The Tongling Non-ferrous Metals(Group) company was known forproducing the first copper ingot afterthe founding of new China.Through 44years and generations of exploration, thecompany has now become a large nationalcon...The Tongling Non-ferrous Metals(Group) company was known forproducing the first copper ingot afterthe founding of new China.Through 44years and generations of exploration, thecompany has now become a large nationalconglomerate of more than 30 units, includingsix mines, two smelting plants and threecopper processing factories, coordinated withmining, dressing, smelting and deepprocessing, with its products reaching 150varieties. The Jinlong Copper Co. Ltd.,jointly invested by this company and Japan’sSumitomo co., is the largest Sino-Foreignjoint venture in Anhui Province and theChina National Non-ferrous Metals IndustryCorporation, and is planned to go into operationin 1996. By then, the Tongling Non-ferrousMetals (Group) Company will be highlightedin China’s copper industry. In June 1993, the Ministry of ForeignTrade and Economic Cooperation authorizedthe company with the right of import andexport operation. In October the same year,the company established its own foreigntrade institution--the Tongling Non-ferrousMetals Import and Export Company,展开更多
The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can serio...The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can seriously affect oral function, facial appearance, and mental health. As anterior crossbite tends to worsen with growth, early orthodontic treatment can harness growth potential to normalize maxillofacial development or reduce skeletal malformation severity, thereby reducing the difficulty and shortening the treatment cycle of later-stage treatment. This is beneficial for the physical and mental growth of children. Therefore,early orthodontic treatment for Class Ⅲ malocclusion is particularly important. Determining the optimal timing for early orthodontic treatment requires a comprehensive assessment of clinical manifestations, dental age, and skeletal age, and can lead to better results with less effort. Currently, standardized treatment guidelines for early orthodontic treatment of Class Ⅲ malocclusion are lacking. This review provides a comprehensive summary of the etiology, clinical manifestations, classification, and early orthodontic techniques for Class Ⅲ malocclusion, along with systematic discussions on selecting early treatment plans. The purpose of this expert consensus is to standardize clinical practices and improve the treatment outcomes of Class Ⅲ malocclusion through early orthodontic treatment.展开更多
Muscle Shortening Maneuver(MSM)is a rehabilitation technique successfully applied to several pathological conditions.The concept is to passively elongate and shorten the target muscle group of the affected limb.As a r...Muscle Shortening Maneuver(MSM)is a rehabilitation technique successfully applied to several pathological conditions.The concept is to passively elongate and shorten the target muscle group of the affected limb.As a result,the functionality(muscle strength and range of motion)of that limb is improved.The existing system induces these oscillations manually or without any feedback control,which can compromise the effectiveness and standardization of MSM.In this paper,we present a mechatronic system that can precisely deliver motion oscillations to the upper limb for a controllable execution of MSM.First,we collected the parameters(frequency and amplitude of the oscillations)from a system where a motor was heuristically used by a well-experienced therapist to induce the oscillations(without any feedback control).Based on these specifications,we chose the motor and rebuilt the experimental setup,implementing a sliding mode control with a sliding perturbation observer.With our system,the operator can choose a given frequency and amplitude of the oscillations within the range we experimentally observed.We tested our system with ten participants of different anthropometry.We found that our system can accurately reproduce oscillations in the frequency range 0.8 to 1.2 Hz and amplitude range 2 to 6 cm,with a maximum percentage normalized root mean square error around 7%.展开更多
Numerical simulation and experimental research on Linear Friction Welding(LFW) for GH4169 superalloy were carried out. Based on the joint microstructure and mechanical properties,a suitable welding process was determi...Numerical simulation and experimental research on Linear Friction Welding(LFW) for GH4169 superalloy were carried out. Based on the joint microstructure and mechanical properties,a suitable welding process was determined, which provided an important theoretical basis for the manufacture and repair of aeroengine components such as the superalloy blisk. The results show that the joint strain rate gradually increases with the increase of welding frequency, and the deformation resistance of the thermoplastic metal increases in the welding process, resulting in the interface thermoplastic metal not being extruded in time to form a flash, so the joint shortening amount gradually decreases. The thermoplastic metal in the center of the welding surface is kept at high welding temperature for a long time, resulting in the decrease of the joint strength. The microhardness of the joint shows a “W” distribution perpendicular to the weld, and most of the joints break in the Thermo-Mechanically Affected Zone(TMAZ) with high tensile strength and low elongation.When the welding area is increased without changing the aspect ratio of the welding surface, the interface peak temperature increases gradually, and the joint shortening amount decreases with the increase of the welding interface size.展开更多
