最新刊期
卷 55 ， 期 5 ， 2016
- 摘要：The quality of a face recognition system heavily depends on the amount of labeled training data. Bias would probably exist in both in-class and between-class scatter when there is few labeled data. Considering the cost of manual labeling is too high, an alternative choice is to make use of existing data which is related to the objective problem. In this way, it is able to alleviate the dependence of manual labeling via exploring numerous related data, offering a feasible solution to the case of lacking sufficient labeled training samples. To this end, a face transfer learning approach based on the sparse subspace clustering and robust principal component analysis is proposed, which allows employing unlabeled source data under the multi subspace assumption and mining useful information for the objective problem.关键词：sparse subspace clustering;low rank matrix decomposition;robust principal component analysis;cross-domain face transfer learning
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发布时间：2023-12-11 - 摘要：In order to avoid the staircasing effect and edge blurring problem. A variable TVpnorm was defined, and an adaptive TVp(ATVp) regularization model was proposed. Combining the AOS numerical method, a complete ATVpregularization algorithm was shown, where p can be adaptive selected according to different image areas. The characteristics make the new model preserve the edge information better and avoid the staircasing effect while image restoration. Experiments showed that compared with the existing regularization models, it improved the restoration results in both visual effects and SBR and PSNR.关键词：image restoration;ATVpregularization;AOS method
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发布时间：2023-12-11 - 摘要：The dynamic characteristics of humanoid robot are complex, coupled and nonlinear. Therefore, the balance control for humanoid robot is significant in research. The research of an intelligent humanoid service robot system is presented. Firstly, the intelligent biped humanoid robot (HUBO) is used as a test platform to analyze its balance system and gait generation based on ZMP algorithm in different situations. The control methods are also analyzed to ensure the walking balance for the HUBO. Then, using Simulink, the balance control performance is verified via simulations. Finally, the system parameters are analyzed through the simulation results to guarantee a better performance for gait balance control.关键词：humanoid robot;balance control;ZMP algorithm;gait planning
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发布时间：2023-12-11 - 摘要：Using the variant fountain theorem, a class of fractional Hamiltonian systems are studied. With establishing appropriate work space and variational structure, the existence of nontrivial solutions for the superquadratic fractional Hamiltonian systems is obtained, and the obtained results extend and improve some known results.关键词：fractional Hamiltonian systems;fountain theorem;nontrivial solutions
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发布时间：2023-12-11 - 摘要：A subgroup H of G is called 〖XCM.TIF〗subnormal in G, if there exists a subnormal subgroup K of G such that G=HKand H1K is a proper subgroup of G for every maximal subgroup H1of H. The structure of finite groups is investigated and some new results for p nilpotent groups, nilpotent groups and p supersolvable groups are obtained by using 〖XCM.TIF〗subnormal subgroups with given order.关键词：〖XCM.TIF〗subnormal subgroups;p nilpotent groups;nilpotent groups;p supersolvable groups;Sylow subgroups
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发布时间：2023-12-11 - 摘要：Silicon nitride (SiNx) film with excellent quality in both passivation and antireflection was deposited by mid-frequency (MF) magnetron sputtering process. The structure, optical property and other relevant performances of the thin films were investigated. The results show that, in the range of 300-1 100 nm, the average reflection of the textured silicon decreased from 14.86% to 5.50% and 6.58% respectively by applying two different single layer of SiNx films. The average reflection further decreased to a value of 4.03% when a multilayer of m-SiNx+ SiOxNyfilm was applied. Meanwhile, a hydrogen doped silicon nitride (SiNx∶H) film was prepared for the passivation purpose. Based on the parameter optimization, two series of the composite films including SiNx∶H (15 nm in thickness) + SiNx+ SiOxNyand SiNx∶H (30 nm in thickness) + SiNx+ SiOxNywere prepared. The average reflections of the composite films reached at 5.88% and 5.43%, respectively. The films were then applied to the crystalline silicon solar cells, an open circuit voltage of 575 mV were achieved, indicating the composite film with a good passivation property.关键词：solar cell;hydrogen doped silicon nitride;anti-reflection film;passivation film;mid-frequency magnetron sputtering
