全文获取类型
收费全文 | 369篇 |
免费 | 24篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 260篇 |
金属工艺 | 3篇 |
机械仪表 | 2篇 |
建筑科学 | 6篇 |
矿业工程 | 1篇 |
能源动力 | 9篇 |
轻工业 | 56篇 |
水利工程 | 2篇 |
无线电 | 5篇 |
一般工业技术 | 31篇 |
冶金工业 | 3篇 |
自动化技术 | 13篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 89篇 |
2021年 | 96篇 |
2020年 | 24篇 |
2019年 | 19篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 17篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 14篇 |
2012年 | 27篇 |
2011年 | 12篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2003年 | 3篇 |
排序方式: 共有393条查询结果,搜索用时 15 毫秒
71.
Karolina Labus Lukasz Radosinski Piotr Kotowski 《International journal of molecular sciences》2021,22(18)
The presented research is focused on an investigation of the effect of the addition of polyvinyl alcohol (PVA) to a gelatin-based hydrogel on the functional properties of the resulting material. The main purpose was to experimentally determine and compare the properties of hydrogels differing from the content of PVA in the blend. Subsequently, the utility of these matrices for the production of an immobilized invertase preparation with improved operational stability was examined. We also propose a useful computational tool to predict the properties of the final material depending on the proportions of both components in order to design the feature range of the hydrogel blend desired for a strictly specified immobilization system (of enzyme/carrier type). Based on experimental research, it was found that an increase in the PVA content in gelatin hydrogels contributes to obtaining materials with a visibly higher packaging density, degree of swelling, and water absorption capacity. In the case of hydrolytic degradation and compressive strength, the opposite tendency was observed. The functionality studies of gelatin and gelatin/PVA hydrogels for enzyme immobilization indicate the very promising potential of invertase entrapped in a gelatin/PVA hydrogel matrix as a stable biocatalyst for industrial use. The molecular modeling analysis performed in this work provides qualitative information about the tendencies of the macroscopic parameters observed with the increase in the PVA and insight into the chemical nature of these dependencies. 相似文献
72.
Lakshmipriya Perincherry Monika Urbaniak Izabela Pawowicz Karolina Kotowska Agnieszka Wakiewicz ukasz Stpie 《International journal of molecular sciences》2021,22(18)
Fusarium species are common plant pathogens that cause several important diseases. They produce a wide range of secondary metabolites, among which mycotoxins and extracellular cell wall-degrading enzymes (CWDEs) contribute to weakening and invading the host plant successfully. Two species of Fusarium isolated from peas were monitored for their expression profile of three cell wall-degrading enzyme coding genes upon culturing with extracts from resistant (Sokolik) and susceptible (Santana) pea cultivars. The extracts from Santana induced a sudden increase in the gene expression, whereas Sokolik elicited a reduced expression. The coherent observation was that the biochemical profile of the host plant plays a major role in regulating the fungal gene expression. In order to uncover the fungal characteristics in planta, both pea cultivars were infected with two strains each of F. proliferatum and F. oxysporum on the 30th day of growth. The enzyme activity assays from both roots and rhizosphere indicated that more enzymes were used for degrading the cell wall of the resistant host compared to the susceptible host. The most commonly produced enzymes were cellulase, β-glucosidase, xylanase, pectinase and lipase, where the pathogen selectively degraded the components of both the primary and secondary cell walls. The levels of beauvericin accumulated in the infected roots of both cultivars were also monitored. There was a difference between the levels of beauvericin accumulated in both the cultivars, where the susceptible cultivar had more beauvericin than the resistant one, showing that the plants susceptible to the pathogen were also susceptible to the toxin accumulation. 相似文献
73.
Effect of complexation of oxidised corn starch with mineral elements on physicochemical properties 下载免费PDF全文
Sławomir Pietrzyk Teresa Fortuna Lesław Juszczak Dorota Gałkowska Karolina Królikowska Karolina Zięba 《International Journal of Food Science & Technology》2015,50(4):934-941
The objective of this study was to determine the effect of complexation of oxidised starch with mineral elements on its physicochemical properties. Corn starch was oxidised with sodium hypochlorite and, afterwards, modified with ions of potassium, magnesium and iron. Thus, native and modified starches were analysed for: contents of mineral elements, colour parameters (L*a*b*), water binding capacity and solubility in water at temperature of 60 and 80 °C. Thermodynamic characteristics of gelatinisation by DSC, molecular weight distribution by GPC, intrinsic viscosity and pasting properties by RVA were studied. The efficiency of incorporation of metal ions into oxidised corn starch was about 30%, 20% and 20% for potassium, magnesium and iron ions, respectively. The complexation with potassium ions caused the greatest changes in the molecular weight distribution and the intrinsic viscosity of starches and viscosity of starch pastes. Only modification of starch with iron ions affected the colour parameters of the starch. Incorporation of metal ions into starch resulted also in changes in its water binding capacity and solubility in water. 相似文献
74.
