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排序方式: 共有175条查询结果,搜索用时 46 毫秒
31.
Jianmei Liu Hong Wang Zhi Ma Qianheng Duan Yangyang Fei Xiangdong Meng 《Entropy (Basel, Switzerland)》2022,24(7)
In this paper, we consider the optimization of the quantum circuit for discrete logarithm of binary elliptic curves under a constrained connectivity, focusing on the resource expenditure and the optimal design for quantum operations such as the addition, binary shift, multiplication, squaring, inversion, and division included in the point addition on binary elliptic curves. Based on the space-efficient quantum Karatsuba multiplication, the number of CNOTs in the circuits of inversion and division has been reduced with the help of the Steiner tree problem reduction. The optimized size of the CNOTs is related to the minimum degree of the connected graph. 相似文献
32.
Ge Zhao Tengteng Yang Huimin Cheng Lin Wang Yunzhe Liu Yubin Gao Jianmei Zhao Na Liu Xiumei Huang Junhui Liu Xiyue Zhang Ying Xu Jun Wang Junwei Wang 《Molecules (Basel, Switzerland)》2022,27(22)
To better guide microbial risk management and control, growth kinetic models of Salmonella with the coexistence of two other dominant background bacteria in pork were constructed. Sterilized pork cutlets were inoculated with a cocktail of Salmonella Derby (S. Derby), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli), and incubated at various temperatures (4–37 °C). The predictive growth models were developed based on the observed growth data. By comparing R2 of primary models, Baranyi models were preferred to fit the growth curves of S. Derby and P. aeruginosa, while the Huang model was preferred for E. coli (all R2 ≥ 0.997). The secondary Ratkowsky square root model can well describe the relationship between temperature and μmax (all R2 ≥ 0.97) or Lag (all R2 ≥ 0.98). Growth models were validated by the actual test values, with Bf and Af close to 1, and MSE around 0.001. The time for S. Derby to reach a pathogenic dose (105 CFU/g) at each temperature in pork was predicted accordingly and found to be earlier than the time when the pork began to be judged nearly fresh according to the sensory indicators. Therefore, the predictive microbiology model can be applied to more accurately predict the shelf life of pork to secure its quality and safety. 相似文献
33.
Chunmei Wu Tianyi Li Dongju Li Shanshan Jia Jianmei Huang Haimin Lei Mei Zhang 《中国化学快报》2021,32(7):2174-2178
Chinese herbal medicines(CHMs) play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHMs,pesticide residues in CHMs remain a serious issue and are the bottleneck for the global development of CHMs.In this work,we applied molecularly imprinted membrane electrospray mass spectrometry(MIM-ESI MS) for rapid detecting 4 classes of pesticide residues in CHMs,including organophosphorus(OPP),carbamates,pyrethroids and neonicotinoids in CHMs.Compared with our previous ambient ionization method MESI,MIM-ESI is capable of achieving a ~50-fold increase in the detection limit of conventional analytical methods owing to the specificity recognition and unique enrichment of MIM.The optimal experimental conditions were determined,and the method was further validated for its sensitivity and specificity.Our data showed that MIM-ESI MS is applicable for the direct quantitation of pesticide residues in CHMs.This detection technology may help to ensure the quality of CHMs in the future. 相似文献
34.
Atom transfer radical polymerization (ATRP) of MMA was conducted successfully at ambient temperature (25 °C) using 2-bromomethyl-4,5-diphenyloxazole as initiator, CuBr/2,2′-bipyridine (BPY) as catalyst, and 1,4-Dioxane as solvent. Factors such as the reaction temperature, mole ratio of monomer and catalyst to initiator, solvent and so on, which can affect the ATRP system, were discussed in the paper. Chain extension was conducted using polymer as the macro-initiator which was characterized via 1H NMR. The optical property of initiator was well preserved in the obtained PMMA, and the end-functionalized PMMA exhibited obvious fluorescent emission at 367 nm. 相似文献
35.