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发布时间：2023-12-11 - 摘要：In view of the traditional collaborative filtering algorithm in E-Commerce system data sparseness and scalability issues, a hybrid user and item based personalized collaborative filtering recommender algorithm in E-Commerce was proposed. Combined with user based collaborative filtering and item based collaborative filtering, the algorithm uses the clustering technology to cluster twice, and can get better performance. Experiments results show that the algorithm is superior to other recommendation algorithms obviously in the aspect of recommender quality, precision and recall rate.关键词：collaborative filtering;E-commerce;personalized recommender;cluster
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发布时间：2023-12-11 - 摘要：Numerical models of 2D twin fibers pull-out test have been created based on material meso-level heterogeneity. The influence of mechanical property of twin fibers pull-out test with embedment have been studied. Load-displacement curves, interface shear stress distribution curves and load-step-AE (Acoustic Emission) curves were obtained with various embedment depth. Crack evolution and shear stress distribution with various embedment of specimens under interface control are, therefore, investigated. The results show that the change of embedment depth has great influence on failure process and shear stress distribution. With the embedment increasing, peak load and toughness increase either.关键词：embedment;twin fibers pull-out test;shear stress;acoustic emission
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发布时间：2023-12-11 - 摘要：Principal component analysis network (PCANet) is a popular deep learning classification method, which has caused wide attention in the area of computer vision due to its practical applications in face recognition, hand-written digit recognition, texture classification, and object recognitions. On the basis of PCANet. The kernel principal component analysis network (KPCANet) method is proposed for face recognition. The model is constructed by four processing components, including principal component analysis (PCA), kernel principal component analysis (KPCA), binary hashing, and block-wise histograms. The performance of the proposed method is evaluated using two public face datasets, i.e., Extended Yale B database and AR face database. The results show that KPCANet outperforms PCANet method. Especially when the face images have large variations about illuminations and expressions, KPCANet gives better recognition results.关键词：kernel principal component analysis network;deep learning;face recognition;kernel transformation
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发布时间：2023-12-11 - 摘要：In view of the problem of big memory requirement and high computational complexity in the traditional wavelet transform algorithm, a hybrid line-based 7/5 lifting scheme wavelet transform algorithm is proposed. In the proposed algorithm, the line-based wavelet transform is used to reduce requirement of buffer in image compression, and the lifting scheme which is implemented by BT7/5 filter is used to reduce computation complex. The experimental results show that the proposed algorithm has similar the quality of compression with JPEG2000 and requires smaller memory than the traditional wavelet transform algorithm. Meanwhile, the proposed algorithm has lower computational complexity than the lines-based wavelet algorithm variant.关键词：image compression;line-based wavelet transforms;lifting scheme
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发布时间：2023-12-11 - 摘要：Based on anmino used as hydrogen transfer bridges, chiral transition mechanism of α-alanine molecule was studied under the water environment through the B3LYP methods of density functional theory and the MP2 methods of perturbation theory as well as the smd models of SCRF. The result of structural analysis suggested that the bond angles 1C-13H-14O and 18O-15H-6N between transition state aTS2·2H2O of seven membered ring and aTS2·3H2O of nine membered ring were significantly larger than that 1C-13H-14O and 14O-15H-6N of transition state aTS2·1H2O of five membered ring. There were two channels in the chiral transition reaction, in which one the hydrogen of chiral carbon used the imino N as a bridge and was transferred to the other side to achieve chiral transition, the other that was firstly transferred to carbonyl and then to the other side using amino as a bridge. Calculations of potential energy surface showed that the first channel was the dominant reaction channel, where the process of the hydrogen from chiral carbon to amino was the rate determining step and the energy barrier is reduced to 122.5 kJ·mol-1when using three water molecules as transfer media. The water molecules had good catalytic effect on the proton transfer in α-Ala molecule, and the solvent effect on water made the energy barrier of the non proton transfer reaction increase slightly.关键词：chiral transition;α-Ala;density functional theory;perturbation theory;SCRF;transition state
