Considerable progress has been achieved in friction stir welding （FSW） of steels in every aspect of tool fab- rication, microstructure control and properties evaluation in the past two decades. With the development ...Considerable progress has been achieved in friction stir welding （FSW） of steels in every aspect of tool fab- rication, microstructure control and properties evaluation in the past two decades. With the development of reliable welding tools and precise control systems, FSW of steels has reached a new level of technical maturity. High-quality, long welds can be produced in many engineering steels. Compared to traditional fusion welding, FSW exhibits unique advantages producing joints with better properties. As a result of active control of the welding temperature and/or cooling rate, FSW has the capability of fabricating steel joints with excellent toughness and strength. For example, unfavorable phase transformations that usu- ally occur during traditional welding can be avoided and favorable phase fractions in advanced steels can be maintained in the weld zone thus avoiding the typical property degradations associated with fusion welding. If phase transformations do occur during FSW of thick steels, optimization of microstructure and properties can be attained by controlling the heat input and post-weld cooling rate.展开更多
Correct detection and identification of single-phase to-ground faults not effectively grounded in distribution systems is a major challenge for protection engineers.This paper proposes a novel traveling wave based pro...Correct detection and identification of single-phase to-ground faults not effectively grounded in distribution systems is a major challenge for protection engineers.This paper proposes a novel traveling wave based protection method to solve this problem.The proposed method compares the polarities of current and voltage traveling waves measured immediately after the fault inception to determine the fault direction.Nuisance tripping is avoided by using the power frequency voltages detected on the busbar to inhibit operation.The power frequency voltages ensure that the system does not mal-operate due to noise and also provide discrimination for phase-to-phase and three-phase faults.The wavelet transform and modulus maxima theories are used to extract the polarity of traveling waves measured at the relaying point.The simulation studies demonstrate correct operation of protection,which is independent of fault distance,fault inception angle,fault path resistance,and the method used for neutral grounding.展开更多
Plant pathogens deliver effector proteins that alter host processes to create an environment conducive to colonization. Attention has focused on identifying the targets of effectors and how their manipulation facil- i...Plant pathogens deliver effector proteins that alter host processes to create an environment conducive to colonization. Attention has focused on identifying the targets of effectors and how their manipulation facil- itates disease. RXLR effector Pi04089 from the potato blight pathogen Phytophthora infestans accumu- lates in the host nucleus and enhances colonization when transiently expressed in planta. Its nuclear local- ization is required for enhanced P. infestans colonization. Pi04089 interacts in yeast and in planta with a putative potato K-homology （KH） RNA-binding protein, StKRBPI. Co-localization of Pi04089 and StKRBP1, and bimolecular fluorescence complementation between them, indicate they associate at nuclear speckles. StKRBP1 protein levels increased when it was co-expressed with Pi04089. Indeed, such accumu- lation of StKRBP1 was observed also on the first day of leaf colonization by the pathogen. Remarkably, overexpression of StKRBP1 significantly enhances P. infestans infection. Mutation of the nucleotide- binding motif GxxG to GDDG in all three KH domains of StKRBP1 abolishes its interaction with Pi04089, its localization to nuclear speckles, and its increased accumulation when co-expressed with the effector. Moreover, the mutant StKRBP1 protein no longer enhances leaf colonization by P. infestans, implying that nucleotide binding is likely required for this activity. We thus argue that StKRBP1 can be regarded as a sus- ceptibility factor, as its activity is beneficial to the pathogen.展开更多
土壤水分特征曲线模型作为实验测定土壤水分特征数据的一种替代方法,因其具有计算方便快捷和便于嵌入数值模拟程序的优点,开始受到越来越广泛的关注。虽然文献中存在众多的土壤水分特征曲线模型,但是这些模型的适用范围及拟合性能尚不...土壤水分特征曲线模型作为实验测定土壤水分特征数据的一种替代方法,因其具有计算方便快捷和便于嵌入数值模拟程序的优点,开始受到越来越广泛的关注。虽然文献中存在众多的土壤水分特征曲线模型,但是这些模型的适用范围及拟合性能尚不明确。为了获得更加准确适用的土壤水分特征曲线,在实际应用中通常需要花费大量时间和精力去测试各种模型。为了解决上述问题,在国内外研究成果的基础上收集整理了12种典型的土壤水分特征曲线模型,并利用包含不同质地、有机质含量及容重的8种土壤的实测土壤水分特征数据来评估比较这些模型的模拟性能。模型性能通过均方根误差(RMSE)、平均偏差(AD)、AIC准则(Akaike Information Criterion)和纳什效率系数(NSE)4个指标评估。研究结果表明:大部分的模型能够提供比较接近于实际的拟合结果,评价指标值也比较相近。其中,KCGS2006(包含3个参数)和K1999模型(包含2个参数)拟合效果最好,而Gregson1987(包含1个参数)的拟合效果最差。该研究可以深入了解各种土壤水分特征曲线模型的适用性与局限性,更好地为生态环境建设和农业可持续发展研究中土壤水力参数的选取提供依据和参考。展开更多
