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Synthesis of Novel Bisoxazoline Ligands for the Enantioselective Diels-Alder Reaction

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Chinese Chemical Letters 2006年第8期17卷 1033-1036页

作者： qing Hua BIAN jun liu Ming Ming YIN Min WANG College of Science China Agricultural University Beijing 100094

Four novel bisoxazoline ligands 8a-d were synthesized from （S）-amino alcohols and could be formed effective catalysts （up to 77% ee for endo isomer） with Cu（OTf）2 for enantioselective Diels-Alder addition. The f... 详细信息

关键词： Asymmetry catalytic bisoxazoline Diels-Alder reaction ligand.

Application of artificial neural network to calculation of solitary wave run-up

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Water Science and Engineering 2010年第3期3卷 304-312页

作者： You-xing WEI Deng-ting WANG qing-jun liu College of Harbour Coastal and Offshore Engineering Hohai University Nanjing 210098 P. R. China River and Harbor Engineering Department Nanjing Hydraulic Research Institute Nanjing 210024 P. R. China

The prediction of solitary wave run-up has important practical significance in coastal and ocean engineering, but the calculation precision is limited in the existing models. For improving the calculation precision, a solitary wave run-up calculation model was established based on artificial neural networks in this study. A back-propagation （BP） network with one hidden layer was adopted and modified with the additional momentum method and the auto-adjusting learning factor. The model was applied to calculation of solitary wave run-up. The correlation coefficients between the neural network model results and the experimental values was 0.996 5. By comparison with the correlation coefficient of 0.963 5, between the Synolakis formula calculation results and the experimental values, it is concluded that the neural network model is an effective method for calculation and analysis of solitary wave ran-up.

关键词： solitary wave run-up artificial neural network back-propagation (BP) network,additional momentum method auto-adjusting learning factor

The synthesis of porphyrin-anthraquinone dyad via an azo-rearrangement

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Chinese Chemical Letters 2011年第5期22卷 539-542页

作者： Cheng Jie Li Ya qing Feng Xiu jun liu Tian Yi Zhang School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

One novel porphyrin P-Q2 is planned to be synthesized by condensation between ATPP and ***,after separation by chromatography and characterization with IR,~1H NMR,HR-MS and X-ray,P-Q1 is obtained *** the structure of P-Q1 with that of P-Q2,it is realized that an intramolecular cyclization rearrangement takes place when the azo group is situated in the O-position to the amido *** rearrangement offers a new way to prepare indazole *** addition,the spectral properties of P-Q1 have been studied by UV-vis and steady state fluorescence *** fluorescence quenching is observed in the preliminary emission spectrum due to the proposed electron transfer from the excited porphyrin to the anthraquinone moieties.

关键词： Porphyrin Anthraquinone Azo-rearrangement Fluorescence quenching

A New Approach of Data-driven Simulation and its Application to Solar Active Region 12673

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Research in Astronomy and Astrophysics 2024年第12期24卷 45-54页

作者： Zhi-Peng liu Chao-Wei Jiang Xin-Kai Bian qing-jun liu Peng Zou Xue-Shang Feng Institute of Space Science and Applied Technology Harbin Institute of Technology

The solar coronal magnetic field is a pivotal element in the study of eruptive phenomena, and understanding its dynamic evolution has long been a focal point in solar physics. Numerical models, driven directly by observation data, serve as indispensable tools in investigating the dynamics of the coronal magnetic field. This paper presents a new approach to electric field inversion, which involves modifying the electric field derived from the DAVE4VM velocity field using ideal Ohm's law. The time series of the modified electric field is used as a boundary condition to drive a magnetohydrodynamics model, which is applied to simulate the magnetic field evolution of active region12673. The simulation results demonstrate that our method enhances the magnetic energy injection through the bottom boundary, as compared with energy injection calculated directly from the DAVE4VM code, and reproduces the evolution of the photospheric magnetic flux. The coronal magnetic field structure is also in morphological similarity to the coronal loops. This new approach will be applied to the high-accuracy simulation of eruption phenomena and provide more details on the dynamical evolution of the coronal magnetic field.

