According to the investigations on the oil and gas pipelines such as the Lan-Cheng-Chong pipeline and the Southwest pipeline, there are two ways of laying pipeline: pipelines paralleling (approximately) to the main...According to the investigations on the oil and gas pipelines such as the Lan-Cheng-Chong pipeline and the Southwest pipeline, there are two ways of laying pipeline: pipelines paralleling (approximately) to the main slide direction and pipelines perpendicular (approximately) to the main slide direction. If earth-retaining walls have been built for pipelines paralleling to the main slide direction, they will prevent the lands from sliding; On the contrary, without earth-retaining walls, the sharp broken rocks in the backfilling soil will scratch the safeguard of the pipeline when the landslides take place. Pipelines perpendicular to the main slide direction can be classified into four types according to the relative positions between pipelines and landslides: Pipelines over the slide planes, pipelines inside the fracture strips of slide planes, pipelines below the slide planes and pipelines behind the backsides of landslides. The different dynamical mechanisms of the process in which landslide acts against pipelines are analyzed based on whether the pipelines are equipped with fixed frusta, because the sliding resistance depends on whether and how many fixed frusta are equipped and the distance between frusta.展开更多
Purpose–The traction cable is paralleled with the existing traction network of electrified railway through transverse connecting line to form the scheme of long distance power supply for the traction network.This pap...Purpose–The traction cable is paralleled with the existing traction network of electrified railway through transverse connecting line to form the scheme of long distance power supply for the traction network.This paper aims to study the scheme composition and power supply distance(PSD)of the scheme.Design/methodology/approach–Based on the structure of parallel traction network(referred to as“cable traction network(CTN)”),the power supply modes(PSMs)are divided into cableþdirect PSM and cableþautotransformer(AT)PSM(including Japanese mode,French mode and new mode).Taking cableþJapanese AT PSM as an example,the scheme of long distance power supply for CTN under the PSMs of co-phase and out-of-phase power supply are designed.On the basis of establishing the equivalent circuit model and the chain circuit model of CTN,taking the train working voltage as the constraint condition,and based on the power flow calculation of multiple train loads,the calculation formula and process for determining the PSD of CTN are given.The impedance and PSD of CTN under the cableþAT PSM are simulated and analyzed,and a certain line is taken as an example to compare the scheme design.Findings–Results show that the equivalent impedance of CTN under the cableþAT PSM is smaller,and the PSD is about 2.5 times of that under the AT PSM,which can effectively increase the PSD and the flexibility of external power supply location.Originality/value–The research content can effectively improve the PSD of traction power supply system and has important reference value for the engineering application of the scheme.展开更多
Chinese long distance binding is explored in terms of a feature orientated approach: a long distance anaphor with barren or impoverished φ features is obliged to acquires φ features (or phi features) from its adjace...Chinese long distance binding is explored in terms of a feature orientated approach: a long distance anaphor with barren or impoverished φ features is obliged to acquires φ features (or phi features) from its adjacent NPs in its upward movement at LF, and that this feature obtaining process, governed by rules that are summarized in terms of Feature Saturation Process (FSP), provides answers to long distance binding. Accordingly, binding is seen as an instance of a perfect match of features possessed by a saturated anaphor and an NP at LF. An anaphor is bound when it moves to INFL with its φ features matched with a feature functioning NP, whereas a middle way anaphor with unsaturated φ features is not bound. This approach satisfactorily explains the binding relations in sentences of long distance coreference and providing alternative answers to other issues of binding. It is further shown that the binding of Chinese reflexive ziji (自己)to its antecedent(s) results from a sequence of local dependency through movement.展开更多
It was ascertained that there is a great margin between the theoretical values and experimental medians of the field strength of RWM and RID signals during high solar activity period at Chinese Great Wall Station on A...It was ascertained that there is a great margin between the theoretical values and experimental medians of the field strength of RWM and RID signals during high solar activity period at Chinese Great Wall Station on Antarctica. The calculated values are, on average, less than the experimental, especially on the propagation path between RID and Antarctica. The field strength by the experiment may be used as the basic data for the research of HF propagation over the very long distance. Because of the large deviation it seems to be necessary to study HF propagation over the very long distance in details, especially the propagation model.展开更多
Loop heat pipes(LHPs)are attractive two-phase thermal control devices for satellites,electronics and many other applications.They are capable of transporting heat efficiently for long distances up to several meters at...Loop heat pipes(LHPs)are attractive two-phase thermal control devices for satellites,electronics and many other applications.They are capable of transporting heat efficiently for long distances up to several meters at any orientation.This paper investigated the heat transfer characteristics of loop heat pipes with long distances and small diameter transport lines.Small stainless steel tubes of 2 mm and 3 mm in inner diameters were chosen as liquid lines and vapor lines of the LHPs.The local thermal resistances in the evaporator of the 6 m-LHP were researched and analyzed,which indicated that the thermal resistance between the aluminum block and the vapor in the vapor channel accounted for a major proportion of the total thermal resistance.The effect of heat sink temperatures on the performance of the 6 m-LHP were compared with 10°C,15°C,20°C and 25°C cooling water temperatures.Moreover,the thermal characteristics of LHPs with transport distances of 2 m and 16 m were also experimentally investigated.The 16 m-LHP could achieve a heat transfer capacity of 100 W and the 2 m-LHP could reach more than 339 W,on the premise of the evaporator temperature below 100°C.The thermal resistance of the 2 m-LHP could achieve 0.125°C/W.展开更多
