Control of desertification can not only ameliorate the natural environment of arid regions but also convert desertified land into significant terrestrial carbon sinks,thereby bolstering the carbon sequestration capaci...Control of desertification can not only ameliorate the natural environment of arid regions but also convert desertified land into significant terrestrial carbon sinks,thereby bolstering the carbon sequestration capacity of arid ecosystems.However,longstanding neglect of the potential carbon sink benefits of desertification management,and its relationship with environmental factors,has limited the exploration of carbon sequestration potential.Based on CO_(2) flux and environmental factors of artificial protective forest in the Taklamakan Desert from 2018 to 2019,we found that the carbon storage capacity of the desert ecosystem increased approximately 140-fold after the establishment of an artificial shelter forest in the desert,due to plant photosynthesis.Precipitation levels less than 2 mm had no impact on carbon exchange in the artificial shelter forest,whereas a precipitation level of approximately 4 mm stimulated a decrease in the vapor pressure deficit over a short period of about three days,promoting photosynthesis and enhancing the carbon absorption of the artificial shelter forest.Precipitation events greater than 8 mm stimulated soil respiration to release CO_(2) and promoted plant photosynthesis.In the dynamic equilibrium where precipitation stimulates both soil respiration and photosynthesis,there is a significant threshold value of soil moisture at 5 cm(0.12 m^(3) m^(-3)),which can serve as a good indicator of the strength of the stimulatory effect of precipitation on both.These results provide important data support for quantifying the contribution of artificial afforestation to carbon sequestration in arid areas,and provide guidance for the development and implementation of artificial forest management measures.展开更多
<strong>Objective:</strong> To probe into the effect of catgut implantation at Baliao and Xingfu One Acupuncture Point on dysdefecation in patients with incomplete spinal cord injury (SCI). <strong>M...<strong>Objective:</strong> To probe into the effect of catgut implantation at Baliao and Xingfu One Acupuncture Point on dysdefecation in patients with incomplete spinal cord injury (SCI). <strong>Methods:</strong> Three SCI patients voluntarily accepted catgut embedding at Baliao and Xingfu One Acupuncture point. Before and after treatment, they were filled out the self-rating scale of defecation, including the data of defecation frequency, total defecation time, defecation effort, fecal texture, fecal characteristics and fecal incontinence, etc. <strong>Results:</strong> Compared with the baseline data, constipation was improved and fecal incontinence was disappeared. <strong>Conclusions:</strong> Catgut implantation at Baliao and Xingfu One Acupuncture Point is effectual for patients with neurogenic dysporia secondary to incomplete SCI.展开更多
Tazhong is the hinterland and a sandstorm high-frequency area of the Taklimakan Desert. However, little is known about the detailed time-series of aeolian sand transport in this area. An experiment to study the sand-d...Tazhong is the hinterland and a sandstorm high-frequency area of the Taklimakan Desert. However, little is known about the detailed time-series of aeolian sand transport in this area. An experiment to study the sand-dust horizontal flux of near-surface was carried out in Tazhong from January to December 2009. By measur- ing the sand-dust horizontal flux throughout sixteen sand-dust weather processes with a 200-cm tall Big Spring Number Eight （BSNE） sampler tower, we quantitatively analyzed the vertical variation of the sand-dust horizontal flux. And the total sand-dust horizontal flux of different time-series that passed through a section of 100 cm in width and 200 cm in height was estimated combining the data of saltation movement continuously recorded by piezo- electric saltation sensors （Sensit）. The results indicated that, in the surface layer ranging from 0-200 cm, the inten- sity of sand-dust horizontal flux decreased with the increase of the height, and the physical quantities obeyed power function well. The total sand-dust horizontal flux of the sixteen sand-dust weather processes that passed through a section of 100 cm in width and 200 cm in height was about 2,144.9 kg, the maximum of one sand-dust weather event was about 396.3 kg, and the annual total sand-dust horizontal flux was about 3,903.2 kg. The high levels of aeolian sand transport occurred during daytime, especially from 13：00 to 16：00 in the afternoon. We try to develop a new method for estimation of the detailed time-series of aeolian sand transport.展开更多
The development and progress of soil wind erosion are influenced by the factors of climate, terrain, soil and vegetation, etc. This paper, taking Tazhong region, a town in the centre of the Taklimakan Desert, as an ex...The development and progress of soil wind erosion are influenced by the factors of climate, terrain, soil and vegetation, etc. This paper, taking Tazhong region, a town in the centre of the Taklimakan Desert, as an example and using comparative and quantitative methods, discussed the effects of climate, surface roughness （including vegetation cover） and surface soil properties on soil wind erosion. The results showed that the climate factor index C of annual wind erosion is 28.3, while the maximum of C is 13.9 in summer and it is only 0.7 in winter. The value of C has a very good exponential relationship with the wind speed. In Tazhong region, the surface roughness height is relatively small with a mean of 6.32 x 10 Sm, which is in favor of soil wind erosion. The wind erosion is further enhanced by its sandy soil types, soil particle size, lacking of vegetation and low soil moisture content. The present situation of soil wind erosion is the result of concurrent effects of climate, vegetation and surface soil properties.展开更多
