首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21篇
  免费   3篇
  国内免费   5篇
电工技术   1篇
综合类   1篇
化学工业   10篇
金属工艺   1篇
轻工业   3篇
石油天然气   9篇
无线电   2篇
一般工业技术   1篇
自动化技术   1篇
  2021年   1篇
  2019年   1篇
  2018年   2篇
  2017年   2篇
  2016年   1篇
  2015年   2篇
  2011年   1篇
  2000年   1篇
  1999年   1篇
  1997年   3篇
  1996年   2篇
  1995年   5篇
  1994年   1篇
  1992年   2篇
  1991年   2篇
  1989年   1篇
  1988年   1篇
排序方式: 共有29条查询结果,搜索用时 15 毫秒
1.
Owing to its high content of omega‐6/omega‐3 fatty acids and bioactive minor components with antioxidant activities, hemp seed oil is now recognized for its health benefits by a large number of consumers. This paper primarily discusses the profile of minor components in hemp seed oil and their beneficial and adverse effects on oil quality. While tocopherols, polyphenols and phytosterols prevent oxidative deterioration of hemp seed oil, the high amount of chlorophyll can be detrimental to oil quality.  相似文献   
2.
石油羧酸盐的磁化降吸附研究   总被引:1,自引:0,他引:1  
探讨了磁化前后,石油羧酸盐表面活性剂在高岭土表面静吸附规律的变化。实验发现,经磁化处理的石油羧酸盐表面活性剂,在高岭土表面的吸附速度变快,液固比变小,吸附等温线仍有最大值,但已大为下降,从而推断其吸附模式发生改变。  相似文献   
3.
Wang C  Lv P  Wei W  Tao S  Hu T  Yang J  Meng C 《Nanotechnology》2011,22(41):415101
A multifunctional 'all-in-one' nanocomposite is fabricated using a colloid, template and surface-modification method. This material encompasses magnetic induced target delivery, cell uptake promotion and controlled drug release in one system. The nanocomposite is characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, N(2) adsorption and vibrating sample magnetometry. The prepared material has a diameter of 350-400 nm, a high surface area of 420.29 m(2) g(-1), a pore size of 1.91 nm and a saturation magnetization of 32 emu g(-1). Doxorubicin (DOX) is loaded in mesopores and acid-sensitive blockers are introduced onto the orifices of the mesopores by a Schiff base linker to implement pH-dependent self-release. Folate was also introduced to improve DOX targeted delivery and endocytosis. The linkers remained intact to block pores with ferrocene valves and inhibit the diffusion of DOX at neutral pH. However, in lysosomes of cancer cells, which have a weak acidic pH, hydrolysis of the Schiff base group removes the nanovalves and allows the trapped DOX to be released. These processes are demonstrated by UV-visible absorption spectra, confocal fluorescence microscopy images and methyl thiazolyl tetrazolium assays in vitro, which suggest that the smart nanocomposite successfully integrates targeted drug delivery with internal stimulus induced self-release and is a potentially useful material for nanobiomedicine.  相似文献   
4.
近年来弥散性已被验证为油层岩石的一种基本物理性质,并被认为是混溶驱替过程孔隙介质内两种混溶流体不稳定混合能力的一种度量。本文描述实验确定岩石弥散性的理论和方法;并根据实验结果讨论弥散性与渗透率、平均颗粒直径、毛管压力、Koval非均质系数等岩石物性参数以及与水驱油效率的相关性。  相似文献   
5.
6.
粉煤灰中的残余碳   总被引:4,自引:0,他引:4  
粉煤灰中的残余碳是燃煤锅炉中煤未完全燃烧所产生的固体废弃物。残余碳的形成主要与燃料煤的组成和性质、锅炉特点、燃烧温度、空气量(燃烧时的氧气供给量)及燃烧时间(O工在锅炉内的停留时间)等因素有关。残余碳通常以单体半焦或焦炭、粘结在粉煤灰颗粒表面或包裹在粉煤灰颗粒中等几种形式存在,残余碳的粒度分布、比表面积、H和O的含量都有其特殊性。粉煤灰中的残余碳,不仅能反映锅炉的运行情况、影响锅炉烟气中COX的含  相似文献   
7.
