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Semiconductor photoinduced cycloreversion of the dimer of methyl 2-naphthoate

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chinese Journal of chemistry 1997年第3期15卷 260-264页

作者： Tung, ch Ying, YM Institute of Photographic chemistry Chinese Academy of Sciences Beijing 100101 China

The dimer of methyl 2-naphthoate (I) has been found to undergo efficient cycloreversion to its monomer, methyl naphthalene-2-carboxylate (2) on illuminated ZnO and TiO2 but not on CdS. An electron transfer and cation radical chain mechanism is proposed. Quantum yields, solvent effect. the role of oxygen, and the quenching of the reaction were investigated, and were consistent with the proposed mechanism.

关键词： semiconductor photoinduced cycloreversion electron transfer

Can a dam type of an alpine lake be derived from lake geometry?A negative result

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Journal of Mountain Science 2021年第3期18卷 614-621页

作者： Adam EMMER Vojtěch CURIN University of Graz Institute of Geography and Regional ScienceCascade|The Mountain Processes and Mountain Hazards GroupGraz 8010Austria Czech Academy of Sciences Prague 16500Czechia Global change Research Institute Czech University of Life Sciences PragueFaculty of Environmental SciencesBrno 60300Czechia

Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is *** a consequence,numerous region-and nation-wide GLOF assessment studies have been published *** studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by ***,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual *** lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mechanism(dam overtopping/dam breach)and thus GLOF *** this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam *** dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the *** only promising results are obtained for extreme values(selected bins)of the *** instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed ***,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra.

关键词： Alpine lake High mountain lake GLOFs Glacial lake Moraine-dammed Bedrock-dammed Negative result Cordillera Blanca

Practice of Glycemic Self-Monitoring in Diabetic Patients Followed at the Endocrinology Department of Donka University Hospital in Guinea

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Open Journal of Endocrine and Metabolic Diseases 2024年第2期14卷 33-38页

作者： Mamadou Dian Mamoudou Diallo Mamadou Mansour Diallo Mamadou chérif Diallo Alpha Mamadou Diallo Kadija Dieng Abdoul Mazid Diallo Mody Abdoulaye Barry Kadidiatou Bah El’Hadj Zainoul Bah Mamadou Alpha Diallo Ibrahima Condé Ousmane Kourouma Amadou Kaké Diabetology Unit Labe Regional Hospital Labé Guinea Faculty of Health Sciences and Techniques Gamal Abdel Nasser University of Conakry Conakry Guinea Endocrinology and Diabetology Department of Donka University Hospital Conakry Guinea Pediatrics Department of Donka University Hospital Conakry Guinea

Diabetes is a chronic pathology whose evolution is marked by micro and macroangiopathic complications. Optimal management can prevent the onset of complications and improve patients’ quality of life. Objectives: To determine the frequency of self-monitoring of blood glucose and to describe the errors found during self-monitoring in diabetic patients followed at the Endocrinology Department of Donka University Hospital in Guinea. Materials and methods: Descriptive cross-sectional study carried out between August and September 2020 involving diabetic patients followed up at the Endocrinology and Diabetology Department of the Donka National Hospital, chU Conakry. Results: A total of 301 patients were enrolled, with an average age of 44.24 ± 21.01 years. 64.12% were female. Type 2 diabetes predominated in 64% of cases. The mean duration of diabetes was 6.14 ± 4.67 years, and 75.08% of patients lived in urban areas. Patients were on insulin in 36.21% of cases, insulin and biguanides (26.25%), hypoglycemic sulfonamide and biguanides (19.27%) and biguanides in 18.27% of cases. The frequency of self-monitoring of blood glucose was 43%, and 38% of patients made errors, notably reusing lancets (60%), not checking the expiration date (55.65%) and not washing their hands (48%). Conclusion: This study shows that self-monitoring of blood glucose is not performed by the majority of patients. Numerous errors were identified during blood glucose testing. Continued therapeutic education on the use of blood glucose meters will help empower patients and improve their quality of life.

关键词： Self-Monitoring of Blood Glucose Diabetes Conakry University Hospital

Multirange Fractal Analysis on the Negative Correlation between Fractal Dimension of Fractured Surface and Toughness of Materials

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Journal of Materials Science & Technology 1996年第4期12卷 318-320页

作者： Lung, CW Jiang, JA Zhang, ch International Centre for Materials Physics Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of factorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals.

