最新刊期
卷 58 ， 期 6 ， 2019
- 摘要：This study is aimed to address the main deficiencies in the quality standard of Citri Grandis Exocarpium (CGE) in current Chinese Pharmacopoeia, including the confusion of the plant origins and the inconsistency between the actual and the specified medicinal parts. Based on large amounts of historical evolution studies, market researches and testing results, several suggestions were proposed as follows: Citrus grandis‘Tomentosa’ (CGT) was the original plant source of CGE while (L.) Osbeck (CGO) was used as a substitute when shortage of CGT resources. However, there were great differences between the chemical compositions and contents of CGT and CGO, and thus it is necessary to make them distinguished. We suggested that CGT should be used as the only plant origin of CGE. Meanwhile, the medicinal parts of CGE gradually transformed from the epicarp to immature fruit during the practical process, the immature fruit had the same chemical compositions with epicarp and higher contents of the active components. So we suggested supplementing the medicinal parts of CGE with immature fruit. Furthermore, we established the grade standard of CGE, which could be applied to distinguish the plant origins and evaluate the quality grades. In conclusion, this study provides suggestions for the improvement of the quality standard of CGE, which is of great significance for standardizing its marketing activities, promoting the rational use of plant resources and accelerating CGE into the international market.关键词：Citri Grandis Exocarpium;plant origin;medicinal part;grade quality standards
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发布时间：2023-12-11 - 摘要：The metabolites by solid fermentation of the symbiotic fungusFusariumsp. ZMT01 from the intestinal tract ofOxya chinensisThunber were studied. The molecules were isolated from the ethanol extract by the modern chromatography technology. Their structures were elucidated by spectral methods. The antifungal activities were evaluated using the dilution method. Eight compounds were isolated, they are, are,3-phenylcyclopent-2-en-1-one(1),2-hydroxy-3-phenylcyclopent-2-en-1-one(2),kojic acid(3), kojic acid monomethyl ether(4),(S)-5-hydroxy-2,6-dimethyl-4H-furo[3,4-g]benzopyran-4,8 (6H)-dione(5),7,8-dimethylbenzo [g] pteridine-2,4(1H,3H)-dione(6),(9Z,11E)-8,13-di-hydroxyoctadeca-9,11-dienoicacid.(7)andstigma 7,22-dien-3β,5α,6α-triol(8). Among them, compounds1and2were first isolated as natural products. The1H NMR and13C NMR data of compound2were also reported firstly. Compounds 5-7 were obtained fromFusariumsp. for the first time. Compound 5 exhibited high inhibitory activities againstFusarium graminearumSchw. and ColletotrichumgloeosporioidesPenz..关键词： Fusariumsp.Oxya chinensisThunber
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发布时间：2023-12-11 - 摘要：This work investigated the protein expression levels of moving rat liver under the exposure of PM2.5 by using different loading swimming training modes. The result provides a theoretical basis for the effects of aerobic exercise on liver function in the exposed environment of PM2.5. The rat training modes under the PM2.5 exposure were set up as follow:PM2.5exposure section (E), low exposure section (LES), middle exposure section (MES) and high exposure section (HES) Elisa method was applied to detect the expression level of TNF-α and Western blot assay was used to evaluate the protein expression of PPAR-γ. The results showed that the TNF-α of MES was lower than that of other sections with the -effective-statistical significance atP<0.05. The PPAR-γ expression levels of LES and MES were significantly higher than that of E with the effective statistical significance at P<0.05. Therefore, under the exposure of PM2.5 , moderate-intensity training could effectively stimulate the cell factor and promote the signal deliver between Islet cell, as a result, the functions of the liver can be influenced.