In this paper, the sand transport during a sand-dust storm in the Tazhong area of the central Taklimakan Desert from 11：29 to 23：56 on July 19, 2008 was observed and measured in real time. The sand flux at Tazhong w...In this paper, the sand transport during a sand-dust storm in the Tazhong area of the central Taklimakan Desert from 11：29 to 23：56 on July 19, 2008 was observed and measured in real time. The sand flux at Tazhong was estimated using sand transport empirical formulas. The critical friction velocity at Tazhong was 0.24 m/s and the functional relation between the wind speed and sediment discharge at the height of 2 m was established. It was also found that the calculated values by Lettau＇s sediment discharge formula were close to those of the instrument measurements. The horizontal sand flux and the vertical sand flux during this sand-dust storm at Tazhong were respectively 258.67×10-4 kg/（m·s） and 40.07×10-7 kg/（m2·s）.展开更多
The different height mass concentrations of dust aerosol data from the atmosphere environment observation station （Ta- zhong Station） was continuously observed by instruments of Grimm 1.108, Thermo RP 1400a and TSP ...The different height mass concentrations of dust aerosol data from the atmosphere environment observation station （Ta- zhong Station） was continuously observed by instruments of Grimm 1.108, Thermo RP 1400a and TSP from January of 2009 to February of 2010 in the Taklimakan Desert hinterland. Results show that： （1） The mass concentration value of 80 m PMl0 was higher, but PM2.5 and PM1.0 concentrations at 80 m was obviously lower than 4 m PMl0, and the value of 80 m PM1.0 mass concentration was the lowest. （2） The PM mass concentrations gradually decreased from night to sunrise, with the lowest concentration at 08：00, with the mass concentration gradually increased, up to the highest concentration around 18：00, and then decreased again. It was exactly the same with the changes of wind speed. （3） The high monthly average mass concentration of TSP mainly appeared from March to September, and the highest concentration was in April and May, subsequently gradually decreased. Also, March-September was a period with high value area of PM monthly average mass concentration, with the highest monthly average mass concentration of 846.0 p.g/m3 for 4 m PM^0 appeared in May. The concentration of PM10 was much higher than those of PM2.5 and PM1.0 at 80 m. There is a small difference between the concentration of PM2.5 and PM~ 0. Dust weather was the main factor which influenced the concentration content of the different diameter dust aerosol, and the more dust weather days, the higher content of coarse particle, conversely, fine particle was more. （4） The mass concentration of different diameter aerosols had the following sequence during dust weather： clear day 〈 blowing dust 〈 floating and blowing dust 〈 sandstorm. In different dust weather, the value of PM^o/TSP in fine weather was higher than that in floating weather, and much higher than those in blowing dust and sandstorm weather. （5） During the dust weather process, dust aerosol concentration gradually decreased with particle size decreasing. The dust aerosol mass concentration at different heights and diameter would have a peak value area every 3-4 days according to the strengthening process of dust weather.展开更多
During the course of a major sandstorm from April 17 to April 23, 2008 in the Taklimakan Desert, data pertaining to the mass concentrations of different-sized atmospheric particulate matter were observed continuously ...During the course of a major sandstorm from April 17 to April 23, 2008 in the Taklimakan Desert, data pertaining to the mass concentrations of different-sized atmospheric particulate matter were observed continuously with Grimm 1.108, Thermo RP 1400a, TSP, and CAWS-600 instruments. The results showed that： （1） during the entire sandstorm process there were some dif- ferences between the daily mean particle concentration peaks and the hourly mean particle concentration peaks because the actual sandstorm lasted for only about 4 hr, whereas more particles were accumulated in the floating dust days before and after the actual sandstorm; （2） the intensity of the sandstorm was enhanced with the increase of wind speed, and this was related to the peak mass concentrations of atmospheric particulate matter; the wind speed directly affected the concentration of atmospheric particulate matter： the higher the wind speed, the higher the mass concentration （〉0.23 μm was 39,496.5 μg/m^3, and 〉20.0 μm was 5,390.7μg/m^3）; （3） the concentration changes of PM10 and TSP were also related to the course and intensity of the sandstorm; and （4） the mass concentration of atmospheric particulate matter had the following sequence during the dust weather： clear day 〈 floating dust 〈 floating and blowing dust 〈 sandstorm. Temperature, relative humidity, and barometric pressure are important factors affecting the strength of storms, which could also indirectly affect the concentration change of atmospheric particulate matter.展开更多
Objective: To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in patients with neurological lower urinary tract dysfunction (NLUTD). Methods: From June 2012 to July 20...Objective: To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in patients with neurological lower urinary tract dysfunction (NLUTD). Methods: From June 2012 to July 2013, patients with NLUTD were prospectively randomized and assigned to either a bladder irrigation group or a no bladder irrigation group. Bladder irrigations were performed twice a week by urologists. Patients were followed up at 6 months respectively. Primary outcomes were Incontinence-Specific Quality-of-Life Instrument (I-QoL), the rate incidences of bladder stone. All adverse events were also noted. Results: A total of 80 eligible patients participated and 78 (97.5%) patients (bladder irrigation, n = 39;no bladder irrigation, n = 39) completed 24 weeks of follow-up. Out of the 78 patients, 19 (24.3%) developed bladder stones. All occurred in no bladder irrigation group. In 8 of the 19 patients (42.1%), stones were only detected by cystoscopy. The bladder stones were mostly thin with an eggshell appearance (78.95% for diameter of stone < 5 mm, 84.21% for volume of bladder stone < 0.2 cm3). Bladder stones were removed by vigorous bladder irrigation guided by ultrasound (73.68%) or endoscopic lithotripsy (26.32%). The I-QOL was significantly better in the bladder irrigation group than in no bladder irrigation group at weeks 6, 12, 18, and 24 of follow-up. Conclusion: Bladder irrigation may be more effective and safer than no bladder irrigation for reducing the morbidity of bladder stone in spinal cord injury patients.展开更多