关键词： Fracture

Electronic Absorption Spectroscopy of H2X （X=O, Te, Po）： Theoretical Treatment of Spin-Orbit Effects

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chinese Journal of chemical Physics 2009年第2期22卷 171-177页

作者： chérif A. A. Ndoye chantal Daniel Laboratoire de chimie Quantique Institut de Chimie UMR 7177 CNRS-Université de Strasbourg 4 Rue Blaise Pascal 67000 Strasbourg France

The electronic spectroscopy of H2X （X=O, Te, Po） was investigated by means of spinorbit configuration interaction （EPCISO） and restricted active space state interaction （SORASSI）. The transition energies to the low-lying singlet and triplet states of H2O, in which the SO interaction is zero, compare rather well with the experimental data as well as to other theoretical values. The theoretical electronic absorption spectrum is characterized by three allowed transitions A^1B1 （2px（O）→σ^＊g/3s（O））, B^1A1（σg→σ^＊g/3s（O）） and A^1S2（σg→σ^＊u） calculated at 7.68, 9.94, and 11.72 eV, respectively. The theoretical absorption spectra of H2X （X=Te, Po） are shifted to the red with the A^1B1 （npx（X）→σ^＊g） states calculated at 5.06 eV （H2Te） and 4.40 eV （H2Po） and the A^1B2 （σg→σ^＊u） states calculated at 7.89 eV （H2Te） and 7.77 eV （H2Po）. The largest SO splitting amounts to 0.34 eV and is found for the lowest a^3A1 of H2Po. In H2Te the SO effects are still negligible with a maximum splitting of 0.04 eV for the lowest a^3B2. The two methods lead to comparable results but the EPCISO approach depends strongly on the reference wavefunction.

关键词： Spin-orbit Excited state Group Ⅵ dihydride

Ship Hull Slamming Analysis with Nonlinear Boundary Element Method

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china Ocean Engineering 1997年第4期12卷 411-418页

作者： Lu, ch He, YS Shanghai Jiao Tong Univ Dept Mech Engn Shanghai 200030 Peoples R China

A boundary element method is developed for calculating the flare ship hull slamming problem. The nonlinear free surface elevation and the linear element assumption are employed. The method has been verified by comparisons with results for the water entry of wedges with various deadrise angles. Numerical results show that the pressure distribution varies greatly with the ship hull with different curvilinear equations, and the slamming features are also different; From the numerical simulation, the authors found that the structural damage of the flare hull might be caused by the increasing hydrodynamic pressure over an extensive area on the flare when the upper part of the flare comes into contact with water.

关键词： slamming boundary element method ship full slamming analysis

Asymptotic periodic solutions of some generalized Burgers equations

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Applied Mathematics(A Journal of chinese Universities) 2018年第4期33卷 390-408页

作者： Smriti Nath ch.Srinivasa Rao Department of Mathematics Indian Institute of Technology Madras

In this paper, we construct asymptotic periodic solutions of some generalized Burgers equations using a perturbative approach. These large time asymptotics(constructed) are compared with relevant numerical solutions o... 详细信息

关键词： periodic solution large time asymptotics generalized Burgers equations

Isomeric structures, isomerization and decomposition of silylenoids H2SiMX(MX=KF,KCl LiBr,NaBr and KBr)

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chinese Journal of chemistry 1995年第6期13卷 481-486页

作者： Feng, DC Feng, SY Deng, ch SHANDONG UNIV INST THEORET CHEMSHANDONG 250100PEOPLES R CHINA

The isomeric structures, isomerization and decomposition of silylenoids H(2)SiMX (MX=KF, KCl, LiBr, NaBr and KBr) have been investigated by ab initio molecular orbital theory. These silylenoids have four kinds of very similar equilibrium structures. The three-membered ring and p-complex structures should be stable and experimentally detectable. The lifetime of sigma-complex and tetrahedral structures would be very short and experimentally undetectable.

关键词： silylenoids H(2)SiMX isomeric structures isomerization decomposition

chemical pattern recognition applied to materials optimal design and industry optimization

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chinese Science Bulletin 1997年第10期42卷 793-799页

作者： chen, NY Li, ch Qin, P Shanghai Institute of Metallurgy Chinese Academy of Sciences Shanghai China

The multi-dimensional spaces, spanned by the dimensionless numbers describing the equilibrium states or the macroscopic chemical kinetics of complicated chemical reaction systems, have been used for the data processing of the process-es in materials preparation or industrial production. It has been found that there are four common topological types of the rela-tions between the optimization zone and the operation zone in the multi-dimensional spaces. Various computation methods us-ing pattern recognition, artificial neural network and genetic algorithm are used for model-building and optimization strategy searching. An integrated system named KDPAG has been built for materials optimal design or industrial optimization. Appli-cation to chemical, petrochemical and metallurgical industries and materials optimal design gives good results.

关键词： chemical pattern recognition materials design industrial optimization.