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发布时间：2023-12-11 - 摘要：The study investigated the chiral enantiomer transition of α-alanine zwitterion and the catalysis of water molevules(clusters) in water/liquid phase environment by using the WB97X-D method based ondensity functional theory dispersion correction and MP2 method for multibody perturbation theroy, and combining with the study of reaction channel showed that the chiral enantiomer transition of monomer α-alanine zwitterion in water/liquid phase environment had one channel, and that had two channels when water molecules (clusters) acted as proton transfer carrier. Calculation of the potential energy surface showed that the activation energy of chiral enantiomer transition of monomer α-alanine zwitterion was 281.6 kJ/mol, and that was reduced to 146.1 and 141.8 kJ/mol by the catalysis of two and three water clusters, respectively.The results showed that the catalysis of water molecules clusters in water/liquid phase environment can enable α-alanine zwitterion to realize chiral enantiomer transition in trace amount
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发布时间：2023-12-11 - 摘要：Disaster induced by softening of saturated red-bed soft rocks is one of the major problems encountered frequently in the engineering construction in South China area. Three tests were conducted using the self-developed TAW-100 meso-mechanical triaxial test system of soft rock, including a disintegration test of soft rock in water, a creep test of soft rock under hydro-mechanical coupling condition and a triaxial test by observing the whole deformation and failure process of cracked soft rock under hydro-mechanical coupling condition. The mechanical failure behaviors of saturated soft rock in different engineering environments were investigated to analyze the influences of water, loading, cracks and their coupling effect on mechanical properties of soft rock. Results showed that the process of disintegration and failure of soft rock includes the stages of new crack initiation, slow development, accelerating expansion to penetration and failure. The characteristics of creeping stages of soft rock were consistent during the whole creep process. The coupling effect of water, stress and cracks will accelerate the deformation and damage of soft rock and influence the local mechanical characteristics, the duration of each stage and the final failure mode. The energy transformation and energy dissipation of seepage, chemical and damage in the whole process of soft rock softening under waterstressfracture interaction are analyzed based on the energy theory.关键词：red-bed soft rock;coupled hydro-mechanical;crack propagation;creeping;deformation and failure
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发布时间：2023-12-11 - 摘要：The morphological characteristics of coarse grains of residual granite soils have a significant impact on their engineering mechanical properties. However, accurately and quantitatively characterizing the real and complex shapes of soil particles one by one has always been one of the main difficulties in the study of constitutive models and numerical models. To find statistical laws from disordered and irregular geometric characteristics of soil particles seemingly based on statistical mechanics, the maximum projection profile of extensive coarse particles in four grain groups was obtained by means of optical microscopy and digital image processing, and then using Fast Fourier Transform (FFT) method to obtain Fourier descriptorsDnwhich contains all the morphological information of particle contour. The particle profile can be reconstructed accurately and randomly with amplitudeCnand phase φn. On the basis of analyzing the statistical mechanics law of particle geometry, the geometrical morphology of coarse grains, including mean elongation, angularity and surface texture, was quantitatively described for residual granite soils in South China in four particle size intervals. Finally, the difference of grain morphological parameters between undisturbed residual granite soil, alluvial river sands and offshore alluvial quartz sands was discussed. The results show thatD2of 0.5-1.0 mm coarse grains is the largest andD2-D85-10 mm coarse grains is the smallest, which means that the larger the coarse particle size of residual soil or alluvial soil is, the higher the regularity of the particles is. Compared with the coarse grains in alluvial river sands and sea sands, the values ofDn(n>8) reflecting meso-and micro0scopic characteristics of grain surface roughness in each grain size range of granite residual soil are basically similar, for having not experienced longterm transportation. The larger coarse grains in alluvial sands with low values ofDn(n>8) are mostly rock debris, and the mineral components are mainly amphibole and epidote. This indicates that they are rounded in the process of transportation, which reduces the degree of surface roughness. However, the value ofDn(n>8) of 0.5-1.0 mm granular group is basically the same as that