关键词： magnetohydrodynamics (MHD) methods: numerical Sun: coronal mass ejections (CMEs) Sun: flares

Changes in Texture and Retorting Yield in Oil Shale During Its Bioleaching by Bacillus Mucilaginosus

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Chemical Research in Chinese Universities 2013年第2期29卷 294-298页

作者： ZHANG Xue-qing REN He-jun liu Na ZHANG Lan-ying ZHOU Rui Key Lab of Groudwater Resources and Environment Ministry of Education College of Environment and Resources Jilin University Changchun 130012 P. R. China

Bioleaching of oil shale by Bacillus mucilaginosus was carried out in a reaction column for 13 d. The pH value of the leaching liquor decreased steadily from 7.5 to 5.5 and the free silicon dioxide concentration reached approximately 200 mg/L in it. Scanning electron microscopy（SEM） observations revealed that a mass of small particles separated from the matrix of oil shale. Energy dispersive spectrometry（EDS） analysis implied that the total content of Si,O, A1 was decreased in the particle area of the matrix. These facts indicate that the silicate was removed, leading to the structural transformation of oil shale. Comparison of the shale oil yields before and after bioleaching illustrated that approximately 10% extra shale oil was obtained. This finding suggests that the demineralisation of the oil shale by silicate bacteria improves shale oil yield.

关键词： Oil shale Bacillus mucilaginosus Bioleaching Shale oil yield

Neurochip based on light-addressable potentiometric sensor with wavelet transform de-noising

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第5期11卷 323-331页

作者： qing-jun liu Wei-wei YE Hui YU Ning HU Li-ping DU Ping WANG Biosensor National Special Laboratory Key Laboratory of Biomedical Engineering of Ministry of Education Department of Biomedical Engineering Zhejiang University Hangzhou 310027 China State Key Laboratory of Transducer Technology Chinese Academy of Sciences Shanghai 200050 China

Neurochip based on light-addressable potentiometric sensor(LAPS),whose sensing elements are excitable cells,can monitor electrophysiological properties of cultured neuron networks with cellular signals well *** we report a kind of neurochip with rat pheochromocytoma(PC12) cells hybrid with LAPS and a method of de-noising signals based on wavelet *** were cultured on LAPS for several days to form networks,and we then used LAPS system to detect the extracellular potentials with signals de-noised according to decomposition in the time-frequency *** signal was decomposed into various scales,and coefficients were processed based on the properties of each *** last,signal was reconstructed based on the new *** results show that after de-noising,baseline drift is removed and signal-to-noise ratio is *** suggests that the neurochip of PC12 cells coupled to LAPS is stable and suitable for long-term and non-invasive measurement of cell electrophysiological properties with wavelet transform,taking advantage of its time-frequency localization analysis to reduce noise.

关键词： Neurochip Light-addressable potentiometric sensor(LAPS) Wavelet transform Threshold De-noising

Invalidation manner and mechanism of new type NbO electrolytic capacitor anode

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Journal of Central South University of Technology 2005年第z1期12卷 18-22页

作者： LI Jian YI Dan-qing WEN jun-jie liu Hui-qun ZHONG Hui School of Materials Science and Engineering Central South University Changsha 410083 China School of Materials Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China School of Materials Science and Engineering Central South University Changsha 410083 China School of Metallurgical Science and Engineering Central South University Changsha 410083 China

Niobium suboxide powder was pressed and sintered in vacuum into NbO electrolytic capacitor sintered anode..High voltage and constant current formation experiment was performed on NbO electrolytic capacitor anode,during which electrolyte was 0.01 % Ha PO4 solution, temperature was 90 C and current was 50 mA per gram sample. Through the relationship between anode voltage and time and scanning electron microscopy(SEM) images of invalidated anode and normal forming anode, invalidation manner and mechanism of NbO electrolytic capacitor anode were discussed. The results show that, the main invalidation manner of NbO electrolytic capacitor anode is not short circuit but open circuit, which is different to that of traditional Ta electrolytic capacitor anode. The reason of invalidation is that anode oxide film whose thickness increases gradually penetrates the "connection neck" among anode powder particles, which leads to the open circuit invalidation of anode. Compared with Ta electrolytic capacitor,NbO electrolytic capacitor has better security.

