全文获取类型
收费全文 | 90篇 |
免费 | 9篇 |
专业分类
电工技术 | 1篇 |
综合类 | 37篇 |
化学工业 | 32篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 1篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 1篇 |
一般工业技术 | 13篇 |
出版年
2024年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 14篇 |
2005年 | 10篇 |
2004年 | 15篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
排序方式: 共有99条查询结果,搜索用时 46 毫秒
41.
42.
为实现城市受污染河流的环境需水量的合理调配,以各蓄水构筑物的调水量为决策变量,研究了在保证河流生态环境需求的基础上,实现整个流域的污染负荷的环境容量最大化、水量最大节约和调水成本最小化的方法,建立了环境需水调度的模糊多目标规划模型.模型中采用整合的非线性梯度隶属度函数作为目标函数,以遗传算法作为求解此模型的工具,并将该模型用于大庆市黎明河流域的环境水量调配,取得较好的效果. 相似文献
43.
44.
反硝化脱硫工艺中生物硫分布特征及分离方法 总被引:2,自引:0,他引:2
为探寻反硝化脱硫工艺生物硫分离方法,运行反硝化脱硫系统获得生物硫在系统中分布特征,并对生物硫进行粒径分布、Zeta电位、能谱及电镜扫描分析,确定了一种分离生物硫的新方法.结果表明,生物硫在反硝化脱硫系统中水相占65%,污泥相占35%.能谱分析表明,生物硫硫元素占60%以上,电镜分析显示生物硫表面具有多聚糖、蛋白质等官能团,生物硫Zeta电位平均为-20 mV带负电(在± 30 mV之间),得出生物硫具有胶体特性.进一步用阳离子絮凝剂实验分离生物硫获得99%分离率.混凝沉淀方法能有效地分离回收生物硫. 相似文献
45.
46.
47.
In order to obtain a novel polyamide having excellent heat-resistant properties which could be anticipated as a thermal modifier for aliphatic polyamide,a series of new semi-aromatic polyamides (BO6,BO8,BO10) containing benzoxazole unit were synthesized based on 5-amino-2-(p-aminophenyl) benzoxazole (ABO) and aliphatic acids (adipic,suberic and sebacic acid) by means of Yamazaki phosphorylation method.The effect of reaction temperature on the inherent viscosity of the polymers was studied,and the structures of products were characterized by FTIR,1 H-NMR,and the heat resistance of the polymers was studied by DSC and TG.The results showed that the reaction temperature gives the polymers the highest viscosity at around 90 ℃,130 ℃ and 130 ℃ for BO6,BO8 and BO10,respectively.The heat resistance of the new semi-aromatic polyamides is much higher than that of the common aliphatic polyamides.In addition,the products show good solvent resistance and crystallization properties. 相似文献
48.
A method of detection hydroxyl radical ( · OH) produced by electrochemical oxidation in organic wastewater treatment was developed. Benzoic acid with weak fluorescence may reacted with hydroxyl radical to produce 3-hydroxybenzonic acid with intense fluorescence, whose characteristic fluorescence excitation and e- mission wavelength were at 305 nm and 410 nm. The 3-hydroxybenzonic acid was separated from electroehenaical oxidation system by HPLC. Two major hydroxylated products were quantified corresponding to 3-hydroxybenzonic, 4-hydroxybenzonic acid. Therefore the quantity of hydroxyl radical in the reactive system should be primarily calculated. The optimal experimental program was obtained by studying the determination conditions, which were benzoic acid of 1.0 mmol/L, electrolysis time of 60 min, current density of 39 mA/cm^2 , supporting electrolyte (Na2SO4 ) of 0. 02 mol/L, and the low rate of sparged-air of 25 mL/s. The results show that this method is stable, sinaple and rapid and can be used as a convenient method for the determination of hydroxyl radical. 相似文献
49.
孙德智 《哈尔滨工业大学学报》1993,25(4):119-121
The liquid surfactant membrane(LSM)systems consist of three phases.Twomiscible phases which feed and strip solute respectively are separated from each otherby a third organic membrane phase that is immiscible with both.The technique ofLSM has received considerable attention for its high surface area to volume ratio, 相似文献
50.