Q value of anelastic S-wave attenuation in Yunnan region

The study of seismic attenuation property is a major subject in seismology. Seismic waves recorded by seismic stations （seismographs） contain source effect, seismic wave propagation effect, site response of seismic stations and instrumental response. The path effect of seismic wave propagation, site response of seismic stations and instrumental response must be taken out in the study of source property with seismic data. The path effect of seismic wave propagation （seismic attenuation） involves an important influential factor, the anelastic attenuation of medium, which is measured with quality factor Q, apart from geometric attenuation with the distance. As a basic physical parameter of the Earth medium, Q value is essential for quantitative study of earthquakes and source property （e.g. determination of source parameters）, which is widely used in earthquake source physics and engineering seismology.

Time Course of Q Value after Myopic Laser-assisted In Situ Keratomileusis

Objective To assess the time course of Q value after myopic laser-assisted in situ keratomileusis(LASIK) and preliminarily evaluate the determinants of the difference of Q value between before and after LASIK.Methods We performed a retrospective,longitudinal investigation on patients undergoing wavefront optimized LASIK therapy for emmetropization.A total of 418 eyes from 222 cases were examined preoperatively,and partly followed up at one week(172 eyes),one month(134 eyes) and three months(51 eyes) after surgery.The horizontal,vertical and total Q values of cornea were calculated from eccentricity measured at the central 6-mm corneal zones respectively.Potential determinants of the change of Q value were analyzed using multiple linear regressions.Results The mean Q value was-0.17±0.13 preoperatively,and 0.99±0.70,0.97±0.66,and 0.86±0.41 one week,one and three months postoperatively,respectively.One way analysis of variance(ANOVA) demonstrated significant differences between measurements made before surgery and at all postoperative times(at one week,one and three months;all P<0.0001,Bonferroni post hoc),but no significant differences were found among postoperative groups.Significant differences of Q values between horizontal and vertical meridians were found before surgery and at all postoperative times(all P<0.0001).Multiple regression analysis revealed that change of Q value significantly correlated with manifest refraction spherical equivalent(r=0.116,P<0.0001) and axial length(r=0.264,P<0.0001).Conclusions Over the study period,the primary changes in Q value occur within 1 week after surgery,and then become slightly decreased and nearly stable.Manifest refraction spherical equivalent and axial length play a significant role in the change of postoperative Q value.

On Q Values and Other Energy Parameters for Superheavy Element Synthesis

Q value and optimal exciting energy of hypothetical superheavy nuclei in cold fusion reaction are calculated with relativistic mean field model and semiemperical shell model mass equation (SSME) and the validity of the two models is tested. To give useful references for the experiments in the superheavy nuclei synthesized in cold fusion reactions,the Q value, fusion barrier and optimal exciting energy for the possible target plus projectile combinations suggested by Gupta et al. are calculated and the most possible target plus projectile combinations are pointed out according to our calculations.

The Q value variations in the preparing pro－cess of rock rupture

In this paper, the 'spectral amplitude ratio method'(SAR) , 'energy method'(EN) and 'coda wave method'(CW) are used to calculate the Q value variations of gneiss in the preparing rupture process. The obtained results show that the variation state of Q values by SAR features the shape of relative stability gradual increment to the maximum then decrement and final rupture.The variation state of Q values by EN is just contrary to that by SAR,i.e.with the shape of stability decrement increment and final rupture . The varation state of Q values by CW is similar to that by EN, its main frequency features the shape of relatively high value decrement to the minimum increment and final rupture.But to the high frequency (higher than the main frequency),the variation state of Q values features the shape of the stable value increment to the maximum decrement and final rupture.At the same time, the results by coda wave amplitude spectrum show that, when stress reaches 70% of rupture stress, the high frequency component of S wave rapidly reduces( Q c increasing); at the time of impending the main rupture, the main frequency component reduces with a large scale( Q c increasing again), this may be the reason which causes the different variation states of two coda Q values.The result of amplitude spectra of P, S(initial wave) waves also show that with the appearance of microcracks the frequency band of S wave turn to be narrow, the high frequency component is reduced quickly, i.e. the S wave spectra have different variation states with different frequeny components. That is why the Q s obtained by different methods have different variation characteristics.