Due to its excellent biocompatibility and biodegradability,Mg and its alloys are considered to be promising materials for manufacturing of vascular sent.However,the manufacture of high-precision and high-performance M...Due to its excellent biocompatibility and biodegradability,Mg and its alloys are considered to be promising materials for manufacturing of vascular sent.However,the manufacture of high-precision and high-performance Mg alloys minitubes is still a worldwide problem with a long manufacturing processing caused by the poor workability of Mg alloys.To solve this problem,the cyclic extrusion compression(CEC)was used to pretreat the billet by improving the workability of Mg alloys,finally shortening the manufacturing process.After CEC treatment,the size of grains and second phase particles of Mg alloys were dramatically refined to 3.2μm and 0.3μm,respectively.Only after three passes of cold drawing,the wall thickness of minitube was reduced from 0.200 mm to 0.135 mm and a length was more than 1000 mm.The error of wall thickness was measured to be less than 0.01 mm,implying a high dimensional accuracy.The yield strength(YS),ultimate tensile strength(UTS)and elongation of finished minitube were 220±10 MPa,290±10 MPa and 22.0±0.5%,respectively.In addition,annealing can improve mechanical property and corrosion resistance of minitubes by improving the homogeneity of the microstructure and enhancing the density of basal texture.展开更多
Fluid shortening is an important ingredient in the production of sponge cake. Peanut oil with 0, 43% and 85% of diacylglycerol content was used as the base oil. Different emulsifiers, such as glycerol monostearate, so...Fluid shortening is an important ingredient in the production of sponge cake. Peanut oil with 0, 43% and 85% of diacylglycerol content was used as the base oil. Different emulsifiers, such as glycerol monostearate, soy lecithin and sucrose ester, and their respective amounts, were investigated. It was found that the addition of emulsifiers had a positive effect on water-absorbing capacity, air-absorbing capacity and viscosity of the oils. Glycerol monostearate was the preferred emulsifier for fluid shortening with a recommended addition of 1.5%. The effects of different diacylglycerol content on fluid shortening and their impact on sponge cake production was also investigated. The onset oxidation temperature of the oil could be increased from 253.21 ℃ for PO-TAG-based fluid shortening to 263.70 ℃ for PO-DAG85-based fluid shortening. And the increase in diacylglycerol content leading to a lower specific gravity of the batter, which was 1.06 g/mL, 1.02 g/mL and 0.98 g/mL prepared by PO-DAG, PO-DAG43 and PO-DAG85 shortening, respectively. The results showed that diacylglycerols can be used as base oils in fluid shortening to improve the crystal network and stability of fluid shortenings, thereby reducing the specific gravity of the batter and improving the structural properties of the cake. This will extend the potential applications of diacylglycerols and increase the variety of base oils available for fluid shortening preparation.展开更多
The demand for high-data-rate underwater acoustic communications(UACs)in marine development is increasing;however,severe multipaths make demodulation a challenge.The decision feedback equalizer(DFE)is one of the most ...The demand for high-data-rate underwater acoustic communications(UACs)in marine development is increasing;however,severe multipaths make demodulation a challenge.The decision feedback equalizer(DFE)is one of the most popular equalizers in UAC;however,it is not the optimal algorithm.Although maximum likelihood sequence estimation(MLSE)is the optimal algorithm,its complexity increases exponentially with the number of channel taps,making it challenging to apply to UAC.Therefore,this paper proposes a complexity-reduced MLSE to improve the bit error rate(BER)performance in multipath channels.In the proposed algorithm,the original channel is first shortened using a channel-shortening method,and several dominant channel taps are selected for MLSE.Subsequently,sphere decoding(SD)is performed in the following MLSE.Iterations are applied to eliminate inter-symbol interference caused by weak channel taps.The simulation and sea experiment demonstrate the superiority of the proposed algorithm.The simulation results show that channel shortening combined with SD can drastically reduce computational complexity,and iterative SD performs better than DFE based on recursive least squares(RLS-DFE),DFE based on improved proportionate normalized least mean squares(IPNLMS-DFE),and channel estimation-based DFE(CE-DFE).Moreover,the sea experimental results at Zhairuoshan Island in Zhoushan show that the proposed receiver scheme has improved BER performance over RLSDFE,IPNLMS-DFE,and CE-DFE.Compared with the RLS-DFE,the BER,after five iterations,is reduced from 0.0076 to 0.0037 in the 8–12 k Hz band and from 0.1516 to 0.1145 in the 13–17 k Hz band at a distance of 2000 m.Thus,the proposed algorithm makes it possible to apply MLSE in UAC in practical scenarios.展开更多
Shortening is one of important word formations which demands attentions of both teachers and students. The paper first briefly introduces shortening words in English into clipped words, initialisms, acronyms and blend...Shortening is one of important word formations which demands attentions of both teachers and students. The paper first briefly introduces shortening words in English into clipped words, initialisms, acronyms and blends,and then it mainly explores the reasons why shortening words appear and become popular.展开更多
The eastern margin of the Qaidam Basin lies in the key tectonic location connecting the Qinling, Qilian and East Kunlun orogens. The paper presents an investigation and analysis of the geologic structures of the area ...The eastern margin of the Qaidam Basin lies in the key tectonic location connecting the Qinling, Qilian and East Kunlun orogens. The paper presents an investigation and analysis of the geologic structures of the area and LA-ICP MS zircon U-Pb dating of Paleozoic and Mesozoic magmatisms of granitoids in the basement of the eastern Qaidam Basin on the basis of 16 granitoid samples collected from the South Qilian Mountains, the Qaidam Basin basement and the East Kunlun Mountains. According to the results in this paper, the basement of the basin, from the northern margin of the Qaidam Basin to the East Kunlun Mountains, has experienced at least three periods of intrusive activities of granitoids since the Early Paleozoic, i.e. the magmatisms occurring in the Late Cambrian （493.1±4.9 Ma）, the Silurian （422.9±8.0 Ma-420.4±4.6 Ma） and the Late Permian-Middle Triassic （257.8±4.0 Ma-228.8＋1.5 Ma）, respectively. Among them, the Late Permian - Middle Triassic granitoids form the main components of the basement of the basin. The statistics of dated zircons in this paper shows the intrusive magmatic activities in the basement of the basin have three peak ages of 244 Ma （main）, 418 Ma, and 493 Ma respectively. The dating results reveal that the Early