Based on automatic continuous surface ozone concentration observation data from June 10, 2010 to March 20, 2012 in the Taklimakan Desert hinterland, combined with corresponding meteorological data, the temporal, seaso...Based on automatic continuous surface ozone concentration observation data from June 10, 2010 to March 20, 2012 in the Taklimakan Desert hinterland, combined with corresponding meteorological data, the temporal, seasonal and daily variation characteristics of surface ozone concentrations under different weather conditions were analyzed. At the same time, the main fac- tors affecting ozone variation are discussed. Results show that： （1） Daily variation of ozone concentration was characterized by one obvious peak, with gentle changes during the night and dramatic changes during the day. The lowest concentration was at 09：00 and the highest was at 18：00. Compared to urban areas, there was a slight time delay. （2） Ozone concentration variation had a weekend effect phenomenon. Weekly variation of ozone concentration decreased from Monday to Wednesday with the lowest in Wednesday, and increased after Thursday with the highest in Sunday. （3） The highest monthly average concentration was 89.6 I.tg/m3 in June 2010, and the lowest was 32.0 ~g/m3 in January 2012. Ozone concentration reduced month by month from June to December in 2010. （4） Ozone concentration in spring and summer was higher than in autumn and winter. The variation trend agreed with those in other large and medium-sized cities. （5） Under four different types of weather, daily ozone concentration var- ied most dramatically in sunny days, followed by slight variation in rain days, and varied gently in cloudy days. Ozone concentra- tion varied inconspicuously before a sandstorm appearance, and dropped rapidly at the onset of a sandstorm. （6） Daily variation of radiation was also characterized by a single peak, and the variation was significantly earlier than ozone concentration variation. Sun radiation intensity had a direct influence on the photochemical reaction speed, leading to variation of ozone concentration. （7） Daily average ozone concentration in dust weather was higher than in slight rain and clear days. The variation of near surface ozone concentration could also be affected by meteorological factors such as relative humidity, wind speed, wind direction and sunshine hours. Thus, numerous factors working together led to ozone pollution.展开更多
In order to reveal the variation characteristics of ozone （03） concentration in the atmosphere boundary layer over a desert in winter, an observation experiment was carried out in the Tazhong area by means of a teth...In order to reveal the variation characteristics of ozone （03） concentration in the atmosphere boundary layer over a desert in winter, an observation experiment was carried out in the Tazhong area by means of a tethered balloon during January 18-25, 2008. The vertical distribution of O3 concentration and its correlation with temperature and humidity were analyzed based on experimental observation data and related data. Results show that： （1） The concentration of O3 mainly ranges from 10 to 50 μg/L, with a maximum of 56.1 μg/L, minimum of 2.6 μg/L, and a daily average concentration of 34.4 μg/L. （2） O3 profiles can be divided into three types： peak, uniform, and growth, where uniform accounts for the majority. （3） Temperature and moisture are influential on O3 concentrations in atmospheric boundary layer. Temperature inversion and water vapor increase in an atmospheric boundary layer leads to a decrease of O3. （4） O3 concentration has an obvious daily change in Tazhong. It is lower at night, begins to increase after sunrise, and reaches a maximum at noon. The maximum appears at 17：00 BJT （Beijing Time）, and the minimum appears at 08：00 BJT.展开更多
<strong>Objective:</strong> Explore the rule of autonomic nervous dysfunction in the patients with urination disorder after high level spinal cord injury, and seek a safe, objective and accurate method to ...<strong>Objective:</strong> Explore the rule of autonomic nervous dysfunction in the patients with urination disorder after high level spinal cord injury, and seek a safe, objective and accurate method to evaluate autonomic nervous function. <strong>Patients and Method:</strong> 48 patients with dysuria after cervicothoracic SCI were selected. Before, during and after imaging urodynamic examination with slow filling in supine position, blood pressure and ECG were monitored simultaneously. The symptoms of sweating, shivering, headache, flushing and chills were observed and recorded. The study of the relationship among the changes of blood pressure, heart rate and urodynamic indexes and the above symptoms was analyzed. <strong>Results:</strong> They were divided into three groups: group A (no obvious abnormality), group B (hyperactivity) and group C (hypoactivity) according to their BP, HR and existing the symptoms or not. <strong>Conclusion:</strong> The incidence of autonomic dysfunction in the high level SCI patients with dysuria was very high (79.17%), most of them were hyperactivity, and a few were low function. The changes of SBP and DBP in the hypoactivity group all appeared an increasing and then declining trend, while the change of HR in the low function one was lower than normal and decreased continuously. The main inducements of AD are neurogenic detrusor overactivity, detrusor sphincter dyssynergia, elevated abdominal pressure and abnormal bladder sensitivity. The asymptomatic patients had a higher occurrence rate (43.75%). Only by imaging urodynamic examination with slow filling and synchronous blood pressure monitoring, can autonomic nervous function of the patients be evaluated safely, objectively, early and accurately.展开更多