Purpose:Supracondylar fractures of the humerus cause significant morbidity in children.Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury.Uncertainty surrounds...Purpose:Supracondylar fractures of the humerus cause significant morbidity in children.Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury.Uncertainty surrounds the optimal Kirschner wire configuration and diameter for closed reduction and pinning of these fractures.This study describes current practice and examined the association between wire configuration or diameter and outcomes(clinical and radiological)in the operative management of paediatric supracondylar fractures.Methods:Children presenting w让h GartlandⅡorⅢsupracondylar fractures at five hospitals in southwest England were eligible for inclusion.Collaborators scrutinised paper and electronic case notes.Outcome measures were maintenance of reduction and iatrogenic nerve injury.Results:Altogether 209 patients were eligible for inclusion:15.7%had a documented neurological deficit at presentation;3.9%who were neurologically intact at presentation sustained a new deficit caused by treatment and 13.4%experienced a clinically significant loss of reduction following fixation.Maintenance of reduction was significantly better in patients treated specifically with crossed×3 Kirschner wire configuration compared to all other configurations.The incidence of iatrogenic nerve injury was not significantly different between groups treated with different wire configurations.Conclusion:We present a large multicentre cohort study showing that crossed×3 Kirschner wires are associated with better maintenance of reduction than crossed×2 or lateral entry wires.Greater numbers would be required to properly investigate nerve injury relating to operative management of supracondylar fractures.We found significant variations in practice and compliance w让h the British Orthopaedic Association Standard for Trauma(BOAST)11 guidelines.展开更多
To ameliorate soil oxygen deficiencies around subsurface drip irrigation(SDI) drippers, aerated irrigation(AI) was introduced to supply aerated water to the soil through venturi installed in the SDI pipeline. The obje...To ameliorate soil oxygen deficiencies around subsurface drip irrigation(SDI) drippers, aerated irrigation(AI) was introduced to supply aerated water to the soil through venturi installed in the SDI pipeline. The objectives of this study were to assess the effects of AI on soil respiration(SR), air-filled porosity(AFP), soil temperature(ST), and oxygen concentrations(OCC). Total soil respiration(TSR), biological activity temperature index(BAT), and soil oxygen consumption(OCS) based on SR, ST, and OCC, respectively, were subsequently calculated to explore the relationships between TSR, BAT, OCS, OCC, and AFP. Greenhouse-based experiments included two treatments: AI and unaerated SDI(CK), during the tomato growing season in the fall of 2015. The results showed that compared with CK, AI treatment significantly increased OCC and AFP(by 16 and 7.4%, respectively), as well as TSR and OCS(by 24.21 and 22.91%, respectively)(P<0.05). Mean fruit yield with AI treatment was also 23% higher(P<0.05) than that with CK. When BAT was controlled, partial correlations between TSR, OCS, OCC, and AFP were all significant in the AI treatment but not in the CK treatment. TSR was more sensitive to the interaction effects of OCC, OCS, AFP, and BAT under the AI treatment. Thus, the significantly increased TSR with AI appeared to be due to the favorable soil aeration conditi ons(higher OCC and AFP). Furthermore, the improvements in soil aeration conditions and respiration with AI appeared to facilitate the improvement in fruit yields, which also suggests the economic benefits of AI.展开更多
AIM: To systematically analyze the randomized trials comparing the oncological and clinical effectiveness of laparoscopic total mesorectal excision(LTME) vs open total mesorectal excision(OTME) in the management of re...AIM: To systematically analyze the randomized trials comparing the oncological and clinical effectiveness of laparoscopic total mesorectal excision(LTME) vs open total mesorectal excision(OTME) in the management of rectal cancer.METHODS: Published randomized, controlled trials comparing the oncological and clinical effectiveness of LTME vs OTME in the management of rectal cancer were retrieved from the standard electronic medical databases. The data of included randomized, controlled trials was extracted and then analyzed according to the principles of meta-analysis using RevMan? statistical software. The combined outcome of the binary variables was expressed as odds ratio(OR) and the combined outcome of the continuous variables waspresented in the form of standardized mean