24 resultados para Period-cohort Analysis
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
In non-western society,researches on social development and personality change focused on economic development and social modernization. The present study is aimed at exploring the relationship between the social transformation and personality changes of Chinese people by using so-called indigenous personality measurement of CPAI (Chinese Personality Assessment Inventory). Meanwhile, the influence of CPAI measurement itself and measurement theory were also taken into consideration. In study 1, two sets of CPAI data collected in a 10 year interval were analyzed. At the same time, the CPAI-2 data was analyzed in terms of modernization level of various cities from which the data were collected. However, this study didn’t consider the importance of “equivalence” of the measurement, CPAI. In study 2, we detected DIF (Differential item functioning) across the different period groups to confirm if CPAI was equal to people in different period. In this process, both CTT and IRT method were used. The outcome reminded us that there were some DIF items. In study 3, to make sure that the personality measurement is fair to people in different period, we only saved those items whose DIF effect size lower than 0.01, and used IRT method to estimate test-taker’s personality. Then, cohort analysis was used to explore the pattern of personality change of Chinese people. In study 4, we factor-analyzed the DIF items to find the relation between social transformation and the latent personality variable which were composed of DIF items. From these 4 studies, we could got the following conclusions: (1) The CPAI 22 traits could be divided into two categories, with the changing of age, period and cohort, type I traits didn’t change, they were Logical vs Affective Orientation, Enterprise, Responsibility, Inferiority vs Self-Acceptance, Optimism vs Pessimism, Face, Family, Defensive, Graciousness vs Meanness; While with the changing of age, period and cohort, type II traits changed, they were Leadership, Self vs. Social Orientation, Veraciousness vs Slickness, Traditionalism vs Modernity, Harmony, Renqing, Meticulousness, Extraversion vs Introversion, Emotionality, Practical Mindedness, Internal vs External Locus of Control, Thrift vs Extravagance, Discipline. Meanwhile DIF items measured 5 psychologycial characteristics which changed greatly with the changing of age, period and cohort, they were Life attitude of Cynicism-realism, Psychological maladjustment, Coping style of Waiyuanneifang, Self-efficacy, the value of Individualism. (2) In sum, Chinese people in 1992 were more traditional than those in 2001, and with the 10-year of rapid development, according to the market economy’s needs, Chinese people became more individualism. (3) The DIF method of CTT and IRT were comparable. But, in generally, IRT method was more accurate and valid in detecting DIF as were as estimating personality. (4) The DIF outcomes showed that CPAI had good item validity. Meanwhile, it’s possible to develop a subscale by using CPAI items to assess some psychological characteristics. In this current study, according to their stability and variability, we could divided personality traits and psychological characteristics into 3 categories, and the outcome supported the hypothesis of “Six Factor Model”, these foundings were of some theoretic meanings. Meanwhile, as the relation between social development and personality change being explored, it certain help Chinese people cope with the rapid changing society. In this study, we also found that it’s possible to develop a subscale by using CPAI items to assess obverse personality traits and it had some practical use. Furthermore, the use of different measurement theory and cohort analysis embodied some innovation in methodology.