Super High Definition (SHD) movies were successfully transmitted as streaming contents at about 300 Mbps for the first time over a long distance IP network (more than 3,000 km), in conjunction with the experimental ve...Super High Definition (SHD) movies were successfully transmitted as streaming contents at about 300 Mbps for the first time over a long distance IP network (more than 3,000 km), in conjunction with the experimental verification of traffic control and scalable multicast technologies.展开更多
This paper presents a performance analysis of novel doubledampedtuned alternating current (AC) filters in high voltage direct current(HVDC) systems. The proposed double-damped tuned AC filters offer theadvantages of i...This paper presents a performance analysis of novel doubledampedtuned alternating current (AC) filters in high voltage direct current(HVDC) systems. The proposed double-damped tuned AC filters offer theadvantages of improved performance of HVDC systems in terms of betterpower quality, high power factor, and lower total harmonic distortion (THD).The system under analysis consists of an 878 km long HVDC transmissionline connecting converter stations at Matiari and Lahore, two major cities inPakistan. The main focus of this research is to design a novel AC filter usingthe equivalent impedance method of two single-tuned and double-dampedtuned AC filters. Additionally, the impact of the damping resistor on the ACchannel is examined. TheTHDof theHVDCsystem with and without currentAC filters was also compared in this research and a double-damped tuned ACfilter was proposed. The results of the simulation represent that the proposeddouble-damped tuned AC filter is far smaller in size, offers better powerquality, and has a much lower THD compared to the AC filters currently inplace in the converter station. The simulation analysis was carried out utilizingpower systems computer-aided design (PSCAD) software.展开更多
Effective vertical mobility is a crucial element in the design and construction of tall buildings.This paper reviews recent“smart”developments in elevator technologies and analyzes how they affect the construction a...Effective vertical mobility is a crucial element in the design and construction of tall buildings.This paper reviews recent“smart”developments in elevator technologies and analyzes how they affect the construction and operation of tall buildings.In an approachable and non-technical discourse,it maps out,arranges,and compiles complicated and dispersed information on various elements of elevator design.It discusses hardware-based innovations,such as AC and gearless motors,machine-room-less(MRL)elevators,regenerative drives,elevator ropes,and LED lighting,as well as software-based solutions,such as destination dispatching systems,people flow solutions,standby mode,and predictive maintenance applications.Future vertical transportation models are also discussed,including multi-directional elevators and circulating multi-car elevators.Lastly,the paper suggests fruitful avenues for further studies on the subject,such as robotics,3D printing,and the impact of the COVID-19 pandemic on elevator design.展开更多
The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic (500-39...The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic (500-397 Ma), and the Tianshan region, as a collision zone of the early period in the Late Paleozoic (Late Devonian-Early Carboniferous, 385-323 Ma), are all the result of nearly N-S trending shortening and collision (according to recent magnetic orientation). In the Late Devonian-Early Carboniferous period (385-323 Ma), regional NW trending faults displayed features of dextral strike-slip motion in the Altay and Junggar regions. In the Tianshan region, nearly EW-trending regional faults are motions of the thrusts. However, in the Late Carboniferous-Early Permian period (323-260 Ma), influenced by the long-distance effect induced from the Ural collision zone, those areas suffered weaker eastward compression, the existing NW trending faults converted into sinistral strike-slip in the Altay and Junggar regions, and the existing nearly E-W trending faults transferred into dextral strike-slip faults in the Tianshan region. The Rocks of those regions in the Late Carboniferous-Early Permian period (323-260 Ma) were moderately ruptured to a certain tension-shear, and thus formed a number of world famous giant endogenic metal ore deposits in the Tianshan-Altay region. As to the Central Asian continent, the most powerful collision period may not coincide with the most favorable endogenic metallogenic period. It should be treated to "the orogenic metallogeny hypothesis" with caution in that region.展开更多
This paper aims to make it clear that syntactic analysis should be based on the lexical information given in the lexicon.For this purpose,lexical information of the syntactic argument is to be taken the form like[VP N...This paper aims to make it clear that syntactic analysis should be based on the lexical information given in the lexicon.For this purpose,lexical information of the syntactic argument is to be taken the form like[VP NKP,_,DKP,AKP]for the ditransitive verb give in English.The argument structure projects to syntactic structure.The NKP in this structure becomes VP-subject,but there is another subject called S-subject(Sentence-Subject)below S node.This amounts to Two-Subject Hypothesis for English.Between these two subjects,there intervene Conjugation-Like Elements,enriched by close examination of English verbal conjugation.Two-Subject Hypothesis perfectly accounts for peculiarities of the Expletive There(ET)construction.Restructuring can also explain the so-called Long Distance Wh-interrogative without introducing Wh-movement,and it can also explain why the imperative verbs are taking the base forms.It can also explain the characteristics of adjective imperatives by the same principles as applied to verbal imperatives.We try to deal with the other subtle problems,to get fruitful results.Restructuring approach,we think,provides more convincing explanations than the movement one.展开更多