difference(SMD). RESULTS: Data from eleven randomized, controlled trials on 2143 patients were retrieved from the electronic databases. There was a trend towards the higher risk of surgical site infection(OR = 0.66; 95%CI: 0.44-1.00; z = 1.94; P < 0.05), higher risk of incomplete total mesorectal resection(OR = 0.62; 95%CI: 0.43-0.91; z = 2.49; P < 0.01) and prolonged length of hospital stay(SMD,-1.59; 95%CI:-0.86--0.25; z = 4.22; P < 0.00001) following OTME. However, the oncological outcomes like number of harvested lymph nodes, tumour recurrence and risk of positive resection margins were statistically similar in both groups. In addition, the clinical outcomes such as operative complications, anastomotic leak and all-cause mortality were comparable between both approaches of mesorectal excision.CONCLUSION: LTME appears to have clinically and oncologically measurable advantages over OTME in patients with primary rectal cancer in both short term and long term follow ups.展开更多
Freeze‒thaw induced landslides(FTILs)in grasslands on the Tibetan Plateau are a geological disaster leading to soil erosion.These landslides reduce biodiversity and intensify landscape fragmentation,which in turn are ...Freeze‒thaw induced landslides(FTILs)in grasslands on the Tibetan Plateau are a geological disaster leading to soil erosion.These landslides reduce biodiversity and intensify landscape fragmentation,which in turn are strengthen by the persistent climate change and increased anthropogenic activities.However,conventional techniques for mapping FTILs on a regional scale are impractical due to their labor-intensive,costly,and time-consuming nature.This study focuses on improving FTILs detection by implementing image fusion-based Google Earth Engine(GEE)and a random forest algorithm.Integration of multiple data sources,including texture features,index features,spectral features,slope,and vertical‒vertical polarization data,allow automatic detection of the spatial distribution characteristics of FTILs in Zhidoi county,which is located within the Qinghai‒Tibet Engineering Corridor(QTEC).We employed statistical techniques to elucidate the mechanisms influencing FTILs occurrence.The enhanced method identifies two schemes that achieve high accuracy using a smaller training sample(scheme A:94.1%;scheme D:94.5%)compared to other methods(scheme B:50.0%;scheme C:95.8%).This methodology is effective in generating accurate results using only~10%of the training sample size necessitated by other methods.The spatial distribution patterns of FTILs generated for 2021 are similar to those obtained using various other training sample sources,with a primary concentration observed along the central region traversed by the QTEC.The results highlight the slope as the most crucial feature in the fusion images,accounting for 93%of FTILs occurring on gentle slopes ranging from 0°to 14°.This study provides a theoretical framework and technological reference for the identification,monitoring,prevention and control of FTILs in grasslands.Such developments hold the potential to benefit the management of grassland ecosystem,reduce economic losses,and promote grassland sustainability.展开更多
Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined...Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined effects of uterine, placental and embryo/fetal function. The number of living conceptuses that the uterus is capable of supporting is greater during early gestation compared to later gestation. Plots of log fetal weight versus log placental weight also indicate that fetal weights are less sensitive to reduced placental weight （and therefore reduced intrauterine space） in early gestation compared to late gestation. However, even in late gestation, mechanisms still exist that maintain fetal growth when the size of the placenta is reduced. One such mechanism is likely to be improved development of the folded placental-epithelial/maternal-epithelial bilayer. Fold depth, and therefore the maternal fetal interactive surface, increases as gestation advances and is greater in placenta from smal fetuses. On the fetal side of the placenta, the epithelial bilayer is embedded in stromal tissue. Glycosaminoglycans are major components of stroma, including hyaluronan and heparan sulfate. Hyaluronidases and heparanases are present within placental tissues, and likely play roles in modification of stromal components to facilitate fold development. Glycosaminoglycans are polymers of forms of glucose （glucosamine, glucuronic acid, iduronic acid） suggesting that glycosaminoglycan synthesis may compete with the glucose needs of the developing fetus. Pig conceptuses are fructogenic, such that a substantial portion of glucose transferred from mother to fetus is converted to fructose. Fructose is an intermediate product in the synthesis of glucosamine from glucose, and glucosamine is linked to regulation of trophoblast cell proliferation through regulation of mTOR. These findings suggest a link between glucose, fructose, glucosamine synthesis, GAG production, and placental morphogenesis, but the details of these i展开更多
