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排序方式: 共有8996条查询结果,搜索用时 15 毫秒
1.
《Ceramics International》2022,48(11):15268-15273
SiC/SiC mini-composites reinforced with SiC fibers coated with different numbers of ZrSiO4 sublayers prepared via a non-hydrolytic sol-gel process were fabricated. The tensile strength and work of fracture of the prepared SiC/SiC mini-composites were determined, and the relationship between their mechanical properties and fracture morphologies was discussed. The toughening mechanism and the variation tendency of their mechanical properties were further elaborated by analyzing the interfacial debonding morphologies of the SiC/SiC mini-composites with 1 and 4 layers of ZrSiO4 interphase as well as the results of prior studies. A relatively rare phenomenon—the delamination of the multilayer ZrSiO4 interphase in the SiC/SiC mini-composites but not on the SiC fibers—was observed, which clearly demonstrated the weak bonding between the ZrSiO4 sublayers in the SiC/SiC mini-composites. The ZrSiO4 sublayer delamination mechanism was then explained based on the high-magnification morphologies found in and beside the ZrSiO4 interphase. 相似文献
2.
Xiuyun Guo Junjun Wu Xiangren Meng Yawei Zhang Zengqi Peng 《International Journal of Food Science & Technology》2022,57(4):2556-2567
This study investigated the effects of l -lysine (Lys) and l -histidine (His) on the oxidative characteristics and gel properties of porcine myofibrillar proteins (MP). Results showed that Lys and His had a strong ferrous ion-chelating ability and hydroxyl radical-scavenging activity. Moreover, Lys and His inhibited the protein carbonyl formation and MP aggregation at 0.2 M and 0.6 M NaCl, respectively, in a dose-dependent manner. Furthermore, 2 and 4 mg mL−1 Lys and His decreased the oxidation-induced loss of the tertiary structure of MP accompanied by the lower surface hydrophobicity. The water-holding capacity and gel strength of MP gels increased with increasing Lys and His concentrations due to more regular and lamellar structures with smaller and homogeneous pores at 0.6 M NaCl and more orderly crosslinking via fibrous filament at 0.2 M NaCl. In summary, Lys and His chelated the ferrous ions and scavenged hydroxyl radicals, decreased the oxidation-induced physicochemical changes, thus preventing oxidative damage during the formation of a three-dimensional gel network, which resulted in better gel quality. 相似文献
3.
目的 对某福利院一起肠炎沙门菌食源性疾病进行调查和溯源,为研究相关食源性疾病提供参考。方法采用流行病学、食品卫生学和脉冲场凝胶电泳(PFGE)同源性分析等方法,分析本次食源性疾病事件。结果 确认本次事件中病例23名,患病率5.65%(23/407);现场采集病例肛拭子15份和厨房工作人员肛拭子3份、留样菜品3份、水果2份以及冰棒1份,其中从11份病例肛拭子中检出肠炎沙门菌,PFGE结果显示11株肠炎沙门菌的DNA条带图谱相似性为96.4%,聚类分析为同一型,结合流行病学调查,初步判断菌株来自同一克隆系。结论 综合流行病学、食品卫生学和实验室检测结果,确定为一起肠炎沙门菌引起的食源性疾病,福利院应加强对特殊人群的饮食安全管理,制定相应的食源性疾病突发事件应急处理预案,防止此类事故再发生。 相似文献
4.
《Ceramics International》2022,48(4):5312-5320
Ce3+ and Pr3+ co?doped Lu3Al5O12 phosphors were synthesized by the sol–gel process, and their crystal structure, photoluminescence (PL) properties, and energy transfer (ET) from the Ce3+ to Pr3+ were studied. The Lu2.94?yAl5O12:0.06Ce3+, yPr3+ phosphors (0.002 ≤ y ≤ 0.008) showed the green?yellow emission from the 2D3/2 → 2F5/2, 7/2 transition of Ce3+ and the red emission at 610 and 637 nm, which were caused by the 1D2→3H4 and 3P0→3H5 transitions of Pr3+, respectively. The optimal concentration of Pr3+ for efficient ET was found to be x = 0.006. The electric quadrupole?quadrupole interaction was responsible for the concentration quenching in the Lu2.94?yAl5O12:0.06Ce3+, yPr3+ phosphors, based on Dexter's theory. The incorporation of Pr3+ for Lu3+ enhanced the red PL intensity in the Lu2.94Al5O12:0.06Ce3+ phosphor. 相似文献
5.
6.
