气孔的

The leaf epidermis structures of 6 species of Rhododendron had been observed under LM and SEM. The results show that all share together common features as follows: the leaf blades are typical back-abdomen bifacial types, the upper epidermis are formed by two or three layer bigger cells which inside layer cell is bigger than outside one, and the upper epidermis are covered with thicker cuticle.

利用光学显微镜和扫描电子显微镜观察了6种杜鹃属植物的叶片结构，结果表明，它们具有共同形态结构特征：典型的异面叶，上表皮由2~3层细胞组成，内大外小或内、外等大，有较厚的角质膜，无气孔器分布；下表皮均由1层细胞组成，排列紧密；栅栏组织由2层以上长柱形细胞组成，排列紧密；海绵组织细胞较短，排列较疏松，细胞间隙较大；均有表皮附属物。

Guard cells are biochemically and anatomically the most complicated cells in the epidermal layer and are unique amongst the plant cells.

近年来，国际上十分关注气孔运动的调控机理，在保卫细胞内外的信息传递和转导途径的研究方面取得重要进展。

A comparison of photosynthetic rate, transpiration rate, w ater use efficiency, stomatal conductance, intercellular CO 2 concentration and vapor pressure deficit at the leaf surface between Poaceae C 4 plants (Chloris virgata and Setaria viridis) an d Chenopodiaceae C 3 plants (Chenopodium album and Chenopodium glaucum) under the simulated photosynthetic radiation was conducted in this st udy.

利用人工模拟光源研究了两种 C4 光合途径禾本科植物和两种 C3光合途径藜科植物的光合速率、蒸腾速率、水分利用率、气孔导度、胞间 CO2 浓度及叶面饱和蒸气压亏缺随模拟光辐射增强的变化规律及 Gs、Ci、Vpdl对 Tr和 WUE的影响。

The carbon foam were prepared by self-bubbling at high pressure from AR pitch added sodium dodecyl benzene sulfonate and Span-40, respectively. The bulk density, pore rate, compressive strength, thermal conductivity at room temperature and crystallitic parameters of carbon foam were measured. The rheological properties of AR pitch and pore structure of carbon foam were investigated.

以十二烷基苯磺酸钠和Span-40表面活性剂为添加剂，AR沥青为原料，制备炭素泡沫材料，测定了材料的体积密度、显气孔率、压缩强度、常温热导率以及微晶结构参数，研究了添加表面活性剂后AR沥青的流变性能和炭素泡沫材料孔胞结构的变化。

The comprehensive evalucation resulted in a strong drought resistance group including ZXY04P-201、ZXY03P-227、ZXY03P-122 and ZX Y04P-136, a weak drought resistance group including ZXY04P-101、ZXY04P-89,ZXY04P-239 and a intermediate group including the others according to the the above indicators. 3. The results of study on drought mechanism for 4 Dactylis glomerata L. under continuously water stress and rewatering show: the water saturation deficit of leaves arose hastily, and ZXY04P-239 changed most obviously while ZXY04P-201 changed only slightly under drought stress. ZXY03P-173 and ZXY04P-201 increased in the relative plasmalemma permeability and the soluble sugar content while thant of ZXY04P-75 and ZXY04P-239 showed the trend of initial increasing, reaching the peak at the 8th day, then decreasing under drought stress.

20份鸭茅种质幼苗期抗旱性研究表明，干旱胁迫条件下，所有材料的株高、生物量显著下降，叶片脯氨酸和可溶性糖作为重要的渗透调节物质，其含量迅速增加，质膜相对透性的数值变大，细胞膜受伤害程度增大，水分饱和亏缺值变大，植物保水能力变弱，胞间CO2浓度增大；净光合速率、蒸腾速率、气孔导度和叶绿素含量等指标测定值减小，通过20份鸭茅种质苗期抗旱性综合评价，发现ZXY04P-201、ZXY03P-227、ZXY03P-122、ZXY04P-136属强抗旱性材料，ZXY04P-101、ZXY04P-89、ZXY04P-239属弱抗旱性材料，其他属于中等抗旱性材料。

The New Rice Variety Liaoxing 1,with high eurytopicity has higher photosynthesis rate,higher stoma conductance,higher SPAD,higher ingather quotiety than other largely planted varieties in Liaoning Province,when planted in the rice area from 39°N to 43°N.Different from other varieties,when planted in four spots in different latitudes,the yield components of Liaoxing 1 change little and so it keeps higher yield level.

水稻新品种辽星1号具有很强的广适性，从北纬39°到北纬43°布点试验，用L6400光效测定仪测定辽星1号及其对照品种的光合速率、气孔导度、叶绿素含量、经济系数等指标，在4个不同纬度，辽星1号的各项指标均显著地高于辽宁其它主栽品种；产量结构没有发生很大变化，产量始终表现出较高水平。

Using count the leave.and flow cytometric to identifiy ploidy levels for the regenerated plants derived from antherculture in burley tobacco in this article,it shows that using count the chloroplast method could identify the ploidy levels simply and economic but it cannot identify the mixoploid accurately, so it easily lead to misidentify.

本文分别用气孔保卫细胞叶绿体计数和流式细胞仪两种方法来鉴定花药培养再生植株染色体的倍性，结果发现叶绿体计数法可以简单经济的检测烟草花药培养再生植株的染色体倍性，但它不能准确地鉴定出混倍体植株，易造成误判。

Experiment result indicates that laser power density,welding speed,pulse frequency and pulse width are the key factors of pulse laser welding and that the polishment,close touch of butt joint faces have an important effect on the air vents number in welding line and the mechanical performance of welding line.

实验结果表明：对焊面的打磨、抛光和紧密接触对防止焊缝中产生过多的气孔和提高焊缝的机械性能有重要作用；激光功率密度、焊接速度、脉冲宽度和脉冲频率四个参数是实现脉冲激光焊接的关键因素。

SiC/Al composites were fabricated by pressureless infiltration technique, based on infiltration dynamics mechanism and technic method ,the effects of holding time and cooling way on the residual porosity of composites were discussed.

采用无压浸渗法制备了SiC/Al复合材料，从浸渗动力学和工艺方法的角度探讨了浸渗保温时间和降温方式对复合材料的残余气孔率的影响。

It was found the flow velocity gradients around the gas-tunnel was high enough to cause air mixture and sand-core washing-out, the casting should be with good sinkhead and gas-venting ability.

对铸造过程充型模拟的计算结果可知，在气道附近区域，流体流动的速度梯度很大，容易出现卷气、冲刷砂芯等现象，因此，在这些区域出现气孔、针孔和缩孔、砂孔等缺陷的可能性很大，为此，必须保证铸件凝固补缩良好、排气通畅。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。