Paleozoic magmatism of granitoids mainly occurred on the northern margin of the Qaidam Basin and the southern margin of the Qilian Mountains, with only weak indications in the East Kunlun Mountains. However, the distribution of Permo-Triassic （P-T） granitoids occupied across the whole basement of the eastern Qaidam Basin from the southern margin of the Qilian Mountains to the East Kunlun Mountains. An integrated analysis of the age distribution of P-T granitoids in the Qaidam Basin and its surrounding mountains shows that the earliest P-T magmatism （293.6-270 Ma） occurred in the northwestern part of the basin and expanded eastwards and southwards, resulting in the P-T intrusive magmatism that ran through the whole basin basement. As the Cenozoic basement thrust system developed in the eastern Qaidam Basin, the nearly N-S-trending shortening and deformation in the basement of the basin tended to intensify from west to east, which went contrary to the distribution trend of N-S-trending shortening and deformation in the Cenozoic cover of the basin, reflecting that there was a transformation of shortening and thickening of Cenozoic crust between the eastern and western parts of the Qaidam Basin, i.e., the crustal shortening of eastern Qaidam was dominated by the basement deformation （triggered at the middle and lower crust）, whereas that of western Qaidam was mainly by folding and thrusting of the sedimentary cover （the upper crust）.展开更多
The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collisio...The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collision since -55 Ma have been well recorded. Based on the latest progress in high-resolution stratigraphy, a technique of balanced section was applied to six pieces of northeast- southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began to shorten deformation nearly synchronous to the early collision, manifesting as a weak compression, the deformation increased significantly during the Middle and Late Eocene, and then weakened slightly and began to accelerate rapidly since the Late Miocene, especially since the Quaternary, reflecting this powerful compressional deformation and rapid uplift of the northern Tibetan Plateau around the Qaidam Basin.展开更多
The Ailaoshan-Red River（ASRR） shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed...The Ailaoshan-Red River（ASRR） shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed linearly along the shear zone,e.g.Xuelongshan,Diancangshan, Ailaoshan and Day Nui Con Voi from north to south.They bear a lot of lines of evidence for the tectonic evolution of the eastern Tibetan at different crustal levels in different tectonic stages.Controversy still exists on the deformation structures,microstructures and their relationship with metamorphisms along the ASRR.In this paper detailed microstructural and EBSD（Electron Backscattered Diffraction） fabric analysis of some highly sheared granitic rocks from different massifs along the ASRR are conducted.High temperature structures and microstructures are preserved in unsheared gneisses,in weakly sheared xenoliths or in some parts of the highly sheared rocks（mylonites）.Several types of high temperature quartz c-axis fabrics show symmetrical patterns or transitions from symmetrical to asymmetrical patterns.The former are attributed to coaxial deformation during regional shortening in an early stage of the Indian-Eurasian tectonic interaction and the latter are related to the transitions from coaxial compression to noncoaxial shearing during the post-collisional ASRR left lateral shearing.展开更多
Aging is the most prominent risk factor contributing to the development of neurodegenerative disorders. In the United States, over 35 million of elderly people suffer from age-related diseases. Aging impairs the self-...Aging is the most prominent risk factor contributing to the development of neurodegenerative disorders. In the United States, over 35 million of elderly people suffer from age-related diseases. Aging impairs the self-repair ability of neuronal cells, which undergo progressive deterioration. Once initiated, this process hampers the already limited regenerative power of the central nervous system, making the search for new therapeutic strategies particularly difficult in elderly affected patients. So far, mesenchymal stem cells have proven to be a viable option to ameliorate certain aspects of neurodegeneration, as they possess high proliferative rate and differentiate in vitro into multiple lineages. However, accumulating data have demonstrated that during longterm culture, mesenchymal stem cells undergo spontaneous transformation. Transformed mesenchymal stem cells show typical features of senescence, including the progressive shortening of telomers, which results in cell loss and, as a consequence, hampered regenerative potential. These evidences, in line with those observed in mesenchymal stem cells isolated from old donors, suggest that senescence may represent a limit to mesenchymal stem cells exploitation in therapy, prompting scholars to either find alternative sources of pluripotent cells or to arrest the age-re- lated transformation. In the present review, we summarize findings from recent literature, and critically discuss some of the major hurdles encountered in the search of appropriate sources of mesenchymal stem cells, as well as benefits arising from their use in neurodegenerative diseases. Finally, we provide some insights that may aid in the development of strategies to arrest or, at least, delay the aging of mesenchymal stem cells to improve their therapeutic potential.展开更多
By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt, China, we concluded that it had experienced five tectonic stages： （1） the formation stage （T3x） of the miniatur...By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt, China, we concluded that it had experienced five tectonic stages： （1） the formation stage （T3x） of the miniature of Longmen Mountain, early Indosinian movement, and Anxian tectonic movement created the Longmen Mountain; （2） the stable tectonic stage （J1） where weaker tectonic movement resulted in the Longmen Mountain thrust belt being slightly uplifted and slightly subsiding the foreland basin; （3） the intense tectonic stage （J2-3）, namely the early Yanshan movement; （4） continuous tectonic movement （K-E）, namely the late Yanshan movement and early Himalayan movement; and （5） the formation of Longmen Mountain （N-Q）, namely the late Himalayan movement. During those tectonic deformation stages, the Anxian movement and Himalayan movement played important roles in the Longmen Mountain＇s formation. The Himalayan movement affected Longmen Mountain the most; the strata thrust intensively and were eroded severely. There are some klippes in the middle part of the Longmen Mountain thrust belt because a few nappes were pushed southeastward in later tectonic deformation.展开更多