Photoacoustic microscopy(PAM) has quickly developed into a noninvasive biomedical imaging technique to achieve detection, diagnosis, and monitoring.Compared with Q-switched neodymium-doped yttrium aluminum garnet or o...Photoacoustic microscopy(PAM) has quickly developed into a noninvasive biomedical imaging technique to achieve detection, diagnosis, and monitoring.Compared with Q-switched neodymium-doped yttrium aluminum garnet or optical parametric oscillator lasers, a low-cost and small-size laser diode(LD) used as an alternative light source is conducive to achieving the miniaturization and integration for preclinical transformation.However, the LD’s low peak output power needs the high numerical aperture objective to attain tight focus, which limits the working distance(WD) of the system in only2–3 mm, resulting in not achieving the backward coaxial confocal mode.Here, we present a compact visible LD-based PAM system with a reflective objective to achieve a 22 mm long WD and a 10 μm lateral resolution.Different depth subcutaneous microvascular networks in label-free mouse ears have successfully reappeared in vivo with a signal-to-noise ratio up to14 d B by a confocal alignment.It will be a promising tool to develop into a handy tool for subcutaneous blood vessel imaging.展开更多
Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in si...Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in situ microscope to assist photoelectron spectroscopy.The configuration of long objective distance of 200 mm with two-mirror reflection has been introduced.Large magnification of 5×to 100×,lateral resolution of 4.08μm,and longitudinal resolution of 4.49μm have been achieved.Meanwhile,the testing result shows larger focal depth of this in situ optical microscope.Similar configurations could also be applied to other electronic microscopes to improve their probing capability.展开更多
Volume transmission (VT) is a widespread mode of intercellular communication that occurs in the extracellular fluid (ECF) and in the cerebrospinal fluid (CSF) of the brain with VI signals moving from source to t...Volume transmission (VT) is a widespread mode of intercellular communication that occurs in the extracellular fluid (ECF) and in the cerebrospinal fluid (CSF) of the brain with VI signals moving from source to target cells via energy gradients leading to diffusion and convection (flow). The VT channels are diffuse forming a plexus in the extracellular space, while in wiring transmission (WT) the channels (axons, terminals) are private. The speed is slow (seconds-minutes) in VT while rapid in the millisecond range in w-r. The extracellular space is the substrate for VT, which is modulated by the extracellular matrix. Extrasynaptic VT is linked to synaptic transmission and likely often takes place due to incomplete diffusion barriers with the synaptic transmitter reaching extrasynaptic domains of the pre-and post-synaptic membrane of the synapse, the astroglia, and even adjacent synapses. Indications exist for the existence of striatal D2-1ike receptor-mediated extrasynaptic form of dopamine (DA) VT at the local circuit level in vivo in the human striatum. Synaptic glutamate via extrasynaptic VT can act on extrasynaptic metabotropic glutamate receptors located on the astroglia leading to Ca2~ mediated astrocytic glutamate release into the extracellular space (ECS). Long distance peptide VT and CSF VT is the major long distance VT with distances more than 1 mm and flow in the CSF. Indications for long distance vr of beta-endorphin and oxytocin are obtained. We propose that monogamy in the female prairie vole may take place through an increase in oxytocin v-r, especially in nucleus accumbens. Release of extracellular vesicles containing receptors, proteins, RNAs and mtDNA from cellular networks in the central nervous system (CNS) into the ECF and CSF may be a fundamental communication in the CNS. It represents a special form of volume transmission, the Roamer subtype of VT. It may greatly contribute to dynamic events of synaptic plasticity but also to spread of pathological proteins in protein conformational disorders. V'i" also occurs in the peripheral nervous system and associated cells. Short and long distance VT may take place in meridian channels via diffusion and flow in the interstitial fluid. Acupuncture can produce VT signals by releasing transmitters and modulators from nerve terminals and mast cells.展开更多
In order to evaluate the secondary aerosol formation potential at a suburban site of Beijing,in situ perturbation experiments in a potential aerosol mass(PAM) reactor were carried out in the winter of 2014.The varia...In order to evaluate the secondary aerosol formation potential at a suburban site of Beijing,in situ perturbation experiments in a potential aerosol mass(PAM) reactor were carried out in the winter of 2014.The variations of secondary aerosol formation as a function of time,OH exposure,and the concentrations of gas phase pollutants and particles were reported in this study.Two periods with distinct secondary aerosol formation potentials,marked as Period Ⅰ and Period Ⅱ,were identified during the observation.In Period Ⅰ,the secondary aerosol formation potential was high,and correlated well to the air pollutants,i.e.,SO2,NO2,and CO.The maximal secondary aerosol formation was observed with an aging time equivalent to about 3 days of atmospheric oxidation.In period Ⅱ,the secondary aerosol formation potential was low,with no obvious correlation with the air pollutants.Meanwhile,the aerosol mass decreased,instead of showing a peak,with increasing aging time.Backward trajectory analysis during the two periods confirmed that the air mass in Period Ⅰwas mainly from local sources,while it was attributed mostly to long distance transport in Period Ⅱ.The air lost its reactivity during the long transport and the particles became highly aged,resulting in a low secondary aerosol formation potential.Our experimental results indicated that the in situ measurement of the secondary aerosol formation potential could provide important information for evaluating the contributions of local emission and long distance transport to the aerosol pollution.展开更多