of each granular group of granite residual soil, and the surface roughness is higher, which is related to the higher quartz content in the coarse grains of the two groups. This indicates that the fracture and destruction of quartz particles will occur in the process of transportation. The particles are broken into small ones, but their surface will not be ground round. And the geometric characteristics of soil particles are affected by the mineral composition of particles. A linear relationship between log (Dn) and log (n) is found in double logarithmic coordinates. The model parameters of different kinds of soils are calculated to characterize the geometrical shape of coarse particles in different types of soils quantitatively, which lays a foundation for the subsequent discrete element modeling of coarse particles.关键词：residual granite soil;coarse particles;FFT;Fourier descriptors;morphological characteristics
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发布时间：2023-12-11 - 摘要：The spatial distribution and network characteristics of airports in mainland China were analyzed, then improved average travel time was used to analyze airport accessibility and correlation analysis method is adopted to study transport, service, operations and environment. The results showed that airports density in the east is larger than that in the west region. There are 27 airports with more than 1 000 flights in a week, among them 22 airports are located in provincial capital cities, and only 5 airports are in non-provincial capital cities, i.e. Shenzhen, Xiamen, Dalian, Qingdao and Sanya, respectively. The top three of the busiest routes are those between Shenzhen-Beijing, Shenzhen-Shanghai and ShanghaiBeijing, and main departure & destination cities for the top 20 of the busiest routes are Shanghai, Beijing, Shenzhen, Chengdu, Chongqing, Guangzhou and Xiamen. From the perspective of accessibility, eastern regions show higher accessibility than western regions in China. High accessibility areas include Beijing-Tianjin-Hebei, the Yangtze River Delta and the Pearl River Delta. Furthermore, the airport accessibility is often affected by transport, service, operations and environment, among which the most important factors are related to number of connected airports, outbound flights in peak hours, outbound domestic direct-flights and actual outbound flights. The correlation values are 0.706, 0.822, 0.777 and 0.808, respectively. The accessibility also has a strong correlation with number of parking, number of runways, GDP and population, with correlation values of 0.776,0.701,0.679 and 0.695, respectively.关键词：airport;spatial distribution;density;accessibility;correlation
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发布时间：2023-12-11 - 摘要：The regional air quality model WRF/CMAQ combined with sensitivity tests was used to study the reduction of ozone pollution peak in Foshan, a city in the center of the Pearl River Delta (PRD). Sensitivity tests based on the WRF/CMAQ model included reducing the emissions of two O3precursors (VOCs and NOx) and reducing the emissions from traffic, industries (excluding solvents), and solvents in Foshan, respectively. The results showed that the ozone pollution in Foshan City was most sensitive to VOCs. Reducing the emission of VOCs by 30% decreased the ozone peak concentration by up to about 10%. However, the reduction of NOxemissions increased the ozone concentrations in some areas. Reduction in emissions of traffic and industrial sectors led to increase or decrease of ozone concentrations in different areas because VOCs and NOxemissions were reduced simultaneously. The major emission species in the solvent industry were VOCs. It could significantly decrease ozone peak concentration when reducing the emissions of the solvent industry. Therefore, the solvent industry was the key sector of ozone peak reduction. This study also conducted sensitivity tests of reducing emissions for different days ahead. The results showed that the effects of reducing emission for 1-day in advance were better than 0-day but not significantly different from 2-day and 3-day in advance. In conclusion, reducing emissions 1-day in advance was the most effective and economical control strategy to reduce the peak of ozone in Foshan city area.关键词：WRF/CMAQ model;ozone pollution;sensitivity experiment