With the rapid advancement of computing and information technology at the turn of the 21st century,the power of data collection and processing has multiplied tremendously.Based on this a game-changing advancement,scie...With the rapid advancement of computing and information technology at the turn of the 21st century,the power of data collection and processing has multiplied tremendously.Based on this a game-changing advancement,science is at the advent of the “fourth paradigm”of massive data plus artificial intelligence,in which the efficiency of scientific research is continuously improved,research time is shortened,and research cost is reduced[1].展开更多
The Yinwashan and Xinminpu faults are located in the Jiuxi Basin in the western end of the Hexi Corridor. The determination of their activity and slip rates is of great significance for understanding the eastward exte...The Yinwashan and Xinminpu faults are located in the Jiuxi Basin in the western end of the Hexi Corridor. The determination of their activity and slip rates is of great significance for understanding the eastward extension of the Altyn Tagh fault. Based on geological and geomorphologic field survey, trench excavation, optically stimulated luminescence dating, we define the fault geometry and kinematic properties of the two faults. Based on fault scarps measurement using differential GPS and 10 Be surface exposure dating, we determined vertical slip rate of 0.09±0.01 mm/yr for the Yinwashan fault and 0.1±0.02 mm/yr for the Xinminpu fault. Using the dips observed in trenches and natural sections, we estimated horizontal shortening rates of 0.05±0.03 and 0.23±0.06 mm/yr, respectively. No significant strike slip motion is observed on these two faults, and we infer that this region was dominated by horizontal shortening in the Late Quaternary. Although the shortening rate is quite low on each individual fault, together with other faults in this area, these two faults have an essential role in transferring slip from the eastern end of the Altyn Tagh fault and in accommodating the northeastward growth of Tibetan Plateau.展开更多
We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeli...We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be requiredfor peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.展开更多
Reconstruction of the paleoaltitude history of the Tibetan Plateau is critical for understanding the linkage between tectonics and its effect on regional and global climate change.Presently,most of the paleoaltitude s...Reconstruction of the paleoaltitude history of the Tibetan Plateau is critical for understanding the linkage between tectonics and its effect on regional and global climate change.Presently,most of the paleoaltitude studies are concentrated on the southern and southeastern part of the Tibetan Plateau,and few studies have been conducted in the central-northern part.In this paper we focused on the Wudaoliang Formation in the Tuotuohe Basin,central to northern Tibetan Plateau,to reconstruct paleoaltitude based on carbonate oxygen isotopes.The carbonate samples are primary or have experienced an early stage of digenesis.Based on the thermodynamic and empirical model results,the paleoaltitude of the Wudaoliang Formation is found to be around 2700–3260 m(average of 2980±280 m)in the early Miocene(~24 Ma).Integrating paleoaltitude results from Wudaoliang Basin and our results,we conclude that crustal shortening and tectonic activity were strong during the late Eocene to late Oligocene-early Miocene and relatively weak during the early Miocene in the central-northern Tibetan Plateau.展开更多
The M-BCJR algorithm based on the Ungerboeck observation model is a recent study to reduce the computational complexity for faster-than-Nyquist(FTN)signaling[1].In this paper,we propose a method that can further reduc...The M-BCJR algorithm based on the Ungerboeck observation model is a recent study to reduce the computational complexity for faster-than-Nyquist(FTN)signaling[1].In this paper,we propose a method that can further reduce the complexity with the approximately same or better bit error rate(BER)performance compared to[1].The information rate(IR)loss for the proposed method is less than 1%compared to the true achievable IR(AIR).The proposed improvement is mainly by introducing channel shortening(CS)before the M-BCJR equalizer.In our proposal,the Ungerboeck M-BCJR algorithm and CS can work together to defeat severe inter-symbol interference(ISI)introduced by FTN signaling.The ISI length for the M-BCJR algorithm with CS is optimized based on the criterion of the IR maximization.For the two cases=0.5 and=0.35,compared to Ungerboeck M-BCJR without CS benchmark[1],the computational complexities of Ungerboeck M-BCJR with CS are reduced by 75%.Moreover,for the case=0.35,the BER performance of Ungerboeck M-BCJR with CS outperforms that of the conventional M-BCJR in[1]at the low signal to noise ratio region.展开更多
The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic -Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision si...The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic -Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision since～55 Ma have been well recorded.Based on the latest progress in high-resolution stratigraphy,a technique of balanced section was applied to six pieces of northeast-southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began展开更多
