全文获取类型
收费全文 | 492篇 |
免费 | 45篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 195篇 |
金属工艺 | 13篇 |
机械仪表 | 11篇 |
建筑科学 | 10篇 |
能源动力 | 9篇 |
轻工业 | 112篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 27篇 |
一般工业技术 | 57篇 |
冶金工业 | 34篇 |
自动化技术 | 63篇 |
出版年
2023年 | 11篇 |
2022年 | 45篇 |
2021年 | 44篇 |
2020年 | 14篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2017年 | 19篇 |
2016年 | 29篇 |
2015年 | 20篇 |
2014年 | 23篇 |
2013年 | 32篇 |
2012年 | 27篇 |
2011年 | 27篇 |
2010年 | 25篇 |
2009年 | 23篇 |
2008年 | 19篇 |
2007年 | 27篇 |
2006年 | 17篇 |
2005年 | 15篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 14篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有538条查询结果,搜索用时 609 毫秒
111.
Volpini R Marucci G Buccioni M Dal Ben D Lambertucci C Lammi C Mishra RC Thomas A Cristalli G 《ChemMedChem》2011,6(6):1074-1080
Guanosine, released extracellularly from neurons and glial cells, plays important roles in the central nervous system, including neuroprotection. The innovative DELFIA Eu‐GTP binding assay was optimized for characterization of the putative guanosine receptor binding site at rat brain membranes by using a series of novel and known guanosine derivatives. These nucleosides were prepared by modifying the purine and sugar moieties of guanosine at the 6‐ and 5′‐positions, respectively. Results of these experiments prove that guanosine, 6‐thioguanosine, and their derivatives activate a G protein‐coupled receptor that is different from the well‐characterized adenosine receptors. 相似文献
112.
Dal Ben D Antonini I Buccioni M Lambertucci C Marucci G Thomas A Volpini R Cristalli G 《ChemMedChem》2011,6(7):1163-1171
Neuropeptide?S (NPS) is a 20-amino acid peptide of great interest due to its possible involvement in several biological processes, including food intake, locomotion, wakefulness, arousal, and anxiety. Structure-activity relationship studies of NPS have identified key points for structural modifications with the goal of modulating NPS receptor (NPSR) agonist activity or achieving antagonism at the same receptor. Only limited information is available for nonpeptide NPSR antagonists. In the last year, several studies have been reported in literature which present various series of small molecules as antagonists of this receptor. The results allow a comparison of the structures and activities of these molecules, leading to the design of new ligands with increased potency and improved pharmacological and pharmacokinetic profiles. This work presents a brief overview of the available information regarding structural features and pharmacological characterization of published nonpeptide NPSR antagonists. 相似文献
113.
Gabriella Roventi Tiziano Bellezze Romeo Fratesi 《Journal of Applied Electrochemistry》2013,43(8):839-846
Zn–SiC composite coatings were obtained on mild steel substrate by electrodeposition technique with high-current efficiency. A slightly acidic chloride bath, containing SiC nanoparticles and gelatine as additive, was used. The electrodeposition was carried out under galvanostatic control with pulsed direct current; the effect of experimental parameters (temperature, average current density and particles concentration) on composition, morphology and structure of the deposit was studied. Coatings were characterized by means of scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffractometry and Vickers microhardness measurements. Zn–SiC electrodeposits with the best characteristics were obtained by performing electrodepositions at 45 °C, with 20 g L?1 SiC in the bath and with average current density in the range 100–150 mA cm?2. Under these experimental conditions, homogeneous and compact coatings, with low-grain size and SiC content ranging from 1.7 to 2.1 wt%, were found to be electrodeposited. Microhardness measurements showed for these deposits an increase of about 50 % with respect to those without nanoparticles obtained in the same experimental conditions. 相似文献
114.