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发布时间：2023-12-11 - 摘要：For the research on the safety limit of nuclear power plant containment under extreme conditions (i.e. being subjected to earthquake and internal pressure simultaneously), a detailed three-dimensional finite element model for containment of CPR1000 was established. Considering the nonlinear properties of materials, the acceleration, displacement and strain responses of nuclear containment under seismic load, internal pressure and combination of them were simulated by ABAQUS software. As the result has shown: 1)When the concrete cracking area of the containment penetrates the inner and outer layers, the nuclear leaks may occur, which is regarded as the safety limit of the containment. So when the internal pressure is applied only, the anti-pressure safety limit of the containment is 120 kPa. 2)Comparing with the containment under the seismic load of 0.2 g simultaneously, the safety limit becomes 100 kPa, which decreases by 16.7%. 3)Likewise, the seismic safety limit of containment is 0.4 g when there is only seismic load. But when it is subjected to internal pressure of 50 kPa, limit downs to 0.3g, which is reduced by 25 %. 3)In addition, the acceleration and displacement responses of the containment have no much change under the simultaneous load of the internal pressure below 100 kPa and the earthquake below 0.4 g, comparing with applying them respectively.关键词：nuclear power plant;containment vessel;nonlinear;seismic response;internal pressure
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发布时间：2023-12-11 - 摘要：Orthogonal experimental method was used to optimize the electrical injection regeneration conditions of boron-doped p-type monocrystalline silicon PERC solar cells to decrease their LID (light induced degradation) effects. The variation of efficiencies of the PERC solar cells before and after regeneration and during the subsequent 12 h LID was measured by a VS-6821M solar cell I-V tester, and the ratio of the efficiency after 12 h LID to the initial efficiency before regeneration was used as the standard for discerning good regeneration condition from bad one. Threelevel orthogonal experimental results show that whether the interaction is considered or not, the optimal regeneration conditions are both 30 min,170 ℃,18 A under the studied parameter range (10-30 min，140-200 ℃，6-18 A). On this basis, the optimal regeneration condition was further optimized to 30 min,175 ℃,18 A by using five-level orthogonal experiments. The efficiency of a PERC solar cell regenerated using the optimal processing condition increases by 1%-2% relative to the initial value before regeneration, and remains stable in the following 12 h light soaking at 1 Sun light intensity and 45 ℃, and the efficiency after 12 h LID process is still about 1% higher than the initial efficiency.关键词：boron-doped Czochralski silicon;PERC solar cell;light induced degradation (LID);regeneration;orthogonal experimental method
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发布时间：2023-12-11 - 摘要：Solid fluidization cutter suction mining technology is one of the solutions to the bottleneck of gas hydrate production in the surface of the seabed. The cutter suction head is the core component of the cutter suction mining, and the single tooth parameter is the key to determine the breaking performance of the cutter suction head. Using the substitute sample and the singletooth linear simulation cutting device, the experimental research on the influence of the singletooth structure parameters and process parameters of the cutter head on the single-tooth load and the particle size of the broken particles was carried out. The results indicate that the load of a single tooth increases binomially with the increase of the cutting width, and decreases with the increase of the front edge angle. The particle size of the broken particles increases with the increase of the single tooth width, and decreases with the increase of the front edge angle. The crushing effect of the front edge angle of 60° is the best. The distribution of the side inclination to the single tooth load and the broken particle size is affected by the brittle collapse of the groove wall.关键词：marine gas hydrate;cutter suction exploitation;cutting head singletooth;working load;particle size distribution
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发布时间：2023-12-11 - 摘要：In this paper, the seepage finite element method (FEM) is used to simulate the transient seepage of Beijiang dike, and anti-seepage solutions is designed and optimized.Firstly, the measured data of pressure gauge tube are compared with the steady-state calculation model, and the calculated results are basically in agreement with the measured data.Then, the transient seepage field after the sudden rise of water level in a short time is calculated. Finally, relief wells are selected as seepage control measures and optimized. The results show that higher safety measures should be made for transient at the same level as steady state. When the water level is 15.78 m, the slope reaches 0.5, and the embankment is damaged. The drainage and decompression effect of relief wells is greatly affected by penetration depth. With the increase of penetration depth, the effect of drainage and decompression in the same permeability coefficient soil layer increases gradually, and the effect of drainage and decompression in the depth of 3/5 and 4/5 is relatively small due to geological strips. Due to the different geological conditions, the same relief wells are placed in different positions with a wide gap in effect.，the anti-seepage effect is the best when the horizontal distance is 95 m, and the effect is the best when the depth is 16.5 m.关键词：dike engineering;seepage analysis;relief well;numerical simulation