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发布时间：2023-12-11 - 摘要：In the present study, 15 derivatives of protoberberine (3-17) along with berberine (1) and jatrorrhizine (2) were evaluated for their antineoplastic activities against acute lymphoid leukemia cells (including Reh and Nalm-6 cells) in terms of proliferation inhibition. Compounds 4 (9-bromoethylberberine), 5 (9-chloroethylberberine) and 6 (9-bromopropylberberine) showed most significant inhibitory activities with IC50values of 0.45, 0.39, and 0.57 μmol/L against Reh cells, while Nalm-6 cells were less sensitive to 4,5,6, with IC50values of 3.6, 4.3 and 1.17 μmol/L, respectively, which were both stronger than that of the lead compound berberine (1) and jatrorrhizine (2) (> 20 μmol/L, respectively). Furthermore, 4 and 5 could induce apoptosis in acute lymphoid leukemia cells as evidenced by cleavage of PARP in a dosedependent manner, decrease of procaspase-3, increase of active caspase-3 and increase of the levels of cytochrome c in cytoplasm. Moreover, the Reh cells treated with 4 and 5 at the concentration of 0.5 μmol/L for 36 h could significantly lead to the down regulation of β-catenin, and the result demonstrated that the mechanism of the derivatives on tumor were partially involved in the Wnt/β-catenin signal pathway. A PAMPA permeability study of 1, 4, 5, 7 and 11 suggested that side chain substituted derivatives in 9-position could improve the membrane permeability of berberine. It will be helpful for application in vivo assay. These findings suggest that these derivertives may be considered for future studies as promising therapeutic candidate for acute lymphoid leukemia.关键词：protoberberine;derivatives;antineoplastic activities;PAMPA;apoptosis
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发布时间：2023-12-11 - 摘要：The NiSe2nanotubes were synthesized at room temperature using t-Se nanotubes as a template and N2H4·H2O as a reductant in alkalescent solution. The structure of the NiSe2nanotubes was characterized using scanning electron microscope (SEM), X-ray powder diffraction (XRD) and X-ray photoelectronic spectroscopy (XPS). The formation mechanism of NiSe2nanotubes was investigated. The electrochemical property of NiSe2nanotubes was researched by cyclic voltammetry method in different medium solution.关键词：room temperature;NiSe2;electrochemical
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发布时间：2023-12-11 - 摘要：One neutral iridium (Ⅲ) complex Ir(ppy)2(fppy) (ppy = 2-phenylpyridine, fppy = 4-(2-pyridinyl)benzaldehyde) was synthesized, and the structure was characterized by single crystal X-ray diffraction analysis as well as EA, MS and NMR. The photophysical property of the complex was studied by UV-visible absorption spectroscopy, fluorescence emission spectroscopy and the fluorescence lifetime both in solid state and solution at room temperature. In addition, the electrochemical property of the complex was studied by cyclic voltammetry.关键词：iridium (Ⅲ) complex;synthesis;photoluminescence;crystal structure
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发布时间：2023-12-11 - 摘要：Land cover classification system is the basis for urban landscape studies. In recent years, the rapid development of earth observation technique provides the researches of land cover with a great amount of remote sensing images with high resolution. Many scientists have established various types of systems base on the distinguishing features of different remotely sensed data, but none of which can be used pervasively or be widely recognized in the international academia. In this paper, we proposed a classification system based on the sharpened GF-1 data with 2 meter resolution and fit for the urban area. We took Guangzhou city as an example to illustrate the application of this classification system. In this classification system, we focus on the characteristics of urban ecosystem and make it a hierarchy system without overlapping within the classes. The first two layers of the system are solid and classified with certain scientific basis, and the third layer is open for different uses. We divided the first layer into 4 parts, which include: buildup area, vegetation, water and bare land. The second layer combined with residential and commercial area, industrial district, road; forest, bush, grass, paddy field; river, pond etc. The classification results reach the precision of 90.1% and cover all parts of layer two, which is technically practicable.关键词：urban land cover;classification system;GF-1;landscape classification
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发布时间：2023-12-11 - 摘要：Based on samples collected with CTD water sampler at a depth of 5 m from 18 sites in southern South China Sea during later autumn, 2013， species composition and abundance of planktonic ciliate and its relationship with the environment variables were investigated. A total 17 species belonging to 10 genera and two orders (Tintinnida and Oligotrichida) were identified. Among them, there were five dominant species (dominance Y≥002), including Rhabdonella sanyahensis, Strombidium conicum, Eutintinnus stramentus, Codonellopsis morchella, Strombidium globosaneum. The mean abundance of ciliate was (36.5±3.8) ind./L (10~80 ind./L). Ciliates abundance distribution presents a patchy distribution, and the distribution of planktonic ciliates may be closely related to ocean circulation. Canonical correspondence analysis demonstrated that the nutrient level and Chlorophyll a concentration were the most important factors affecting the spatial pattern of planktonic ciliate communities in southern South China Sea.关键词：planktonic ciliate;southern South China Sea;community structure;environmental factors;multivariate analysis