Plants face a constantly changing environment,requiring fine tuning of their growth and development.Plants have therefore developed numerous mechanisms to cope with environmental stress conditions.One striking exam-pl...Plants face a constantly changing environment,requiring fine tuning of their growth and development.Plants have therefore developed numerous mechanisms to cope with environmental stress conditions.One striking exam-ple is root response to water deficit.Upon drought(which causes osmotic stress to cells),plants can among other responses alter locally their root system architecture(hydropatterning)or orientate their root growth to optimize water uptake(hydrotropism).They can also modify their hydraulic properties,metabolism and development coordi-nately at the whole root and plant levels.Upstream of these developmental and physiological changes,plant roots must perceive and transduce signals for water availability.Here,we review current knowledge on plant osmotic per-ception and discuss how long distance signaling can play a role in signal integration,leading to the great phenotypic plasticity of roots and plant development.展开更多
The pre-calling behavior of female adults of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae) collected in southern Japan and southeastern Asian countries was investigated. Most females started callin...The pre-calling behavior of female adults of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae) collected in southern Japan and southeastern Asian countries was investigated. Most females started calling on days 1-4 after adult emergence. In three populations obtained in Saga prefecture in Kyushu mainland, Japan, two different patterns of pre-calling period (PCP) were observed: one was the above-mentioned pattern shown by most individuals, and the other was a pattern in which females sexually matured within several hours after emergence. Diel periodicity was shown in the time of calling activity, and its pattern varied among the populations. Pre-calling period was stable over successive generations in the laboratory.展开更多
Morphology-based studies have suggested a very depauperate bee fauna for islands in the South West Pacific, and recent genetic studies since have indicated an even smaller endemic fauna with many bee species in this r...Morphology-based studies have suggested a very depauperate bee fauna for islands in the South West Pacific, and recent genetic studies since have indicated an even smaller endemic fauna with many bee species in this region resulting from human-aided dispersal. These introduced species have the potential to both disrupt native pollinator suites as well as augment crop pollination, but for most species the timings of introduction are unknown. We examined the distribution and nesting biology of the long-tongued bee Braunsapis puangensis that was first recorded from Fiji in 2007. This bee has now become widespread in Fiji and both its local abundance and geographical range are likely to increase dramatically. The impacts of this invasion are potentially enormous for agriculture and native ecosystems, but they also provide opportunities for understanding how social insect species adapt to new environments. We outline the major issues associated with this recent invasion and argue that a long-term monitoring study is needed.展开更多
Semantic annotation of Web objects is a key problem for Web information extraction. The Web contains an abundance of useful semi-structured information about real world objects, and the empirical study shows that stro...Semantic annotation of Web objects is a key problem for Web information extraction. The Web contains an abundance of useful semi-structured information about real world objects, and the empirical study shows that strong two-dimensional sequence characteristics and correlative characteristics exist for Web information about objects of the same type across different Web sites. Conditional Random Fields (CRFs) are the state-of-the-art approaches taking the sequence characteristics to do better labeling. However, as the appearance of correlative characteristics between Web object elements, previous CRFs have their limitations for semantic annotation of Web objects and cannot deal with the long distance dependencies between Web object elements efficiently. To better incorporate the long distance dependencies, on one hand, this paper describes long distance dependencies by correlative edges, which are built by making good use of structured information and the characteristics of records from external databases; and on the other hand, this paper presents a two-dimensional Correlative-Chain Conditional Random Fields (2DCC-CRFs) to do semantic annotation of Web objects. This approach extends a classic model, two-dimensional Conditional Random Fields (2DCRFs), by adding correlative edges. Experimental results using a large number of real-world data collected from diverse domains show that the proposed approach can significantly improve the semantic annotation accuracy of Web objects.展开更多
文摘According to the investigations on the oil and gas pipelines such as the Lan-Cheng-Chong pipeline and the Southwest pipeline, there are two ways of laying pipeline: pipelines paralleling (approximately) to the main slide direction and pipelines perpendicular (approximately) to the main slide direction. If earth-retaining walls have been built for pipelines paralleling to the main slide direction, they will prevent the lands from sliding; On the contrary, without earth-retaining walls, the sharp broken rocks in the backfilling soil will scratch the safeguard of the pipeline when the landslides take place. Pipelines perpendicular to the main slide direction can be classified into four types according to the relative positions between pipelines and landslides: Pipelines over the slide planes, pipelines inside the fracture strips of slide planes, pipelines below the slide planes and pipelines behind the backsides of landslides. The different dynamical mechanisms of the process in which landslide acts against pipelines are analyzed based on whether the pipelines are equipped with fixed frusta, because the sliding resistance depends on whether and how many fixed frusta are equipped and the distance between frusta.
