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91.
产品/服务配置规则获取的主要方式是用数据挖掘技术从设计实例数据库中提取.客户化服务方案配置规则为服务功能需求和方案特征间的关联规则.考虑到常用关联规则挖掘算法Apriori具有运算复杂的缺点,提出基于PIETM(Principle of Inclusion—Exclusion and Transaction Mapping)算法的配置规则挖掘方法,考虑置信度和有趣度指标,提取强关联规则.针对配置实例数据库数据量较大时,配置规则挖掘的效率会降低且会产生大量冗余规则的问题,采用二元语义模型表达定性的服务功能需求,将同类客户群的功能需求进行合并,替换多样化的功能需求,减少规则的冗余.最后以一工程机械制造企业服务方案配置规则挖掘为例,验证了所提方法的有效性.  相似文献   
92.
Schisandra chinensis (Turcz.) Baill., a traditional Chinese medicine, has been clinically used for the treatment of insomnia for centuries. The insomnia mechanism and the possible active ingredients of S. chinensis remain largely unknown. The objective of this study was to develop a method to detect its components which could pass through the blood brain barrier (BBB) by determining the brain microdialysate and brain tissue homogenate samples and then obtain the pharmacokinetic profile in brain for comprehensive understanding of its hypnotic clinical efficacy. Therefore, an efficient, sensitive and selective ultra fast liquid chromatography/tandem mass spectrometry method for the simultaneous determination of six sedative and hypnotic lignans (schisandrin, schisandrol B, schisantherin A, deoxyshisandrin, γ‐schisandrin and gomisin N) of Schisandra chinensis (Turcz.) Baill. in rat brain tissue homogenate and brain microdialysates has been developed and validated. The analysis was performed on a Shim‐pack XR‐ODS column (75 mm × 3.0 mm, 2.2 µm) using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid water. The method was validated in brain homogenate and microdialysate samples, which all showed good linearity over a wide concentration range (r2 > 0.99), and the obtained lower limit of quantification was 0.1 ng · ml?1 for the analytes in brain microdialysate samples. The intra‐ and inter‐day assay variability was less than 15% for all analytes. The study proved the six lignans, as sedative and hypnotic ingredients, could pass through the BBB with brain targeting, distributed mainly in the hypothalamus and possessed complete pharmacokinetics process in brain. The results also indicated that significant difference in pharmacokinetic parameters of the analytes was observed between two groups, while absorptions of these analytes in insomniac group were significantly better than those in normal group. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
93.
By taking advantage of UV‐Raman spectroscopy and high‐resolution TEM (HRTEM), combined with the focused ion beam (FIB) technique, the transformation from GaOOH into α‐Ga2O3 and then into β‐Ga2O3 was followed. We found that the stepwise transformations took place from the surface region before developing into the bulk of single particles without particle agglomeration and growth. During the transformation from GaOOH into α‐Ga2O3, the elimination of water vapor through the dehydroxylation of GaOOH resulted in the formation of micropores in the single particles, whilst maintaining their particle size. For the phase transformation from α‐Ga2O3 into β‐Ga2O3, the nucleation of β‐Ga2O3 was found to occur at the surface defects and this process could be retarded by occupying these defects with a small amount of La2O3. By finely controlling the process of the phase transformation, the β‐Ga2O3 domains gradually developed from the surface into the bulk of the single particles without particle agglomeration. Therefore, the surface structure of the α‐Ga2O3 single particles can be easily tuned and a particle with an α@β core–shell phase structure has been obtained.  相似文献   
94.
95.
A one-pot strategy for the fabrication of the quantum dots loaded cerasome has been successfully developed based on the condensation of dihexadecylamine and 3-isocyanatopropyltriethoxysilane, followed by spontaneous encapsulation and solubilization of hydrophobic quantum dots into the hybrid liposomal cerasomes in combination of self-assembly and sol-gel process. Fourier transform infrared spectroscopy and mass spectra prove the formation of the intermediate organoalkoxysilane with a lipid-like structure, which forms cerasome vesicles. After encapsulation into cerasome, quantum dots become well dispersed in aqueous solution. Such water-soluble QD cerasomes exhibit a better photostability and retain the luminescence property of the original hydrophobic quantum dots.  相似文献   
96.
