查询词典 null

Concha F%Barrientos A%Munoz L A phenomenological model of a hydrocyclone London , 1996,null

刘晓敏%蒋明虎脱油型水力旋流器空气核的稳定性分析石油学报， 2004，6

The null hypothesis is that the efficient estimator is a consistent and efficient estimator of the true parameters.

2， 如果上述理论逻辑通的话，将内生变量 X 作为解释变量， IV 和其他变量（ X2）作为解释变量，看 IV 是否显著，它应该显著。

Santa Regina I%Leonardi S%Rapp M Foliar nutrient dynamics and nutrient-use efficiency in Castanea sativa coppice stands of southern Europe 10.1093/forestry/74.1.1 Forestry , 2001,null

徐福余%王力华%李培芝%许思明%张颂云若干北方落叶树木叶片养分的内外迁移：Ⅰ。浓度和含量的变化应用生态学报， 1997，1

Cowper G R%Symonds P S Strain Hardening and Strain-rate Effects in the Impact Loading of Cantilever Beams Brown Univ Division of Applied Mathematics Report No.28 , 1957,null

封加波 对薄层柱壳爆炸膨胀断裂过程的研究高压物理学报， 1988，(2)章冠人韧性和脆性断裂的分形维数爆炸与冲击， 1996，2

Chen Weimin%Guo Xiaoming Annual change in zooplanktonic crustacea and their relationship with physico-chemical factors in Chonghu Lake International Journal of Ecology and Environmental Sciences , 1987,null

陈伟民%秦伯强太湖梅梁湾冬末春初浮游动物时空变化及其环境意义湖泊科学， 1998，(4)黄祥飞湖泊生态调查观测与分析北京：中国标准出版社， 1999，null

Check to ensure that the current value is not null/Nothing.

检查以确保目前的值不为null /没有。

The next parameter should be null unless you want to use a custom software rasterizer, which is very unlikely.

下一个参数应该是空，除非你想使用自定义的软件光栅，这是非常不可能的。

Dawe R O%Oswald T R%Robson I A Oil Recovery Process Using Mobility Control Fluid Comprising Alkylated Diphenyl Oxide Sulfonates and Foam Forming Amphoteric Suffactants US Pat Appl,US5203411 , 1993,null

张玉芬%乔聪震%张金昌%李成岳离子液体合成长链烷基苯 10.3321/j.issn：1000-8144.2003.10.004 石油化工， 2003，(10)彭朴采油用表面活性剂北京：化学工业出版社， 2003，null

Other than the difference with default values for optional arguments, you should assign a default when a passed argument has a null value.

和PHP不同的是可选参数，你需要比较它是否是空的，再赋给它一个默认值。

Fan Delian Metal Enrichment-Layer in Lower Cambrian Black Rock in South China. Study on Sediment and Petrology 北京:科学出版社, 1981,null

范德廉 南方几省下寒武统黑色岩系及层状多金属富集层北京：科学出版社， 1981，null

He has to relate with three women in the movie, and yet remain implicitly faithful to the unseen Lucinda.

让克劳德布里亚里成功地饰演试验了一个难度很大的角色：和三个女人打交道，但还要底下对观众未曾谋面的卢馨达保持忠诚。

The experiment was conducted to study effects of inulin on the growth performance, indices of immune organs and serum immunoglobulin of laying chicklings as well as the performance of inulin which replaced the antibiotics in diets by adding 0.2%, 0.4% and 0.8% of inulin, respectively.

试验旨在通过在蛋用雏鸡日粮中添加0.2%、0.4%和0.8%的菊粉，研究菊粉对蛋雏鸡生长性能、免疫器官指数和血清免疫球蛋白的影响，以及菊粉替代抗生素对蛋雏鸡的应用效果。