全文获取类型
收费全文 | 640篇 |
免费 | 20篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 127篇 |
金属工艺 | 9篇 |
机械仪表 | 13篇 |
建筑科学 | 25篇 |
能源动力 | 15篇 |
轻工业 | 79篇 |
水利工程 | 2篇 |
无线电 | 33篇 |
一般工业技术 | 103篇 |
冶金工业 | 174篇 |
原子能技术 | 1篇 |
自动化技术 | 75篇 |
出版年
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 37篇 |
2020年 | 16篇 |
2019年 | 16篇 |
2018年 | 16篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 15篇 |
2014年 | 17篇 |
2013年 | 23篇 |
2012年 | 29篇 |
2011年 | 40篇 |
2010年 | 25篇 |
2009年 | 20篇 |
2008年 | 20篇 |
2007年 | 20篇 |
2006年 | 24篇 |
2005年 | 16篇 |
2004年 | 23篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 15篇 |
1998年 | 50篇 |
1997年 | 25篇 |
1996年 | 26篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 1篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有660条查询结果,搜索用时 443 毫秒
651.
In vitro control of post-harvest fruit rot fungi by some plant essential oil components 总被引:1,自引:0,他引:1
Camele I Altieri L De Martino L De Feo V Mancini E Rana GL 《International journal of molecular sciences》2012,13(2):2290-2300
Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare), previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products. 相似文献
652.
Luigi Bellocchio Alessio Danilo Inchingolo Angelo Michele Inchingolo Felice Lorusso Giuseppina Malcangi Luigi Santacroce Antonio Scarano Ioana Roxana Bordea Denisa Hazballa Maria Teresa DOria Ciro Gargiulo Isacco Ludovica Nucci Rosario Serpico Gianluca Martino Tartaglia Delia Giovanniello Maria Contaldo Marco Farronato Gianna Dipalma Francesco Inchingolo 《International journal of molecular sciences》2021,22(15)
Background: marijuana, the common name for cannabis sativa preparations, is one of the most consumed drug all over the world, both at therapeutical and recreational levels. With the legalization of medical uses of cannabis in many countries, and even its recreational use in most of these, the prevalence of marijuana use has markedly risen over the last decade. At the same time, there is also a higher prevalence in the health concerns related to cannabis use and abuse. Thus, it is mandatory for oral healthcare operators to know and deal with the consequences and effects of cannabis use on oral cavity health. This review will briefly summarize the components of cannabis and the endocannabinoid system, as well as the cellular and molecular mechanisms of biological cannabis action in human cells and biologic activities on tissues. We will also look into oropharyngeal tissue expression of cannabinoid receptors, together with a putative association of cannabis to several oral diseases. Therefore, this review will elaborate the basic biology and physiology of cannabinoids in human oral tissues with the aim of providing a better comprehension of the effects of its use and abuse on oral health, in order to include cannabinoid usage into dental patient health records as well as good medicinal practice. Methods: the paper selection was performed by PubMed/Medline and EMBASE electronic databases, and reported according to the PRISMA guidelines. The scientific products were included for qualitative analysis. Results: the paper search screened a total of 276 papers. After the initial screening and the eligibility assessment, a total of 32 articles were considered for the qualitative analysis. Conclusions: today, cannabis consumption has been correlated to a higher risk of gingival and periodontal disease, oral infection and cancer of the oral cavity, while the physico-chemical activity has not been completely clarified. Further investigations are necessary to evaluate a therapeutic efficacy of this class of drugs for the promising treatment of several different diseases of the salivary glands and oral diseases. 相似文献
653.
Pomegranate juice is consumed widely for its possible health benefits. The aril juice from 15 pomegranate cultivars grown in Georgia were analysed for juice yield based on fresh weight (FW) and physico-chemical properties, using blender and mechanical press extraction. Blender had a higher juice yield (42.04% FW) compared to mechanical press (38.05% FW). Total phenolics and antioxidant capacity was determined by Folin–Ciocalteau method and ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays, respectively. Total monomeric anthocyanins were determined by pH differential method and RP-HPLC. The major anthocyanin was delphinidin 3-glucoside. High negative and significant (p ? 0.05) correlations were found between pH and titratable acidity (TA). The total soluble solids content (TSS) averaged 15.59 in blender and 14.94 °Brix in mechanical press. Chemical analysis of juice showed significant differences among cultivars and extraction methods. Overall, blender was more efficient than mechanical press juice extraction. 相似文献
654.