Lg coda Q_0 value and its relation with the tectonics in Chinese mainland and adjacent regions

We have collected 432 vertical component records from 45 stations of new CENC （China Earthquake Network Center） in Chinese mainland and adjacent regions. These records were used to calculate Q0 （Q at 1Hz） and η values of Lg coda from each station by the stack spectral ratio （SSR） method. Then the tomography method was applied to obtaining lateral variation of Q0 and η values in Chinese mainland and adjacent regions. The result indicates that Q0 value varies between 150 and 600 in the studied areas. Yunnan, southwest Sichuan, and northwest Myanmar show the lowest Q0 value （Q0〈240） and the crust of these regions is characterized by complicated crack and strong hydrothermal activity. The highest Q0 value （Qo〉510） exists in the border of southern Mongolia, Alxa and Ordos block. The η value varies between 0.45 and 0.75 in Chinese mainland and its adjacent regions.

Research on the Characteristics of the Coda Q Value in the Jiangsu Area

In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The results show that the Jiangsu area is a high Q value area as a whole,but the Q value differs obviously between different regions,characterized generally as high in the south and low in the north. This study focuses on 4 sub-regions where the stations are relatively dense,the tectonic features are distinguishing,and the calculation results of coda Q0 are fairly concentrated,and obtains the characteristic relationship between the Q value and frequency of the 4 regions. The region from south Jiangsu to the Yangtze River estuary and that around the Maoshan fault zone are the high Q value areas in Jiangsu; the region from central Jiangsu to the waterfront area is the low Q value area in Jiangsu Province,and the Lianyungang region in northern Jiangsu is the moderate Q value area. Comparing the tectonic activity and seismicity of the 4 different Q value sub-regions,there is a certain correlation between Q value,crustal movement and seismicity.

Ultrasonic attenuation estimation based on time-frequency analysis

The quality factor(or Q value)is an important parameter for characterizing the inelastic properties of rock.Achieving a Q value estimation with high accuracy and stability is still challenging.In this study,a new method for estimating ultrasonic attenuation using a spectral ratio based on an S transform(SR-ST)is presented to improve the stability and accuracy of Q estimation.The variable window of ST is used to solve the time window problem.We add two window factors to the Gaussian window function in the ST.The window factors can adjust the scale of the Gaussian window function to the ultrasonic signal,which reduces the calculation error attributed to the conventional Gaussian window function.Meanwhile,the frequency bandwidth selection rules for the linear regression of the amplitude ratio are given to further improve stability and accuracy.First,the feasibility and influencing factors of the SR-ST method are studied through numerical testing and standard sample experiments.Second,artificial samples with different Q values are used to study the adaptability and stability of the SR-ST method.Finally,a further comparison between the new method and the conventional spectral ratio method(SR)is conducted using rock field samples,again addressing stability and accuracy.The experimental results show that this method will yield an error of approximately 36%using the conventional Gaussian window function.This problem can be solved by adding the time window factors to the Gaussian window function.The frequency bandwidth selection rules and mean slope value of the amplitude ratio used in the SR-ST method can ensure that the maximum error of different Q values estimation(Q>15)is less than 10%.

Non-growing season soil CO_2 efflux and its changes in an alpine meadow ecosystem of the Qilian Mountains,Northwest China

Most soil respiration measurements are conducted during the growing season.In tundra and boreal forest ecosystems,cumulative,non-growing season soil CO2 fluxes are reported to be a significant component of these systems＇ annual carbon budgets.However,little information exists on soil CO2 efflux during the non-growing season from alpine ecosystems.Therefore,comparing measurements of soil respiration taken annually versus during the growing season will improve the accuracy of estimating ecosystem carbon budgets,as well as predicting the response of soil CO2 efflux to climate changes.In this study,we measured soil CO2 efflux and its spatial and temporal changes for different altitudes during the non-growing season in an alpine meadow located in the Qilian Mountains,Northwest China.Field experiments on the soil CO2 efflux of alpine meadow from the Qilian Mountains were conducted along an elevation gradient from October 2010 to April 2011.We measured the soil CO2 efflux,and analyzed the effects of soil water content and soil temperature on this measure.The results show that soil CO2 efflux gradually decreased along the elevation gradient during the non-growing season.The daily variation of soil CO2 efflux appeared as a single-peak curve.The soil CO2 efflux was low at night,with the lowest value occurring between 02：00-06：00.Then,values started to rise rapidly between 07：00-08：30,and then descend again between 16：00-18：30.The peak soil CO2 efflux appeared from 11：00 to 16：00.The soil CO2 efflux values gradually decreased from October to February of the next year and started to increase in March.Non-growing season Q10 （the multiplier to the respiration rate for a 10℃ increase in temperature） was increased with raising altitude and average Q10 of the Qilian Mountains was generally higher than the average growing season Q10 of the Heihe River Basin.Seasonally,non-growing season soil CO2 efflux was relatively high in October and early spring and low in the winter.The soil CO2 efflux was positively correlated with soil temperature and soil water content.Our results indicate that in alpine ecosystems,soil CO2 efflux continues throughout the non-growing season,and soil respiration is an important component of annual soil CO2 efflux.