The U.S.National Institute of Standards and Technology(NIST)published the Community Resilience Planning Guide in 2016.The NIST Guide advocates for a participatory process for developing a performance measurement frame...The U.S.National Institute of Standards and Technology(NIST)published the Community Resilience Planning Guide in 2016.The NIST Guide advocates for a participatory process for developing a performance measurement framework for the jurisdiction’s resilience against a scenario hazard.The framework centers around tables of expected and desired recovery times for selected community assets,such as electricity,water,and natural gas infrastructures.The NIST Guide does not provide a method for estimating the expected recovery times.However,building high-fidelity computer models for such estimations requires substantial resources that even larger ju-risdictions cannot cost-justify.The most promising approach to recovery time estimation is to systematically use data elicited from people to tap into the wisdom of the(knowledgeable)crowd.This paper describes a novel research-through-design project to enable the computer-supported elicitation of recovery time series data.This work is the first in the literature to examine people’s ability to estimate recovery curves and how design in-fluences such estimations.Its main contribution to resilience planning is three-fold:development of a new elicitation tool called Restimate,understanding its potential user base,and providing insights into how it can facilitate resilience planning.Restimate is the first tool to enable evidence-based expert elicitation in any community with limited resources for resilience planning.Beyond resilience planning,those who facilitate high-stakes planning activities under large uncertainties(e.g.,mission-critical system design and planning)will benefit from a similar research-through-design process.展开更多
The Permian Basin is one of the most prolific,and currently one of the most active,oil and gas basins in the USA.The Lower Permian strata in the Permian Basin have produced more than 14 billion barrels of oil(BBO),mak...The Permian Basin is one of the most prolific,and currently one of the most active,oil and gas basins in the USA.The Lower Permian strata in the Permian Basin have produced more than 14 billion barrels of oil(BBO),making it the largest volume of hydrocarbon in the basin.Sedimentation in the Midland Basin during late Leonardian through early Guadalupian(ca.272-269 Ma)resulted in progradation of shelf edge and ultimately closure of the basin by Middle Permian time.We analyzed a merged seismic survey covering parts of the Permian Basin(i.e.,Central Basin Platform and Midland Basin)in Andrews,Ector,and Midland Counties,Texas.The seismic survey and well logs show the presence of gently dipping(ca.1°)clinoforms in the Upper San Andres and Grayburg Formations on the eastern edge of the Central Basin Platform and western Midland Basin.The seismic attributes,curvature,and spectral decomposition identify low sinuosity slope channels oriented north-south,but such channels do not appear beyond the slope.The shelf edge shifts from north to south during deposition of the Upper San Andres and Grayburg Formations.We identify five basinward shifts noted by the migration of the shelf edge toward the basin center and the presence of channel features along the depositional slope.The petrophysical analysis indicates that channels cut into carbonate rocks and are filled by siliciclastic sediments;this interpretation is supported by the most negative curvature anomalies along the channel axes caused by the differential compaction between the carbonate and siliciclastic rocks.There are a few channels with a northwest-southeast strike,which matches the direction of the Concho Lineament observed by satellite data.Such observations are consistent with previous interpretations of the northern Midland Basin closure during Middle-Late Permian time.展开更多
Mitochondrial dysfunction and neurodegeneration:Progressive neurodegenerative diseases affect a significant proportion of the population;in a single year,there are as many as 276 million disabilities and 9 million dea...Mitochondrial dysfunction and neurodegeneration:Progressive neurodegenerative diseases affect a significant proportion of the population;in a single year,there are as many as 276 million disabilities and 9 million deaths as a result of neurological diseases.展开更多
