全文获取类型
收费全文 | 79篇 |
免费 | 120篇 |
国内免费 | 25篇 |
专业分类
化学 | 44篇 |
力学 | 3篇 |
综合类 | 6篇 |
数学 | 17篇 |
物理学 | 154篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 3篇 |
2019年 | 2篇 |
2018年 | 9篇 |
2017年 | 1篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 1篇 |
2009年 | 18篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 63篇 |
2002年 | 15篇 |
2001年 | 5篇 |
2000年 | 17篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1996年 | 6篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1982年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有224条查询结果,搜索用时 484 毫秒
61.
Tong Xu Yi Zhong Yan liu Hong Yu Zhiping Mao 《Journal of Thermal Analysis and Calorimetry》2013,111(1):27-33
In this study, polyimide (PI) fabric was coated with montmorillonite (MMT) which performed as a kind of flame retardant. Thermogravimetric analysis showed that PI coated with MMT left as much as 69 % char after heating to 700 °C, about 15 % more than uncoated PI fabric. Cone calorimeter testing (heat flux: 60 kW m?2) showed that coated fabric reduced the total heat release and showed resistance to degradation from direct flame. Post-burn residues of samples were examined with SEM and revealed that the weave structure and fiber shape in all coated fabrics were preserved. In addition, heat-insulting test showed that the temperature difference of coated PI could reach 400 °C after 10 min at 800 °C. These results demonstrate that MMT coating is relatively effective for improving flame-retardant behavior to PI fabric. 相似文献
62.
63.
64.
65.
66.
薄膜梯度扩散-原子吸收光谱法富集测量水中痕量镉 总被引:1,自引:0,他引:1
建立了薄膜梯度扩散-原子吸收光谱(DGT-AAS)法富集测量水中痕量镉的分析方法。先以海藻酸钠(SA)溶液为结合相的DGT技术(SA DGT)原位分离富集水中Cd~(2+),再以AAS法测定DGT结合相中镉的含量,最后依据DGT方程计算水中Cd~(2+)浓度。DGT-AAS法测得配制水中Cd~(2+)的回收率为95.6%~102.7%,相对标准偏差(RSD)为1.5%~3.1%;测得河水和人工湖水中加标Cd~(2+)的DGT有效态分数分别为22.46%和15.19%。当采样时间为48h,SA DGT对水中Cd~(2+)的富集倍数为20倍,可显著降低分析方法的检测限,实现水中痕量Cd~(2+)的定量检测。 相似文献
67.
68.
Vladimir?KozlovEmail author Nikolay?Kuznetsov 《Archive for Rational Mechanics and Analysis》2011,201(2):631-645
The two-dimensional nonlinear problem of steady gravity waves on water of finite depth is considered. The Benjamin–Lighthill
conjecture is proved for these waves provided Bernoulli’s constant attains near-critical values. In fact this is a consequence
of the following more general results. If Bernoulli’s constant is near-critical, then all corresponding waves have sufficiently
small heights and slopes. Moreover, for every near-critical value of Bernoulli’s constant, there exist only the following
waves: a solitary wave and the family of Stokes waves having their crests strictly below the crest of this solitary wave;
this family is parametrised by wave heights which increase from zero to the height of the solitary wave. All these waves are
unique up to horizontal translations. Most of these results were proved in our previous paper (Kozlov and Kuznetsov in Arch
Rational Mech Anal 197, 433–488, 2010), in which it was supposed that wave slopes are bounded a priori. Here we show that the latter condition is superfluous by
proving the following theorem. If any steady wave has the free-surface profile of a sufficiently small height, then the slope
of this wave is also small. 相似文献
69.
70.
随着我国民航运输业的飞速发展,机场噪声影响问题日趋严重。通过向航空公司或旅客收取噪声费来筹集机场噪声治理资金是民航发达国家的通用做法。本文提出了基于飞机噪声特性、噪声烦恼度、噪声治理投入费用和资金回收周期等因素的机场噪声收费模型。飞机噪声特性根据ACI的机场噪声分类确定,噪声烦恼度借助Mamdani模型构建。应用表明,该收费模型关键因素考虑全面,计算方法先进简洁,费率合理,符合国际民航组织倡导的以支定收原则,有助于形成航空公司/旅客减噪激励机制同时又不致抑制机场航空业务增长。 相似文献