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发布时间：2023-12-11 - 摘要：This paper considers a non-orthogonal multiple access (NOMA) network consisting of a multi-antenna base station, multiple users and an information receiver. The working process of the network can be divided into two phases, namely downlink wireless power transfer phase and uplink information transmission phase. In the downlink wireless power transfer phase, the base station transfers power wirelessly to the users, and in the uplink information transmission phase, the users use their harvested energy to transmit information to the information receiver in a NOMA manner. When the users initial energy is low and thus cannot support its communication requirement, the wireless power transfer phase will be activated. We investigate the activation condition of the wireless power transfer phase. Furthermore, to maximize the throughput of uplink information transmission, we jointly optimize the time allocation between the downlink and uplink, the energy covariance matrix of wireless power transfer at the base station and transmit power of the users. Based on the Lagrangian multiplier method, we propose an optimal algorithm to find the solution to the considered problem in closed-form. Simulation results show that the proposed algorithm achieves much higher throughput performance than some benchmark schemes.关键词：non-orthogonal multiple access;wireless powered communication networks;activate condition;throughput;resource allocation
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发布时间：2023-12-11 - 摘要：Measures of controlling traffic operation and emissions are developing to be dynamic and detailed. We applied the dynamic speed data of social vehicles from traffic real-time platform and GPS data of buses from practical tests, then used LWLR (Locally Weighted Linear Regression) to forecast average speeds and operating mode distributions of some urban buses in Guangzhou. Finally a model for estimating emission factors (for liquefied natural gas buses) and electricity consumptions (for electric buses) was built. The results showed that, the average speeds of buses were positively correlated with those of social vehicles. The operating mode distributions under different average speeds had regular patterns. With the increase of the average speeds of buses, the frequency of Bin1 (idling mode) decreased, the frequencies of Bin11-12 increased firstly and then decreased, and the frequencies of Bin13-15 (denoted low speed and acceleration) were partly transformed to those of Bin16-17 (denoted high speed and acceleration). The proposed algorithm reflected the no-linear trend that the speeds of buses increased with that of social vehicles, and the mean absolute percentage error of speeds of buses was 1985%. The mean absolute percentage errors of NOxemission factors and electricity consumptions of buses were 20.27% and 26.52%.关键词：bus;social vehicle;operating mode;emission factor;electricity consumption
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发布时间：2023-12-11 - 摘要：To study the symmetry and conserved quantity of fractional non-conservative dynamic systems, the Noether theorem based on El-Nabulsi periodic law quasi-fractional model in event space is proposed and studied. Firstly, the fractional order variational problem based on the El-Nabulsi periodic law quasifractional model is established in the event space, and the differential equations of the holonomic nonconservative system and the nonholonomic nonconservative system are derived. Secondly, based on the invariance of the action functional under the infinitesimal transformation, the definition and criterion of the Noether symmetric transform and the Noether quasi-symmetric transformation are given. Finally, the Noether theorem based on the El-Nabulsi periodic law quasifractional model in the event space is proposed and proved. Two examples are given to illustrate the application of the results.关键词：event space;Noethers theorem;quasi-fractional model;fractional integral extended by periodic laws
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发布时间：2023-12-11 - 摘要：LetGbe a graph withnvertex, and A(G) be an adjacency matrix of a graphG. Then the polynomial π(G，x)=per(xI－A(G))is called the permanental polynomial ofGwhereIthe unit matrix of ordern. The permanental sum ofGis the sum of the absolute valutes of the cofficients ofπ(G，x). The unicyclic graphs havingIth minimal permanental sum are determined, whereI=3,4,5,6,7.关键词：unicyclic graph;permanental polynomial;permanental sum
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发布时间：2023-12-11 - 摘要：In pertinent literature, the Suzuki type common fixed point theorem in complete metric space has been established. Based on this theorem, the Suzuki type common fixed point theorem for two mappings in a completeb-metric space is established.
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发布时间：2023-12-11
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