Excessive use of nitrogen (N) fertilizers in agricultural systems increases the cost of production and risk of environmental pollution. Therefore, determination of optimum N requirements for plant growth is necessary....Excessive use of nitrogen (N) fertilizers in agricultural systems increases the cost of production and risk of environmental pollution. Therefore, determination of optimum N requirements for plant growth is necessary. Previous studies mostly established critical N dilution curves based on aboveground dry matter (DM) or leaf dry matter (LDM) and stem dry matter (SDM), to diagnose the N nutrition status of the whole plant. As these methods are time consuming, we investigated the more rapidly determined leaf area index (LAI) method to establish the critical nitrogen (Nc) dilution curve, and the curve was used to diagnose plant N status for winter wheat in Guanzhong Plain in Northwest China. Field experiments were conducted using four N fertilization levels (0, 105, 210 and 315 kg ha?1) applied to six wheat cultivars in the 2013–2014 and 2014–2015 growing seasons. LAI, DM, plant N concentration (PNC) and grain yield were determined. Data points from four cultivars were used for establishing the Nc curve and data points from the remaining two cultivars were used for validating the curve. The Nc dilution curve was validated for N-limiting and non-N-limiting growth conditions and there was good agreement between estimated and observed values. The N nutrition index (NNI) ranged from 0.41 to 1.25 and the accumulated plant N deficit (Nand) ranged from 60.38 to –17.92 kg ha?1 during the growing season. The relative grain yield was significantly affected by NNI and was adequately described with a parabolic function. The Nc curve based on LAI can be adopted as an alternative and more rapid approach to diagnose plant N status to support N fertilization decisions during the vegetative growth of winter wheat in Guanzhong Plain in Northwest China.展开更多
Healthy soils are important to ensure satisfactory crop growth and yield. Poultry litter (PL), as an organic fertilizer, has proven to supply the soil with essential macro and micronutrients, enhance soil fertility, a...Healthy soils are important to ensure satisfactory crop growth and yield. Poultry litter (PL), as an organic fertilizer, has proven to supply the soil with essential macro and micronutrients, enhance soil fertility, and improve crop productivity. Integrating this treatment has the potential to improve soil physical and biological properties by increasing soil carbon, C. However, rapid decomposition and mineralization of PL, particularly in the hot and humid southeastern U.S., resulted in losing C and reduced its effect on soil health. Biochar and lignite have been proposed to stabilize and mitigate C loss through application of fresh manure. However, their combined effects with PL on C sequestration and soil health components are limited. A field experiment was conducted on Leeper silty clay loam soil from 2017 to 2020 to evaluate the combined effect on soil properties when applying biochar and lignite with PL to cotton (Gossypium hirsutum L.). The experimental design was a randomized complete block involving nine treatments replicated three times. Treatments included PL and inorganic nitrogen, N, fertilizer with or without biochar and lignite, and an unfertilized control. Application rates were 6.7 Mgkg⋅ha−1</sup> for PL, 6.7 Mgkg⋅ha−1</sup></sup> for biochar and lignite and 134 kg⋅ha−1</sup><sup></sup> for inorganic N fertilizer. Integration of PL and inorganic fertilizer with biochar and lignite, resulted in greater soil infiltration, aggregate stability, plant available water, reduced bulk density and penetration resistance as compared to the sole applications of PL and inorganic fertilizer.展开更多
Quantum entanglements between integer-order and fractional-order orbital angular momentums(OAMs)have been previously discussed.However,the entangled nature of arbitrary rational-order OAM has long been considered a my...Quantum entanglements between integer-order and fractional-order orbital angular momentums(OAMs)have been previously discussed.However,the entangled nature of arbitrary rational-order OAM has long been considered a myth due to the absence of an effective strategy for generating arbitrary rational-order OAM beams.Therefore,we report a single metadevice comprising a bilaterally symmetric grating with an aperture,creating optical beams with dynamically controllable OAM values that are continuously varying over a rational range.Due to its encoded spiniform phase,this novel metagrating enables the production of an average OAM that can be increased without a theoretical limit by embracing distributed singularities,which differs significantly from the classic method of stacking phase singularities using fork gratings.This new method makes it possible to probe the unexplored niche of quantum entanglement between arbitrarily defined OAMs in light,which could lead to the complex manipulation of microparticles,high-dimensional quantum entanglement and optical communication.We show that quantum coincidence based on rational-order OAM-superposition states could give rise to low cross-talks between two different states that have no significant overlap in their spiral spectra.Additionally,future applications in quantum communication and optical micromanipulation may be found.展开更多