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发布时间：2023-12-11 - 摘要：Protein loaded CA-gel／PLGA composite microspheres were prepared by a novel SPG membrane emulsification method, which was modified from the traditional preparation method of PLGA microspheres. The formation of the sustainedrelease gel was based on the ionic interaction between Sa and calcium ion. The drug loading of composite microspheres was significantly increased from 6.94% to 8.35%, entrapment efficiency was increased from 62.47% to 75.16%，and the burst release rate was declined from 42.32% to 30.84%. Drug release test showed that nearly 40.29% of drug was continuously and steadily released from the composite microspheres in 2~40 days. The drug release curves were corresponded to Peppas-Sahlin equation (R2> 0.99) for both the traditional microspheres and composite microspheres, which means that the release mechanism was mainly diffusion and dissolution. The results from scanning electron microscopy and freezing microtomy demonstrated that the composite microspheres were more compact in structure, and its surface hole number and porosity were smaller than traditional PLGA microspheres. The enhanced fluorescence intensity was observed from the laser confocal scan microscopy, indicating that more protein drugs were wrapped inside composite microspheres. In conclusion, the CA-gel／PLGA composite microspheres can effectively increase drug loading and entrapment efficiency and reduce the burst release.关键词：SPG membrane emulsification;CA-gel/ PLGA composite microspheres;entrapment efficiency;burst-release
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发布时间：2023-12-11 - 摘要：The purpose of study is to establish a method to improve the ethanol output by saccharification and fermentation of food waste in an order to realize the industrialization in the future. By the way of combining two or three kinds of enzymes to obtain an optimization, it was shown that positive synergism effect was observed between glucoamylase (120 U/g) and isoamylase (300 U/g), and the glucose concentration in the hydrolysate reached 130.29 g/L. Simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF) of food waste have been conducted using Saccharomyces cerevisiae CICC 1346 and 120 U/g of glucoamylase and 300 U/g of isoamylase. The yields of ethanol in SSF and SHF were 49.48 and 45.89 g/L, and the conversion rates from glucose to ethanol were 91.7% and 77.1%, respectively. Compared to the SHF process, the SSF one was easier to operate and showed shorter fermentation period but higher ethanol production rate, which makes it more suitable for industrial application.关键词：food waste;isoamylase;SSF;SHF;ethanol
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发布时间：2023-12-11 - 摘要：There has not been an agreement reached for a long time on the occurrence, host rocks and genesis of primary diamond deposits beneath the Yangtze Craton, China. In this paper, the surface features and FTIR of 199 macro diamonds from lamproite rocks and 16 diamonds from the surrounding river basins in Zhenyuan collected by No.101 Guizhou Geological Brigade were studied by non-destructive techniques including FTIR spectroscopic techniques, aiming at finding out valuable geological prospecting information/indication. The results showed that most primary diamonds are small in size and fragmentized, and are characterized by strong dissolution features or attaching materials on surface. Most diamonds display blue-white fluorescence other than phosphorescence. FTIR results confirmed the majority of the diamonds are type IIa, but their proportion is less than previous estimation and observation. Compared with Hunan and Guizhou placer diamonds, it is believed that the host lamproite rocks of the primary diamonds in Zhenyuan is not the primary source of those placer diamonds discovered in Guizhou and Hunan provinces. Based on field survey and research of the geological occurrence, it is concluded that lamporite rocks in Zhenyuan may be shallow phase rather than deep root phase, implying it has the potential to discover new primary diamond deposits in Guizhou.关键词：primary diamonds;lamporite;exploration;the Yangtze craton;Guizhou province