Inversion of source parameters for moderate and small earthquakes in Beijing region

According to the geological structural features, Beijing and the adjacent areas can be divided into two regions of plain in the east and mountain in the west. Among the stations covered by the telemetered digital seismic station network of Earthquake Administration of Beijing Municipality, the stations in the plain area are all borehole ones and the stations in the western mountainous region are all located on the surface bedrock. In the paper, 511 wave- form data recorded by the network from Oct. 2001 to Oct. 2004 are used in the researches for the entire Beijing region, the western mountainous region and the eastern plain area, respectively. The Q values are calculated for each area by Atkinson′s method and compared with the existed data. The reliability of the Q values and the reasons for the difference in the Q values are also discussed. Then, the source parameters and site response are inverted by the Moya′s method, in which two models are used. The first model uses the Q values, earthquakes and stations in the sub-areas and the second model uses the Q values, earthquakes and stations in the entire Beijing region. The results indicate that the source parameters and site responses obtained by two models are basically consistent with each other. It also indicates that the source parameters obtained by these methods are not affected by the size of station network.

The Influence of the Balance of Dispersion and Nonlinearity on the Transmission Quality in Fiber

This article analyzes the effect of the balance of dispersion and nonlinearity on the quality of a transmission system with super Gauss pulse input by altering the input power and adding a section of dispersion compensation fiber (DCF). The same mechanisms are applied to a 2-channel wave divide multiplex system(WDM) as well. DCF is proved to be a good solution in both situations.

How to Enhance Brand Value of Smart Service Enterprises Based on Tobin Q:A Financial Perspective Investigation of China's Property Industry

The development of digital technology and the construction of smart cities urge service enterprises to seek competitive advantages by building smart service brands.However,there are few studies explore the brand value,brand strategies,and corresponding business strategies of smart service providers from the financial perspective.This paper selects listed property companies from China as the sample and explores the value of the smart community service brand of property enterprises based on the observation data.This research introduces the market value measurement index(Tobin q)and discounted cash flow model(DCF)to explore the influence of diversified brand strategies through combining smart brand strategy with naming strategies and business strategies on brand value.The results show that smart community service brand has a significant impact on firms'market value.Compared with the brand extension strategy,the adoption of brand renewal strategy will significantly affect market value.Further,the development of smart value-added services by enterprises will exert a positive impact on their market value.However,the stakeholders are not optimistic about smart technical services by property companies,which could reduce shareholders'expectations of the market value of enterprises.

Soil carbon dioxide fluxes of a typical broad-leaved/Korean pine mixed forest in Changbai Mountain, China

The forest ecosystem plays an important role in the global carbon cycling. A study was conducted to evaluate soil CO2 flux and its seasonal and diurnal variation with the air and soil temperatures by using static closed chamber technique in a typical broad-leaved/Korean pine mixed forest area on the northern slope of Changbai Mountain, Jilin Province, China. The experiment was carried out through the day and night in the growing season (from June to September) in situ and sample gas was analyzed by a gas chromatograph. Results showed that the forest floor was a large net source of carbon, and soil CO2 fluxes had an obvi-ous law of seasonal and diel variation. The soil CO2 flux of broad-leaved/Korean pine mixed forest was in the range of 0.302.42 mmol穖-2穝-1 with the mean value of 0.98 mmol穖-2穝-1. An examination on the seasonal pattern of soil CO2 emission suggested that the variability in soil CO2 flux could be correlated with variations in soil temperature, and the maximum of mean CO2 flux occurred in July ((1.27±23%) mmol穖-2穝-1) and the minimum was in September ((0.50±28%) mmol穖-2穝-1). The fluctuations in diel soil CO2 flux were also correlated with changes in soil temperature; however, there existed a factor for a time lag. Soil CO2 flux from the forest floor was strongly related to soil temperature and had the highest correlation with temperature at 6-cm depth of soil. Q10 values based on air temperature and soil temperature of different soil depths were at the ranges of 2.09–3.40.