文摘The Tongling Non-ferrous Metals(Group) company was known forproducing the first copper ingot afterthe founding of new China.Through 44years and generations of exploration, thecompany has now become a large nationalconglomerate of more than 30 units, includingsix mines, two smelting plants and threecopper processing factories, coordinated withmining, dressing, smelting and deepprocessing, with its products reaching 150varieties. The Jinlong Copper Co. Ltd.,jointly invested by this company and Japan’sSumitomo co., is the largest Sino-Foreignjoint venture in Anhui Province and theChina National Non-ferrous Metals IndustryCorporation, and is planned to go into operationin 1996. By then, the Tongling Non-ferrousMetals (Group) Company will be highlightedin China’s copper industry. In June 1993, the Ministry of ForeignTrade and Economic Cooperation authorizedthe company with the right of import andexport operation. In October the same year,the company established its own foreigntrade institution--the Tongling Non-ferrousMetals Import and Export Company,
文摘The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can seriously affect oral function, facial appearance, and mental health. As anterior crossbite tends to worsen with growth, early orthodontic treatment can harness growth potential to normalize maxillofacial development or reduce skeletal malformation severity, thereby reducing the difficulty and shortening the treatment cycle of later-stage treatment. This is beneficial for the physical and mental growth of children. Therefore,early orthodontic treatment for Class Ⅲ malocclusion is particularly important. Determining the optimal timing for early orthodontic treatment requires a comprehensive assessment of clinical manifestations, dental age, and skeletal age, and can lead to better results with less effort. Currently, standardized treatment guidelines for early orthodontic treatment of Class Ⅲ malocclusion are lacking. This review provides a comprehensive summary of the etiology, clinical manifestations, classification, and early orthodontic techniques for Class Ⅲ malocclusion, along with systematic discussions on selecting early treatment plans. The purpose of this expert consensus is to standardize clinical practices and improve the treatment outcomes of Class Ⅲ malocclusion through early orthodontic treatment.
基金supported by the European Union by the Next Generation EU Project ECS00000017‘Ecosistema dell’Innovazione’Tuscany Health Ecosystem(THE,PNRR,Spoke 9:Robotics and Automation for Health)by the Italian Ministry of Education and Research(MUR)in the framework of the FoReLab project(Departments of Excellence).
文摘Muscle Shortening Maneuver(MSM)is a rehabilitation technique successfully applied to several pathological conditions.The concept is to passively elongate and shorten the target muscle group of the affected limb.As a result,the functionality(muscle strength and range of motion)of that limb is improved.The existing system induces these oscillations manually or without any feedback control,which can compromise the effectiveness and standardization of MSM.In this paper,we present a mechatronic system that can precisely deliver motion oscillations to the upper limb for a controllable execution of MSM.First,we collected the parameters(frequency and amplitude of the oscillations)from a system where a motor was heuristically used by a well-experienced therapist to induce the oscillations(without any feedback control).Based on these specifications,we chose the motor and rebuilt the experimental setup,implementing a sliding mode control with a sliding perturbation observer.With our system,the operator can choose a given frequency and amplitude of the oscillations within the range we experimentally observed.We tested our system with ten participants of different anthropometry.We found that our system can accurately reproduce oscillations in the frequency range 0.8 to 1.2 Hz and amplitude range 2 to 6 cm,with a maximum percentage normalized root mean square error around 7%.
基金supported by the National Natural Science Foundation of China (Nos. 52305420, 52074228 and 51875470)the China Postdoctoral Science Foundation (No. 2023M742830)the Xi’an Beilin District Science and Technology Planning Project, China (No. GX2349)。
文摘Numerical simulation and experimental research on Linear Friction Welding(LFW) for GH4169 superalloy were carried out. Based on the joint microstructure and mechanical properties,a suitable welding process was determined, which provided an important theoretical basis for the manufacture and repair of aeroengine components such as the superalloy blisk. The results show that the joint strain rate gradually increases with the increase of welding frequency, and the deformation resistance of the thermoplastic metal increases in the welding process, resulting in the interface thermoplastic metal not being extruded in time to form a flash, so the joint shortening amount gradually decreases. The thermoplastic metal in the center of the welding surface is kept at high welding temperature for a long time, resulting in the decrease of the joint strength. The microhardness of the joint shows a “W” distribution perpendicular to the weld, and most of the joints break in the Thermo-Mechanically Affected Zone(TMAZ) with high tensile strength and low elongation.When the welding area is increased without changing the aspect ratio of the welding surface, the interface peak temperature increases gradually, and the joint shortening amount decreases with the increase of the welding interface size.
基金supported by the National Key Research and Development Program of China(2021YFC2400703)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1804251).
文摘Due to its excellent biocompatibility and biodegradability,Mg and its alloys are considered to be promising materials for manufacturing of vascular sent.However,the manufacture of high-precision and high-performance Mg alloys minitubes is still a worldwide problem with a long manufacturing processing caused by the poor workability of Mg alloys.To solve this problem,the cyclic extrusion compression(CEC)was used to pretreat the billet by improving the workability of Mg alloys,finally shortening the manufacturing process.After CEC treatment,the size of grains and second phase particles of Mg alloys were dramatically refined to 3.2μm and 0.3μm,respectively.Only after three passes of cold drawing,the wall thickness of minitube was reduced from 0.200 mm to 0.135 mm and a length was more than 1000 mm.The error of wall thickness was measured to be less than 0.01 mm,implying a high dimensional accuracy.The yield strength(YS),ultimate tensile strength(UTS)and elongation of finished minitube were 220±10 MPa,290±10 MPa and 22.0±0.5%,respectively.In addition,annealing can improve mechanical property and corrosion resistance of minitubes by improving the homogeneity of the microstructure and enhancing the density of basal texture.