关键词： niobium suboxide NbO invalidation manner invalidation mechanism electrolytic capacitor anode

Predicting liver metastasis of gastrointestinal tract cancer by diffusion-weighted imaging of apparent diffusion coefficient values

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World Journal of Gastroenterology 2016年第10期22卷 3031-3037页

作者： De-Xian Zheng Shu-Chun Meng qing-jun liu Chuan-Ting Li Xi-Dan Shang Yu-Seng Zhu Tian-jun Bai Shi-Ming Xu Department of Radiology Second People’s Hospital of Liaocheng City Department of Radiology Third People’s Hospital of Liaocheng city Medical Imaging Institute of Shandong Province Shandong Provincial Hospital Department of Gastroenterology Second People’s Hospital of Liaocheng city Department of Radiology People’s Hospital of Liaocheng city

AIM: To determine if efficacy of chemotherapy on liver metastasis of gastrointestinal tract cancer can be predicted by apparent diffusion coefficient(ADC) values of diffusion-weighted imaging(DWI). METHODS: In total, 86 patients with liver metastasis of gastrointestinal tract cancer(156 metastatic lesions) diagnosed in our hospital were included in this study. The maximum diameters of these tumors were compared with each other before treatment, 2 wk after treatment, and 12 wk after treatment. Selected patients were classified as the effective group and the ineffective group, depending on the maximum diameter of the tumor after 12 wk of treatment; and the ADC values at different treatment times between the two groups were compared. Spearman rank correlation was used to analyze the relationship between ADC value and tumor diameter. Receiver operating characteristic curve(ROC curve) was used to analyze the ADC values before treatment to predict the patient's sensitivity and specificity degree of efficacy to the chemotherapy. RESULTS: There was no difference in age between the two groups and in maximum tumor diameter before treatment and 2 wk after treatment. However, after 12 wk of treatment, maximum tumor diameter in the effective group was significantly lower than that in the ineffective group(P < 0.05). Before treatment, ADC values in the ineffective group were significantly higher than those in the effective group(P < 0.05). There was no difference in ADC values between the effective and ineffective groups after 2 and 12 wk of treatment. However, ADC values were significantly higher after 2 and 12 wk of treatment compared to before treatment in the effective group(P < 0.05). Spearman rank correlation analysis showed that ADC value before treatment and the reduced percentage of the maximum tumor diameter after 12 wk of treatment were negatively correlated, while the increase in the percentage of the ADC value 12 wk after treatment and the decrease in the percentage

关键词： Chemotherapy Liver metastatic tumor Magnetic resonance imaging Gastrointestinal tract cancer

Microcirculation disturbance affects rats with acute severe pancreatitis following lung injury

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World Journal of Gastroenterology 2005年第39期11卷 6208-6211页

作者： Xue-Min liu qing-Guang liu jun Xu Cheng-En Pan Department of Hepatobiliary-Surgery Xi'an JiaotongUniversity First Hospital Xi'an 710061 Shaanxi Province China

AIM: To study the effects of microcirculation disturbance(MD) on rats with acute severe pancreatitis (ASP).METHODS: We developed ASP rat models, and anatomized separately after 1, 3, 5, 7, and 9 h. We took out blood and did hemorrheologic examination and erythrocyte osmotic fragility test, checked up the water content, capillary permeability, and genetic expression of intercellular adhesion molecule-1 (ICAM-1) in lung tissues, examined the apoptosis degree of blood vessel endothelium while we tested related gene expression of Bax and Bcl-2in lung tissues. We did the same examination in control ***: The viscosity of total blood and plasma, the hematocrit, and the erythrocyte osmotic fragility were all increased. Fibrinogen was decreased. The water content in lung tissues and capillary permeability were *** degree of blood vessel endothelium was increased too. ICAM-1 genetic expression moved up after1 h and reached its peak value after 9 ***: MD plays an important role in ASP following acute lung injury (ALI). The functional damage of blood vessel endothelium, the apoptosis of capillary vessel endothelium, WBC edging-concentration and the increasing of erythrocyte fragility are the main reasons of ALI.

关键词： Microcirculation Acute pancreatitis Lung injury