The global carbon balance is a core issue in climate change research and a focus of in ternational policy concern[1-3].The"missing carbon sink"caused by approximately 1.6-2.0 Pg Ca-1(1 Pg=1015 g)that is curr...The global carbon balance is a core issue in climate change research and a focus of in ternational policy concern[1-3].The"missing carbon sink"caused by approximately 1.6-2.0 Pg Ca-1(1 Pg=1015 g)that is currently unaccounted for,has long plagued researchers[4,5].Evidence is mounting those seemingly lifeless desert ecosystems,whose roles in the global carbon-cycle have long been neglected,exhib让the unconventional phenomenon of absorption of atmospheric CO2,sequestering enonnous amounts of CO2 and thereby creating a significant carbon-sink[6-9].展开更多
We propose and demonstrate single fiber dual-functionality optical tweezers based on a graded-index multimode fiber. By using the multi-angle fiber grinding and polishing technology, we fabricate the multimode fiber t...We propose and demonstrate single fiber dual-functionality optical tweezers based on a graded-index multimode fiber. By using the multi-angle fiber grinding and polishing technology, we fabricate the multimode fiber tip to be a special tapered shape, contributing to focus the outgoing beam with a large intensity gradient for the first functionality--three-dimensional contactless trapping of a microparticle. By adjusting the radial direction offset between the lead-in single mode fiber and the graded-index multimode fiber, we perform the second functionality--axial shift of the trapped microparticle with respect to the fiber tip without need of moving the fiber probe itself. It is convenient for practical applications, The theoretical and experimental results about the relationship between the radial offset and the equilibrium positions of the microparticle have the good consistency. Tailoring the trap and axial shift of the microparticle based on the graded-index multimode fiber provides convenient avenues for fiber optical tweezers a~）Dlied in practical researches.展开更多
In-fiber integrated optics is an attempt to use silica fiber as a substrate, integrating various optical paths or optical components into a single fiber, to build a functional optical device or component, and to reali...In-fiber integrated optics is an attempt to use silica fiber as a substrate, integrating various optical paths or optical components into a single fiber, to build a functional optical device or component, and to realize a micro optical system, achieving various functions. In-fiber integrated optics is expected to he a new branch of photonics integration. This integration technique enables convenient light beams control and manipulation inside in one fiber. It also provides a research platform with micro and nano scale for interaction between light wave and microfluidic materials. In this review, we briefly summarize the main ideas and key technologies of the in-fiber integrated optics by series integration examples.展开更多
The typical functions of the optical fiber are communication and sensing. However, the fiber functions need to extend to meet the requirements of the development of artificial intelligence. This paper achieves an all-...The typical functions of the optical fiber are communication and sensing. However, the fiber functions need to extend to meet the requirements of the development of artificial intelligence. This paper achieves an all-fiber device with storage and logic computing functions using a single-mode fiber and Ge_(2)Sb_(2)Te_(5)(GST) material.We use the pulse amplitude modulation(the switching energy is about 50 nJ) to switch the GST state for performing the eight-level data storage(3-bit). The all-fiber memory device has the advantages of high optical contrast(about 38%), good reversibility, and high repeatability. We implement the all-optical logic operations(“AND”and “OR”) by using two memory cells in series and parallel. For the first time, we use the single-mode optical fiber to realize storage and computing functions, and this intelligent fiber has tremendous application potential in intelligent optical fiber communication and portends a new paradigm for brain-like computing.展开更多
We propose and demonstrate a dual-channel microfluidic sensor based on a side-hole fiber(SHF)with two longperiod fiber grating(LPFG)structures.There are two air holes in the SHF,which are natural microfluidic channels...We propose and demonstrate a dual-channel microfluidic sensor based on a side-hole fiber(SHF)with two longperiod fiber grating(LPFG)structures.There are two air holes in the SHF,which are natural microfluidic channels.We fabricate two LPFGs(long-period gratings LPG-A and LPG-B)in the SHF with the resonance wavelengths of 1268.7 nm and 1385.8 nm,respectively.Results show that the refractive index sensitivities of LPG-A and LPG-B are?76.0 nm/RIU and?71.1 nm/RIU,respectively.One can measure the refractive index of liquid samples in two channels simultaneously.The proposed dual-channel microfluidic sensor has advantages of good linearity response,fluidic technology compatibility,and easy light input/output coupling and system integration,which helps the sensor to have a potential application in environmental detection and food safety detection.展开更多
In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing ...In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing two opposite sides of a composite multimode-single-mode-multimode fiber structure using a CO;laser.The method improves the sensitivity of the sensor to external environment.Based on the simulation calculation,a liquid level sensor with a length of 3 mm is designed.The experimental transmission spectrum agrees well with the simulation result.The experimental results show that the sensitivity reaches 7080 pm/mm in the liquid level range of 0-1400 μm in water.The temperature sensitivity is24.52 pm/℃ in the range of 20℃-90℃.Due to the ultra-high sensitivity,good linearity,and compact structure,the SSC-LPFG has potential application in the field of high-Drecision liquid level measurement.展开更多
基金jointly supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region(Grant No.2022D01E104)the National Natural Science Foundation General Project(Grant No.41975010)+1 种基金the China Post doctoral Science Foundation(Grant No.2022MD723851)the Scientific and Technological Innovation Team(Tianshan Innovation Team)project(Grant No.2022TSYCTD0007).