基金The Bureau of Science and Information of Guangzhou under grant 2024A04J3254the National Natural Science Foundation of China under grant 32272341the Department of Science and Technology of Guangdong Province under grant numbers 2022B0202010003。
文摘Fluid shortening is an important ingredient in the production of sponge cake. Peanut oil with 0, 43% and 85% of diacylglycerol content was used as the base oil. Different emulsifiers, such as glycerol monostearate, soy lecithin and sucrose ester, and their respective amounts, were investigated. It was found that the addition of emulsifiers had a positive effect on water-absorbing capacity, air-absorbing capacity and viscosity of the oils. Glycerol monostearate was the preferred emulsifier for fluid shortening with a recommended addition of 1.5%. The effects of different diacylglycerol content on fluid shortening and their impact on sponge cake production was also investigated. The onset oxidation temperature of the oil could be increased from 253.21 ℃ for PO-TAG-based fluid shortening to 263.70 ℃ for PO-DAG85-based fluid shortening. And the increase in diacylglycerol content leading to a lower specific gravity of the batter, which was 1.06 g/mL, 1.02 g/mL and 0.98 g/mL prepared by PO-DAG, PO-DAG43 and PO-DAG85 shortening, respectively. The results showed that diacylglycerols can be used as base oils in fluid shortening to improve the crystal network and stability of fluid shortenings, thereby reducing the specific gravity of the batter and improving the structural properties of the cake. This will extend the potential applications of diacylglycerols and increase the variety of base oils available for fluid shortening preparation.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 62101489, 62171405 and 62225114.
文摘The demand for high-data-rate underwater acoustic communications(UACs)in marine development is increasing;however,severe multipaths make demodulation a challenge.The decision feedback equalizer(DFE)is one of the most popular equalizers in UAC;however,it is not the optimal algorithm.Although maximum likelihood sequence estimation(MLSE)is the optimal algorithm,its complexity increases exponentially with the number of channel taps,making it challenging to apply to UAC.Therefore,this paper proposes a complexity-reduced MLSE to improve the bit error rate(BER)performance in multipath channels.In the proposed algorithm,the original channel is first shortened using a channel-shortening method,and several dominant channel taps are selected for MLSE.Subsequently,sphere decoding(SD)is performed in the following MLSE.Iterations are applied to eliminate inter-symbol interference caused by weak channel taps.The simulation and sea experiment demonstrate the superiority of the proposed algorithm.The simulation results show that channel shortening combined with SD can drastically reduce computational complexity,and iterative SD performs better than DFE based on recursive least squares(RLS-DFE),DFE based on improved proportionate normalized least mean squares(IPNLMS-DFE),and channel estimation-based DFE(CE-DFE).Moreover,the sea experimental results at Zhairuoshan Island in Zhoushan show that the proposed receiver scheme has improved BER performance over RLSDFE,IPNLMS-DFE,and CE-DFE.Compared with the RLS-DFE,the BER,after five iterations,is reduced from 0.0076 to 0.0037 in the 8–12 k Hz band and from 0.1516 to 0.1145 in the 13–17 k Hz band at a distance of 2000 m.Thus,the proposed algorithm makes it possible to apply MLSE in UAC in practical scenarios.
文摘Shortening is one of important word formations which demands attentions of both teachers and students. The paper first briefly introduces shortening words in English into clipped words, initialisms, acronyms and blends,and then it mainly explores the reasons why shortening words appear and become popular.
基金supports by the Basic Research Foundation of the Institute of Geomechanics,CAGS,China (DZLXJK200703)the National Natural Science Foundation of China(40342015)+1 种基金SinoProbe-Deep Exploration in China(SinoProbe-08)the National Science Foundation(USA) Instrumentation and Facilities Program (EAR-0443387)
文摘The eastern margin of the Qaidam Basin lies in the key tectonic location connecting the Qinling, Qilian and East Kunlun orogens. The paper presents an investigation and analysis of the geologic structures of the area and LA-ICP MS zircon U-Pb dating of Paleozoic and Mesozoic magmatisms of granitoids in the basement of the eastern Qaidam Basin on the basis of 16 granitoid samples collected from the South Qilian Mountains, the Qaidam Basin basement and the East Kunlun Mountains. According to the results in this paper, the basement of the basin, from the northern margin of the Qaidam Basin to the East Kunlun Mountains, has experienced at least three periods of intrusive activities of granitoids since the Early Paleozoic, i.e. the magmatisms occurring in the Late Cambrian （493.1±4.9 Ma）, the Silurian （422.9±8.0 Ma-420.4±4.6 Ma） and the Late Permian-Middle Triassic （257.8±4.0 Ma-228.8＋1.5 Ma）, respectively. Among them, the Late Permian - Middle Triassic granitoids form the main components of the basement of the basin. The statistics of dated zircons in this paper shows the intrusive magmatic activities in the basement of the basin have three peak ages of 244 Ma （main）, 418 Ma, and 493 Ma respectively. The dating results reveal that the Early Paleozoic magmatism of granitoids mainly occurred on the northern margin of the Qaidam Basin and the southern margin of the Qilian Mountains, with only weak indications in the East Kunlun Mountains. However, the distribution of Permo-Triassic （P-T） granitoids occupied across the whole basement of the eastern Qaidam Basin from the southern margin of the Qilian Mountains to the East Kunlun Mountains. An integrated analysis of the age distribution of P-T granitoids in the Qaidam Basin and its surrounding mountains shows that the earliest P-T magmatism （293.6-270 Ma） occurred in the northwestern part of the basin and expanded eastwards and southwards, resulting in the P-T intrusive magmatism that ran through the whole basin basement. As the Cenozoic basement thrust system developed in the eastern Qaidam Basin, the nearly N-S-trending shortening and deformation in the basement of the basin tended to intensify from west to east, which went contrary to the distribution trend of N-S-trending shortening and deformation in the Cenozoic cover of the basin, reflecting that there was a transformation of shortening and thickening of Cenozoic crust between the eastern and western parts of the Qaidam Basin, i.e., the crustal shortening of eastern Qaidam was dominated by the basement deformation （triggered at the middle and lower crust）, whereas that of western Qaidam was mainly by folding and thrusting of the sedimentary cover （the upper crust）.