Kai Tang Eivind J. Øvrelid Gabriella Tranell Merete Tangstad 《JOM Journal of the Minerals, Metals and Materials Society》2009,61(11):49-55
The diffusion of impurities in solid and liquid silicon is critically reviewed and assessed in this paper. The activation
energies and pre-exponential factors in theArrhenius equation have been evaluated using the least-squares analysis and semi-empirical
correlations. Impurity diffusion coefficients for Ag, Al, As, Au, B, Bi, C, Co, Cr, Cu, Fe, Ga, In, Li, Mn, N, Ni, 0, P, S,
Sb, Te, Ti, and Zn in both solid and liquid silicon have been obtained. The current assessed impurity diffusivities can be
coupled with the assessed thermochemical properties for the simulation of diffusion phenomena in the production of solar grade
cell silicon feedstock. The assessed diffusivities have been applied to simulate the impurity diffusion profiles and the denuded
zone in the intrinsic gettering annealing. 相似文献
115.
Carlo Ricciardi Giancarlo Canavese Riccardo Castagna Gabriella Digregorio Ivan Ferrante Simone L. Marasso Alessandro Ricci Valentina Alessandria Kalliopi Rantsiou Luca S. Cocolin 《Food and Bioprocess Technology》2010,3(6):956-960
The micro- and nano-technologies coupled with a deep knowledge of organic/inorganic interfaces guarantee an exceptional sensitivity
and specificity of the sensor, while the lab-on-a-chip platform reduces assay times and limits sampling and/or sample preparation,
providing compact and portable objects. Therefore, the development of innovative biosensors such as antibody-immobilized microcantilevers
can overcome the evident limits of nowadays technologies, such as time consuming, expensiveness, difficult automation, low
sensitivity, accuracy, and precision for quantitative methods. The present study proposes two device designs for the detection
of food pathogens, exploiting an antibody-immobilized microcantilever biosensors, a novel class of mass detectors. For the
first one, we integrated the mechanical sensors on a microfluidic platform (lab-on-a-chip) to perform online analysis, directly
in liquid environment. We showed that our portable biosensors could easily detect the presence of pathogenic bacteria such
as Salmonella enterica serotype enteritidis in concentration 105 cfu/mL in just 40 min, without any enrichment and/or sample preparation. To increase the mass sensitivity of our analysis,
we also fabricated microstructures optimized for vibrating in vacuum environment. Using a dip-and-dry technique, we showed
that, in such configuration, the experimental limit of detection is as low as 103 cfu/mL. Due to the extremely small volumes needed, our biosensors operating in vacuum have the potentiality of detecting
the presence or absence of a single cell. 相似文献
116.
117.
Enrico Mario Alessandro Fassi Mariangela Garofalo Jacopo Sgrignani Michele Dei Cas Matteo Mori Gabriella Roda Andrea Cavalli Giovanni Grazioso 《International journal of molecular sciences》2022,23(9)
(1) Background: Disfunctions in autophagy machinery have been identified in various conditions, including neurodegenerative diseases, cancer, and inflammation. Among mammalian autophagy proteins, the Atg8 family member GABARAP has been shown to be greatly involved in the autophagy process of prostate cancer cells, supporting the idea that GABARAP inhibitors could be valuable tools to fight the progression of tumors. (2) Methods: In this paper, starting from the X-ray crystal structure of GABARAP in a complex with an AnkirinB-LIR domain, we identify two new peptides by applying in silico drug design techniques. The two ligands are synthesized, biophysically assayed, and biologically evaluated to ascertain their potential anticancer profile. (3) Results: Two cyclic peptides (WC8 and WC10) displayed promising biological activity, high conformational stability (due to the presence of disulfide bridges), and Kd values in the low micromolar range. The anticancer assays, performed on PC-3 cells, proved that both peptides exhibit antiproliferative effects comparable to those of peptide K1, a known GABARAP inhibitor. (4) Conclusions: WC8 and WC10 can be considered new GABARAP inhibitors to be employed as pharmacological tools or even templates for the rational design of new small molecules. 相似文献
118.