Resumo:
The vegetation of the northeast Qinghai-Tibetan Plateau is dominated by alpine meadow and desert-steppe with sparse forests scattered within it. To obtain a better understanding of the phylogeography of one constituent species of the forests in this region, we examined chloroplast trnT-trnF and trnS-trnG sequence variation within Juniperus przewalskii, a key endemic tree species. Sequence data were obtained from 392 trees in 20 populations covering the entire distribution range of the species. Six cpDNA haplotypes were identified. Significant population subdivision was detected (G(ST) = 0.772, N-ST = 0.834), suggesting low levels of recurrent gene flow among populations and significant phylogeographic structure (N-ST > G(ST), P < 0.05). Eight of the nine disjunct populations surveyed on the high-elevation northeast plateau were fixed for a single haplotype (A), while the remaining, more westerly population, contained the same haplotype at high frequency together with two low frequency haplotypes (C and F). In contrast, most populations that occurred at lower altitudes at the plateau edge were fixed or nearly fixed for one of two haplotypes, A or E. However, two plateau edge populations had haplotype compositions different from the rest. In one, four haplotypes (A, B, D and E) were present at approximately equivalent frequencies, which might reflect a larger refugium in the area of this population during the last glacial period. Phylogenetic analysis indicated that the most widely distributed haplotype A is not ancestral to other haplotypes. The contrasting phylogeographic structures of the haplotype-rich plateau edge area and the almost haplotype-uniform plateau platform region indicate that the plateau platform was recolonized by J. przewalskii during the most recent postglacial period. This is supported by the findings of a nested clade analysis, which inferred that postglacial range expansion from the plateau edge followed by recent fragmentation is largely responsible for the present-day spatial distribution of cpDNA haplotypes within the species.
Resumo:
Based on the study of types, even temperature, the character of age-old fluid and fluid pressure of the reservoir fluid-inclusion in the Upper Paleozoic of Ordos Basin , combining with the diagenesis and character of gas geochemistry, reservoir sequence, cause of the low pressure reservoir formation and formation environment have been studied, the following knows are acquired: Abundant fluid-conclusions have developed in sandstone reservoir in Upper Paleozoic of Ordos Basin,and its kinds is numerous , also taking place some changes such as shrinking rock, cracking, stretching after formation. According to formation cause, fluid inclusion is divided into two types:successive and nonsuccessive inclusion. Nonsuccessive inclusion is further divided into brine inclusion, containing salt crystal inclusion, gaseity hydrocarbon conclusion and liquid hydrocarbon conclusion and so on. The gaseity hydrocarbon conclusion distributes at all the Basin, the liquid hydrocarbon conclusion mainly distributes at the East of Basin, and its two kinds of fluorescence color: blue and buff reflects at least two periods of oil filling and oil source of the different maturity. The study of diagenesis has indicated that five periods of diagenesis correspond to five periods inclusion's growth.The first and second period conclusions mainly distribute at the increasing margin of quartz, little amount and low even temperature, containing little gaseity hydrocarbon conclusion; The third and fourth conclusions are very rich, and having multiplicity forms, gaseity hydrocarbon conclusion of different facies, distributing at the increasing margin and crevice of quartz, its even temperature is between 85℃and 135℃;The fifth inclusion is relatively few ,mainly distributing at vein quartz and calcite, and developing few gaseity hydrocarbon conclusion. The fluid in the inclusion is mainly NaCl brine:low and high salinity brine fluid(containing salt crystal).The former salinity is between 0.18% and 18.55%,and mainly centralized distributing at three sectongs: from 0% to 4%, from 6% to 8%, from 10% to 14%, expressing that the alternation of the underground fluid was not intense, the conservation condition was good in different periods. The trapping pressure of the gaseity hydrocarbon conclusion calculated by PVTsim(V10)simulation is between 21.39 MPa and 42.58MPa,the average is 28.99MPa,mainlydistributes at between 24 MPa and 34MPa,and having a character of gradually lower from early to late time. The pressure of SuLiGe and WuShenQi dropped quickly in early time, and YuLin, ShenMu-MIZhi gas area dropped slowly in early and quickly in late time, ha portrait the change of trapping pressure can be divided into three old-age pressure systems: TaiYuan-ShanXi formation, low ShiHeZi formation and high ShiHeZi-ShiQianFeng formation. In plane, the trapping pressure dropped lowly from south to north in main reservoir period, and this reflects the gas migrating direction in the geohistory period. The analysis of gas component and monnmer hydrocarbon isotope indicates that the gas in Upper Paleozoic of Ordos Basin is coal-seam gas. The gas C_1-C_4 rnonnmer hydrocarbon isotopes has distinct differences in different stratums of different areas, and forming YuLin, SuLiGe and ShenMu-MIZhi three different distributing types. To sum up, gas reservoir combination in Upper Paleozoic of Ordos Basin can be divided into three sets of combination of reservoir formation: endogenesis type, near source type and farther source type,and near source gas combinations of reservoir formation is the main gas exploration area for its high gas filling intensity, large reservoir size.