通过油相热分解法在石墨烯(Gr)的表面修饰单分散的Fe3O4纳米颗粒,然后将二亚乙基三胺五乙酸(DTPA)通过多巴胺(DPA)化学键合到到Gr复合物表面,制备了新型磁性纳米复合材料Gr@Fe3O4-DPA-DTPA,采用X射线衍射、透射电镜、振动样品磁强计、傅里叶红外、拉曼和紫外光谱等技术对该材料进行了表征。结果表明,材料对水中的芳香族化合物和重金属离子具有很强的吸附能力,对水中的萘和Cu2+的吸附容量分别达到207.9和72.2mg/g。  相似文献   
97.
尚秀丽  伍家卫  李薇  胡中爱 《化学通报》2013,(12):1132-1136
通过电化学原位聚合法制备多孔网状结构的聚苯胺(PANI)/醋酸纤维素(CA)复合膜电极,该复合膜的内层(与电极接触的一面)呈墨绿色,外层呈白色。采用原子力显微镜(AFM)、扫描电镜(SEM)、红外光谱(FTIR)对其形貌和化学组成进行表征。通过循环伏安、恒电流充放电和电化学阻抗研究了复合膜电极的超级电容特性。结果表明,多孔网状结构的PANI/CA复合材料具有良好的电容性能,其比电容可达到410F/g,并且该超级电容器具有较小的内阻和较好的循环稳定性,300次循环后,容量仍维持在342F/g,比电容的保持率为83.4%。  相似文献   
98.
Combining photothermal therapy and radiotherapy(PTT-RT) with reducing tumor hypoxia acts as an important antitumor modality. However, it is a great challenge to realize photothermal therapy, radiotherapy and exogenous oxygen supply in one nanosystem. To realize a combination of the three functions, we fabricated a red blood cell membrane(RBCm)-camouflaged, red blood cell content(RBCc) and the copper sulfide(CuS) co-loaded dendritic large pore mesoporous silica nanoparticle(DLMSN/CuS/RBCc/ RBCm). The cell membrane coating endowed the nanoparticles with good stability in the physiological environment, and CuS allowed the nanoparticle exhibiting good photothermal and radiosensitization properties. RBCc loaded nanoparticle DLMSN/CuS/RBCc enhanced superior anti-tumor effect than DLMSN/CuS during combined PTT-RT therapy because the introduction of RBCc increased the exogenous oxygen supply. The in vitro study further demonstrated that the combination of photothermal therapy and radiotherapy induced superior antitumor efficacy than single therapy. Our work thus presents a unique multifunctional nanoscale platform favorable for combined PTT and RT.  相似文献   
99.
A novel magnetic covalent organic framework was synthesized via a one-step coating approach with solvothermal reaction employing 2,4,6-tris(4-aminophen-yl)-1,3,5-triazine and 2,4,6-triformylphloroglucinol as two building blocks by covalent bonding. The prepared magnetic covalent organic frameworks were properly characterized by different techniques and employed as adsorbents of magnetic solid-phase extraction. An analytical method was developed for the simultaneous determination of five fungicides in two Chinese herbal medicine samples via magnetic solid-phase extraction coupled to ultra high performance liquid chromatography with tandem mass spectrometry analysis. Under optimized magnetic solid-phase extraction conditions, the method exhibited satisfactory recoveries (74.0−109.6%) with relative standard deviations of 0.4−4.6%, low limits of detection (0.003−0.015 μg/kg), and good linearity (R2 > 0.9960). Compared with the traditional extraction method, the proposed method required a lower amount of adsorbent (3 mg) and extraction time (5 min). The adsorbent also had favorable reusability (not less than eight times). Therefore, the magnetic covalent organic frameworks could be a promising adsorbent for the extraction and quantitation of fungicides in Chinese herbal medicines.  相似文献   
100.
信欣  刘禹  孙影 《化学教育》2021,42(9):67-75
利用SPSS 25.0统计软件对“蓝瓶子”实验进行正交实验设计,通过统计学分析得出最佳实验条件。利用氧化还原传感器(ORP)对“蓝瓶子”振荡体系的电极电势变化曲线进行分析,并针对蓝色的产生和消失过程设计3组对比实验深入探究,阐明其反应原理,意在引导学生深刻理解趣味实验现象背后的微观反应本质。  相似文献   
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