基金funded by Youth Science Foundation Fund Project of National Natural Science Foundation of China(51607148)Science and Technology R&D Program of China State Railway Group Co.,Ltd.(SY2020G001)Project of Sichuan Science and Technology Program(2021YJ0028)。
文摘Purpose–The traction cable is paralleled with the existing traction network of electrified railway through transverse connecting line to form the scheme of long distance power supply for the traction network.This paper aims to study the scheme composition and power supply distance(PSD)of the scheme.Design/methodology/approach–Based on the structure of parallel traction network(referred to as“cable traction network(CTN)”),the power supply modes(PSMs)are divided into cableþdirect PSM and cableþautotransformer(AT)PSM(including Japanese mode,French mode and new mode).Taking cableþJapanese AT PSM as an example,the scheme of long distance power supply for CTN under the PSMs of co-phase and out-of-phase power supply are designed.On the basis of establishing the equivalent circuit model and the chain circuit model of CTN,taking the train working voltage as the constraint condition,and based on the power flow calculation of multiple train loads,the calculation formula and process for determining the PSD of CTN are given.The impedance and PSD of CTN under the cableþAT PSM are simulated and analyzed,and a certain line is taken as an example to compare the scheme design.Findings–Results show that the equivalent impedance of CTN under the cableþAT PSM is smaller,and the PSD is about 2.5 times of that under the AT PSM,which can effectively increase the PSD and the flexibility of external power supply location.Originality/value–The research content can effectively improve the PSD of traction power supply system and has important reference value for the engineering application of the scheme.
文摘Chinese long distance binding is explored in terms of a feature orientated approach: a long distance anaphor with barren or impoverished φ features is obliged to acquires φ features (or phi features) from its adjacent NPs in its upward movement at LF, and that this feature obtaining process, governed by rules that are summarized in terms of Feature Saturation Process (FSP), provides answers to long distance binding. Accordingly, binding is seen as an instance of a perfect match of features possessed by a saturated anaphor and an NP at LF. An anaphor is bound when it moves to INFL with its φ features matched with a feature functioning NP, whereas a middle way anaphor with unsaturated φ features is not bound. This approach satisfactorily explains the binding relations in sentences of long distance coreference and providing alternative answers to other issues of binding. It is further shown that the binding of Chinese reflexive ziji (自己)to its antecedent(s) results from a sequence of local dependency through movement.
基金The research is supported by the National Natural Science Foundation of China State Antarctic Committee
文摘It was ascertained that there is a great margin between the theoretical values and experimental medians of the field strength of RWM and RID signals during high solar activity period at Chinese Great Wall Station on Antarctica. The calculated values are, on average, less than the experimental, especially on the propagation path between RID and Antarctica. The field strength by the experiment may be used as the basic data for the research of HF propagation over the very long distance. Because of the large deviation it seems to be necessary to study HF propagation over the very long distance in details, especially the propagation model.
基金partially supported by the National Natural Science Foundation of China(No.51606207)Youth Innovation Promotion Association,CAS,China(No.2018036)。
文摘Loop heat pipes(LHPs)are attractive two-phase thermal control devices for satellites,electronics and many other applications.They are capable of transporting heat efficiently for long distances up to several meters at any orientation.This paper investigated the heat transfer characteristics of loop heat pipes with long distances and small diameter transport lines.Small stainless steel tubes of 2 mm and 3 mm in inner diameters were chosen as liquid lines and vapor lines of the LHPs.The local thermal resistances in the evaporator of the 6 m-LHP were researched and analyzed,which indicated that the thermal resistance between the aluminum block and the vapor in the vapor channel accounted for a major proportion of the total thermal resistance.The effect of heat sink temperatures on the performance of the 6 m-LHP were compared with 10°C,15°C,20°C and 25°C cooling water temperatures.Moreover,the thermal characteristics of LHPs with transport distances of 2 m and 16 m were also experimentally investigated.The 16 m-LHP could achieve a heat transfer capacity of 100 W and the 2 m-LHP could reach more than 339 W,on the premise of the evaporator temperature below 100°C.The thermal resistance of the 2 m-LHP could achieve 0.125°C/W.
