全文获取类型
收费全文 | 197篇 |
免费 | 8篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 63篇 |
金属工艺 | 1篇 |
机械仪表 | 1篇 |
建筑科学 | 4篇 |
能源动力 | 10篇 |
轻工业 | 23篇 |
水利工程 | 1篇 |
无线电 | 7篇 |
一般工业技术 | 40篇 |
冶金工业 | 32篇 |
原子能技术 | 3篇 |
自动化技术 | 18篇 |
出版年
2023年 | 1篇 |
2022年 | 10篇 |
2021年 | 16篇 |
2020年 | 1篇 |
2019年 | 9篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 12篇 |
2012年 | 10篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 10篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有205条查询结果,搜索用时 31 毫秒
21.
The effect of different cooking times on the GLS content in white cabbage (Brassica oleracea L. var. capitata f. alba) was determined. Cooking of cabbage for 5-30 min caused a gradual decrease in the GLS content. The most efficient reduction of the GLS content (by about 35%) occurred during the first minutes of cooking. As the cooking time was extended by another 5 min, each time the GLS content decreased by 10-15%. Higher losses in indole GLS, as compared to those of aliphatic ones, resulted from more efficient diffusion of those compounds to cooking water. The GLS content in cooking water, irrespective of the cooking time of white cabbage, remained rather stable, whereas the content of indole GLS was between 3.5- and 4-fold higher in comparison to that of aliphatic GLS. Taking into consideration the rate of changes in the content of particular GLS in cabbage and the GLS content in cooking water, it can be stated that glucoiberin was more thermolabile than other GLS. 相似文献
22.
This paper argues that energy efficiency and conservation is a noncontroversial, critical, and equitable option for rich and
poor alike. Although there is growing scientific and political consensus on its significance as an important option at global
and national level, the political momentum for taking action is not commensurate with the potential in the sector or the urgency
with which measures need to be taken to deal with climate change. The current global energy (efficiency) governance framework
is diffuse. This paper submits that there are four substantive reasons why global governance should play a complementary role
in promoting energy efficiency worldwide. Furthermore, given that market mechanisms are unable to rapidly mobilize energy
efficiency projects and that there are no clear vested interests in this field which involves a large number of actors, there
is need for a dedicated agency to promote energy efficiency and conservation. This paper provides an overview of energy efficiency
options presented by IPCC, the current energy efficiency governance structure at global level, and efforts taken at supranational
and national levels, and makes suggestions for a governance framework. 相似文献
23.
Fabrice Burel Hassan Oulyadi Claude Bunel Vladimir Grishchenko Natalya Busko Antonina Barantsova Vitaly Boiko 《Journal of Polymer Research》2011,18(6):2265-2273
Azo-bis(isobutyroamidoxime) was synthesized and used as functionalized initiator to prepare a liquid isoprene bearing amidoxime
end groups via radical polymerization. The polymer was characterized by FT-IR, Gel Permeation Chromatography and NMR. In particular,
the structure of the polymer was investigated using 1D and 2D NMR techniques. The distribution of the different isoprene units
(1,4-trans, 1,4-cis, 1,2 and 3,4), as well as the structure of the amidoxime end-groups was determined. It was found that
the structure of the end groups was governed by the steric hindrance of the initiator. Only 1,4 and 4,1 functionalized end
units were evidenced, with a majority of 4,1 end units. 相似文献
24.
Two series of WO
x
/ZrO2 samples are prepared by equilibrium adsorption from H2O2 solutions at pH 1.8 containing two different precursor anions, [W2O3(O2)4(H2O)2]2− and [H2W12O40]6−. The starting material is amorphous zirconium oxyhydroxide. The maximum W densities obtained are larger than that reported
in the literature for systems synthesized by the same method using aqueous non-peroxide solutions. In the case of the metatungstate
precursor, this increase is attributed to the generation of additional anchoring sites by interaction between the amorphous
support and H2O2. The high uptake achieved when the peroxo complex is used as a precursor is a result of both the ZrO
x
(OH)4-2x
–H2O2 interaction and low nuclearity of the adsorbing anion. The materials are characterized by XRD, DR–UV–vis, Micro-Raman and
FT-IR spectroscopy. The surface acidities of samples with identical W loading prepared by equilibrium adsorption from the
[H2W12O40]6−–H2O2 system and by impregnation with aqueous solution of ammonium metatungstate are investigated by FT-IR spectroscopy of CO adsorbed
at 80 K. 相似文献
25.