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发布时间：2023-12-11 - 摘要：On the basis of the meteorological database including monthly cumulative sunshine hours, temperature and precipitation (1971-2013) from Qinyang Meteorological Bureau, Henan province, the climatic change characteristics and its effect on the growth and production of the Huai medicine were analyzed by the methods of moving average, M-K mutation test and multiple linear regression. The results showed that the average temperature increased at the average speed of 0.3 ℃/10 a in the period of the Huai medicine growth. The average temperature increased 0.4 ℃ /10 a and 0.5 ℃/10 a in winter season and spring season, respectively. Accumulated temperature ≥10℃ presents significantly increasing trend （P＜0.05）and delaying sustained time. The mean annual precipitation decreased slightly. The seasonal distribution of precipitation was corresponding to the water requirement of the Huai medicine in different growth processes，and the frequency of strong precipitation has decreased, which resists the decaying roots or tubers to a certain extent. The cooperative function of the atmospheric temperature and precipitation significantly affects the production of the Huai medicine (P<0.05) in the growth period and in the inflated period of roots and/or tubers. The atmospheric temperature change comprised a crucial factor on the Huai medicine production in Qinyang County. To ensure the Huai medicine quality, production and the market demand, the responding measures need to be adopted in the Huai medicine origin region with the global warming.关键词：climate change;Huai medicine;strategies;origin region
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发布时间：2023-12-11 - 摘要：Based on the meteorological data of 15 stations in Anhui province, influences of different disaster inducing factors on drought and flood were analyzed by using linear regression, Mann-Kendall test method, wavelet analysis and Z index to explore the trend of drought and floor in this province under global warming condition. The results showed that: ① Anhui has experienced a series of climate phase transformation from cold-dry to cold-wet, warm-wet, and warm-dry during recent 53 years, with warming and wetting trend on the whole, but warming and drying since the 21th century. ② The summer and winter precipitation shows an upward trend, while the autumn and spring precipitation decreases; summer precipitation increase makes the largest contribution to the precipitation changes. On the time scale, there are 28, 22, 14 and 4 year oscillation cycles. ③ Droughts and floods in recent 53 years present a seriously overall downward trend, with alternation of floods and droughts and an obvious inter-decadal variation. ④ In the aspect of spatial distribution, droughts mainly occur at the juncture of Wanxi area, while floods mainly occur in the Huaihe River and the Yangtze River downstream.关键词：climate change;drought-flood;Z index;Anhui province
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发布时间：2023-12-11 - 摘要：Based on the statistics and analysis of snow disasters in historical documents in Shanxi province during historical period, the temporal and spatial variations of snow disasters were obtained by using least squares, wavelet analysis and Kriging method. There are 208 recorded snow disasters in Shanxi province, approximately once every 13.125 years on average. The mild, moderate and severe disasters accounted for 16.83%, 72.60% and 10.58%, respectively. Wavelet analysis showed that snow disasters had 5 and 23-year oscillation period and the 23-year oscillation period was the strongest. The snow disaster in Shanxi province showed an increasing trend during the historical period. In April and winter season, snow disasters occurred most frequently, accounting for 15.76% and 34.47% of the total, respectively. The spatial distribution of snow disaster was different, mostly distributed in southern area. It can be concluded that snow disasters were closely related to the climate change; snow disasters occurred most frequently during the Ming and Qing Dynasties; modern time is a period of frequent occurrence of snow disasters.关键词：snow disaster;Shanxi;historical period;temporal and spatial distribution;cold climate
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发布时间：2023-12-11 - 摘要：Improved curve Northam theory was used to classify the urbanization levels of five national urban agglomerations in China along their urbanization development track. The results showed that the Yangtze River Delta and the Pearl River Delta urban agglomerations are of a higher urbanization level and have entered into the maturity and quality improvement stage, and the Beijing-Tianjin-Hebei urban agglomeration shows internal difference and large development space. The Chengdu-Chongqing and the middle Yangtze River urban agglomerations show great potential in urbanization development even though they started urbanizing relatively late. Five national urban agglomerations faces such problems as falsely high urbanization rate, difficulties for floating population to become urban residents, mismatch between the level of urban agglomeration and economic status and lack of basic public infrastructure and facilities. The urbanization development approach under the newtype urbanization framework in the future is one keeping ecological civilization concept throughout the whole process of new urbanization construction, adhering to industry development drive, coordinated development of new type of urbanization and modernization, scale and extensive urbanization transition to intensive development of new urbanization.关键词：agglomeration;development track;new-type urbanization;approaches research
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发布时间：2023-12-11
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