基金co-supported by the President Fund and Innovation Program of Chinese Academy of Sciences(no.:kzcx2-yw-104)the Chinese National Science Foundation grants(no.:40334038)the Science and Technology Key Project of Ministry of Education of China(no.:306016).
文摘The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collision since -55 Ma have been well recorded. Based on the latest progress in high-resolution stratigraphy, a technique of balanced section was applied to six pieces of northeast- southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began to shorten deformation nearly synchronous to the early collision, manifesting as a weak compression, the deformation increased significantly during the Middle and Late Eocene, and then weakened slightly and began to accelerate rapidly since the Late Miocene, especially since the Quaternary, reflecting this powerful compressional deformation and rapid uplift of the northern Tibetan Plateau around the Qaidam Basin.
基金supported by the National Key Basic Research and Development(973) Project (2009CB421001)National Natural Science Foundation of China(40872139)+2 种基金China Geological Survey (1212010661311)Ministry of Land and Resources (200811008)the Ministry of Education,Proiect 111 (B07011)
文摘The Ailaoshan-Red River（ASRR） shear zone is one of the major Southeast Asian tectonic discontinuities that have figured the present tectonic framework of the eastern Tibet.Several metamorphic massifs are distributed linearly along the shear zone,e.g.Xuelongshan,Diancangshan, Ailaoshan and Day Nui Con Voi from north to south.They bear a lot of lines of evidence for the tectonic evolution of the eastern Tibetan at different crustal levels in different tectonic stages.Controversy still exists on the deformation structures,microstructures and their relationship with metamorphisms along the ASRR.In this paper detailed microstructural and EBSD（Electron Backscattered Diffraction） fabric analysis of some highly sheared granitic rocks from different massifs along the ASRR are conducted.High temperature structures and microstructures are preserved in unsheared gneisses,in weakly sheared xenoliths or in some parts of the highly sheared rocks（mylonites）.Several types of high temperature quartz c-axis fabrics show symmetrical patterns or transitions from symmetrical to asymmetrical patterns.The former are attributed to coaxial deformation during regional shortening in an early stage of the Indian-Eurasian tectonic interaction and the latter are related to the transitions from coaxial compression to noncoaxial shearing during the post-collisional ASRR left lateral shearing.
基金part supported by the Department of Biomedical Sciences and Biotechnologies,Medical School,University of Catania,Italy(National Grant.PON 01_00110)
文摘Aging is the most prominent risk factor contributing to the development of neurodegenerative disorders. In the United States, over 35 million of elderly people suffer from age-related diseases. Aging impairs the self-repair ability of neuronal cells, which undergo progressive deterioration. Once initiated, this process hampers the already limited regenerative power of the central nervous system, making the search for new therapeutic strategies particularly difficult in elderly affected patients. So far, mesenchymal stem cells have proven to be a viable option to ameliorate certain aspects of neurodegeneration, as they possess high proliferative rate and differentiate in vitro into multiple lineages. However, accumulating data have demonstrated that during longterm culture, mesenchymal stem cells undergo spontaneous transformation. Transformed mesenchymal stem cells show typical features of senescence, including the progressive shortening of telomers, which results in cell loss and, as a consequence, hampered regenerative potential. These evidences, in line with those observed in mesenchymal stem cells isolated from old donors, suggest that senescence may represent a limit to mesenchymal stem cells exploitation in therapy, prompting scholars to either find alternative sources of pluripotent cells or to arrest the age-re- lated transformation. In the present review, we summarize findings from recent literature, and critically discuss some of the major hurdles encountered in the search of appropriate sources of mesenchymal stem cells, as well as benefits arising from their use in neurodegenerative diseases. Finally, we provide some insights that may aid in the development of strategies to arrest or, at least, delay the aging of mesenchymal stem cells to improve their therapeutic potential.
基金support from the National Natural Science Foundation of China (grant No.40672143,40472107,and 40172076)the National Major Fundamental Research and Development Project (grant No.2005CB422107 and G1999043305)+1 种基金the Development Foundation of Key Laboratory for Hydrocarbon Accumulation of Education Ministry (grant No.2003-03)the Project of Southwestern Exploration and Development Division Company,SINOPEC (GJ-51-0602).