Resumo:
The objective of this study is to conduct a bibliometric analysis of all biological invasions-related publications in the Science Citation Index (SCI) from 1991 to 2007. The indicator citation per publication (CPP) was used to evaluate the impact of articles, journals, and institutions. In the 3323 articles published in 521 journals, 7261 authors from 1905 institutions of 100 countries participated. As the most productive country of biological invasions research, the US will benefit from more collaboration between institutions, countries, and continents. In addition, analysis of keywords was applied to reveal research trends.
Resumo:
With the widespread exposure of people to nicotine through recreational use of tobacco products, research into nicotine has attracted increasing attention. Tobacco smoking is by far the most important cause of lung cancer. As the world's largest producer and consumer of tobacco products, China bears a large proportion of the global burden of smoking-related disease; therefore, information on nicotine publications should be collected to formulate future research policy. In the present study, we investigated nicotine-related research articles published by Chinese authors that were indexed in the Science Citation Index (SCI) from 1991 to 2007. An indicator "citations per publication" (CPP) was used in the study to evaluate the impact of journals, articles, and institutes. The quantity of publications has increased at a quicker pace than the worldwide trend. Article visibility, measured as the frequency of being cited, also increased during the period. However, the overall quality of articles, based on the impact factor of journals publishing those articles, dropped behind the worldwide average level. There has been an increase in international collaboration, mainly with researchers in the USA. The average CPP of international co-authorship articles was higher than that of single country publications. Besides the USA, nicotine research in China will benefit from more collaboration with Taiwan, England, and Germany. Some 110 of 264 articles were published by a single institute, and the top six institutes were compared from various angles. Seventy-two subject categories were covered, and trends (in terms of both quantity and quality) of nicotine research in China were compared with worldwide trends. In addition, analysis of keywords in both nicotine and lung cancer research fields was applied to indicate research interests. Mutual cooperation among multiple disciplines needs further strengthening.
Resumo:
Dynamical behaviors and frequency characteristics of an active mode-locked laser with a quarter wave plate (QWP) are numerically studied by using a set pf vectorial laser equation. Like a polarization self-modulated laser, a frequency shift of half the cavity mode spacing exists between the eigen-modes in the two neutral axes of QWP. Within the active medium, the symmetric gain and cavity structure maintain the pulse's circular polarization with left-hand and right-hand in turn for each round trip. Once the left-hand or right-hand circularly polarized pulse passes through QWP, its polarization is linear and the polarized direction is in one of the directions of i45o with respect to the neutral axes of QWP. The output components in the directions of i45" from the mirror close to QWP are all linearly polarized with a period of twice the round-trip time.
Resumo:
There are seven strong earthquakes with M >= 6.5 that occurred in southern California during the period from 1980 to 2005. In this paper, these earthquakes were studied by the LURR (Load/Unload Response Ratio) method and the State Vector method to detect if there are anomalies before them. The results show that LURR anomalies appeared before 6 earthquakes out of 7 and State Vector anomalies appeared before all 7 earthquakes. For the LURR method, the interval between maximum LURR value and the forthcoming earthquake is 1 to 19 months, and the dominant mean interval is about 10.7 months. For the State Vector method, the interval between the maximum modulus of increment State Vector and the forthcoming earthquake is from 3 to 27 months, but the dominant mean interval between the occurrence time of the maximum State Vector anomaly and the forthcoming earthquake is about 4.7 months. The results also show that the minimum valid space window scale for the LURR and the State Vector is a circle with a radius of 100 km and a square of 3 degrees 3 degrees, respectively. These results imply that the State Vector method is more effective for short-term earthquake prediction than the LURR method, however the LURR method is more effective for location prediction than the State Vector method.
