An improved absolute calibration technology based on indirect measurements was developed through two probative experiments, the performance of which was evaluated by applying the approach to in situ sea surface height...An improved absolute calibration technology based on indirect measurements was developed through two probative experiments, the performance of which was evaluated by applying the approach to in situ sea surface height (SSH) at the Tianheng Island (tidal gauge) and the satellite nadir (GPS buoy). Using Geoid/MSS (mean sea surface) data, which accounted for a constant offset between nadir and onshore tidal gauge water levels, and TMD (tidal model driver), which canceled out the time-varying offsets, nadir SSH (sea surface height) could be indirectly acquired at an onshore tidal gauge instead of from direct offshore observation. The approach extrapolated the onshore SSH out to the offshore nadir with an accuracy of (1.88±0.20) cm and a standard deviation of 3,3 cm, which suggested that the approach presented was feasible in absolute altimeter calibration/validation (Cal/Val), and the approach enormously facilitated the obtaining SSH from the offshore nadir.展开更多
Modeling height–diameter relationships is an important component in estimating and predicting forest development under different forest management scenarios. In this paper, ten widely used candidate height–diameter ...Modeling height–diameter relationships is an important component in estimating and predicting forest development under different forest management scenarios. In this paper, ten widely used candidate height–diameter models were fitted to tree height and diameter at breast height(DBH)data for Populus euphratica Oliv. within a 100 ha permanent plots at Arghan Village in the lower reaches of the Tarim River, Xinjiang Uyghur Autonomous Region of China. Data from 4781 trees were used and split randomly into two sets:75 % of the data were used to estimate model parameters(model calibration), and the remaining data(25 %) were reserved for model validation. All model performances were evaluated and compared by means of multiple model performance criteria such as asymptotic t-statistics of model parameters, standardized residuals against predicted height,root mean square error(RMSE), Akaike’s informationcriterion(AIC), mean prediction error(ME) and mean absolute error(MAE). The estimated parameter a for model(6) was not statistically significant at a level of a = 0.05. RMSE and AIC test result for all models showed that exponential models(1),(2),(3) and(4) performed significantly better than others. All ten models had very small MEs and MAEs. Nearly all models underestimated tree heights except for model(6). Comparing the MEs and MAEs of models, model(1) produced smaller MEs(0.0059) and MAEs(1.3754) than other models. To assess the predictive performance of models, we also calculated MEs by dividing the model validation data set into 10-cm DBH classes. This suggested that all models were likely to create higher mean prediction errors for tree DBH classes[20 cm. However, no clear trend was found among models.Model(6) generated significantly smaller mean prediction errors across all tree DBH classes. Considering all the aforementioned criteria, model(1): TH ? 1:3 t a= e1 t b?eàc?DBHT and model(6): TH ? 1:3 t DBH2= ea t b?DBH t c ? DBH2T are recommended as suitable models for describing the height–diameter relationship of P. euphratica. The limitations of other models showing poor performance in predicting tree height are discussed. We provide explanations for these shortcomings.展开更多
Low-power laser therapy has been used for the non-surgical treatment of mild to moderate carpal tunnel syndrome,although its efficacy has been a long-standing controversy.The laser parameters in low-power laser therap...Low-power laser therapy has been used for the non-surgical treatment of mild to moderate carpal tunnel syndrome,although its efficacy has been a long-standing controversy.The laser parameters in low-power laser therapy are closely related to the laser effect on human tissue.To evaluate the efficacy of low-power laser therapy,laser parameters should be accurately measured and controlled,which has been ignored in previous clinical trials.Here,we report the measurement of the effective optical power of low-power laser therapy for carpal tunnel syndrome.By monitoring the backside reflection and scattering laser power from human skin at the wrist,the effective laser power can be inferred.Using clinical measurements from 30 cases,we found that the effective laser power differed significantly among cases,with the measured laser reflection coefficient ranging from 1.8% to 54%.The reflection coefficient for 36.7% of these 30 cases was in the range of 10–20%,but for 16.7% of cases,it was higher than 40%.Consequently,monitoring the effective optical power during laser irradiation is necessary for the laser therapy of carpal tunnel syndrome.展开更多