Karolina Bossak-Ahmad Dr. Tomasz Frączyk Prof. Dr. Wojciech Bal Dr. Simon C. Drew 《Chembiochem : a European journal of chemical biology》2020,21(3):331-334
The apparent affinity of human serum albumin (HSA) for divalent copper has long been the subject of great interest, due to its presumed role as the major Cu2+-binding ligand in blood and cerebrospinal fluid. Using a combination of electronic absorption, circular dichroism and room-temperature electron paramagnetic resonance spectroscopies, together with potentiometric titrations, we competed the tripeptide GGH against HSA to reveal a conditional binding constant of log c =13.02±0.05 at pH 7.4. This rigorously determined value of the Cu2+ affinity has important implications for understanding the extracellular distribution of copper. 相似文献
75.
New calcium‐free Na2O–Al2O3–P2O5 bioactive glasses with potential applications in bone tissue engineering 下载免费PDF全文
Oliwia Jeznach Marcin Gajc Karolina Korzeb Andrzej Kłos Krzysztof Orliński Ryszard Stępień Małgorzata Krok‐Borkowicz Łucja Rumian Krzysztof Pietryga Katarzyna Reczyńska Elżbieta Pamuła Dorota A. Pawlak 《Journal of the American Ceramic Society》2018,101(2):602-611
Sodium aluminophosphate glasses were evaluated for their bone repair ability. The glasses belonging to the system 45Na2O–xAl2O3‐(55‐x)P2O5, with x = (3, 5, 7, 10 mol%) were prepared by a melt‐quenching method. We assessed the effect of Al2O3 content on the properties of Na2O–Al2O3–P2O5 (NAP) glasses, which were characterized by density measurements, DSC analyses, solubility, bioactivity in simulated body fluid and cytocompatibility with MG‐63 cells. To the best of our knowledge, this is the first investigation of calcium‐free Na2O–Al2O3–P2O5 system glasses as bioactive materials for bone tissue engineering. 相似文献
76.
Karolina Schickle Jennifer Spitz Sabine Neuss Rainer Telle 《Journal of the European Ceramic Society》2018,38(1):271-277
Zirconia has been commonly used in the dental industry because of its excellent biological, mechanical and aesthetic properties. This material, however, is classified as nearly inert. To bioactivate the ceramic surface, biomimetic depositions of calcium phosphate coatings have been developed. We demonstrate an accelerated biomimetic coating method on zirconia using a specific pre-treatment with biological agents. We have chosen bovine serum albumin as a standard protein. Through the pre-treatment of the zirconia using a hydroxylation or additionally immobilizing the bovine serum albumin on the surface, we could influence the CaP deposition rate. Immunohistochemical analyses verified the presence of BSA on the zirconia surfaces. After immersion in simulated body fluid at 40 °C, the samples were analyzed by scanning electron microscopy and X-ray diffraction to visualize the CaP formation. Here we could show as proof-of-principle that it is possible to accelerate biomimetic coating processes on zirconia implants containing BSA on their surface. 相似文献
77.
Marzena?Joanna?KurasEmail author Karolina?Perz Wac?aw?Lechos?aw?Ko?odziejski 《Polymer Bulletin》2017,74(12):5029-5048
In our study, a Zn(II) ion-imprinted polymer (ZnIP) and non-imprinted polymer (NIP) were synthesized via free-radical polymerization. 1-Vinylimidazole, ethylene glycol dimethacrylate, 2-hydroxyethylmethacrylate and 2,2′-azobisisobutyronitrile were used as functional, cross-linking monomers and free-radical initiator, respectively. The obtained polymer was characterized by various analytical methods (Fourier Transform Infrared Spectroscopy, Transmission Electron Microscopy, Wavelength Dispersive X-ray Fluorescence, UV VIS, thermal analysis). The sorption properties of ZnIP and NIP were evaluated after removal of Zn(II) ions from the polymer network. The optimum pH for adsorption was 7.0. The maximum adsorption capacity at the pH was 5.2 and 0.22 mg/g for ZnIP and NIP, respectively. To determine the selectivity, the polymer was equilibrated with the binary mixture of Zn(II) ions and the interfering ions [Cu(II), Ni(II) or Co(II)]. The relative selectivity of ZnIP was 22.57, 5.44 and 46.17 for Cu(II), Ni(II) and Co(II) ions, respectively. The proposed ZnIP sorbent was applied to determine the zinc ions in urine samples by Wavelength Dispersive X-ray Fluorescence. 相似文献
78.
