全文获取类型
收费全文 | 327篇 |
免费 | 15篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 95篇 |
机械仪表 | 12篇 |
建筑科学 | 9篇 |
能源动力 | 15篇 |
轻工业 | 34篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 24篇 |
一般工业技术 | 45篇 |
冶金工业 | 47篇 |
原子能技术 | 10篇 |
自动化技术 | 49篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 27篇 |
2021年 | 9篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 19篇 |
2012年 | 21篇 |
2011年 | 16篇 |
2010年 | 17篇 |
2009年 | 16篇 |
2008年 | 18篇 |
2007年 | 15篇 |
2006年 | 9篇 |
2005年 | 10篇 |
2004年 | 7篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 6篇 |
1999年 | 1篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 5篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1965年 | 1篇 |
1914年 | 1篇 |
1912年 | 1篇 |
排序方式: 共有344条查询结果,搜索用时 15 毫秒
91.
Bujari Armir Gaggi Ombretta Luglio Michele Palazzi Claudio E. Quadrio Giacomo Roseti Cesare Zampognaro Francesco 《Mobile Networks and Applications》2020,25(3):1114-1121
Mobile Networks and Applications - Immersive technology is expected to become a key player in the next wave of consumer electronics with potential applications spanning a wide variety of sectors.... 相似文献
92.
Ilenia Rossetti Cesare Biffi Gian Franco Tantardini Mario Raimondi Edoardo Vitto Davide Alberti 《International Journal of Hydrogen Energy》2012
A power unit constituted by a reformer section, a H2 purification section and a fuel cell stack is being tested c/o the Dept. of Physical Chemistry and Electrochemistry of Università degli Studi di Milano, on the basis of a collaboration with HELBIO S.A. Hydrogen and Energy Production Systems, Patras (Greece), supplier of the unit, and some sponsors (Linea Energia S.p.A., Parco Tecnologico Padano and Provincia di Lodi, Italy). The system size allows to co-generate 5 kWe (220 V, 50 Hz a.c.) + 5 kWt (hot water at 65 °C) as peak output. Bioethanol, obtainable by different non-food-competitive biomass, is transformed into syngas by a pre-reforming and reforming reactors couple and the reformate is purified from CO to a concentration below 20 ppmv, suitable to feed a proton exchange membrane fuel cell (PEMFC) stack that will be integrated in the fuel processor in a second step of the experimentation. This result is achieved by feeding the reformate to two water gas shift reactors, connected in series and operating at high and low temperature, respectively. CO concentration in the outcoming gas is ca. 0.4 vol% and the final CO removal to meet the specifications is accomplished by two methanation reactors in series. The second methanation step acts merely as a guard, since ca. 15 ppmv of CO are obtained already after the first reactor. 相似文献
93.
A system level implementation of a large area hybrid detector is presented. The detector used in this system consists of an array of hydrogenated amorphous silicon photodiodes directly connected to a CMOS readout chip, which is vertically integrated over the sensor array using flip-chip bonding. In particular, the proposed solution relies on a stack of interconnection layers, deposited on top of the photodiode array, to route each individual pixel output to a separate pre-amplifier channel. This avoids the need for a geometrical matching between the sensor array and the chip contact pads. As a consequence, conventional non-pixelated readout chip can be used and easy-scalable large area detectors can be produced. The CMOS chip is connected to an electronic board, providing the interfaces needed to read the signals as well as providing voltage references and power to the chip. The signals are collected and pre-processed by an FPGA chip, providing a very compact and flexible setup. 相似文献
94.
Angelica Miccolis Michele Galluccio Teresa Anna Giancaspero Cesare Indiveri Maria Barile 《International journal of molecular sciences》2012,13(12):16880-16898
FAD synthase (FADS, EC 2.7.7.2) is a key enzyme in the metabolic pathway that converts riboflavin into the redox cofactor, FAD. Human FADS is organized in two domains: -the 3′phosphoadenosine 5′phosphosulfate (PAPS) reductase domain, similar to yeast Fad1p, at the C-terminus, and -the resembling molybdopterin-binding domain at the N-terminus. To understand whether the PAPS reductase domain of hFADS is sufficient to catalyze FAD synthesis, per se, and to investigate the role of the molybdopterin-binding domain, a soluble “truncated” form of hFADS lacking the N-terminal domain (Δ1-328-hFADS) has been over-produced and purified to homogeneity as a recombinant His-tagged protein. The recombinant Δ1-328-hFADS binds one mole of FAD product very tightly as the wild-type enzyme. Under turnover conditions, it catalyzes FAD assembly from ATP and FMN and, at a much lower rate, FAD pyrophosphorolytic hydrolysis. The Δ1-328-hFADS enzyme shows a slight, but not significant, change of Km values (0.24 and 6.23 μM for FMN and ATP, respectively) and of kcat (4.2 × 10−2 s−1) compared to wild-type protein in the forward direction. These results demonstrate that the molybdopterin-binding domain is not strictly required for catalysis. Its regulatory role is discussed in light of changes in divalent cations sensitivity of the Δ1-328-hFADS versus wild-type protein. 相似文献
95.
