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排序方式: 共有54条查询结果,搜索用时 219 毫秒
1.
In this paper, we extend the Bonferroni mean (BM) operator with the picture fuzzy numbers (PFNs) to propose novel picture fuzzy aggregation operators and demonstrate their application to multicriteria decision making (MCDM). On the basis of the algebraic operational rules of PFNs and BM, we introduce some aggregation operators: the picture fuzzy Bonferroni mean, the picture fuzzy normalized weighted Bonferroni mean, and the picture fuzzy ordered weighted Bonferroni mean. Then, a new picture fuzzy MCDM method is proposed with the help of the proposed operators. Lastly, a practical application of proposed model is given to verify the developed model and related results of the proposed model is compared with the results of the existing models to indicate its applicability.  相似文献   
2.
Inhibition of hepatic cholesterol biosynthesis by chloroquine   总被引:1,自引:0,他引:1  
Chloroquine is shown to be a potent inhibitor of cholesterol biosynthesis by isolated rat hepatocytes. Half-maximal inhibition of cholesterogenesis occurs at ca. 10μM chloroquine. Chloroquine does not affect fatty acid synthesis by isolated hepatocytes. This suggests that chloroquine acts on the cholesterol biosynthetic pathway beyond the cytosolic acetyl-CoA branchpoint of cholesterol and fatty acid synthesis.  相似文献   
3.
In this study, the synthesis and application of biocompatible steviol glycosides based polyurethane/poly (ε-caprolactone) (PU/PCL) fibers was performed by electrospinning as a potential wound dressing materials that can be used for the closure of nonhealing wounds. During electrospinning, steviol glycoside-based polyurethane structures were used in blend formation with poly (ε-caprolactone) for easy producibility. Steviol glycosides are a natural abundant and easily accessible source as the main component of the wound dressing material due to their free hydroxyl groups, high biocompatibility, and hydrophilicity. The structure of steviol glycosides is composed of saccharide units and the free OH groups. Thus, steviol glycosides act as a crosslinker within the polyurethane structure and provides mechanical strength. For the production of steviol glycosides based PU/PCL fibers first, the steviol glycosides as a monomer were isolated from the stevia rebudiana. Then, polyurethane structures containing stevia glycoside were synthesized with hexamethylene diisocyanate, lactose and PEG-200 by solution polymerization technique. PCL was added to the prepared polyurethanes in a ratio of 1:2 and formation of nanofiber structure. The prepared wound dressing material was characterized by Fourier transform infrared, atomic force microscopy, and scanning electron microscope techniques. Swelling degree, water content and oxygen permeability assay of the steviol glycosides based PU/PCL wound dressing material was determined. In biocompatibility test, cell viability value of PU/PCL fibrous materials in indirect cytotoxicity test was determined as 86.9% and cell adhesion on hybrid PU/PCL fibers was showed as morphological. In accordance with this target, the steviol glycosides based PU/PCL wound dressing material can be produced easily and low cost. As a result, the wound dressing materials obtained with their high biocompatibility and low costs will be an effective and fast method for the healing of open wounds of diabetics.  相似文献   
4.
The aim of this study is to design a classifier based expert system for early diagnosis of the organ in constraint phase to reach informed decision making without biopsy by using some selected features. The other purpose is to investigate a relationship between BMI (body mass index), smoking factor, and prostate cancer. The data used in this study were collected from 300 men (100: prostate adenocarcinoma, 200: chronic prostatism or benign prostatic hyperplasia). Weight, height, BMI, PSA (prostate specific antigen), Free PSA, age, prostate volume, density, smoking, systolic, diastolic, pulse, and Gleason score features were used and independent sample t-test was applied for feature selection. In order to classify related data, we have used following classifiers; scaled conjugate gradient (SCG), Broyden–Fletcher–Goldfarb–Shanno (BFGS), and Levenberg–Marquardt (LM) training algorithms of artificial neural networks (ANN) and linear, polynomial, and radial based kernel functions of support vector machine (SVM). It was determined that smoking is a factor increases the prostate cancer risk whereas BMI is not affected the prostate cancer. Since PSA, volume, density, and smoking features were to be statistically significant, they were chosen for classification. The proposed system was designed with polynomial based kernel function, which had the best performance (accuracy: 79%). In Turkish Family Health System, family physician to whom patients are applied firstly, would contribute to extract the risk map of illness and direct patients to correct treatments by using expert system such proposed.  相似文献   
5.