Resumo:
A recurrent artificial neural network was used for 0-and 7-days-ahead forecasting of daily spring phytoplankton bloom dynamics in Xiangxi Bay of Three-Gorges Reservoir with meteorological, hydrological, and limnological parameters as input variables. Daily data from the depth of 0.5 m was used to train the model, and data from the depth of 2.0 m was used to validate the calibrated model. The trained model achieved reasonable accuracy in predicting the daily dynamics of chlorophyll a both in 0-and 7-days-ahead forecasting. In 0-day-ahead forecasting, the R-2 values of observed and predicted data were 0.85 for training and 0.89 for validating. In 7-days-ahead forecasting, the R-2 values of training and validating were 0.68 and 0.66, respectively. Sensitivity analysis indicated that most ecological relationships between chlorophyll a and input environmental variables in 0-and 7-days-ahead models were reasonable. In the 0-day model, Secchi depth, water temperature, and dissolved silicate were the most important factors influencing the daily dynamics of chlorophyll a. And in 7-days-ahead predicting model, chlorophyll a was sensitive to most environmental variables except water level, DO, and NH3N.
Resumo:
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (similar to 23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (similar to 20 MYA) and Late Miocene (similar to 9 MYA) and serve as examples counter to out-of-Africa dispersal.
Resumo:
The spatial and temporal dynamics of physical variables, inorganic nutrients and phytoplankton chlorophyll a were investigated in Xiangxi Bay from 23 Feb. to 28 Apr. every six days, including one daily sampling site and one bidaily sampling site. The concentrations of nutrient variables showed ranges of 0.02-3.20 mg/L for dissolved silicate (Si); 0.06-2.40 mg/L for DIN (NH4N + NO2N + NO3N); 0.03-0.56 mg/L for PO4P and 0.22-193.37 mu g/L for chlorophyll a, respectively. The concentration of chlorophyll a and inorganic nutrients were interpolated using GIS techniques. The results indicated that the spring bloom was occurred twice in space during the whole monitoring period (The first one: 26 Feb.-23 Mar.; the second one: 23 Mar.-28 Apr.). The concentration of DIN was always high in the mouth of Xiangxi Bay, and PO4P was high in the upstream of Xiangxi Bay during the whole bloom period. Si seems no obvious difference in space in the beginning of the spring bloom, but showed high heterogeneity in space and time with the development of spring bloom. By comparing the interpolated maps of chlorophyll a and inorganic variables, obvious consumptions of Si and DIN were found when the bloom status was serious. However, no obvious depletion of PO4P was found. Spatial regression analysis could explained most variation of Chl-a except at the begin of the first and second bloom. The result indicated that Si was the factor limiting Chl-a in space before achieved the max area of hypertrophic in the first and second bloom period. When Si was obviously exhausted, DIN became the factor limiting the Chl-a in space. Daily and bidaily monitoring of Site A and B, representing for high DIN: PO4P ratio and low DIN:PO4P ratio, indicated that the concentration of Si was decreased with times at both site A and B, and the dramatically drop of DIN was found in the end monitoring at site B. Multiple stepwise regression analysis indicated that Si was the most important factor affect the development of spring bloom both at site A and B in time series.
