全文获取类型
收费全文 | 76篇 |
免费 | 2篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 25篇 |
金属工艺 | 2篇 |
轻工业 | 8篇 |
无线电 | 6篇 |
一般工业技术 | 28篇 |
冶金工业 | 1篇 |
自动化技术 | 7篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 10篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有78条查询结果,搜索用时 15 毫秒
41.
Lapointe SL Alessandro RT Robbins PS Khrimian A Svatos A Dickens JC Otálora-Luna F Kaplan F Alborn HT Teal PE 《Journal of chemical ecology》2012,38(4):408-417
An unsaturated hydroxy-ester pheromone was isolated from the headspace and feces of male Diaprepes abbreviatus, identified, and synthesized. The pheromone, methyl (E)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate, was discovered by gas chromatography-coupled electroantennogram detection (GC-EAD), and identified by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). The synthesis yielded an 86:14 mixture of methyl (E)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate (active) and methyl (Z)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate (inactive), along with a lactone breakdown product. The activity of the synthetic E-isomer was confirmed by GC-EAD, GC-MS, NMR, and bioassays. No antennal response was observed to the Z-isomer or the lactone. In a two-choice olfactometer bioassay, female D. abbreviatus moved upwind towards the synthetic pheromone or natural pheromone more often compared with clean air. Males showed no clear preference for the synthetic pheromone. This pheromone, alone or in combination with plant volatiles, may play a role in the location of males by female D. abbreviatus. 相似文献
42.
Lukas Werner Ales Machara Tomas Hudlicky 《Advanced Synthesis \u0026amp; Catalysis》2010,352(1):195-200
A short chemoenzymatic and azide‐free synthesis of oseltamivir was attained with the key steps consisting of a one‐pot Dauben–Michno oxidative transposition and amination and a reductive transposition of an acrylate. 相似文献
43.
Iveta Vojtechova Kristyna Maleninska Viera Kutna Ondrej Klovrza Klara Tuckova Tomas Petrasek Ales Stuchlik 《International journal of molecular sciences》2021,22(6)
Maternal immune activation (MIA) during pregnancy represents an important environmental factor in the etiology of schizophrenia and autism spectrum disorders (ASD). Our goal was to investigate the impacts of MIA on the brain and behavior of adolescent and adult offspring, as a rat model of these neurodevelopmental disorders. We injected bacterial lipopolysaccharide (LPS, 1 mg/kg) to pregnant Wistar dams from gestational day 7, every other day, up to delivery. Behavior of the offspring was examined in a comprehensive battery of tasks at postnatal days P45 and P90. Several brain parameters were analyzed at P28. The results showed that prenatal immune activation caused social and communication impairments in the adult offspring of both sexes; males were affected already in adolescence. MIA also caused prepulse inhibition deficit in females and increased the startle reaction in males. Anxiety and hypolocomotion were apparent in LPS-affected males and females. In the 28-day-old LPS offspring, we found enlargement of the brain and decreased numbers of parvalbumin-positive interneurons in the frontal cortex in both sexes. To conclude, our data indicate that sex of the offspring plays a crucial role in the development of the MIA-induced behavioral alterations, whereas changes in the brain apparent in young animals are sex-independent. 相似文献
44.
Ales Gosar Marko Nagode Simon Oman 《Fatigue & Fracture of Engineering Materials & Structures》2019,42(1):307-320
This paper details an advanced method of continuous fatigue damage prediction of rubber fibre composite structures. A novel multiaxial energy‐based approach incorporating a mean stress correction is presented and also used to predict the fatigue life of a commercial vehicle air spring. The variations of elastic strain and complementary energies are joined to form the energy damage parameter. Material parameter α is introduced to adapt for any observed mean stress effect as well as being able to reproduce the well‐known Smith‐Watson‐Topper criterion. Since integration to calculate the energies is simplified, the approach can be employed regardless of the complexity of the thermo‐mechanical load history. Several numerical simulations and experimental tests were performed in order to obtain the required stress‐strain tensors and the corresponding fatigue lives, respectively. In simulations, the rubber material of the air spring was simulated as nonlinear elastic. The mean stress parameter α , which controls the influence of the mean stress on fatigue life, was adjusted with respect to those energy life curves obtained experimentally. The predicted fatigue life and the location of failure are in very good agreement with experimental observations. 相似文献
45.
A novel electrospray ionization (ESI) mass spectrometric approach for the structure elucidation of ionic organotin(IV) compounds or complexes with weakly bonded ligands as for example monodentate carboxylates or sulfonates is proposed using both positive-ion and negative-ion ESI tandem mass spectra. The ionization mechanism of organotin(IV) compounds involves the cleavage of the most labile bond with an ionic character yielding two complementary ions, [Cat]+ and [An]-. Positively charged species containing tin atom, [Cat]+, are analyzed in the positive-ion mode and negatively charged species without the tin atom, [An]-, in the negative-ion mode. Fragmentation patterns of [C24H29N2Sn]+, [C21H22NSn]+, and [C17H30NSn]+ ions are proposed based on the detailed interpretation of MSn spectra, which is simplified by an easy recognition of characteristic tin isotopic clusters in particular fragment ions. Proposed fragmentation mechanisms are supported by comparison with MSn spectra of deuterium-labeled analogues. The applicability of this method is illustrated on two sets of organotin(IV) compounds, including seven [2,6-bis(dimethylaminomethyl)phenyl]diphenyltin(IV) derivatives with small inorganic counteranions X (Br, NO3, SCN, BF4, SeCN, CN, PF6), six organotin(IV) complexes containing two C,N-chelating ligands with azo dyes, and the identification of unknown hydrolysis products. 相似文献
46.