Yasmine Al-Sabagh Hayley Hope Allyssa Thorpe Bryan William Jenkins Shahnaza Hamidullah Malik Asfandyaar Talhat Cara Beth Suggett Cristine Joelle Reitz Mina Rasouli Tami Avril Martino Jibran Younis Khokhar 《International journal of molecular sciences》2022,23(9)
Alcohol use is a contributor in the premature deaths of approximately 3 million people annually. Among the risk factors for alcohol misuse is circadian rhythm disruption; however, this connection remains poorly understood. Inhibition of the circadian nuclear receptor REV-ERBα is known to disrupt molecular feedback loops integral to daily oscillations, and impact diurnal fluctuations in the expression of proteins required for reward-related neurotransmission. However, the role of REV-ERBα in alcohol and substance use-related phenotypes is unknown. Herein, we used a Rev-erbα knockout mouse line and ethanol two-bottle choice preference testing to show that disruption of Rev-erbα reduces ethanol preference in male and female mice. Rev-erbα null mice showed the lowest ethanol preference in a two-bottle choice test across all genotypes, whereas there were no ethanol preference differences between heterozygotes and wildtypes. In a separate experiment, alcohol-consuming wildtype C57Bl/6N mice were administered the REV-ERBα/β inhibitor SR8278 (25 mg/kg or 50 mg/kg) for 7 days and alcohol preference was evaluated daily. No differences in alcohol preference were observed between the treatment and vehicle groups. Our data provides evidence that genetic variation in REV-ERBα may contribute to differences in alcohol drinking. 相似文献
655.
Francesca Punzo Maura Argenziano Chiara Tortora Alessandra Di Paola Margherita Mutarelli Elvira Pota Martina Di Martino Daniela Di Pinto Maria Maddalena Marrapodi Domenico Roberti Francesca Rossi 《International journal of molecular sciences》2022,23(15)
Acute lymphoblastic leukemia type B (B-ALL) is the most common kind of pediatric leukemia, characterized by the clonal proliferation of type B lymphoid stem cells. Important progress in ALL treatments led to improvements in long-term survival; nevertheless, many adverse long-term consequences still concern the medical community. Molecular and cellular target therapies, together with immunotherapy, are promising strategies to overcome these concerns. Cannabinoids, enzymes involved in their metabolism, and cannabinoid receptors type 1 (CB1) and type 2 (CB2) constitute the endocannabinoid system, involved in inflammation, immune response, and cancer. CB2 receptor stimulation exerts anti-proliferative and anti-invasive effects in many tumors. In this study, we evaluated the effects of CB2 stimulation on B-ALL cell lines, SUP-B15, by RNA sequencing, Western blotting, and ELISA. We observe a lower expression of CB2 in SUP-B15 cells compared to lymphocytes from healthy subjects, hypothesizing its involvement in B-ALL pathogenesis. CB2 stimulation reduces the expression of CD9, SEC61G, TBX21, and TMSB4X genes involved in tumor growth and progression, and also negatively affects downstream intracellular pathways. Our findings suggest an antitumor role of CB2 stimulation in B-ALL, and highlight a functional correlation between CB2 receptors and specific anti-tumoral pathways, even though further investigations are needed. 相似文献
656.
Martino Zito Danilo D'Angela Giuseppe Maddaloni Gennaro Magliulo 《Computer-Aided Civil and Infrastructure Engineering》2023,38(12):1699-1726
A shake table protocol for seismic assessment and qualification of acceleration-sensitive nonstructural elements (NEs) is developed. The paper critically reviews existing protocols and highlights their criticalities, pointing out the need for the development of novel assessment and qualification approaches and protocols. The protocol is developed in light of these criticalities, considering the most recent advances in the field and the specific expertise of the research team. The most significant and contributing parts of the developed protocol consist of the definition of novel required response spectra and the generation of signals for seismic performance evaluation tests. The reliability and robustness of the protocol are evidenced in the paper considering real-floor motions as a reference, also proving the superiority of the developed protocol with respect to the reference alternatives. The defined approach and procedures are generally applicable and easily extendable to different case studies, as the process is highly versatile and modifiable. The implementation of the developed approach and protocol in the literature and in practice will significantly enhance seismic assessment and qualification of acceleration-sensitive NEs. This will possibly have a strong impact on public safety and economy. 相似文献
657.