Jolanta R. Grzechowiak Iwona Wereszczako-Zieliska Karolina Mroziska 《Catalysis Today》2007,119(1-4):23-30
Alumina–titania supports containing 5–50 wt.% of TiO2 were prepared by coprecipitation method using inorganic precursors (sodium aluminate and titanium chloride). DTA-TGA, XRD, SEM, TPDNH3, and IR spectroscopy were used to characterise these materials. The study shows that the promoting effect of nickel on the HDS activity of molybdenum catalysts supported on Al2O3TiO2 is significantly lower than that for molybdenum catalyst supported on Al2O3, and depends on the TiO2 content. The SEM results show that in the case of rich Al support (20 wt.% of TiO2) molybdenum was aggregated on the external surface of the catalyst, whereas it was uniformly dispersed on the external surface of alumina. Results also show that molybdenum is preferably supported on aluminum oxide. Application of Al2O3TiO2 oxides enhances the HDN activity of nickel–molybdenum catalysts. The highest HDN efficiency was obtained for the NiMo/Al2O3TiO2 catalyst containing 50 wt.% of TiO2. HDN activity was found to depend on protonic acidity and anatase content. 相似文献
79.
Karolina Planeta Zuzanna Setkowicz Mateusz Czyzycki Natalia Janik-Olchawa Damian Ryszawy Krzysztof Janeczko Rolf Simon Tilo Baumbach Joanna Chwiej 《International journal of molecular sciences》2022,23(2)
Glioblastoma multiforme (GBM) is a particularly malignant primary brain tumor. Despite enormous advances in the surgical treatment of cancer, radio- and chemotherapy, the average survival of patients suffering from this cancer does not usually exceed several months. For obvious ethical reasons, the search and testing of the new drugs and therapies of GBM cannot be carried out on humans, and for this purpose, animal models of the disease are most often used. However, to assess the efficacy and safety of the therapy basing on these models, a deep knowledge of the pathological changes associated with tumor development in the animal brain is necessary. Therefore, as part of our study, the synchrotron radiation-based X-ray fluorescence microscopy was applied for multi-elemental micro-imaging of the rat brain in which glioblastoma develops. Elemental changes occurring in animals after the implantation of two human glioma cell lines as well as the cells taken directly from a patient suffering from GBM were compared. Both the extent and intensity of elemental changes strongly correlated with the regions of glioma growth. The obtained results showed that the observation of elemental anomalies accompanying tumor development within an animal’s brain might facilitate our understanding of the pathogenesis and progress of GBM and also determine potential biomarkers of its extension. The tumors appearing in a rat’s brain were characterized by an increased accumulation of Fe and Se, whilst the tissue directly surrounding the tumor presented a higher accumulation of Cu. Furthermore, the results of the study allow us to consider Se as a potential elemental marker of GBM progression. 相似文献
80.
Karolina Wojtunik-Kulesza Tomasz Oniszczuk Jarosaw Modoch Iwona Kowalska Jarosaw Szponar Anna Oniszczuk 《International journal of molecular sciences》2022,23(3)
Neurodegenerative disorders such as Alzheimer’s disease (AD) are distinguished by the irreversible degeneration of central nervous system function and structure. AD is characterized by several different neuropathologies—among others, it interferes with neuropsychiatrical controls and cognitive functions. This disease is the number one neurodegenerative disorder; however, its treatment options are few and, unfortunately, ineffective. In the new strategies devised for AD prevention and treatment, the application of plant-based natural products is especially popular due to lesser side effects associated with their taking. Moreover, their neuroprotective activities target different pathological mechanisms. The current review presents the anti-AD properties of several natural plant substances. The paper throws light on products under in vitro and in vivo trials and compiles information on their mechanism of actions. Knowledge of the properties of such plant compounds and their combinations will surely lead to discovering new potent medicines for the treatment of AD with lesser side effects than the currently available pharmacological proceedings. 相似文献