Ankylosis of the temporomandibular joint leads in children to serious disorders such as loss of dentition, growth retardation of the lower jaw, facial asymmetry etc. During the period from 1993 till 1997 we treated 12 children incl. eight who had unilateral and four bilateral ankylosis. In six patients, after elimination of the ankylosis, reconstruction of the head was made with a total of nine costochondral grafts. In entire all patients the temporal muscle or a silicone plate was interposed between the skull base and mandible. Postoperative complications were minimal. Surgical treatment, which is only half of the issue of treatment, must be followed by long-term careful rehabilitation. The results which were achieved contributed in a significant way to a more favourable further development of the children. 相似文献
26.
J Koz?owski 《Canadian Metallurgical Quarterly》1993,44(2-3):277-279
The spectrofluorimetric method of bez(a)pyrene was used without separating it from other polycyclic aromatic hydrocarbons. On the basis of that method the content of that compound was measured in air contaminated with gas after burning of gas cookers. The study showed that this compound is not present in Warsow when earth gas is burning, but burning of propane-butane mixture contaminates air with this compound in a considerable degree. 相似文献
27.
Though tumours of the scalp and skull are not very common certain severe and extensive forms are associated frequently with intracranial propagation and therefore their reconstruction represents often a major problem requiring the use of a series of surgical methods. Their treatment requires the use of expanders, local flaps, pedicled cutaneous and musculocutaneous flaps, as well as free flaps. This report deals with 10 patients with localized extensive tumours larger than 120 cm2 within the region of the scalp and skull subjected to various reconstruction procedures. The applied surgical techniques are discussed and attention is devoted also to the involvement of bone in the above mentioned localization as well as to the problems associated with these lesions. 相似文献
28.
L Gregorini J Marco C Palombo M Kozàkovà GB Anguissola B Cassagneau M Bernies A Distante I Marco J Fajadet A Zanchetti 《Canadian Metallurgical Quarterly》1998,31(5):992-1001
OBJECTIVES: We sought to evaluate the efficacy of alpha-adrenergic blocking agents in counteracting left ventricular (LV) dysfunction occurring after transient ischemia in humans. BACKGROUND: The mechanisms underlying postischemic LV dysfunction are largely unknown. METHODS: Percutaneous transluminal coronary angioplasty (PTCA) provides a clinical model of ischemia and reperfusion. In 50 patients undergoing coronary stenting for 77+/-5% stenosis, LV function was monitored by transesophageal echocardiography during and 30-min after PTCA. Fifteen minutes after stenting, 15 patients received 12 microg/kg body weight of the alpha-blocker phentolamine intracoronarily, 15 patients received 600 microg/kg of the alpha1-blocker urapidil intravenously, 10 patients received the combination of phentolamine and 1.2 mg of propranolol intracoronarily, and 10 patients received saline. RESULTS: Fifteen minutes after successful coronary dilation, significant contractile dysfunction occurred in previously ischemic and nonischemic myocardium. LV dysfunction was accompanied by an increase in coronary resistance and diffuse vasoconstriction. Alpha-blockers counteracted LV dysfunction and coronary resistance and the increase in vasoconstriction. Phentolamine and urapidil increased global LV shortening from 34+/-9% to 45+/-8% and to 49+/-8%, respectively (p < 0.05). After the administration of propranolol combined with phentolamine, LV dysfunction remained unchanged (34+/-6%), as in control subjects. CONCLUSIONS: LV dysfunction occurs after PTCA, as described in animal models after ischemia. Alpha-blockers abolished LV, macrocirculatory and microcirculatory dysfunction, whereas the alpha-blocker effect was prevented by combining alpha- and beta-blockers. The evidence of diffuse rather than regional dysfunction, together with the opposite effects of alpha- and beta-blockade, supports the hypothesis of neural mechanisms eliciting postischemic LV dysfunction. 相似文献
29.
30.