高度的减小，曲面弓形折流板换热器的壳程压力降降低的百分比增大。

Result:(1) The max supporting weight of saddle-backed waist splint is 90 kg in the bed exercise, applicable to people who have spine length 73cm~67cm( about body height 178cm~165cm)(2) the height of the gas filled pillow is 5cm~15cm (3) The height of the gas filled pillow should be adjusted according to different patient (4) the press on the abdomen deliver by front part of saddle-backed waist splint is 3336 kpa; Standard piece of waist line is 94cm~70cm, elastic force is 180N .

结果：﹙1﹚鞍式腰托在卧床锻炼时的最大承重量为90㎏，适用脊柱长度为 73 ㎝67 ㎝（约身高178 ㎝165 ㎝）。﹙2﹚充气垫枕的高度为5㎝15㎝。﹙3﹚针对不同病人的身高﹐应适当的调整充气垫枕的高度以及指导锻炼时的拉伸高度。﹙4﹚下地后鞍式腰托前板能给腹部压力为3336kpa；标准件的弹性腰围为64㎝ 90㎝﹑弹性力为180N。结论：鞍式腰托在通过力学测试以及临床应用﹐已基本符合脊柱胸腰段（T11L2）椎体屈曲型稳定性压缩骨折的复位要求，具有简便安全而有效的整复与固定作用。具有较强的实用性，值得进一步研究开发。

For example, flight level 250 represents a pressure altitude of 25,000 feet.

FL 250表示压力高度为 25000英尺。

PRESSURE ALTITUDE, The altitude displayed when the barometric pressure on the altimeter is set to 29.92 inches of mercury.

压力高度，当高度表上的气压调至29.92英寸汞柱时显示的高度。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。