Effects of Enhanced UV-B Radiation on Soil Respiration of Barley Field

[Objective] The aim was to investigate the changing characteristics of soil respiration in clear day with enhanced UV-B radiation and in cloudy day without external UV-B radiation forcing.[Methods] Based on measuring soil respiration rate of barley field at jointing stage in typical clear day and cloudy day by means of Li-8100,the effects of enhanced UV-B radiation by 20% on soil respiration rate were studied. [Results] The results showed that enhanced UV-B radiation inhibited soil respiration of barley field obviously. In clear day,the average soil respiration rate of normal barley field(B) was 1.02 μmol/(m2·s) higher than that of barley field with the enhanced UV-B radiation by 20%(BU) . For cloudy day,the average soil respiration rate of B treatment was 0.71 μmol/(m2·s) lower than BU treatment without external UV-B radiation forcing. In clear day,UV-B radiation rise resulted into the decrease of Q10 value of soil respiration in barley field,but there was an increase in cloudy day without external UV-B radiation forcing,leading to various changes of soil respiration rate. [Conclusions] Supplemental UV-B radiation could inhibit soil respiration rate of barley filed significantly,thus affected the increase of crop yield.

Study on inelastic attenuation coefficient, site response and source parameters in Shanxi region

Based on 310 horizontal-component digital seismograms recorded at 14 seismic stations in Shanxi Digital Seis-mograph Network, the inelastic attenuation coefficient in Shanxi region is studied. By the methods of Atkinson and Moya, the site response of each station and several source parameters are obtained and the inversion results from both methods are compared and analyzed. The frequency-dependent inelastic attenuation coefficient Q is estimated as Q( f )=323.2 f 0.506. The site responses of 14 seismic stations do not show significant amplification, which is consistent with their basement on rock. We also found the dependence of corner frequency on seismic moment, seismic moment on stress drop, source radius on stress drop.

Effect of intracorneal ring segment implantation on corneal asphericity

AIM： To evaluate the visual, refractive and corneal asphericity changes after intrastromal corneal ring segment（ICRS） implantation for visual rehabilitation of keratoconus.METHODS： A total of 42 eyes of 32 patients were included. After creation of intrastromal tunnels of 5.01±0.03 mm inner diameter, 5.71±0.03 mm outer diameter and at 384.21±34.12 μm depth, 1 or 2 ICRS of 150-300 μm thickness and 90°-210° arc length were implanted. Changes in uncorrected distance visual acuity（UDVA）, corrected distance visual acuity（CDVA）, refractive errors, mean simulated keratometry readings SimK_（avg）, anterior and posterior corneal asphericity values（Q_（ant） and Q_（post）, respectively） measured with Scheimpflug topography were evaluated retrospectively. RESULTS： There was a significant improvement in UDVA and CDVA, along with a significant decrease in refractive spherical equivalent（SE）, cylinder and SimK_（avg） postoperatively（P〈0.001 for all）. Mean Qant increased from-1.06±0.48 to-0.57±0.58 postoperatively（P〈0.001）. Change in mean Qpost was insignificant（P=0.92）. Postoperative changes in UDVA and CDVA were not correlated with the postoperative changes in SE and cylinder（P〉0.05 for all）; but were correlated with the preoperative SimK_（avg） and Q_（ant） values（P〈0.001 for all）. CONCLUSION： ICRS implantation seems to approximate the anterior corneal asphericity of ＂advanced prolate＂ shape to ＂optimal prolate＂ shape and an ＂ideal Q value＂ of-0.46; which may have a role in improved UDVA and CDVA postoperatively, besides decreased refractive cylinder values.

The updated crustal attenuation in North China using M_L amplitude tomography

We have updated the lateral variations of the quality factor Q0（Q at 1 Hz） beneath the crust of North China using ML amplitude tomography with near three times data.The data were selected from the Annual Bulletin of Chinese Earthquakes（ABCE） in 1985-2009,including 26 283 ML amplitude readings from 4 204 events recorded by 38 stations.The result is similar with previous research but has higher resolution.Estimated Q0 values are consistent with tectonic and topographic structure in North China.Q0 is low in the active tectonic regions having many faults,such as Bohai bay,North China basin,the Shanxi and Yinchuan grabens,while it is high in the stable Ordos craton.Q0 values are low in several topographically low-lying areas,such as the North China,Taikang-Hefei,and Subei-Huanghai Sea basins,whereas it is high in mountainous and uplift regions exhibiting surface expressions of crystalline basement rocks：the Yinshan,Yanshan,Taihang,Qinling and Dabie mountains,Luxi and Jiaoliao uplifts.Quality factor estimates are also consistent with Pn and Sn velocity patterns.High velocity values in general correspond with high Q0 and vice versa.This coincides with a common temperature influence in the crust and uppermost mantle.