文摘Super High Definition (SHD) movies were successfully transmitted as streaming contents at about 300 Mbps for the first time over a long distance IP network (more than 3,000 km), in conjunction with the experimental verification of traffic control and scalable multicast technologies.
基金supported by Creative Challenge Research Program (2021R1I1A1A01052521)the BK-21 FOUR program through the National Research Foundation of Korea (NRF)under the Ministry of Education.
文摘This paper presents a performance analysis of novel doubledampedtuned alternating current (AC) filters in high voltage direct current(HVDC) systems. The proposed double-damped tuned AC filters offer theadvantages of improved performance of HVDC systems in terms of betterpower quality, high power factor, and lower total harmonic distortion (THD).The system under analysis consists of an 878 km long HVDC transmissionline connecting converter stations at Matiari and Lahore, two major cities inPakistan. The main focus of this research is to design a novel AC filter usingthe equivalent impedance method of two single-tuned and double-dampedtuned AC filters. Additionally, the impact of the damping resistor on the ACchannel is examined. TheTHDof theHVDCsystem with and without currentAC filters was also compared in this research and a double-damped tuned ACfilter was proposed. The results of the simulation represent that the proposeddouble-damped tuned AC filter is far smaller in size, offers better powerquality, and has a much lower THD compared to the AC filters currently inplace in the converter station. The simulation analysis was carried out utilizingpower systems computer-aided design (PSCAD) software.
文摘Effective vertical mobility is a crucial element in the design and construction of tall buildings.This paper reviews recent“smart”developments in elevator technologies and analyzes how they affect the construction and operation of tall buildings.In an approachable and non-technical discourse,it maps out,arranges,and compiles complicated and dispersed information on various elements of elevator design.It discusses hardware-based innovations,such as AC and gearless motors,machine-room-less(MRL)elevators,regenerative drives,elevator ropes,and LED lighting,as well as software-based solutions,such as destination dispatching systems,people flow solutions,standby mode,and predictive maintenance applications.Future vertical transportation models are also discussed,including multi-directional elevators and circulating multi-car elevators.Lastly,the paper suggests fruitful avenues for further studies on the subject,such as robotics,3D printing,and the impact of the COVID-19 pandemic on elevator design.
文摘The research on Paleozoic tectonics and endogenic metallogeny in the Tianshan-Altay region of Central Asia is an important and significant project. The Altay region, as a collision zone of the Early Paleozoic (500-397 Ma), and the Tianshan region, as a collision zone of the early period in the Late Paleozoic (Late Devonian-Early Carboniferous, 385-323 Ma), are all the result of nearly N-S trending shortening and collision (according to recent magnetic orientation). In the Late Devonian-Early Carboniferous period (385-323 Ma), regional NW trending faults displayed features of dextral strike-slip motion in the Altay and Junggar regions. In the Tianshan region, nearly EW-trending regional faults are motions of the thrusts. However, in the Late Carboniferous-Early Permian period (323-260 Ma), influenced by the long-distance effect induced from the Ural collision zone, those areas suffered weaker eastward compression, the existing NW trending faults converted into sinistral strike-slip in the Altay and Junggar regions, and the existing nearly E-W trending faults transferred into dextral strike-slip faults in the Tianshan region. The Rocks of those regions in the Late Carboniferous-Early Permian period (323-260 Ma) were moderately ruptured to a certain tension-shear, and thus formed a number of world famous giant endogenic metal ore deposits in the Tianshan-Altay region. As to the Central Asian continent, the most powerful collision period may not coincide with the most favorable endogenic metallogenic period. It should be treated to "the orogenic metallogeny hypothesis" with caution in that region.
文摘This paper aims to make it clear that syntactic analysis should be based on the lexical information given in the lexicon.For this purpose,lexical information of the syntactic argument is to be taken the form like[VP NKP,_,DKP,AKP]for the ditransitive verb give in English.The argument structure projects to syntactic structure.The NKP in this structure becomes VP-subject,but there is another subject called S-subject(Sentence-Subject)below S node.This amounts to Two-Subject Hypothesis for English.Between these two subjects,there intervene Conjugation-Like Elements,enriched by close examination of English verbal conjugation.Two-Subject Hypothesis perfectly accounts for peculiarities of the Expletive There(ET)construction.Restructuring can also explain the so-called Long Distance Wh-interrogative without introducing Wh-movement,and it can also explain why the imperative verbs are taking the base forms.It can also explain the characteristics of adjective imperatives by the same principles as applied to verbal imperatives.We try to deal with the other subtle problems,to get fruitful results.Restructuring approach,we think,provides more convincing explanations than the movement one.
