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Additional file 1. Supplementary Table 1. Baseline characteristics of patients with and without BI in ALS. Supplementary Table 2. Correlation of CCM parameters with disease severity and progression in ALS. Supplementary Table 3. CCM parameters in patients with and without BI in ALS.

The shock resistance of multi-body structure in confined fluid is a hot topic in recent years because of widely using in nuclear reactors, evaporator and so on. The added mass coefficient of elastic rods which is influenced by many factors is one of key parameters in the research of shock resistance. So the added mass coefficient of elastic rods in confined fluid is deduced based on potential flow theory and validated by an experiment. Taylor expansion and coordinate transformation are used in theoretical derivation. In the experiment, rods are stimulated by exciter and impactor and the results show that the added mass coefficient is related to the distance between rod and the boundary, distance between two rods, vibration phase, vibration direction, modes and the number of rods. There is no obvious difference between vibration and impact. Finally, the conclusion can be used in rapid engineering design of similar structure.

Satellite retrievals of the column-averaged dry air mole fractions of CO2 (XCO2) could help to improve carbon flux estimation due to their good spatial coverage. In this study, in order to assimilate the GOSAT (Greenhouse Gases Observing Satellite) XCO2 retrievals, the Global Carbon Assimilation System (GCAS) is upgraded with new assimilation algorithms, procedures, a localization scheme, and a higher assimilation parameter resolution. This upgraded system is referred to as GCASv2. Based on this new system, the global terrestrial ecosystem (BIO) and ocean (OCN) carbon fluxes from 1 May 2009 to 31 December 2015 are constrained using the GOSAT ACOS (Atmospheric CO2 Observations from Space) XCO2 retrievals (Version 7.3). The posterior carbon fluxes from 2010 to 2015 are independently evaluated using CO2 observations from 52 surface flask sites. The results show that the posterior carbon fluxes could significantly improve the modeling of atmospheric CO2 concentrations, with global mean bias decreases from a prior value of 1.6 ± 1.8 ppm to −0.5 ± 1.8 ppm. The uncertainty reduction (UR) of the global BIO flux is 17 %, and the highest monthly regional UR could reach 51 %. Globally, the mean annual BIO and OCN carbon sinks and their interannual variations inferred in this study are very close to the estimates of CarbonTracker 2017 (CT2017) during the study period, and the inferred mean atmospheric CO2 growth rate and its interannual changes are also very close to the observations. Regionally, over the northern lands, the strongest carbon sinks are seen in temperate North America, followed by Europe, boreal Asia, and temperate Asia; in the tropics, there are strong sinks in tropical South America and tropical Asia, but a very weak sink in Africa. This pattern is significantly different from the estimates of CT2017, but the estimated carbon sinks for each continent and some key regions like boreal Asia and the Amazon are comparable or within the range of previous bottom-up estimates. The inversion also changes the interannual variations in carbon fluxes in most TransCom land regions, which have a better relationship with the changes in severe drought area (SDA) or leaf area index (LAI), or are more consistent with previous estimates for the impact of drought. These results suggest that the GCASv2 system works well with the GOSAT XCO2 retrievals and shows good performance with respect to estimating the surface carbon fluxes; meanwhile, our results also indicate that the GOSAT XCO2 retrievals could help to better understand the interannual variations in regional carbon fluxes.

International audience; China's fossil-fuel CO2 (FFCO2) emissions accounted for approximately 28 % of the global total FFCO2 in 2016. An accurate estimate of China's FFCO2 emissions is a prerequisite for global and regional carbon budget analyses and the monitoring of carbon emission reduction efforts. However, significant uncertainties and discrepancies exist in estimations of China's FFCO2 emissions due to a lack of detailed traceable emission factors (EFs) and multiple statistical data sources. Here, we evaluated China's FFCO2 emissions from nine published global and regional emission datasets. These datasets show that the total emissions increased from 3.4 (3.0-3.7) in 2000 to 9.8 (9.2-10.4) Gt CO2 yr-1 in 2016. The variations in these estimates were largely due to the different EF (0.491-0.746 t C per t of coal) and activity data. The large-scale patterns of gridded emissions showed a reasonable agreement, with high emissions being concentrated in major city clusters, and the standard deviation mostly ranged from 10 % to 40 % at the provincial level. However, patterns beyond the provincial scale varied significantly, with the top 5 % of the grid level accounting for 50 %-90 % of total emissions in these datasets. Our findings highlight the significance of using locally measured EF for Chinese coal. To reduce uncertainty, we recommend using physical CO2 measurements and use these values for dataset validation, key input data sharing (e.g., point sources), and finer-resolution validations at various levels.

Satellite XCO2 retrievals could help to improve carbon flux estimation because of their good spatial coverage. In this study, to assimilate the GOSAT XCO2 retrievals, the Global Carbon Assimilation System (GCAS) is upgraded with new assimilation algorithms, procedures and a localization scheme, a higher assimilation parameter resolution and so on, and hence is named as GCASv2. Based on this new system, the global terrestrial ecosystem (BIO) and ocean (OCN) carbon fluxes from May 1, 2009 to Dec 31, 2015 are constrained using the GOSAT ACOS XCO2 retrievals (Version 7.3). The posterior carbon fluxes from 2010 to 2015 are independently evaluated using CO2 observations from 52 surface flask sites. The results show that the posterior carbon fluxes could significantly improve the modeling of atmospheric CO2 concentrations, with global mean BIAS decreases from a prior value of 1.6 ± 1.8 ppm to -0.5 ± 1.8 ppm. Globally, the mean annual BIO and OCN carbon sinks and their interannual variations inferred in this study are very close to the estimates of CT2017 during the study period, and the inferred mean atmospheric CO2 growth rate and its interannual changes are also very close to the observations. Regionally, over the northern lands, there are the strongest carbon sinks in North America Temperate, followed by Europe, Boreal Asia, and Temperate Asia; and in tropics, there are strong sinks in Tropical South America and Tropical Asia, but a very weak sink in Africa. This pattern is significantly different from the estimates of CT2017, but the estimated carbon sinks in each continent and some key regions like Boreal Asia and Amazon are comparable or in the range of previous bottom-up estimates. The inversion also changes the interannual variations of carbon fluxes in most TRANSCOM land regions, which have a better relationship with the changes of severe drought area or LAI, or are more consistent with previous estimates for the impact of drought. These results suggest that the GCASv2 system works well with the GOSAT XCO2 retrievals, and has a good performance in estimating the surface carbon fluxes, meanwhile, our results also indicate that the GOSAT XCO2 retrievals could help to better understand the interannual variations of regional carbon fluxes.

In hands-free telephone systems and mobile communication devices, it is often desirable for the devices to operate at large sound volume, which can result in obvious nonlinear acoustic echoes due to overload of small loudspeaker. These nonlinear echoes can't be fully eliminated by linear AEC (Acoustic Echo Cancellation) algorithm, so the conversation quality is affected seriously. Since the nonlinear echoes contain additional harmonics in high frequency, which breaks the linear relation required for fullband linear AEC, these harmonics, however, becomes additive noise in subband system. Therefore, in this paper, a subband AEC method based on polyphase filter bank is proposed. It is found that ERLE (Echo Return Loss Enhancement) of the proposed method outperforms the fullband counterpart constantly in nonlinear situation, especially with tone-like signals, where ERLE improves more than 15 dB. The results are validated through both simulation and real signals.