More than 170 years after causing the potato famine in Ireland,late blight is still considered one of the most devastating crop diseases.Commercial potato breeding efforts depend on natural sources of resistance to pr...More than 170 years after causing the potato famine in Ireland,late blight is still considered one of the most devastating crop diseases.Commercial potato breeding efforts depend on natural sources of resistance to protect crops from the rapidly evolving late blight pathogen,Phytophthora infestans.We have identified and mapped a novel broad-spectrum disease resistance gene effective against P.infestans from the wild,diploid potato species Solanum bulbocastanum.Diagnostic resistance gene enrichment sequencing(dRenSeq)was used to confirm the uniqueness of the identified resistance.RenSeq and GenSeq-based mapping of the resistance,referred to as Rpi-blb4,alongside recombinant screening,positioned the locus responsible for the resistance to potato chromosome 5.The interval spans approximately 2.3 Mb and corresponds to the DM reference genome positions of 11.25 and 13.56 Mb.展开更多
Transcranial direct current stimulation(tDCS)is a promising method for altering cortical excitability with clinical implications.It has been increasingly used in neurodevelopmental disorders,especially attention-defic...Transcranial direct current stimulation(tDCS)is a promising method for altering cortical excitability with clinical implications.It has been increasingly used in neurodevelopmental disorders,especially attention-deficit hyperactivity disorder(ADHD),but its efficacy(based on effect size calculations),safety,and stimulation parameters have not been systematically examined.In this systematic review,we aimed to(1)explore the effectiveness of tDCS on the clinical symptoms and neuropsychological deficits of ADHD patients,(2)evaluate the safety of tDCS application,especially in children with ADHD,(3)model the electrical field intensity in the target regions based on the commonly-applied and effective versus less-effective protocols,and(4)discuss and propose advanced tDCS parameters.Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach,a literature search identified 14 empirical experiments investigating tDCS effects in ADHD.Partial improving effects of tDCS on cognitive deficits(response inhibition,working memory,attention,and cognitive flexibility)or clinical symptoms(e.g.,impulsivity and inattention)are reported in10 studies.No serious adverse effects are reported in 747 sessions of tDCS.The left and right dorsolateral prefrontal cortex are the regions most often targeted,and anodal tDCS the protocol most often applied.An intensity of 2 mA induced stronger electrical fields than 1 mA in adults with ADHD and was associated with significant behavioral changes.In ADHD children,however,the electrical field induced by 1 mA,which is likely larger than the electrical field induced by 1 mA in adults due to the smaller head size of children,was sufficient to result in significant behavioral change.Overall,tDCS seems to be a promising method for improving ADHD deficits.However,the clinical utility of tDCS in ADHD cannot yet be concluded and requires further systematic investigation in larger sample sizes.Cortical regions involved in ADHD pathophysiology,stimulation parameters(e.g.intensity,durati展开更多
文摘Considerable progress has been achieved in friction stir welding （FSW） of steels in every aspect of tool fab- rication, microstructure control and properties evaluation in the past two decades. With the development of reliable welding tools and precise control systems, FSW of steels has reached a new level of technical maturity. High-quality, long welds can be produced in many engineering steels. Compared to traditional fusion welding, FSW exhibits unique advantages producing joints with better properties. As a result of active control of the welding temperature and/or cooling rate, FSW has the capability of fabricating steel joints with excellent toughness and strength. For example, unfavorable phase transformations that usu- ally occur during traditional welding can be avoided and favorable phase fractions in advanced steels can be maintained in the weld zone thus avoiding the typical property degradations associated with fusion welding. If phase transformations do occur during FSW of thick steels, optimization of microstructure and properties can be attained by controlling the heat input and post-weld cooling rate.