Dr. Ilaria Bargigia Dr. Elena Zucchetti Dr. Ajay Ram Srimath Kandada Dr. Miguel Moreira Dr. Caterina Bossio Dr. Walter P. D. Wong Prof. Paulo Barbeitas Miranda Dr. Paolo Decuzzi Prof. Cesare Soci Prof. Cosimo D'Andrea Prof. Guglielmo Lanzani 《Chembiochem : a European journal of chemical biology》2019,20(4):532-536
In this work the photophysics of poly(3-hexylthiophene) nanoparticles (NPs) is investigated in the context of their biological applications. The NPs, made as colloidal suspensions in aqueous buffers, present a distinct absorption band in the low-energy region. On the basis of systematic analysis of absorption and transient absorption (TA) spectra taken under different pH conditions, this band is associated with charge-transfer states generated by the polarization of loosely bound polymer chains and originating from complexes formed with electron-withdrawing species. Importantly, the ground-state depletion of these states upon photoexcitation is active even on microsecond timescales, thus suggesting that they act as precursor states for long-living polarons; this could be beneficial for cellular stimulation. Preliminary transient absorption microscopy results for NPs internalized within the cells reveal the presence of long-living species, further substantiating their relevance in biointerfaces. 相似文献
96.
Simone Failla Cesare Melandri Luca Zoli Guido Zucca Diletta Sciti 《Journal of the European Ceramic Society》2018,38(9):3089-3095
B4C-TiB2 composites were contaminated with WC to study the effect on densification, microstructure and properties. WC was introduced through a mild or a high energy milling with WC-6?wt%Co spheres or directly as sintering aid to 50?vol% B4C / 50?vol%TiB2 mixtures. High energy milling was very effective in improving the densification thanks to the synergistic action of WC impurities, acting as sintering aid, and size reduction of the starting TiB2-B4C powders. As a result, the sintering temperature necessary for full densification decreased to 1860?°C and both strength and hardness benefited from the microstructure refinement, 860?±?40 MPa and 28.5?±?1.4?GPa respectively. High energy milling was then adopted for producing 75?vol% B4C/25?vol% TiB2 and 25?vol% B4C/ 75vol%TiB2 mixtures. The B4C-rich composition showed the highest hardness, 32.2?±?1.8?GPa, whilst the TiB2-rich composition showed the highest value of toughness, 5.1?±?0.1?MPa?m0.5. 相似文献
97.
Simultaneous removal of Cd,Co, Cu,Mn, Ni,and Zn from synthetic solutions on a hemp‐based felt. II. Chemical modification 下载免费PDF全文
Sonia Loiacono Grégorio Crini Bernard Martel Gilles Chanet Cesare Cosentino Marina Raschetti Vincent Placet Giangiacomo Torri Nadia Morin‐Crini 《应用聚合物科学杂志》2017,134(32)
In this study, we propose a chemical pretreatment to improve the performance of a hemp‐based material in felt form used as an adsorbent for removing the metals from aqueous mixtures of Cd, Co, Cu, Mn, Ni, and Zn. The felt was coated with a maltodextrin‐1,2,3,4‐butane tetracarboxylic polymer in order to provide ion‐exchange properties to the material by introducing carboxylic groups. It was characterized by solid‐state 13C‐NMR technique and by energy‐dispersive X‐ray spectroscopy. This new adsorbent was then used in batch experiments and its performances were compared with those of non‐modified hemp. Different controlling experimental conditions have been investigated. Modified hemp exhibited strong adsorption capacities due to a chemisorption mechanism (complexation, ion exchange): up to 25 mg/L (in reality, 150 mg of metals per L), all metals in the solution were removed. A modified hemp dosage of 1 g was able to remove 13.91 mg of metals in 100 mL of solution at a concentration of 25 mg/L for each metal, whereas nonmodified hemp only removed 7.4 mg in the same experimental conditions. Adsorption of metals reached equilibrium in 60 min and the performances were pH‐independent between 3 and 6, but dependent on the presence of NaCl, except for Cu. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45138. 相似文献
98.