文摘Control of desertification can not only ameliorate the natural environment of arid regions but also convert desertified land into significant terrestrial carbon sinks,thereby bolstering the carbon sequestration capacity of arid ecosystems.However,longstanding neglect of the potential carbon sink benefits of desertification management,and its relationship with environmental factors,has limited the exploration of carbon sequestration potential.Based on CO_(2) flux and environmental factors of artificial protective forest in the Taklamakan Desert from 2018 to 2019,we found that the carbon storage capacity of the desert ecosystem increased approximately 140-fold after the establishment of an artificial shelter forest in the desert,due to plant photosynthesis.Precipitation levels less than 2 mm had no impact on carbon exchange in the artificial shelter forest,whereas a precipitation level of approximately 4 mm stimulated a decrease in the vapor pressure deficit over a short period of about three days,promoting photosynthesis and enhancing the carbon absorption of the artificial shelter forest.Precipitation events greater than 8 mm stimulated soil respiration to release CO_(2) and promoted plant photosynthesis.In the dynamic equilibrium where precipitation stimulates both soil respiration and photosynthesis,there is a significant threshold value of soil moisture at 5 cm(0.12 m^(3) m^(-3)),which can serve as a good indicator of the strength of the stimulatory effect of precipitation on both.These results provide important data support for quantifying the contribution of artificial afforestation to carbon sequestration in arid areas,and provide guidance for the development and implementation of artificial forest management measures.
文摘<strong>Objective:</strong> To probe into the effect of catgut implantation at Baliao and Xingfu One Acupuncture Point on dysdefecation in patients with incomplete spinal cord injury (SCI). <strong>Methods:</strong> Three SCI patients voluntarily accepted catgut embedding at Baliao and Xingfu One Acupuncture point. Before and after treatment, they were filled out the self-rating scale of defecation, including the data of defecation frequency, total defecation time, defecation effort, fecal texture, fecal characteristics and fecal incontinence, etc. <strong>Results:</strong> Compared with the baseline data, constipation was improved and fecal incontinence was disappeared. <strong>Conclusions:</strong> Catgut implantation at Baliao and Xingfu One Acupuncture Point is effectual for patients with neurogenic dysporia secondary to incomplete SCI.
基金funded by the National Natural Science Foundation of China (41175017)the Central Scientific Research Institute of the public basic scientific research business professional ( IDM201103)the R&D Special Fund for Public Welfare Industry (Meteorology)(GYHY201106025)
文摘Tazhong is the hinterland and a sandstorm high-frequency area of the Taklimakan Desert. However, little is known about the detailed time-series of aeolian sand transport in this area. An experiment to study the sand-dust horizontal flux of near-surface was carried out in Tazhong from January to December 2009. By measur- ing the sand-dust horizontal flux throughout sixteen sand-dust weather processes with a 200-cm tall Big Spring Number Eight （BSNE） sampler tower, we quantitatively analyzed the vertical variation of the sand-dust horizontal flux. And the total sand-dust horizontal flux of different time-series that passed through a section of 100 cm in width and 200 cm in height was estimated combining the data of saltation movement continuously recorded by piezo- electric saltation sensors （Sensit）. The results indicated that, in the surface layer ranging from 0-200 cm, the inten- sity of sand-dust horizontal flux decreased with the increase of the height, and the physical quantities obeyed power function well. The total sand-dust horizontal flux of the sixteen sand-dust weather processes that passed through a section of 100 cm in width and 200 cm in height was about 2,144.9 kg, the maximum of one sand-dust weather event was about 396.3 kg, and the annual total sand-dust horizontal flux was about 3,903.2 kg. The high levels of aeolian sand transport occurred during daytime, especially from 13：00 to 16：00 in the afternoon. We try to develop a new method for estimation of the detailed time-series of aeolian sand transport.
基金funded by the National key Technology R & D Program (2008BAC40B05-01)the National Natural Science Foundation of China (40775019)Xinjiang Uygur Autonomous Region Science and Technology Key Project (200833119)
文摘The development and progress of soil wind erosion are influenced by the factors of climate, terrain, soil and vegetation, etc. This paper, taking Tazhong region, a town in the centre of the Taklimakan Desert, as an example and using comparative and quantitative methods, discussed the effects of climate, surface roughness （including vegetation cover） and surface soil properties on soil wind erosion. The results showed that the climate factor index C of annual wind erosion is 28.3, while the maximum of C is 13.9 in summer and it is only 0.7 in winter. The value of C has a very good exponential relationship with the wind speed. In Tazhong region, the surface roughness height is relatively small with a mean of 6.32 x 10 Sm, which is in favor of soil wind erosion. The wind erosion is further enhanced by its sandy soil types, soil particle size, lacking of vegetation and low soil moisture content. The present situation of soil wind erosion is the result of concurrent effects of climate, vegetation and surface soil properties.
基金funded by the National Key Technology R&D Program (2008BAC40B05-01)the National Department of Public Benefit (Meteorology) Research Foundation (GYHY201006012)+3 种基金 Science and Technology Key Project of Xinjiang Uygur autonomous region (200833119)the Research Foundation of China Desert Meteorology (Sqj2010014, Sqj2010007)the Meteorological New Technology Projects of China Meteorological Administration (CMATG2010M29) the Research Foundation of China Arid Meteorology (IAM201013)
文摘In this paper, the sand transport during a sand-dust storm in the Tazhong area of the central Taklimakan Desert from 11：29 to 23：56 on July 19, 2008 was observed and measured in real time. The sand flux at Tazhong was estimated using sand transport empirical formulas. The critical friction velocity at Tazhong was 0.24 m/s and the functional relation between the wind speed and sediment discharge at the height of 2 m was established. It was also found that the calculated values by Lettau＇s sediment discharge formula were close to those of the instrument measurements. The horizontal sand flux and the vertical sand flux during this sand-dust storm at Tazhong were respectively 258.67×10-4 kg/（m·s） and 40.07×10-7 kg/（m2·s）.