《Ceramics International》2022,48(9):12585-12591
In this study, zinc oxide (ZnO) nanofibers were prepared using the electrospinning method, and the effects of different spinning voltages and annealing temperatures on the fiber structure were tested. La0.8Sr0.2FeO3 (LSFO) perovskite film was prepared by a sol-gel method. Then we dip LSFO on ZnO nanofiber and grow it on the interdigital gold electrode substrate for gas sensors. The results show that the ZnO/LSFO heterostructure gas sensor has a good sensing response to H2S gas and exhibits good gas selectivity. The best gas response is 52.17% under 4 ppm H2S and work temperature 200°C, which has good recovery and reproducibility. 相似文献
7.
Rong Yang Anqi Xu Yanting Chen Nan Sun Jinjie Zhang Ru Jia Tao Huang Wenge Yang 《Journal of texture studies》2020,51(6):968-978
In order to ameliorate the gel quality of Dosidicus gigas surimi, the effects of laver powder on gel properties, rheological properties, and water-holding capacity (WHC) were investigated. Results indicated that the addition of laver powder could significantly increase the hardness, chewiness, and breaking force of surimi gels. However, the texture indexes and gel strength began to decline when additional amount exceeded 0.6%. Rheological results demonstrated that the addition of laver powder increased the storage modulus (G′) and viscosity of surimi, prolonged protein denaturation temperature in surimi gels. Moreover, the WHC of surimi gel was improved with the increase of laver powder. Further analyses in low-field nuclear magnetic resonance revealed that laver powder could shorten the transverse relaxation time, enhanced the combination with water, and altered the distribution of different water categories. The proportion of bound water and immobilized water reached its maximum and minimum at 0.6% of laver powder, respectively. Correlation analyses showed that WHC of surimi gel was negatively correlated well with the proportion of loose-bound water, but positively correlated with the strong-bound water and free water. In conclusion, the results supported that 0.6% was the optimal additional amount of laver powder for the squid-based surimi production based on the current ingredients of surimi products. 相似文献
8.
A Smart Flexible Solid State Photovoltaic Device with Interfacial Cooling Recovery Feature through Thermoreversible Polymer Gel Electrolyte 下载免费PDF全文
Quasi‐solid‐state dye‐sensitized solar cells (DSSCs) fabricated with lightweight flexible substrates have a great potential in wearable electronic devices for in situ powering. However, the poor lifespan of these DSSCs limits their practical application. Strong mechanical stresses involved in practical applications cause breakage of the electrode/electrolyte interface in the DSSCs greatly affecting their performance and lifetime. Here, a mechanically robust, low‐cost, long‐lasting, and environment‐friendly quasi‐solid‐state DSSC using a smart thermoreversible water‐based polymer gel electrolyte with self‐healing characteristics at a low temperature (below 0 °C) is demonstrated. When the performance of the flexible DSSC is hindered by strong mechanical stresses (i.e., from multiple bending/twisting/shrinking actions), a simple cooling treatment can regenerate the electrode/electrolyte interface and recover the performance close to the initial level. A performance recovery as high as 94% is proven possible even after 300 cycles of 90° bending. To the best of our knowledge, this is the first aqueous DSSC device with self‐healing behavior, using a smart thermoreversible polymer gel electrolyte, which provides a new perspective in flexible wearable solid‐state photovoltaic devices. 相似文献
9.
10.
为了研制新型便携式计数测试片检测食品中金黄色葡萄球菌,本文通过正交试验对金黄色葡萄球菌测试片中培养基成份进行优化;研究冷水可溶性凝胶的复配比例,以及优化后的表面活性剂对复配凝胶质构特性的影响。结果表明,金黄色葡萄球菌测试片中培养基组分为胰蛋白胨10 g/L,牛肉膏5 g/L,酵母膏1 g/L,甘氨酸12 g/L,氯化锂5 g/L,尿素0.2 g/L,亚碲酸钾10 mg/L,卵黄粉6 g/L,表面活性剂最优添加量为D-甘露醇4 g/L,丙酮酸钠5 g/L;冷水可溶性凝胶复配比例为瓜尔胶:聚丙烯酸钠=7:3;添加优化后的D-甘露醇和丙酮酸钠的复合冷水可溶性凝胶可获得最优的凝胶质构,其硬度和黏性分别为1362.04 g和630.41 g。将本研究的测试片与国标平板计数方法相比,其检测结果相关性良好(R^2=0.995),可达到相同水平的检出限2CFU/m L和灵敏度(100%)。本文研究的金黄色葡萄球菌测试片可应用于食品中金黄色葡萄球菌的定量检测。 相似文献