基金supported by the Guangdong Province Introduction of Innovative R&D Team (No.2016ZT06G375)National Natural Science Foundation of China (Nos.11664011,51975131, 11804059, and 51805097)+1 种基金Natural Science Foundation of Jiangxi Province (No.20171ACB20027)2017 Hongcheng Plan of Nanchang Yangshen Electronic Technologies Co.,Ltd。
文摘Photoacoustic microscopy(PAM) has quickly developed into a noninvasive biomedical imaging technique to achieve detection, diagnosis, and monitoring.Compared with Q-switched neodymium-doped yttrium aluminum garnet or optical parametric oscillator lasers, a low-cost and small-size laser diode(LD) used as an alternative light source is conducive to achieving the miniaturization and integration for preclinical transformation.However, the LD’s low peak output power needs the high numerical aperture objective to attain tight focus, which limits the working distance(WD) of the system in only2–3 mm, resulting in not achieving the backward coaxial confocal mode.Here, we present a compact visible LD-based PAM system with a reflective objective to achieve a 22 mm long WD and a 10 μm lateral resolution.Different depth subcutaneous microvascular networks in label-free mouse ears have successfully reappeared in vivo with a signal-to-noise ratio up to14 d B by a confocal alignment.It will be a promising tool to develop into a handy tool for subcutaneous blood vessel imaging.
基金supported by the National Natural Science Foundation of China(No.11774427)。
文摘Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in situ microscope to assist photoelectron spectroscopy.The configuration of long objective distance of 200 mm with two-mirror reflection has been introduced.Large magnification of 5×to 100×,lateral resolution of 4.08μm,and longitudinal resolution of 4.49μm have been achieved.Meanwhile,the testing result shows larger focal depth of this in situ optical microscope.Similar configurations could also be applied to other electronic microscopes to improve their probing capability.
基金Supported by grants from the Swedish Research Council (04X-715)Torsten and Ragnar Sderberg Foundation, Hjrnfonden and Marianne and Marcus Wallenberg Foundation to KF,by a grants from the Swedish Royal Academy of Sciences and Karolinska Institutet Forskningsstiftelser 2012 to DOB-E
文摘Volume transmission (VT) is a widespread mode of intercellular communication that occurs in the extracellular fluid (ECF) and in the cerebrospinal fluid (CSF) of the brain with VI signals moving from source to target cells via energy gradients leading to diffusion and convection (flow). The VT channels are diffuse forming a plexus in the extracellular space, while in wiring transmission (WT) the channels (axons, terminals) are private. The speed is slow (seconds-minutes) in VT while rapid in the millisecond range in w-r. The extracellular space is the substrate for VT, which is modulated by the extracellular matrix. Extrasynaptic VT is linked to synaptic transmission and likely often takes place due to incomplete diffusion barriers with the synaptic transmitter reaching extrasynaptic domains of the pre-and post-synaptic membrane of the synapse, the astroglia, and even adjacent synapses. Indications exist for the existence of striatal D2-1ike receptor-mediated extrasynaptic form of dopamine (DA) VT at the local circuit level in vivo in the human striatum. Synaptic glutamate via extrasynaptic VT can act on extrasynaptic metabotropic glutamate receptors located on the astroglia leading to Ca2~ mediated astrocytic glutamate release into the extracellular space (ECS). Long distance peptide VT and CSF VT is the major long distance VT with distances more than 1 mm and flow in the CSF. Indications for long distance vr of beta-endorphin and oxytocin are obtained. We propose that monogamy in the female prairie vole may take place through an increase in oxytocin v-r, especially in nucleus accumbens. Release of extracellular vesicles containing receptors, proteins, RNAs and mtDNA from cellular networks in the central nervous system (CNS) into the ECF and CSF may be a fundamental communication in the CNS. It represents a special form of volume transmission, the Roamer subtype of VT. It may greatly contribute to dynamic events of synaptic plasticity but also to spread of pathological proteins in protein conformational disorders. V'i" also occurs in the peripheral nervous system and associated cells. Short and long distance VT may take place in meridian channels via diffusion and flow in the interstitial fluid. Acupuncture can produce VT signals by releasing transmitters and modulators from nerve terminals and mast cells.