基金supported by Natural Science Founda-tion of China(Nos.41375162,41175017,41175140)China Special Fund for Meteorological Research in the Public Interest(Nos.GYHY201006012,GYHY201106025)
文摘The different height mass concentrations of dust aerosol data from the atmosphere environment observation station （Ta- zhong Station） was continuously observed by instruments of Grimm 1.108, Thermo RP 1400a and TSP from January of 2009 to February of 2010 in the Taklimakan Desert hinterland. Results show that： （1） The mass concentration value of 80 m PMl0 was higher, but PM2.5 and PM1.0 concentrations at 80 m was obviously lower than 4 m PMl0, and the value of 80 m PM1.0 mass concentration was the lowest. （2） The PM mass concentrations gradually decreased from night to sunrise, with the lowest concentration at 08：00, with the mass concentration gradually increased, up to the highest concentration around 18：00, and then decreased again. It was exactly the same with the changes of wind speed. （3） The high monthly average mass concentration of TSP mainly appeared from March to September, and the highest concentration was in April and May, subsequently gradually decreased. Also, March-September was a period with high value area of PM monthly average mass concentration, with the highest monthly average mass concentration of 846.0 p.g/m3 for 4 m PM^0 appeared in May. The concentration of PM10 was much higher than those of PM2.5 and PM1.0 at 80 m. There is a small difference between the concentration of PM2.5 and PM~ 0. Dust weather was the main factor which influenced the concentration content of the different diameter dust aerosol, and the more dust weather days, the higher content of coarse particle, conversely, fine particle was more. （4） The mass concentration of different diameter aerosols had the following sequence during dust weather： clear day 〈 blowing dust 〈 floating and blowing dust 〈 sandstorm. In different dust weather, the value of PM^o/TSP in fine weather was higher than that in floating weather, and much higher than those in blowing dust and sandstorm weather. （5） During the dust weather process, dust aerosol concentration gradually decreased with particle size decreasing. The dust aerosol mass concentration at different heights and diameter would have a peak value area every 3-4 days according to the strengthening process of dust weather.
基金supported by Natural Science Foundation of China (Nos. 41175017,41175140)Public Service sectors (meteorology) research and special funds by the Ministry of Science and Technology (Nos.GYHY201006012,GYHY201106025)
文摘During the course of a major sandstorm from April 17 to April 23, 2008 in the Taklimakan Desert, data pertaining to the mass concentrations of different-sized atmospheric particulate matter were observed continuously with Grimm 1.108, Thermo RP 1400a, TSP, and CAWS-600 instruments. The results showed that： （1） during the entire sandstorm process there were some dif- ferences between the daily mean particle concentration peaks and the hourly mean particle concentration peaks because the actual sandstorm lasted for only about 4 hr, whereas more particles were accumulated in the floating dust days before and after the actual sandstorm; （2） the intensity of the sandstorm was enhanced with the increase of wind speed, and this was related to the peak mass concentrations of atmospheric particulate matter; the wind speed directly affected the concentration of atmospheric particulate matter： the higher the wind speed, the higher the mass concentration （〉0.23 μm was 39,496.5 μg/m^3, and 〉20.0 μm was 5,390.7μg/m^3）; （3） the concentration changes of PM10 and TSP were also related to the course and intensity of the sandstorm; and （4） the mass concentration of atmospheric particulate matter had the following sequence during the dust weather： clear day 〈 floating dust 〈 floating and blowing dust 〈 sandstorm. Temperature, relative humidity, and barometric pressure are important factors affecting the strength of storms, which could also indirectly affect the concentration change of atmospheric particulate matter.
文摘Objective: To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in patients with neurological lower urinary tract dysfunction (NLUTD). Methods: From June 2012 to July 2013, patients with NLUTD were prospectively randomized and assigned to either a bladder irrigation group or a no bladder irrigation group. Bladder irrigations were performed twice a week by urologists. Patients were followed up at 6 months respectively. Primary outcomes were Incontinence-Specific Quality-of-Life Instrument (I-QoL), the rate incidences of bladder stone. All adverse events were also noted. Results: A total of 80 eligible patients participated and 78 (97.5%) patients (bladder irrigation, n = 39;no bladder irrigation, n = 39) completed 24 weeks of follow-up. Out of the 78 patients, 19 (24.3%) developed bladder stones. All occurred in no bladder irrigation group. In 8 of the 19 patients (42.1%), stones were only detected by cystoscopy. The bladder stones were mostly thin with an eggshell appearance (78.95% for diameter of stone < 5 mm, 84.21% for volume of bladder stone < 0.2 cm3). Bladder stones were removed by vigorous bladder irrigation guided by ultrasound (73.68%) or endoscopic lithotripsy (26.32%). The I-QOL was significantly better in the bladder irrigation group than in no bladder irrigation group at weeks 6, 12, 18, and 24 of follow-up. Conclusion: Bladder irrigation may be more effective and safer than no bladder irrigation for reducing the morbidity of bladder stone in spinal cord injury patients.