研究了稀土金属氧化物La2O3,CeO2,Pr2O3,Nd2O3和Sin2O3对Ru-Bd堇青石催化剂的活性的影响。利用BET,BJH,SEM,XRD,CO化学吸附等测试手段对催化剂进行表征,并对催化剂的反应性能进行评价。SEM测试结果显示La2O3呈“虫卵状”聚集在茧青石表面,而CeO2呈立方CaF2型均匀的覆盖在堇青石表面,Ru粒子呈“孤岛状”均匀地分散在铈改性的堇青石载体表面。茧青石载体经CeO2改性后,催化剂的比表面积、比孔容积以及中、微孔数量均有所提高,孔径分布也得到了明显改善。活性数据显示,适量的稀土金属氧化物均能促进Ru-Ba/堇青石催化剂的活性,其中CeO2的改性效果最好,在10MPa,475℃,5000h^-1时CeO2改性的Ru-Ba/茧青石催化剂的氨合成转化率达到9.9%。研究了CeO2对氨浓度随温度、压力、空速变化趋势的影响。 相似文献
36.
Jianmei Wang Huidong Cheng Yan Li Xiaoning Zhang 《Journal of Applied Analysis & Computation》2018,8(2):427-442
Starting from the practical problems of integrated pest management, we establish a predator-prey model for pest control with multi-state dependent impulsive, which adopts two different control methods for two different thresholds. By applying geometry theory of impulsive differential equations and the successor function, we obtain the existence of order one periodic solution. Then the stability of the order one periodic solution is studied by analogue of the Poincar\''{e} criterion. Finally, some numerical simulations are exerted to show the feasibility of the results. 相似文献
37.
The atom transfer radical polymerization (ATRP) of n-octyl acrylate (OA) was successfully carried out using ethyl-2-bromobutyrate as an initiator, and CuBr/2,2′-bipyridine (bpy) as a catalyst under microwave irradiation (MI) at 76.8 °C. The polymerization of n-octyl acrylate under MI showed linear first-order rate plots, a linear increase of the number-average molecular weight Mn with conversion, and low polydispersities, 1.1<Mw/Mn<1.4, where Mw is weight-average molecular weight. The ATRP of n-octyl acrylate is well controlled. Under the same experimental conditions, the apparent rate constant, kpapp, under MI is larger apparently than that under conventional heating. In addition, the effects of concentration of catalyst and other factors on polymerization are reported. 相似文献
38.
反相悬浮聚合分散剂的合成及性能 总被引:8,自引:0,他引:8
聚丙烯酸(钠)的吸水速度快,吸水量大,通常在有机介质环己烷、戊烷、(甲基)环戊烷中进行反相乳液聚合法生产,但一般只能获得颗粒细小的粉末状树脂,在介质中沉降速度慢,工程上易起粉尘危害.吸水树脂颗粒细小也影响树脂性能[1],采用反相悬浮聚合法合成聚丙烯酸... 相似文献
39.
Biao Wang Jianmei Li Huaping Wang Jianming Jiang Yunqi Liu 《Macromolecular Symposia》2004,216(1):189-194
The spinning dope of Multiwalled carbon nanotube/polyacrylonitrile composites was prepared by in-situ polymerization in 50wt% NaSCN solution. The rheological behavior of the dope containing carbon nanotubes from 0.19wt% to 1.9wt% was investigated using rotational rheometry at 60°C.The nanotubes have diameters between 30-50nm and lengths ranging from 6 to 10 μm. The apparent viscosity decreases with the addition of carbon nanotubes; this can be explained by the inhibition of carbon nanotubes during polymerization progress. The spinning dope containing various contents of carbon nanotubes exhibits a shear thickening effect. However, the dynamic rheological test shows there is a peak of complex viscosity with the increasing in frequency. 相似文献
40.
核酸适配体是指通过体外筛选技术从核酸文库中筛选出来,能够高特异性、高亲和力识别靶标物的寡核苷酸序列,具有靶标类型广泛、合成简单、相对分子质量小、化学稳定性高、易于进行生物化学修饰等优点。 核酸适配体能够通过折叠成特定的二维或三维构型与靶标物特异性结合,加上合适的信号转导机制,为重要靶标物的研究提供理想的分子识别与分子检测探针。 荧光检测技术具有高灵敏、高分辨率、易于实现多元分析等优点。 将核酸适配体的分子识别特性与荧光优异的光学检测性能相结合,在生命科学研究领域有着广泛的应用空间。 本文主要综述了核酸适配体荧光探针常见的分子设计和信号响应方式,及其在细胞成像、亚细胞成像中的应用研究,并对核酸适配体探针目前面临的一些挑战进行了讨论,最后对其未来的发展方向进行了展望。 相似文献