Resumo:
Lake Dianchi is in Yunnan Province in southwestern China. In recent years, significant cyanobacterial blooms have occurred in this lake nearly every year because of eutrophication. Monitoring data for the past 5 years acquired by our research group showed that phytoplankton composition alternated between species of Microcystis sp. during warm seasons and those of Aphanizomenon sp. during cool seasons. In March 2003, when phytoplankton composition was highly dominated by Aphanizomenon sp., samples were taken from the lake for toxin detection and immediate strain isolation. A mouse bioassay with extracts from the lyophilized field material showed obvious intoxication from paralytic shellfish poisons (PSPs), and all mice died within 30 min. Further analysis of both field and isolated algal strain Aphanizomenon DC-1 by the postcolumn HPLC-FLD method confirmed its PSP-producing ability The analogues found in the extracts from the field material were neoSTX, dcSTX, and dcGTX3, with contents of 2.279, 1.135, and 0.547 ng/mg DW, respectively. Under laboratory culture condition, toxin content in the Aphanizomenon strain DC-1 varied greatly during different growth phases, with two peaks: in the early-exponential and late-stationary growth phases. When the culture grew at a relatively high rate during the mid- to late-exponential growth phase, toxin content declined gradually. Moreover, the types of toxin in the DC-1 strain varied greatly during a single culture cycle. The HPLC results showed that dcSTX was the only toxin isomer detected throughout the culture period, and its level remained stable. On the other hand, dcGTX2 and GTX4 were the major toxins during the early-exponential and stationary phases, respectively. This article presents the first data on the identification and detection of paralytic shellfish toxins from cyanobacteria in Lake Dianchi. As far as we know, this is also the first report of this type of toxin in inland water bodies in China. Our study indicates the threat associated with PSP toxins in Lake Dianchi and suggests that necessary measures and programs for control are urgently needed to prevent the spread of toxic cyanobacterial blooms. (c) 2006 Wiley Periodicals, Inc.
Resumo:
The eigenmodes confined in the equilateral triangle resonator (ETR) are analyzed by deriving the eigenvalues and the mode field distributions and by the finite difference time domain (FDTD) technique. The analytical results show that the one-period-length for the mode light rays inside the ETR is the perimeter of the ETR, and the number of transverse modes is limited by the condition of total internal reflection. In addition, the sum of the longitudinal mode index and the transverse mode index should be an even number, which limits the number of confined modes again. Based on the FDTD technique and the Pade approximation, we calculate the mode resonant frequencies and the quality factors from the local maximum and the width of the spectral distribution of the intensity The numerical results of mode frequencies agree very well with the analytical results, and the quality factor of the fundamental mode is usually higher than that of the higher order transverse modes. The results show that the ETR is suitable to realize single-made operation as semiconductor microcavity lasers.
Resumo:
By considering all possible high order diffracted waves, the authors investigate the spectral response of two-dimensional gratings for quantum well infrared photodetectors (QWIPs). A new method is proposed that using long period gratings may improve grating quality and reduce the resulting cross talk in grating-coupled QWIPs. A sensitivity analysis indicates that the influence of variation of the grating constant on the coupling efficiency is less sensitive for the long period gratings than for the short ones. A large coupling efficiency has been demonstrated for long period gratings. The calculated wide grating response spectra are in good agreement with the experiment result. (C) 1996 American Institute of Physics.
Resumo:
This study experimentally explored the fine structures of the successive period-doubling bifurcations of the time-dependent thermocapillary convection in a floating half zone of 10 cSt silicone oil with the diameter d (0)=3.00 mm and the aspect ratio A=l/d (0)=0.72 in terrestrial conditions. The onset of time-dependent thermocapillary convection predominated in this experimental configuration and its subsequent evolution were experimentally detected through the local temperature measurements. The experimental results revealed a sequence of period-doubling bifurcations of the time-dependent thermocapillary convection, similar in some way to one of the routes to chaos for buoyant natural convection. The critical frequencies and the corresponding fractal frequencies were extracted through the real-time analysis of the frequency spectra by Fast-Fourier-Transformation (FFT). The projections of the trajectory onto the reconstructed phase-space were also provided. Furthermore, the experimentally predicted Feigenbaum constants were quite close to the theoretical asymptotic value of 4.669 [Feigenbaum M J. Phys Lett A, 1979, 74: 375-378].