The Effect of Bi_2O_3 on the Structure and Microwave Dielectric Properties of Ba_(6-3x)Nd_(8+2x)Ti_(18)O_(54)System(x=2/3)

The structures and dielectric properties of Ba6-3xNd8＋2xTi18O54 system（x=2/3） doped with different contents of Bi2O3, whose final molecular formula is Ba6-3x（Nd1-yBiy）8＋2xTi18O54 were investigated. It is indicated that the dielectric constant increases greatly whereas Q value（f0=4 GHz） decreases with the increase of Bi2O3 content. However, the temperature coefficient could be controlled below 0±30×10^-6/℃ in the experiment. These phenomena are related to the appearance of a new phase, Bi4Ti3O12, which has high dielectric constant. Also, that Bi^3＋（0.13 nm） substitutes for Nd^3＋（0.099 5 nm） will increase the unit cell volume, which will lead to the enlargement of the octahedron B site occupied by Ti^4＋. So the spontaneous polarization of Ti^4＋ ions will be strengthened. Besides, Bi^3＋ will fill up some vacancies which Ba^2＋ or Nd^3＋ ions leave in two A1 sites and four A2 sites. More positive ions polarize, which also contributes to higher dielectric constant. The samples got with the optimium properties are sintered at 1 200 ℃ for 4 h, when y=0.25, ε≈110, Q≈5 400（f0=4 GHz）, TCC=-4.7×10^-6/℃; When y=0.3, ε≈120, Q≈5 000（f0=4 GHz）, TCC=-24×10^-6/℃.

Lower crustal attenuation in northeastern Tibetan Plateau from ML amplitude

This study investigated the crustal attenuation structures of Sg and Lg waves of the northeastern Tibetan Plateau.We collected ML amplitude data recorded at 168 permanent stations between 1985 and 2016 and 11 temporary broadband stations between 2014 and 2016.Detailed Q0 variation maps of Sg and Lg waves were obtained by applying ML amplitude tomography.The average Q0 values of the Sg and Lg wave were 440 and 220,respectively.Relatively high attenuation anomalies of both waves appeared in the central and eastern regions of the Bayan Har Block and the east edge of the Qiangtang Block,which may be related to partial melting,high geotemperature,and strong tectonic processes.High attenuation anomalies were also found in the Qilian Orogenic Belt and Hetao Graben,which may be related to their active tectonic behavior and densely distributed faults.The relatively low attenuation anomalies of both waves were revealed in the Alax and Ordos blocks,Qaidam,Tarim,Qinghai Lake,and Gonghe basins,which can be explained by the tectonically stable properties and ancient composition of geological elements.These results indicate that the path between the highly attenuated lower crust of the Bayan Har Block and the Qilian Orogenic Belt is obstructed by three adjacent low attenuated areas(i.e.,the Qilian,Qinghai Lake,and Gonghe basins);thus,it appears unlikely that a crustal flow channel from the interior of the Tibetan Plateau to the Qilian Orogenic Belt will form.

GENERALIZED FUZZY FILTERS OF BL-ALGEBRAS

The concept of quasi-coincidence of a fuzzy interval value with an interval valued fuzzy set is considered. In fact, this is a generalization of quasi-coincidence of a fuzzy point with a fuzzy set. By using this new idea, the notion of interval valued （∈,∈ ∨q）-fuzzy filters in BL-algebras which is a generalization of fuzzy filters of BL-algebras, is defined, and related properties are investigated. In particular, the concept of a fuzzy subgroup with thresholds is extended to the concept of an interval valued fuzzy filter with thresholds in BL-algebras.

Study on Ba_(6-3x)Sm_(8+2x)Ti_(18)O_(54) Microwave Dielectric Ceramics

The effects of different x values on the dielectric properties in the Ba6-3xSm8+2xTi18O54 microwave dielectric ceramics(0.3≤x≤0.7) were studied. The results showed that the major crystal phase was BaSm2Ti4O12 and the sintering temperature of the ceramics was 1340 ℃ when the x value was 0.67. The dielectric properties were better: εr≈79, tanδ≈1×10-4(1 MHz); εr≈80, Q·f=9230 GHz(3.97 GHz), τf=-17 ppm·℃-1.