Cristina Bertulli Antonio Marzollo Margherita Doria Silvia Di Cesare Claudio La Scola Francesca Mencarelli Andrea Pasini Maria Carmen Affinita Enrico Vidal Pamela Magini Paola Dimartino Riccardo Masetti Laura Greco Patrizia Palomba Francesca Conti Andrea Pession 《International journal of molecular sciences》2020,21(22)
Schimke immuno-osseous dysplasia (SIOD) is a rare multisystemic disorder with a variable clinical expressivity caused by biallelic variants in SMARCAL1. A phenotype–genotype correlation has been attempted and variable expressivity of biallelic SMARCAL1 variants may be associated with environmental and genetic disturbances of gene expression. We describe two siblings born from consanguineous parents with a diagnosis of SIOD revealed by whole exome sequencing (WES). Results: A homozygous missense variant in the SMARCAL1 gene (c.1682G>A; p.Arg561His) was identified in both patients. Despite carrying the same variant, the two patients showed substantial renal and immunological phenotypic differences. We describe features not previously associated with SIOD—both patients had congenital anomalies of the kidneys and of the urinary tract and one of them succumbed to a classical type congenital mesoblastic nephroma. We performed an extensive characterization of the immunophenotype showing combined immunodeficiency characterized by a profound lymphopenia, lack of thymic output, defective IL-7Rα expression, and disturbed B plasma cells differentiation and immunoglobulin production in addition to an altered NK-cell phenotype and function. Conclusions: Overall, our results contribute to extending the phenotypic spectrum of features associated with SMARCAL1 mutations and to better characterizing the underlying immunologic disorder with critical implications for therapeutic and management strategies. 相似文献
99.
The Versatile 2‐Substituted Imidazoline Nucleus as a Structural Motif of Ligands Directed to the Serotonin 5‐HT1A Receptor 下载免费PDF全文
Dr. Fabio Del Bello Dr. Antonio Cilia Prof. Antonio Carrieri Domenico Claudio Fasano Prof. Carla Ghelardini Dr. Lorenzo Di Cesare Mannelli Laura Micheli Prof. Carlo Santini Dr. Eleonora Diamanti Prof. Mario Giannella Dr. Gianfabio Giorgioni Dr. Valerio Mammoli Corinne Dalila Paoletti Dr. Riccardo Petrelli Prof. Alessandro Piergentili Prof. Wilma Quaglia Prof. Maria Pigini 《ChemMedChem》2016,11(20):2287-2298
The involvement of the serotonin 5‐HT1A receptor (5‐HT1A‐R) in the antidepressant effect of allyphenyline and its analogues indicates that ligands bearing the 2‐substituted imidazoline nucleus as a structural motif interact with 5‐HT1A‐R. Therefore, we examined the 5‐HT1A‐R profile of several imidazoline molecules endowed with a common scaffold consisting of an aromatic moiety linked to the 2‐position of an imidazoline nucleus by a biatomic bridge. Our aim was to discover other ligands targeting 5‐HT1A‐R and to identify the structural features favoring 5‐HT1A‐R interaction. Structure–activity relationships, supported by modeling studies, suggested that some structural cliché such as a polar function and a methyl group in the bridge, as well as proper steric hindrance in the aromatic area of the above scaffold, favored 5‐HT1A‐R recognition and activation. We also highlighted the potent antidepressant‐like effect (mouse forced swimming test) of (S)‐(+)‐ 19 [(S)‐(+)‐naphtyline] at very low dose (0.01 mg kg?1). This effect was clearly mediated by 5‐HT1A, as it was significantly reduced by pretreatment with the 5‐HT1A antagonist WAY100635. 相似文献
100.
Impact of Turbidity Currents on Reservoir Sedimentation 总被引:4,自引:0,他引:4
All lakes created on natural rivers are subjected to reservoir sedimentation. The construction of a dam significantly modifies the flow conditions of natural streams inside and downstream of an artificial lake. The sediment concentration is often high during the flood season, and the entering flow shows a greater density than the ambient fluid. Suspended load can therefore be carried along the reservoir bottom to the dam in the form of turbidity currents. This paper presents research results that help to better understand this physical phenomenon, which contributes to reservoir sedimentation. It is based on in situ measurements, a laboratory scale model of turbidity currents and numerical flow simulations. The study of a thousand-year flood in the Luzzone Reservoir in the Swiss Alps using the developed computer model revealed the potential of such a tool. In particular, the impact on the sediment deposits was analyzed. A valuable evaluation of the incidence of such a turbidity flow is presented and its effects are compared to observations. Significant progress has been made in understanding the importance of turbidity currents in reservoir sedimentation. 相似文献