全文获取类型
收费全文 | 4834篇 |
免费 | 464篇 |
国内免费 | 121篇 |
专业分类
电工技术 | 17篇 |
技术理论 | 1篇 |
综合类 | 257篇 |
化学工业 | 1452篇 |
金属工艺 | 155篇 |
机械仪表 | 56篇 |
建筑科学 | 106篇 |
矿业工程 | 60篇 |
能源动力 | 13篇 |
轻工业 | 2019篇 |
水利工程 | 26篇 |
石油天然气 | 62篇 |
武器工业 | 6篇 |
无线电 | 112篇 |
一般工业技术 | 536篇 |
冶金工业 | 489篇 |
原子能技术 | 18篇 |
自动化技术 | 34篇 |
出版年
2024年 | 55篇 |
2023年 | 168篇 |
2022年 | 223篇 |
2021年 | 357篇 |
2020年 | 278篇 |
2019年 | 242篇 |
2018年 | 167篇 |
2017年 | 201篇 |
2016年 | 168篇 |
2015年 | 175篇 |
2014年 | 204篇 |
2013年 | 257篇 |
2012年 | 356篇 |
2011年 | 340篇 |
2010年 | 258篇 |
2009年 | 238篇 |
2008年 | 217篇 |
2007年 | 234篇 |
2006年 | 272篇 |
2005年 | 238篇 |
2004年 | 175篇 |
2003年 | 129篇 |
2002年 | 112篇 |
2001年 | 96篇 |
2000年 | 53篇 |
1999年 | 37篇 |
1998年 | 28篇 |
1997年 | 24篇 |
1996年 | 23篇 |
1995年 | 16篇 |
1994年 | 14篇 |
1993年 | 15篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1951年 | 1篇 |
排序方式: 共有5419条查询结果,搜索用时 31 毫秒
991.
《中国有色金属学会会刊》2022,32(10):3163-3181
This review discussed the relationship among copper, human, and bacteria. Copper plays an important role in human immunity. Copper can boost human immune defense reactions at recommended intake level. The content mainly focused on copper antibacterial activity and copper antibacterial mechanisms. Conclusions stated that copper antibacterial activity is affected by copper homeostasis mechanisms in bacteria, adhesion, humidity, strain specificity, and manufacturing methods of antibacterial agents. For the preparation of particle antibacterial agents and surface antibacterial agents, this review discussed several manufacturing methods, such as sol-gel, cold spray, and biosynthesis belonging to chemical synthesis, physical synthesis, and biological synthesis, respectively. Sol-gel method contributes to the preparation of particle agents and surface agents. Cold spray technique is utilized in synthesis of surface copper agent. Biosynthesis is a novel technology which can be applied in nanoparticle agent preparation. 相似文献
992.
993.
《Journal of Sulfur Chemistry》2013,34(4):427-438
A new synthetic strategy for the synthesis of novel 6-methyl-3′-aryl spiro[isoxazolo[2,3-b][1,2,4]thiadiazole-2,2′-thiazolidin]-4′-ones (9a–9e) and 6-methyl-3′-aryl spiro[isoxazolo[2,3-b][1,2,4]oxadiazole- 2,2′-thiazolidin]-4′-ones (12a–12e) analogs is described. These compounds showed significant antimicrobial activity against all the standard strains. 相似文献
994.
《Journal of Sulfur Chemistry》2013,34(3):223-233
3-Chloro-1-benzothiophene-2-carbonylchloride 1 reacted with anthranilic acid in pyridine to give compound 2. The main aim of the work is to study the behavior of this 4H-3,1-benzoxazin-4-one toward nitrogen nucleophiles. The compound reacted with aromatic amines, hydroxylamine hydrochloride, formamide, thioglycolic acid, thiosemicarbazide and acid chlorides to give various 3-substituted quinazolinones, respectively. The structures of all the synthesized compounds were confirmed by spectral data and have been screened for antibacterial and antifungal activity. 相似文献
995.
996.
采用平板共培养法测定Ti-Zr-Cu合金表面的菌落数,通过CCK8细胞增殖检测、鬼笔环肽细胞染色观察细胞核和细胞骨架形貌、细胞凋亡和黏附能力测定,研究了Ti-Zr-Cu合金的抗菌性能和体外生物相容性。结果表明,空白样品和Ti-Zr合金表面上的菌落密集,而Ti-Zr-Cu合金表面上的菌落数极少。Ti-Zr-Cu合金对金黄色葡萄球菌和大肠杆菌的抗菌率分别达到98.28%和97.67%,表现出优异的抗菌性能。MC3T3-E1在Ti-Zr-Cu合金表面培养1、4、7 d的相对增值率分别为168.8%、109.8%和106.5%,均高于100%,表明这种合金没有细胞毒性。细胞在Ti-Zr-Cu合金表面上的附着和铺展良好,有利于贴壁细胞在其表面黏附和进一步增值,表明Ti-Zr-Cu合金具有良好的生物相容性。Ti-Zr-Cu合金对细胞凋亡没有不良影响。从Ti-Zr-Cu合金表面细胞的SEM照片可见细胞的粘附正常,也表明其具有良好的生物相容性。 相似文献
997.
998.
达巴万星是一种新型注射用半合成糖肽抗生素,适用于复杂感染及多重耐药菌造成感染的抗菌治疗。其对革兰阳性病原体有抗菌活性,且对耐甲氧西林金黄色葡萄球菌(MRSA)具有特别强力的活性;对耐G+病原菌包括耐青霉素和头孢曲松肺炎链球菌、替考拉宁不敏感CoNS、非vanA型肠球菌具有活性;对G+厌氧菌也具有活性。介绍了达巴万星的特性、制备工艺以及临床试验,指出了达巴万星具有独特的药动学性质,通过微生物发酵获得,在治疗导管相关的血源性感染以及皮肤和软组织感染已取得了良好的效果,是理想的第二代糖肽抗生素。 相似文献
999.
Sobell Linda Carter; Sobell Mark B.; Agrawal Sangeeta 《Canadian Metallurgical Quarterly》2009,23(4):672
Although group therapy is widely used for individuals with substance use disorders (SUDs), randomized clinical trials (RCTs) comparing the same treatment in a group versus individual format are rare. This paper presents the results of a RCT comparing guided self-change (GSC) treatment, a cognitive–behavioral motivational intervention, conducted in a group versus individual format with 212 alcohol abusers and 52 drug abusers who voluntarily sought outpatient treatment. Treatment outcomes demonstrated significant and large reductions in clients’ alcohol and drug use during treatment and at the 12-month follow-up, with no significant differences between the group and individual therapy conditions. A therapist time ratio analysis found that it took 41.4% less therapist time to treat clients using the group versus the individual format. Participants’ end-of-treatment group cohesion scores characterized the groups as having high engagement, low levels of interpersonal conflict, and low avoidance of group work, all desirable group characteristics. These findings suggest that the GSC treatment model was effectively integrated into a brief group treatment format. Health care cost containment compels further evaluations of the efficacy of group treatments for SUDs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
1000.