6.
In this work, the thin film of wheat DNA was deposited by spin-coating technique onto glass substrate, and the optical and dielectric properties of the double helix DNA thin film were investigated. The optical constants such as refractive index, extinction coefficient, dielectric constant, dissipation factor, relaxation time, and optical conductivity were determined from the measured transmittance spectra in the wavelength range 190–1100 nm. Meanwhile, the dispersion behavior of the refractive index was studied in terms of the single oscillator Wemple–DiDomenico (W–D) model, and the physical parameters of the average oscillator strength, average oscillator wavelength, average oscillator energy, the refractive index dispersion parameter and the dispersion energy were achieved. Furthermore, the optical band gap values were calculated by W–D model and Tauc model, respectively, and the values obtained from W–D model are in agreement with those determined from the Tauc model. The analysis of the optical absorption data indicates that the optical band gap Eg was indirect transitions. These results provide some useful references for the potential application of the DNA thin films in fiber optic, solar cell and optoelectronic devices.  相似文献   
7.
This paper firstly reports the effect of deoxyribonucleic acid (DNA) molecules extracted from chickpea and wheat plants on the injection/recombination of photogenerated electrons and sensitizing ability of dye‐sensitized solar cells (DSSCs). These high‐yield DNA molecules are applied as both linker bridging unit as well as thin tunneling barrier (TTB) at titanium dioxide (TiO2 )/dye interface, to build up high‐efficient DSSCs. With its favorable energy levels, effective linker bridging role, and double helix structure, bifunctional DNA modifier shows an efficient electron injection, suppressed charge recombination, longer electron lifetime, and higher light harvesting efficiency, which leads to higher photovoltaic performance. In particular, a photoconversion efficiency (PCE) of 9.23% is achieved by the binary chickpea and wheat DNA‐modified TiO2 (CW@TiO2) photoanode. Furthermore, time‐resolved fluorescence spectroscopy measurements confirm a better electron transfer kinetics for DNA‐modified TiO2 photoanodes, implying a higher electron transfer rate (kET). This work highlights a great contribution for the photoanodes that are linked with DNA molecule, which act as both bridging unit and TTB to control the charge recombination and injection dynamics, and hence, boost the photovoltaic performance in the DSSCs.  相似文献   
8.
西昆仑玛尔坎苏地区是中国重要的锰矿资源基地,目前区内仍不断有新的锰矿点被报道,已发现多个大中型锰矿床。该地区锰矿床为海相沉积型矿床,赋矿层位为上石炭统喀拉阿特河组(C2k)与下二叠统玛尔坎雀库塞山组(P1m)。本文在总结玛尔坎苏地区锰矿床成矿规律的基础上,基于MRAS证据权重法,重建了该地区的锰矿床找矿模型。提取并构置了地层、遥感、锰化探异常3个预测要素作为证据因子。(1)地层信息证据因子:上石炭统喀拉阿特河组(C2k)碳酸盐岩与下二叠统玛尔坎雀库塞山组(P1m);(2)遥感证据因子:铁染异常区及羟基异常区;(3)化探证据因子:锰单元素化探异常区域。根据后验概率值圈定三级找矿有利靶区7处,并对找矿靶区进行了验证。通过圈定有利区,为下步找矿新突破提供了新的借鉴。  相似文献   
9.
工厂中经常出现的变动情况决定蒸汽动力系统须具有一定的可调节性。本文以总复合曲线为工具,分析比较了采用背压式汽轮机组和采用抽汽凝汽式汽轮机组的蒸汽动力系统,并用一例子说明如何借助总复合曲线设计可调节性好的蒸汽动力系统。  相似文献   
10.
The electric dipole transition probabilities and the lifetimes of excited levels have been calculated using the weakest bound electron potential model theory (WBEPMT) and the quantum defect orbital theory (QDOT) in atomic fluorine. In the calculations, many of transition arrays included both multiplet and fine-structure transitions are considered. We employed Numerical Coulomb Approximation (NCA) wave functions and numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii in determination of parameters. The necessary energy values have been taken from experimental energy data in the literature. The calculated transition probabilities and lifetimes have been compared with available theoretical and experimental results. A good agreement with results in literature has been obtained. Moreover, some transition probability and the lifetime values not existing in the literature for some highly excited levels have been obtained using these methods.  相似文献   
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