Thiol–Ene Clickable Gelatin: A Platform Bioink for Multiple 3D Biofabrication Technologies
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sarah Bertlein Gabriella Brown Khoon S. Lim Tomasz Jungst Thomas Boeck Torsten Blunk Joerg Tessmar Gary J. Hooper Tim B. F. Woodfield Juergen Groll 《Advanced materials (Deerfield Beach, Fla.)》2017,29(44)
Bioprinting can be defined as the art of combining materials and cells to fabricate designed, hierarchical 3D hybrid constructs. Suitable materials, so called bioinks, have to comply with challenging rheological processing demands and rapidly form a stable hydrogel postprinting in a cytocompatible manner. Gelatin is often adopted for this purpose, usually modified with (meth‐)acryloyl functionalities for postfabrication curing by free radical photopolymerization, resulting in a hydrogel that is cross‐linked via nondegradable polymer chains of uncontrolled length. The application of allylated gelatin (GelAGE) as a thiol–ene clickable bioink for distinct biofabrication applications is reported. Curing of this system occurs via dimerization and yields a network with flexible properties that offer a wider biofabrication window than (meth‐)acryloyl chemistry, and without additional nondegradable components. An in‐depth analysis of GelAGE synthesis is conducted, and standard UV‐initiation is further compared with a recently described visible‐light‐initiator system for GelAGE hydrogel formation. It is demonstrated that GelAGE may serve as a platform bioink for several biofabrication technologies by fabricating constructs with high shape fidelity via lithography‐based (digital light processing) 3D printing and extrusion‐based 3D bioprinting, the latter supporting long‐term viability postprinting of encapsulated chondrocytes. 相似文献
119.
Vincenzo Zara Gabriella De Blasi Alessandra Ferramosca 《International journal of molecular sciences》2022,23(18)
The cytochrome bc1 complex is an essential component of the mitochondrial respiratory chain of the yeast Saccharomyces cerevisiae. It is composed of ten protein subunits, three of them playing an important role in electron transfer and proton pumping across the inner mitochondrial membrane. Cytochrome b, the central component of this respiratory complex, is encoded by the mitochondrial genome, whereas all the other subunits are of nuclear origin. The assembly of all these subunits into the mature and functional cytochrome bc1 complex is therefore a complicated process which requires the participation of several chaperone proteins. It has been found that the assembly process of the mitochondrial bc1 complex proceeds through the formation of distinct sub-complexes in an ordered sequence. Most of these sub-complexes have been thoroughly characterized, and their molecular compositions have also been defined. This study critically analyses the results obtained so far and highlights new possible areas of investigation. 相似文献
120.
Patrizia Ferroni Raffaele Palmirotta Gabriella Egeo Cinzia Aurilia Maria Giovanna Valente Antonella Spila Alberto Pierallini Piero Barbanti Fiorella Guadagni 《International journal of molecular sciences》2022,23(22)
White matter hyperintensities (WMHs) in migraine could be related to inflammatory and antioxidant events. The aim of this study is to verify whether migraine patients with WMHs carry a genetic pro-inflammatory/pro-oxidative status. To test this hypothesis, we analyzed lymphotoxin alpha (LTA; rs2071590T and rs2844482G) and superoxide dismutase 1 (SOD1; rs2234694C) and 2 (SOD2; rs4880T) gene polymorphisms (SNPs) in 370 consecutive patients affected by episodic (EM; n = 251) and chronic (CM; n = 119) migraine and in unrelated healthy controls (n = 100). Brain magnetic resonance was available in 183/370 patients. The results obtained show that genotypes and allele frequencies for all tested SNPs did not differ between patients and controls. No association was found between single SNPs or haplotypes and sex, migraine type, cardiovascular risk factors or disorders. Conversely, the LTA rs2071590T (OR = 2.2) and the SOD1 rs2234694C (OR = 4.9) alleles were both associated with WMHs. A four-loci haplotype (TGCT haplotype: rs2071590T/rs2844482G/rs2234694C/rs4880T) was significantly more frequent in migraineurs with WMHs (7 of 38) compared to those without WMHs (4 of 134; OR = 8.7). We may, therefore, conclude by suggesting that that an imbalance between pro-inflammatory/pro-oxidative and antioxidant events in genetically predisposed individuals may influence the development of WMHs. 相似文献