基金financed by the National Natural Science Foundation of China under Grant 50930072,51120175001,51477084in part by the Beijing Natural Science Foundation under Grant 3152016.
文摘Correct detection and identification of single-phase to-ground faults not effectively grounded in distribution systems is a major challenge for protection engineers.This paper proposes a novel traveling wave based protection method to solve this problem.The proposed method compares the polarities of current and voltage traveling waves measured immediately after the fault inception to determine the fault direction.Nuisance tripping is avoided by using the power frequency voltages detected on the busbar to inhibit operation.The power frequency voltages ensure that the system does not mal-operate due to noise and also provide discrimination for phase-to-phase and three-phase faults.The wavelet transform and modulus maxima theories are used to extract the polarity of traveling waves measured at the relaying point.The simulation studies demonstrate correct operation of protection,which is independent of fault distance,fault inception angle,fault path resistance,and the method used for neutral grounding.
文摘Plant pathogens deliver effector proteins that alter host processes to create an environment conducive to colonization. Attention has focused on identifying the targets of effectors and how their manipulation facil- itates disease. RXLR effector Pi04089 from the potato blight pathogen Phytophthora infestans accumu- lates in the host nucleus and enhances colonization when transiently expressed in planta. Its nuclear local- ization is required for enhanced P. infestans colonization. Pi04089 interacts in yeast and in planta with a putative potato K-homology （KH） RNA-binding protein, StKRBPI. Co-localization of Pi04089 and StKRBP1, and bimolecular fluorescence complementation between them, indicate they associate at nuclear speckles. StKRBP1 protein levels increased when it was co-expressed with Pi04089. Indeed, such accumu- lation of StKRBP1 was observed also on the first day of leaf colonization by the pathogen. Remarkably, overexpression of StKRBP1 significantly enhances P. infestans infection. Mutation of the nucleotide- binding motif GxxG to GDDG in all three KH domains of StKRBP1 abolishes its interaction with Pi04089, its localization to nuclear speckles, and its increased accumulation when co-expressed with the effector. Moreover, the mutant StKRBP1 protein no longer enhances leaf colonization by P. infestans, implying that nucleotide binding is likely required for this activity. We thus argue that StKRBP1 can be regarded as a sus- ceptibility factor, as its activity is beneficial to the pathogen.
