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1.
The presence of calcium deposits in human lesions is largely used as imaging biomarkers of human diseases such as breast cancer. Indeed, the presence of micro- or macrocalcifications is frequently associated with the development of both benign and malignant lesions. Nevertheless, the molecular mechanisms involved in the formation of these calcium deposits, as well as the prognostic significance of their presence in human tissues, have not been completely elucidated. Therefore, a better characterization of the biological process related to the formation of calcifications in different tissues and organs, as well as the understanding of the prognostic significance of the presence of these calcium deposits into human tissues could significantly improve the management of patients characterized by microcalcifications associated lesions. Starting from these considerations, this narrative review highlights the most recent histopathological and molecular data concerning the formation of calcifications in breast, thyroid, lung, and ovarian diseases. Evidence reported here could deeply change the current point of view concerning the role of ectopic calcifications in the progression of human diseases and also in the patients’ management. In fact, the presence of calcifications can suggest an unfavorable prognosis due to dysregulation of normal tissues homeostasis.  相似文献   
2.
Novel antiviral nanotherapeutics, which may inactivate the virus and block it from entering host cells, represent an important challenge to face viral global health emergencies around the world. Using a combination of bioorthogonal copper-catalyzed 1,3-dipolar alkyne/azide cycloaddition (CuAAC) and photoinitiated thiol–ene coupling, monofunctional and bifunctional peptidodendrimer conjugates were obtained. The conjugates are biocompatible and demonstrate no toxicity to cells at biologically relevant concentrations. Furthermore, the orthogonal addition of multiple copies of two different antiviral peptides on the surface of a single dendrimer allowed the resulting bioconjugates to inhibit Herpes simplex virus type 1 at both the early and the late stages of the infection process. The presented work builds on further improving this attractive design to obtain a new class of therapeutics.  相似文献   
3.
In breast cancer adjuvant therapy, respiratory movements continuously modify the irradiated volumes and the anatomical shape of this body region. Fifteen patients were submitted to 3 Computed Tomography (CT) sequences for treatment planning: the first one without any indications to the patient (the standard sequence) and the second and the third one with spontaneous stopped inspiration and expiration, respectively; the patient was always in the same position. The treatment was planned on standard CT images and then applied to the other sequences, maintaining all parameters unvaried, including isocenter position and treatment time. The lung volumes within the fields (and those included in the 95%, 100%, 105% isodoses referred to the prescribed dose) were evaluated with dose/volume histograms. The average irradiated lung was 69 cm3 (DS 28) in standard sequences, 136 cm3 (DS 67) in inspiration and 41 cm3 (DS 25) in expiration. The pulmonary volume within the above isodoses exhibited similar changes. In other words, the lung volume actually irradiated during the whole treatment is smaller than the one which can be calculated on standard CT sequences and it corresponds to expiration volume. The remaining part falls into a wide "twilight zone" relative to dose. Therefore, the true risk of lung toxicity can be similarly lower than the calculable one on standard CT images. Thus, the complication risk (based on dose/volume histograms and normal tissue control probability parameters) could be assessed in new prospective studies, introducing a corrective factor for the irradiated lung volume, because the latter is smaller than that shown by standard CT.  相似文献   
4.
Optical machines with a vision system containing a video camera are designed to perform contact-less three-dimensional measurements. They are becoming more widely used in the industrial sector because of the many possibilities for automation they permit and because of the speed and economies in measurement tasks that can consequently be obtained. Within dimensional control these machines introduce significant characteristics of flexibility, savings and reliability. Therefore the purpose is to identify the principal metrological characteristics of such machines and so characterise the metrological traceability of the measurements obtained from them. The aim is to qualify each part of the optical machine as well as on the whole. Previously, no metrological traceability of this equipment has been provided in primary metrology, either at national (SIT—Sistema di Taratura in Italia—Calibration System in Italy) or at international level (EA–European co-operation for Accreditation). For this reason we develop a mathematical model that permits the evaluation of the measurement uncertainties in the use of such a device. The purpose is to obtain the certification of the measurement results furnished by the optical machine in as broad a context as possible. The experimental results of the tests are introduced for validating the proposed method. This paper provides the basis of the expression of the uncertainty of a measurement result obtained using the optical measurement machines and it shows the necessary requirements for the numerical evaluation of such uncertainty.  相似文献   
5.
6.
The interaction of aromatic hydrocarbons benzene, toluene, o-, m- and p-xylene and of methyl pyridines (in particular 2,6-lutidine) with H-ZSM-5 and H-FER zeolites has been studied. Two different H-ZSM-5 samples with strongly different intensity ratios between the two main OH stretching bands have been used. Benzene, toluene and p-xylene enter easily the cavities and give rise to three different H-bonded complexes. Two of them are strongly bonded while the third is likely a very hindered and distorted one. o-Xylene enters slowly the cavities and m-xylene even more slowly. Faster diffusion occurs at higher temperatures. On the contrary, xylenes do not enter the FER cavities. In spite of its steric hindrance, supposed to be the same of m-xylene, 2,6-lutidine enters fast the ZSM channels and is protonated by the internal sites. On the contrary, it does not enter the FER cavities, but it is protonated too on the external silanols sites. Evidence is provided for some kind of heterogeneity of the internal sites of ZSM-5 zeolite. Additionally, it is concluded that other effects besides the molecular sieving effect may play a role in the access and diffusion of molecules into the zeolite channels.  相似文献   
7.
The interaction of HZSM5 and Mo-ZSM5 with benzene, naphthalene, toluene, ortho-xylene, para-xylene, n-butane, isobutane, n-heptane, and methylcyclohexane, in the range 100–773 K has been investigated using FT-IR spectroscopy. Hydrogen bonded species with the internal bridging and the external terminal OHs has been detected. The reactivity at high temperature has also been studied. The access to the internal cavities and to the strongly acidic OHs is at least partly hindered in the case of Mo-ZSM5. The catalytic activity of ZSM5 was moderated by the addition of molybdenum, with lower cracking and higher liquid yields.  相似文献   
8.
This paper reports an investigation on the Bunsen reaction. An experimental campaign was conducted by means of a stirred reactor. Runs were carried out at a constant temperature in the 30-120 °C range, following a semi-batch procedure by feeding gaseous sulfur dioxide in an iodine/hydriodic acid/water solution. A specific analytical procedure to measure the hydriodic phase composition was implemented. It was observed that both the amount of absorbed SO2 and its conversion lowered as the temperature increased. Secondary reactions were beyond the detection limit in the reactor, even at low temperature and low iodine content. The purification of the produced hydriodic phase was also investigated. It was possible to satisfactorily reduce the impurities content without the occurrence of secondary reactions only when high temperature and high iodine content were applied.  相似文献   
9.
From a technological point of view, poly(lactic acid) (PLA) is one of the most important polymers produced from renewable sources, due to its versatility, relatively acceptable processability, and low cost. However, a significant limitation exists in its slow crystallization kinetics, which results in amorphous products having low mechanical properties and thermal resistance. For this reason, quantitative knowledge of the phenomenon of crystallization kinetics is fundamental. In this work, the crystallization kinetics in quiescent conditions of a commercial grade of PLA was analyzed in terms of nucleation and growth rates by direct morphological observations at different crystallization temperatures (Tc) and by calorimetric analysis in isothermal and non-isothermal conditions. The optical analysis showed a spherulitic morphology with radial growth of the lamellae. The analysis of the growth rate evidenced the α/α'-crystals polymorphism with a transition temperature of ~120°C. Based on experimental observation, the crystallization kinetics of the two crystalline phases were assessed.  相似文献   
10.
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