The absolute energy calibration with photons from π0's for the BESⅢ EMC is discussed. Using 3 million hadronic events, the preliminary results are presented. Precision of about 1% in the photon energy measurement i...The absolute energy calibration with photons from π0's for the BESⅢ EMC is discussed. Using 3 million hadronic events, the preliminary results are presented. Precision of about 1% in the photon energy measurement is obtained from crossing check using photons in ψ(2S)→γχc1,2(1P).展开更多
Accurate and precise wavelength controlling of narrowband excimer lasers is essential for the lithography of an integrated circuit. High-precision wavelength tuning and calibration of a line-narrowed Ar F laser are pr...Accurate and precise wavelength controlling of narrowband excimer lasers is essential for the lithography of an integrated circuit. High-precision wavelength tuning and calibration of a line-narrowed Ar F laser are presented in this work. The laser spectrum is narrowed to a sub-picometer with a line narrowing system. Absolute wavelength calibration of the line-narrowed laser is performed based on the optogalvanic(OG) effect using iron hollow cathode discharge(HCD). An sccuracy of better than 0.1 pm for wavelength tuning and calibration is achieved with our homemade wavemeter.展开更多
The effects of absolute energy calibration on BESⅢ physics are discussed in detail, which mainly involve the effects on τ mass measurement, cross section scan measurement, and generic error determination in other me...The effects of absolute energy calibration on BESⅢ physics are discussed in detail, which mainly involve the effects on τ mass measurement, cross section scan measurement, and generic error determination in other measurements.展开更多
基金The Marine Public Welfare Projects of China under contract No.201105032the National High-Tech Project of China under contract No.2008AA09A403
文摘An improved absolute calibration technology based on indirect measurements was developed through two probative experiments, the performance of which was evaluated by applying the approach to in situ sea surface height (SSH) at the Tianheng Island (tidal gauge) and the satellite nadir (GPS buoy). Using Geoid/MSS (mean sea surface) data, which accounted for a constant offset between nadir and onshore tidal gauge water levels, and TMD (tidal model driver), which canceled out the time-varying offsets, nadir SSH (sea surface height) could be indirectly acquired at an onshore tidal gauge instead of from direct offshore observation. The approach extrapolated the onshore SSH out to the offshore nadir with an accuracy of (1.88±0.20) cm and a standard deviation of 3,3 cm, which suggested that the approach presented was feasible in absolute altimeter calibration/validation (Cal/Val), and the approach enormously facilitated the obtaining SSH from the offshore nadir.
基金supported by the National Natural Science Foundation of China(Grant No:31360200,31270742)German Federal Ministry of Education and Research(BMBF)within the framework of the SuMaRiO project(01LL0918D)the Volkswagen Stiftung(Eco CAR project,Az.88497)
文摘Modeling height–diameter relationships is an important component in estimating and predicting forest development under different forest management scenarios. In this paper, ten widely used candidate height–diameter models were fitted to tree height and diameter at breast height(DBH)data for Populus euphratica Oliv. within a 100 ha permanent plots at Arghan Village in the lower reaches of the Tarim River, Xinjiang Uyghur Autonomous Region of China. Data from 4781 trees were used and split randomly into two sets:75 % of the data were used to estimate model parameters(model calibration), and the remaining data(25 %) were reserved for model validation. All model performances were evaluated and compared by means of multiple model performance criteria such as asymptotic t-statistics of model parameters, standardized residuals against predicted height,root mean square error(RMSE), Akaike’s informationcriterion(AIC), mean prediction error(ME) and mean absolute error(MAE). The estimated parameter a for model(6) was not statistically significant at a level of a = 0.05. RMSE and AIC test result for all models showed that exponential models(1),(2),(3) and(4) performed significantly better than others. All ten models had very small MEs and MAEs. Nearly all models underestimated tree heights except for model(6). Comparing the MEs and MAEs of models, model(1) produced smaller MEs(0.0059) and MAEs(1.3754) than other models. To assess the predictive performance of models, we also calculated MEs by dividing the model validation data set into 10-cm DBH classes. This suggested that all models were likely to create higher mean prediction errors for tree DBH classes[20 cm. However, no clear trend was found among models.Model(6) generated significantly smaller mean prediction errors across all tree DBH classes. Considering all the aforementioned criteria, model(1): TH ? 1:3 t a= e1 t b?eàc?DBHT and model(6): TH ? 1:3 t DBH2= ea t b?DBH t c ? DBH2T are recommended as suitable models for describing the height–diameter relationship of P. euphratica. The limitations of other models showing poor performance in predicting tree height are discussed. We provide explanations for these shortcomings.