Peter A. Banks Gabriele D'Avino Guillaume Schweicher Jeff Armstrong Christian Ruzié Jong Won Chung Jeong-Il Park Chizuru Sawabe Toshihiro Okamoto Jun Takeya Henning Sirringhaus Michael T. Ruggiero 《Advanced functional materials》2023,33(38):2303701
Organic semiconductors with distinct molecular properties and large carrier mobilities are constantly developed in attempt to produce highly-efficient electronic materials. Recently, designer molecules with unique structural modifications have been expressly developed to suppress molecular motions in the solid state that arise from low-energy phonon modes, which uniquely limit carrier mobilities through electron–phonon coupling. However, such low-frequency vibrational dynamics often involve complex molecular dynamics, making comprehension of the underlying electronic origins of electron–phonon coupling difficult. In this study, first a mode-resolved picture of electron–phonon coupling in a series of materials that are specifically designed to suppress detrimental vibrational effects, is generated. From this foundation, a method is developed based on the crystalline orbital Hamiltonian population (COHP) analyses to resolve the origins—down to the single atomic-orbital scale—of surprisingly large electron–phonon coupling constants of particular vibrations, explicitly detailing the manner in which the intermolecular wavefunction overlap is perturbed. Overall, this approach provides a comprehensive explanation into the unexpected effects of less-commonly studied molecular vibrations, revealing new aspects of molecular design that should be considered for creating improved organic semiconducting materials. 相似文献
658.
Elena Visentin Giovanni Niero Martino Cassandro Mauro Penasa Massimo De Marchi 《International Journal of Dairy Technology》2023,76(1):102-110
The interest in analytical methods that accurately measure or predict the elemental profile of dairy foods has been steadily rising. The purpose of this study was to assess the robustness of the energy-dispersive X-ray fluorescence (ED-XRF) technique for the prediction of mineral elements in milk and cheese, avoiding any sample preparation steps. Results highlighted relatively low accuracy of the ED-XRF technique for the quantification of milk mineral elements, with coefficients of determination in validation () from 0.03 (magnesium) to 0.39 (phosphorus). Greater accuracies were obtained for the quantification of cheese minerals, with from 0.26 (sodium) to 0.69 (calcium). 相似文献
659.
Atif Jan Thomas Rembert Sunil Taper Joanna Symonowicz Nives Strkalj Taehwan Moon Yun Seong Lee Hagyoul Bae Hyun Jae Lee Duk-Hyun Choe Jinseong Heo Judith MacManus-Driscoll Bartomeu Monserrat Giuliana Di Martino 《Advanced functional materials》2023,33(22):2214970
Ferroelectric materials offer a low-energy, high-speed alternative to conventional logic and memory circuitry. Hafnia-based films have achieved single-digit nm ferroelectricity, enabling further device miniaturization. However, they can exhibit nonideal behavior, specifically wake-up and fatigue effects, leading to unpredictable performance variation over consecutive electronic switching cycles, preventing large-scale commercialization. The origins are still under debate. Using plasmon-enhanced spectroscopy, a non-destructive technique sensitive to <1% oxygen vacancy variation, phase changes, and single switching cycle resolution, the first real-time in operando nanoscale direct tracking of oxygen vacancy migration in 5 nm hafnium zirconium oxide during a pre-wake-up stage is provided. It is shown that the pre-wake-up leads to a structural phase change from monoclinic to orthorhombic phase, which further determines the device wake-up. Further migration of oxygen ions in the phase changed material is then observed, producing device fatigue. These results provide a comprehensive explanation for the wake-up and fatigue with Raman, photoluminescence and darkfield spectroscopy, combined with density functional theory and finite-difference time-domain simulations. 相似文献
660.
Andrea Dodero Kenza Djeghdi Viola Bauernfeind Martino Airoldi Bodo D. Wilts Christoph Weder Ullrich Steiner Ilja Gunkel 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(6):2205438
Creation of color through photonic morphologies manufactured by molecular self-assembly is a promising approach, but the complexity and lack of robustness of the fabrication processes have limited their technical exploitation. Here, it is shown that photonic spheres with full-color tuning across the entire visible spectrum can be readily and reliably achieved by the emulsification of solutions containing a block copolymer (BCP) and two swelling additives. Solvent diffusion out of the emulsion droplets gives rise to 20–150 µm-sized spheres with an onion-like lamellar morphology. Controlling the lamellar thickness by differential swelling with the two additives enables color tuning of the Bragg interference-based reflection band across the entire visible spectrum. By studying five different systems, a set of important principles for manufacturing photonic colloids is established. Two swelling additives are required, one of which must exhibit strong interactions with one of the BCP blocks. The additives should be chosen to enhance the dielectric contrast, and the formation kinetics of the spheres must be sufficiently slow to enable the emergence of the photonic morphology. The proposed approach is versatile and robust and allows the scalable production of photonic pigments with possible future applications in inks for cosmetics and arts, coatings, and displays. 相似文献