文摘By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt, China, we concluded that it had experienced five tectonic stages： （1） the formation stage （T3x） of the miniature of Longmen Mountain, early Indosinian movement, and Anxian tectonic movement created the Longmen Mountain; （2） the stable tectonic stage （J1） where weaker tectonic movement resulted in the Longmen Mountain thrust belt being slightly uplifted and slightly subsiding the foreland basin; （3） the intense tectonic stage （J2-3）, namely the early Yanshan movement; （4） continuous tectonic movement （K-E）, namely the late Yanshan movement and early Himalayan movement; and （5） the formation of Longmen Mountain （N-Q）, namely the late Himalayan movement. During those tectonic deformation stages, the Anxian movement and Himalayan movement played important roles in the Longmen Mountain＇s formation. The Himalayan movement affected Longmen Mountain the most; the strata thrust intensively and were eroded severely. There are some klippes in the middle part of the Longmen Mountain thrust belt because a few nappes were pushed southeastward in later tectonic deformation.
文摘With the rapid advancement of computing and information technology at the turn of the 21st century,the power of data collection and processing has multiplied tremendously.Based on this a game-changing advancement,science is at the advent of the “fourth paradigm”of massive data plus artificial intelligence,in which the efficiency of scientific research is continuously improved,research time is shortened,and research cost is reduced[1].
基金the Basic Research Project of Institute of Earthquake Science,CEA(No.2019IESLZ01)the National Science Foundation of China(No.41402186)。
文摘The Yinwashan and Xinminpu faults are located in the Jiuxi Basin in the western end of the Hexi Corridor. The determination of their activity and slip rates is of great significance for understanding the eastward extension of the Altyn Tagh fault. Based on geological and geomorphologic field survey, trench excavation, optically stimulated luminescence dating, we define the fault geometry and kinematic properties of the two faults. Based on fault scarps measurement using differential GPS and 10 Be surface exposure dating, we determined vertical slip rate of 0.09±0.01 mm/yr for the Yinwashan fault and 0.1±0.02 mm/yr for the Xinminpu fault. Using the dips observed in trenches and natural sections, we estimated horizontal shortening rates of 0.05±0.03 and 0.23±0.06 mm/yr, respectively. No significant strike slip motion is observed on these two faults, and we infer that this region was dominated by horizontal shortening in the Late Quaternary. Although the shortening rate is quite low on each individual fault, together with other faults in this area, these two faults have an essential role in transferring slip from the eastern end of the Altyn Tagh fault and in accommodating the northeastward growth of Tibetan Plateau.
文摘We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be requiredfor peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.
基金supported by the“Strategic Priority Research Program”of the Chinese Academy of Sciences(XDB26000000)the National Natural Science Foundation of China(No.42572166,41420104008)+3 种基金Open Fund of the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAS(SKLLQG1629,SKLLQG1708)Breeding programs of State Key Laboratory of Loess and Quaternary Geology(SKLLQGPY1804)the“The Second Tibetan Plateau Scientific Expedition and Research”a part of the“Belt&Road”project of IEECAS。
文摘Reconstruction of the paleoaltitude history of the Tibetan Plateau is critical for understanding the linkage between tectonics and its effect on regional and global climate change.Presently,most of the paleoaltitude studies are concentrated on the southern and southeastern part of the Tibetan Plateau,and few studies have been conducted in the central-northern part.In this paper we focused on the Wudaoliang Formation in the Tuotuohe Basin,central to northern Tibetan Plateau,to reconstruct paleoaltitude based on carbonate oxygen isotopes.The carbonate samples are primary or have experienced an early stage of digenesis.Based on the thermodynamic and empirical model results,the paleoaltitude of the Wudaoliang Formation is found to be around 2700–3260 m(average of 2980±280 m)in the early Miocene(~24 Ma).Integrating paleoaltitude results from Wudaoliang Basin and our results,we conclude that crustal shortening and tectonic activity were strong during the late Eocene to late Oligocene-early Miocene and relatively weak during the early Miocene in the central-northern Tibetan Plateau.
基金This work was supported by National Natural Science Foundation of China(No.61961014).
文摘The M-BCJR algorithm based on the Ungerboeck observation model is a recent study to reduce the computational complexity for faster-than-Nyquist(FTN)signaling[1].In this paper,we propose a method that can further reduce the complexity with the approximately same or better bit error rate(BER)performance compared to[1].The information rate(IR)loss for the proposed method is less than 1%compared to the true achievable IR(AIR).The proposed improvement is mainly by introducing channel shortening(CS)before the M-BCJR equalizer.In our proposal,the Ungerboeck M-BCJR algorithm and CS can work together to defeat severe inter-symbol interference(ISI)introduced by FTN signaling.The ISI length for the M-BCJR algorithm with CS is optimized based on the criterion of the IR maximization.For the two cases=0.5 and=0.35,compared to Ungerboeck M-BCJR without CS benchmark[1],the computational complexities of Ungerboeck M-BCJR with CS are reduced by 75%.Moreover,for the case=0.35,the BER performance of Ungerboeck M-BCJR with CS outperforms that of the conventional M-BCJR in[1]at the low signal to noise ratio region.
文摘The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic -Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision since～55 Ma have been well recorded.Based on the latest progress in high-resolution stratigraphy,a technique of balanced section was applied to six pieces of northeast-southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began