基金supported by the Key Research Program of Chinese Academy of Sciences (No. KJZD-EW-TZ-G06-01-15)the National Natural Science Foundation of China (No. 21407158)the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (No. XDB05010300)
文摘In order to evaluate the secondary aerosol formation potential at a suburban site of Beijing,in situ perturbation experiments in a potential aerosol mass(PAM) reactor were carried out in the winter of 2014.The variations of secondary aerosol formation as a function of time,OH exposure,and the concentrations of gas phase pollutants and particles were reported in this study.Two periods with distinct secondary aerosol formation potentials,marked as Period Ⅰ and Period Ⅱ,were identified during the observation.In Period Ⅰ,the secondary aerosol formation potential was high,and correlated well to the air pollutants,i.e.,SO2,NO2,and CO.The maximal secondary aerosol formation was observed with an aging time equivalent to about 3 days of atmospheric oxidation.In period Ⅱ,the secondary aerosol formation potential was low,with no obvious correlation with the air pollutants.Meanwhile,the aerosol mass decreased,instead of showing a peak,with increasing aging time.Backward trajectory analysis during the two periods confirmed that the air mass in Period Ⅰwas mainly from local sources,while it was attributed mostly to long distance transport in Period Ⅱ.The air lost its reactivity during the long transport and the particles became highly aged,resulting in a low secondary aerosol formation potential.Our experimental results indicated that the in situ measurement of the secondary aerosol formation potential could provide important information for evaluating the contributions of local emission and long distance transport to the aerosol pollution.
基金supported in part by the Agence Nationale de la Recherche(ANR-19-CE20-0008-01)the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(Grant Agreement ERC-2017-ADG-788553).
文摘Plants face a constantly changing environment,requiring fine tuning of their growth and development.Plants have therefore developed numerous mechanisms to cope with environmental stress conditions.One striking exam-ple is root response to water deficit.Upon drought(which causes osmotic stress to cells),plants can among other responses alter locally their root system architecture(hydropatterning)or orientate their root growth to optimize water uptake(hydrotropism).They can also modify their hydraulic properties,metabolism and development coordi-nately at the whole root and plant levels.Upstream of these developmental and physiological changes,plant roots must perceive and transduce signals for water availability.Here,we review current knowledge on plant osmotic per-ception and discuss how long distance signaling can play a role in signal integration,leading to the great phenotypic plasticity of roots and plant development.
文摘The pre-calling behavior of female adults of the common cutworm, Spodoptera litura (Lepidoptera: Noctuidae) collected in southern Japan and southeastern Asian countries was investigated. Most females started calling on days 1-4 after adult emergence. In three populations obtained in Saga prefecture in Kyushu mainland, Japan, two different patterns of pre-calling period (PCP) were observed: one was the above-mentioned pattern shown by most individuals, and the other was a pattern in which females sexually matured within several hours after emergence. Diel periodicity was shown in the time of calling activity, and its pattern varied among the populations. Pre-calling period was stable over successive generations in the laboratory.
基金This project was supported by an Australian Pacific Science Foundation grant to S.V.C.G., M.I.S. and M.RS., a National Climate Change Adaptation Research Facil- ity grant awarded to S.V.C.G., and an Endeavour fellow- ship award to S.V.C.G. We thank the University of South Pacific for hosting S.V.G.G.'s research in Fiji.
文摘Morphology-based studies have suggested a very depauperate bee fauna for islands in the South West Pacific, and recent genetic studies since have indicated an even smaller endemic fauna with many bee species in this region resulting from human-aided dispersal. These introduced species have the potential to both disrupt native pollinator suites as well as augment crop pollination, but for most species the timings of introduction are unknown. We examined the distribution and nesting biology of the long-tongued bee Braunsapis puangensis that was first recorded from Fiji in 2007. This bee has now become widespread in Fiji and both its local abundance and geographical range are likely to increase dramatically. The impacts of this invasion are potentially enormous for agriculture and native ecosystems, but they also provide opportunities for understanding how social insect species adapt to new environments. We outline the major issues associated with this recent invasion and argue that a long-term monitoring study is needed.
基金Supported by the National Natural Science Foundation of China under Grant No.90818001the Natural Science Foundation of Shandong Province of China under Grant No.Y2007G24
文摘Semantic annotation of Web objects is a key problem for Web information extraction. The Web contains an abundance of useful semi-structured information about real world objects, and the empirical study shows that strong two-dimensional sequence characteristics and correlative characteristics exist for Web information about objects of the same type across different Web sites. Conditional Random Fields (CRFs) are the state-of-the-art approaches taking the sequence characteristics to do better labeling. However, as the appearance of correlative characteristics between Web object elements, previous CRFs have their limitations for semantic annotation of Web objects and cannot deal with the long distance dependencies between Web object elements efficiently. To better incorporate the long distance dependencies, on one hand, this paper describes long distance dependencies by correlative edges, which are built by making good use of structured information and the characteristics of records from external databases; and on the other hand, this paper presents a two-dimensional Correlative-Chain Conditional Random Fields (2DCC-CRFs) to do semantic annotation of Web objects. This approach extends a classic model, two-dimensional Conditional Random Fields (2DCRFs), by adding correlative edges. Experimental results using a large number of real-world data collected from diverse domains show that the proposed approach can significantly improve the semantic annotation accuracy of Web objects.