利用环戊酮与正戊醛缩合,再经催化氢化制得了2-正戊基环戊酮。研究了环戊酮与正戊醛羟醛缩合反应生成2-亚正戊基环戊酮的各种影响因素,2-正戊基环戌酮与碘甲烷反应合成了三甲基戊基环戊酮香料单体。  相似文献   
8.
澳门回归是我国政府恢复对澳门行使主权 ,完成统一大业的一个重要里程碑。48小时的澳门回归电视直播任务 ,是我们一次难忘的经历。澳门回归电视直播总导播厅设在中央电视台新闻演播室。为了完成这次长时间的直播灯光任务 ,我们根据报道意图 ,进行了反复研究 ,确定首先应反映出澳门回归是喜庆日子 ,要突出欢庆的气氛。这次澳门回归有 3位节目主持人 ,还有现场人物采访。背景设有五星红旗、长城、澳门楼群 ,而且建筑物上到处悬挂着迎风飘扬的彩旗、灯笼 ,尽可能完美地把主持人的形象和雄伟壮观的场景表现在电视屏幕上 ,灯光照明是十分重要的。…  相似文献   
9.
The effect of different solvents (aqueous methanol [70%, v/v], aqueous acetone [80%, v/v], and a solvent mixture [MA] of aqueous methanol [70%, v/v] and aqueous acetone [70%, v/v] in a ratio of 1:1 [v/v]), preheating temperatures (140, 160, and 180°C), and times of exposure (5, 15, and 30 min) on the ultrasonic extraction of the main phenolic compounds from hempseed cake (Cannabis sativa) was investigated. A simplified new high‐performance liquid chromatography (HPLC) method was developed to identify and quantify the main phenolics (namely, Ntrans‐caffeoyltyramine and cannabisin B) in the extracts. Two other main compounds, numbered 3 and 4 , were also detected. The results showed that the nature of the extracting solvent had a significant (P < 0.05) impact on the ultrasonic extraction of phenolic compounds. The acetone extracts exhibited the highest total phenolic content (TPC), followed by MA and methanol. The preheating temperature and time of exposure enhanced the TPC for all solvents examined. The main phenolics, Ntrans‐caffeoyltyramine, cannabisin B, and compound 3 , were positively affected by the temperature and time of exposure, irrespective of the solvents used. In sharp contrast, compound 4 appeared to be thermally sensitive: increasing preheating time and temperature decreased the yields of this compound. This study demonstrated that acetone was the most effective extracting solvent and that preheating enhanced the yield of the main phenolics.  相似文献   
10.
以产纳豆激酶的地衣芽孢杆菌基因工程菌BL10(pP43SNT-SsacC)为出发菌株,开展其全合成培养基的发酵优化研究。通过单因素试验和正交试验优化了全合成培养基成分,获得了最优的培养基组成(g/L):葡萄糖30、NaNO3 30、谷氨酸钠20、柠檬酸钠15、MgSO4·7H2O 0.5、K2HPO4·3H2O 1.5、CaCl2 0.5,pH 7.2。在优化的全合成培养基中,纳豆激酶最高酶活力达到25.59 FU/mL,相比于初始培养基发酵活性(4.27 FU/mL),提高了5 倍。对比分析了全合成培养基和半合成培养基的发酵产物,结果表明,全合成培养基可显著提高纳豆激酶的纯度,与半合成培养基相比,纳豆激酶比活力提高了2 倍。本研究获得了纳豆激酶的全合成培养基成分,显著提高了纳豆激酶发酵活性,并进一步提高了纳豆激酶发酵纯度。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号