Rade Injac Ales Mlinaric Vukosava Djorjevic-Milic Katarina Karljikovic-Rajic Borut Strukelj 《Food Additives & Contaminants》2008,25(4):424-431
A separation technique for zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide in animal feedstuffs by micellar electrokinetic capillary chromatography (MEKC) was developed. The running buffer was 20 mmol l-1 borate, 20 mmol l-1 phosphate, pH 8.4, containing 20 mmol l-1 sodium dodecylsulphate and 10% (v/v) methanol. MEKC was performed at 25°C; the applied voltage was 25 kV with a running pressure of 10 mbar. Simultaneous UV detection for all analytes was at 215 nm. The method was validated for specificity, accuracy, linearity, precision and robustness. It was shown to be specific, accurate (recoveries were 99.7 ± 0.3, 99.9 ± 0.9, 99.8 ± 1.0 and 99.5 ± 0.4, respectively, for oxytetracycline-, sulfacetamide-, polymyxin B- and zinc bacitracin-spiked samples of feed for cow, pigs, chicken and cattle), linear over the tested range (correlation coefficients ≥0.9987) and precise (RSDs below 1.8% for each analyte). The method was applied to determine zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide as additives in animal feed. 相似文献
47.
Anze Kristan Blai Mavcic Matej Cimerman Ales Iglis Martin Tonin Tomaz Slivnik Veronika Kralj-Iglic Matej Daniel 《IEEE transactions on neural systems and rehabilitation engineering》2007,15(2):252-257
Operative fixation of fragments in acetabular fracture treatment is not strong enough to allow weight bearing before the bone is healed. In some patients, even passive or active nonweight-bearing exercises could lead to dislocation of fragments and posttraumatic osteoarthritis. Therefore, early rehabilitation should avoid loading the acetabulum in the regions of fracture lines. The aim of the paper is to estimate acetabular loading in nonweight-bearing upright, supine, and side-lying leg abduction. Three-dimensional mathematical models of the hip joint reaction force and the contact hip stress were used to simulate active exercises in different body positions. The absolute values of the hip joint reaction force and the peak contact hip stress are the highest in unsupported supine abduction (1.3 MPa) and in side-lying abduction (1.2 MPa), lower in upright abduction (0.5 MPa), and the lowest in supported supine abduction (0.2 MPa). All body positions the hip joint reaction force and the peak contact hip stress are the highest in the posterior-superior quadrant of acetabulum, followed by anterior-superior quadrant, posterior-inferior quadrant, and finally anterior-inferior quadrant. Spatial distribution of the average acetabular loading shows that early rehabilitation should be planned according to location of the fracture lines. 相似文献
48.
Klara Castkova Ales Matousek Eva Bartonickova Jaroslav Cihlar Jr. Petr Vanysek Jaroslav Cihlar 《Journal of the American Ceramic Society》2016,99(4):1155-1163
Synthesis of CeO2, Pr2O3, and Sm2O3 nanorods and their sintering have been investigated. In a strongly alkaline medium, nanorods of CeO2, Pr2O3, and Sm2O3 were prepared from trivalent salts of rare earths (Ce, Pr, Sm) via precipitation synthesis. Nanorods were formed by nanocrystallites of fibrous structure, which were produced by the mechanism of self‐arrangement of hexagonal particles of Re(III) hydroxides. The subsequent transformation of hydroxide into oxide proceeded via self‐preservation of the rod‐like structure. In CeO2, the fibrous structure was noncohesive during thermal treatment at temperature of 500°C and higher. Regardless of the shape of the CeO2 particles (spherical versus rod‐like), sintered ceramic was formed by equiaxial grains. The cohesion of the fibrous structure of Pr and Sm oxides was higher than in CeO2. The rod‐like shape of the particles of Pr and Sm oxides was (partially) preserved during sintering. 相似文献
49.
Ales S. Buyakov Yuriy A. Mirovoy Alexey Yu. Smolin Svetlana P. Buyakova 《Ceramics International》2021,47(8):10582-10589
The effect of multi-walled carbon nanotubes (MWCNTs) and hexagonal boron nitride (h-BN) inclusions on the fracture toughness of yttria-stabilized zirconia (YSZ) ceramics has been studied. It is shown that an increase in the MWCNTs and h-BN content has a positive effect on the K1C of zirconia ceramics. The greatest increase in the fracture toughness of YSZ ceramics was observed with the introduction of hexagonal boron nitride particles. For YSZ ceramics, the K1C value was ≈6.1 MPa m1/2, for ceramics with a 5 wt % of h-BN K1C ≈ 9.2 MPa m1/2. It was shown that an increase of the YSZ ceramics fracture toughness with the introduction of MWCNTs and h-BN, both and separately was provided by the combined action of several mechanisms of increasing the work of crack propagation. In addition, in all composites obtained in this work, the transformation of tetragonal ZrO2 into monoclinic was observed. 相似文献
50.