基金supported by Natural Science Foundation of China(Nos.41175017,41175140)China Special Fund for Meteorological Research in the Public Interest(Nos.GYHY201006012,GYHY201106025)
文摘Based on automatic continuous surface ozone concentration observation data from June 10, 2010 to March 20, 2012 in the Taklimakan Desert hinterland, combined with corresponding meteorological data, the temporal, seasonal and daily variation characteristics of surface ozone concentrations under different weather conditions were analyzed. At the same time, the main fac- tors affecting ozone variation are discussed. Results show that： （1） Daily variation of ozone concentration was characterized by one obvious peak, with gentle changes during the night and dramatic changes during the day. The lowest concentration was at 09：00 and the highest was at 18：00. Compared to urban areas, there was a slight time delay. （2） Ozone concentration variation had a weekend effect phenomenon. Weekly variation of ozone concentration decreased from Monday to Wednesday with the lowest in Wednesday, and increased after Thursday with the highest in Sunday. （3） The highest monthly average concentration was 89.6 I.tg/m3 in June 2010, and the lowest was 32.0 ~g/m3 in January 2012. Ozone concentration reduced month by month from June to December in 2010. （4） Ozone concentration in spring and summer was higher than in autumn and winter. The variation trend agreed with those in other large and medium-sized cities. （5） Under four different types of weather, daily ozone concentration var- ied most dramatically in sunny days, followed by slight variation in rain days, and varied gently in cloudy days. Ozone concentra- tion varied inconspicuously before a sandstorm appearance, and dropped rapidly at the onset of a sandstorm. （6） Daily variation of radiation was also characterized by a single peak, and the variation was significantly earlier than ozone concentration variation. Sun radiation intensity had a direct influence on the photochemical reaction speed, leading to variation of ozone concentration. （7） Daily average ozone concentration in dust weather was higher than in slight rain and clear days. The variation of near surface ozone concentration could also be affected by meteorological factors such as relative humidity, wind speed, wind direction and sunshine hours. Thus, numerous factors working together led to ozone pollution.
基金funded by the National Department Public Benefit (Meteorology) Research Foundation (No.GYHY201006012)the National Natural Science Foundation Project (No.40775019)+1 种基金the central level,scientific research institutes for the basic research and development special fund business (No.IDM2006002)Xinjiang Uighur Autonomous Region Science and Technology Key Project (No.200833119)
文摘In order to reveal the variation characteristics of ozone （03） concentration in the atmosphere boundary layer over a desert in winter, an observation experiment was carried out in the Tazhong area by means of a tethered balloon during January 18-25, 2008. The vertical distribution of O3 concentration and its correlation with temperature and humidity were analyzed based on experimental observation data and related data. Results show that： （1） The concentration of O3 mainly ranges from 10 to 50 μg/L, with a maximum of 56.1 μg/L, minimum of 2.6 μg/L, and a daily average concentration of 34.4 μg/L. （2） O3 profiles can be divided into three types： peak, uniform, and growth, where uniform accounts for the majority. （3） Temperature and moisture are influential on O3 concentrations in atmospheric boundary layer. Temperature inversion and water vapor increase in an atmospheric boundary layer leads to a decrease of O3. （4） O3 concentration has an obvious daily change in Tazhong. It is lower at night, begins to increase after sunrise, and reaches a maximum at noon. The maximum appears at 17：00 BJT （Beijing Time）, and the minimum appears at 08：00 BJT.
文摘<strong>Objective:</strong> Explore the rule of autonomic nervous dysfunction in the patients with urination disorder after high level spinal cord injury, and seek a safe, objective and accurate method to evaluate autonomic nervous function. <strong>Patients and Method:</strong> 48 patients with dysuria after cervicothoracic SCI were selected. Before, during and after imaging urodynamic examination with slow filling in supine position, blood pressure and ECG were monitored simultaneously. The symptoms of sweating, shivering, headache, flushing and chills were observed and recorded. The study of the relationship among the changes of blood pressure, heart rate and urodynamic indexes and the above symptoms was analyzed. <strong>Results:</strong> They were divided into three groups: group A (no obvious abnormality), group B (hyperactivity) and group C (hypoactivity) according to their BP, HR and existing the symptoms or not. <strong>Conclusion:</strong> The incidence of autonomic dysfunction in the high level SCI patients with dysuria was very high (79.17%), most of them were hyperactivity, and a few were low function. The changes of SBP and DBP in the hypoactivity group all appeared an increasing and then declining trend, while the change of HR in the low function one was lower than normal and decreased continuously. The main inducements of AD are neurogenic detrusor overactivity, detrusor sphincter dyssynergia, elevated abdominal pressure and abnormal bladder sensitivity. The asymptomatic patients had a higher occurrence rate (43.75%). Only by imaging urodynamic examination with slow filling and synchronous blood pressure monitoring, can autonomic nervous function of the patients be evaluated safely, objectively, early and accurately.
基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0602)the National Natural Science Foundation of China(41521004,41975010 and 41175140)the China University Research Talents Recruitment Program(B13045).