基金supported in part by the National Natural Science Foundation of China,No.61108077
文摘Low-power laser therapy has been used for the non-surgical treatment of mild to moderate carpal tunnel syndrome,although its efficacy has been a long-standing controversy.The laser parameters in low-power laser therapy are closely related to the laser effect on human tissue.To evaluate the efficacy of low-power laser therapy,laser parameters should be accurately measured and controlled,which has been ignored in previous clinical trials.Here,we report the measurement of the effective optical power of low-power laser therapy for carpal tunnel syndrome.By monitoring the backside reflection and scattering laser power from human skin at the wrist,the effective laser power can be inferred.Using clinical measurements from 30 cases,we found that the effective laser power differed significantly among cases,with the measured laser reflection coefficient ranging from 1.8% to 54%.The reflection coefficient for 36.7% of these 30 cases was in the range of 10–20%,but for 16.7% of cases,it was higher than 40%.Consequently,monitoring the effective optical power during laser irradiation is necessary for the laser therapy of carpal tunnel syndrome.
基金Supported by CAS Knowledge Innovation Project (U-602, U-34)National Natural Science Foundation of China (10491300,10491303, 10605030) 100 Talents Program of CAS (U-25 and U-54)
文摘The absolute energy calibration with photons from π0's for the BESⅢ EMC is discussed. Using 3 million hadronic events, the preliminary results are presented. Precision of about 1% in the photon energy measurement is obtained from crossing check using photons in ψ(2S)→γχc1,2(1P).
基金supported by the National Science and Technology Major Project(No.2013ZX02202003)the National Key Research and Development Program(No.2016YFB0402201)+4 种基金K.C.Wong Education Foundation,the Program of Shanghai Technology Research Leader(No.17XD1424800)the Shanghai Sailing Program of Talented Youth in Science and Technology(No.17YF1421200)the Key Technologies R&D Program of Jiangsu(Nos.BE2014001 and BE2016005-4)the Natural Science Foundation of Shanghai(Nos.16ZR1440100and 16ZR1440200)the NSAF Foundation of National Natural Science Foundation of China(Nos.U1330134 and 61405202)
文摘Accurate and precise wavelength controlling of narrowband excimer lasers is essential for the lithography of an integrated circuit. High-precision wavelength tuning and calibration of a line-narrowed Ar F laser are presented in this work. The laser spectrum is narrowed to a sub-picometer with a line narrowing system. Absolute wavelength calibration of the line-narrowed laser is performed based on the optogalvanic(OG) effect using iron hollow cathode discharge(HCD). An sccuracy of better than 0.1 pm for wavelength tuning and calibration is achieved with our homemade wavemeter.
基金National Natural Science Foundation of China (10225522, 10491303, 10775077, 10775142)Research and Development Project of Important Scientific Equipment of CAS (H7292330S7)100 Talents Programme of CAS (U-25)
文摘The effects of absolute energy calibration on BESⅢ physics are discussed in detail, which mainly involve the effects on τ mass measurement, cross section scan measurement, and generic error determination in other measurements.