文摘The global carbon balance is a core issue in climate change research and a focus of in ternational policy concern[1-3].The"missing carbon sink"caused by approximately 1.6-2.0 Pg Ca-1(1 Pg=1015 g)that is currently unaccounted for,has long plagued researchers[4,5].Evidence is mounting those seemingly lifeless desert ecosystems,whose roles in the global carbon-cycle have long been neglected,exhib让the unconventional phenomenon of absorption of atmospheric CO2,sequestering enonnous amounts of CO2 and thereby creating a significant carbon-sink[6-9].
基金supported by the National Natural Science Foundation of China(Nos.11574061,61405043,and 61675053)the 111 Project(No.B13015)the Fundamental Research Funds for Harbin Engineering University of China
文摘We propose and demonstrate single fiber dual-functionality optical tweezers based on a graded-index multimode fiber. By using the multi-angle fiber grinding and polishing technology, we fabricate the multimode fiber tip to be a special tapered shape, contributing to focus the outgoing beam with a large intensity gradient for the first functionality--three-dimensional contactless trapping of a microparticle. By adjusting the radial direction offset between the lead-in single mode fiber and the graded-index multimode fiber, we perform the second functionality--axial shift of the trapped microparticle with respect to the fiber tip without need of moving the fiber probe itself. It is convenient for practical applications, The theoretical and experimental results about the relationship between the radial offset and the equilibrium positions of the microparticle have the good consistency. Tailoring the trap and axial shift of the microparticle based on the graded-index multimode fiber provides convenient avenues for fiber optical tweezers a~）Dlied in practical researches.
基金supported by the National Natural Science Foundation of China(Nos.61535004 and 61735009)the Guangxi Project(No.AD17195074)the National Defense Pre-Research Foundation of China(No.6140414030102)
文摘In-fiber integrated optics is an attempt to use silica fiber as a substrate, integrating various optical paths or optical components into a single fiber, to build a functional optical device or component, and to realize a micro optical system, achieving various functions. In-fiber integrated optics is expected to he a new branch of photonics integration. This integration technique enables convenient light beams control and manipulation inside in one fiber. It also provides a research platform with micro and nano scale for interaction between light wave and microfluidic materials. In this review, we briefly summarize the main ideas and key technologies of the in-fiber integrated optics by series integration examples.
基金National Key Research and Development Program of China (2018YFC1503703)National Natural Science Foundation of China (61775047, 61975039)+2 种基金Natural Science Foundation of Heilongjiang Province of China(YQ2020F011)111 Project (B13015)Fundamental Research Funds for Harbin Engineering University of China。
文摘The typical functions of the optical fiber are communication and sensing. However, the fiber functions need to extend to meet the requirements of the development of artificial intelligence. This paper achieves an all-fiber device with storage and logic computing functions using a single-mode fiber and Ge_(2)Sb_(2)Te_(5)(GST) material.We use the pulse amplitude modulation(the switching energy is about 50 nJ) to switch the GST state for performing the eight-level data storage(3-bit). The all-fiber memory device has the advantages of high optical contrast(about 38%), good reversibility, and high repeatability. We implement the all-optical logic operations(“AND”and “OR”) by using two memory cells in series and parallel. For the first time, we use the single-mode optical fiber to realize storage and computing functions, and this intelligent fiber has tremendous application potential in intelligent optical fiber communication and portends a new paradigm for brain-like computing.
基金supported by the National Key R&D Program of China(No.2018YFC1503703)the National Natural Science Foundation of China(Nos.61975039,61675053,61775047,and 61705051)+1 种基金the 111 Project(No.B13015)the Fundamental Research Funds for Harbin Engineering University of China。
文摘We propose and demonstrate a dual-channel microfluidic sensor based on a side-hole fiber(SHF)with two longperiod fiber grating(LPFG)structures.There are two air holes in the SHF,which are natural microfluidic channels.We fabricate two LPFGs(long-period gratings LPG-A and LPG-B)in the SHF with the resonance wavelengths of 1268.7 nm and 1385.8 nm,respectively.Results show that the refractive index sensitivities of LPG-A and LPG-B are?76.0 nm/RIU and?71.1 nm/RIU,respectively.One can measure the refractive index of liquid samples in two channels simultaneously.The proposed dual-channel microfluidic sensor has advantages of good linearity response,fluidic technology compatibility,and easy light input/output coupling and system integration,which helps the sensor to have a potential application in environmental detection and food safety detection.
基金supported by the Joint Research Fund in Astronomy under cooperative agreement between the National Natural Science Foundation of China (NSFC) and Chinese Academy of Sciences (CAS) (Nos. U1831115, U2031132, U1931206, and U2031130)Natural Science Foundation of Heilongjiang Province (No. ZD2019H003)Fundamental Research Funds for the Central Universities to the Harbin Engineering University
文摘In this paper,a novel liquid level sensor with ultra-high sensitivity is proposed.The proposed sensor is configured by a sliceshaped composite long period fiber grating(SSC-LPFG).The SSC-LPFG is prepared by polishing two opposite sides of a composite multimode-single-mode-multimode fiber structure using a CO;laser.The method improves the sensitivity of the sensor to external environment.Based on the simulation calculation,a liquid level sensor with a length of 3 mm is designed.The experimental transmission spectrum agrees well with the simulation result.The experimental results show that the sensitivity reaches 7080 pm/mm in the liquid level range of 0-1400 μm in water.The temperature sensitivity is24.52 pm/℃ in the range of 20℃-90℃.Due to the ultra-high sensitivity,good linearity,and compact structure,the SSC-LPFG has potential application in the field of high-Drecision liquid level measurement.