文摘土壤水分特征曲线模型作为实验测定土壤水分特征数据的一种替代方法,因其具有计算方便快捷和便于嵌入数值模拟程序的优点,开始受到越来越广泛的关注。虽然文献中存在众多的土壤水分特征曲线模型,但是这些模型的适用范围及拟合性能尚不明确。为了获得更加准确适用的土壤水分特征曲线,在实际应用中通常需要花费大量时间和精力去测试各种模型。为了解决上述问题,在国内外研究成果的基础上收集整理了12种典型的土壤水分特征曲线模型,并利用包含不同质地、有机质含量及容重的8种土壤的实测土壤水分特征数据来评估比较这些模型的模拟性能。模型性能通过均方根误差(RMSE)、平均偏差(AD)、AIC准则(Akaike Information Criterion)和纳什效率系数(NSE)4个指标评估。研究结果表明:大部分的模型能够提供比较接近于实际的拟合结果,评价指标值也比较相近。其中,KCGS2006(包含3个参数)和K1999模型(包含2个参数)拟合效果最好,而Gregson1987(包含1个参数)的拟合效果最差。该研究可以深入了解各种土壤水分特征曲线模型的适用性与局限性,更好地为生态环境建设和农业可持续发展研究中土壤水力参数的选取提供依据和参考。
文摘Purpose:Supracondylar fractures of the humerus cause significant morbidity in children.Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury.Uncertainty surrounds the optimal Kirschner wire configuration and diameter for closed reduction and pinning of these fractures.This study describes current practice and examined the association between wire configuration or diameter and outcomes(clinical and radiological)in the operative management of paediatric supracondylar fractures.Methods:Children presenting w让h GartlandⅡorⅢsupracondylar fractures at five hospitals in southwest England were eligible for inclusion.Collaborators scrutinised paper and electronic case notes.Outcome measures were maintenance of reduction and iatrogenic nerve injury.Results:Altogether 209 patients were eligible for inclusion:15.7%had a documented neurological deficit at presentation;3.9%who were neurologically intact at presentation sustained a new deficit caused by treatment and 13.4%experienced a clinically significant loss of reduction following fixation.Maintenance of reduction was significantly better in patients treated specifically with crossed×3 Kirschner wire configuration compared to all other configurations.The incidence of iatrogenic nerve injury was not significantly different between groups treated with different wire configurations.Conclusion:We present a large multicentre cohort study showing that crossed×3 Kirschner wires are associated with better maintenance of reduction than crossed×2 or lateral entry wires.Greater numbers would be required to properly investigate nerve injury relating to operative management of supracondylar fractures.We found significant variations in practice and compliance w让h the British Orthopaedic Association Standard for Trauma(BOAST)11 guidelines.
基金funded by the National Key Research and Development Program of China (2016YFC0400200 and 2016YFC0400201)the Program of Introducing Talents of Discipline to Universities “111 Project”, China (B12007)
文摘To ameliorate soil oxygen deficiencies around subsurface drip irrigation(SDI) drippers, aerated irrigation(AI) was introduced to supply aerated water to the soil through venturi installed in the SDI pipeline. The objectives of this study were to assess the effects of AI on soil respiration(SR), air-filled porosity(AFP), soil temperature(ST), and oxygen concentrations(OCC). Total soil respiration(TSR), biological activity temperature index(BAT), and soil oxygen consumption(OCS) based on SR, ST, and OCC, respectively, were subsequently calculated to explore the relationships between TSR, BAT, OCS, OCC, and AFP. Greenhouse-based experiments included two treatments: AI and unaerated SDI(CK), during the tomato growing season in the fall of 2015. The results showed that compared with CK, AI treatment significantly increased OCC and AFP(by 16 and 7.4%, respectively), as well as TSR and OCS(by 24.21 and 22.91%, respectively)(P<0.05). Mean fruit yield with AI treatment was also 23% higher(P<0.05) than that with CK. When BAT was controlled, partial correlations between TSR, OCS, OCC, and AFP were all significant in the AI treatment but not in the CK treatment. TSR was more sensitive to the interaction effects of OCC, OCS, AFP, and BAT under the AI treatment. Thus, the significantly increased TSR with AI appeared to be due to the favorable soil aeration conditi ons(higher OCC and AFP). Furthermore, the improvements in soil aeration conditions and respiration with AI appeared to facilitate the improvement in fruit yields, which also suggests the economic benefits of AI.
文摘AIM: To systematically analyze the randomized trials comparing the oncological and clinical effectiveness of laparoscopic total mesorectal excision(LTME) vs open total mesorectal excision(OTME) in the management of rectal cancer.METHODS: Published randomized, controlled trials comparing the oncological and clinical effectiveness of LTME vs OTME in the management of rectal cancer were retrieved from the standard electronic medical databases. The data of included randomized, controlled trials was extracted and then analyzed according to the principles of meta-analysis using RevMan? statistical software. The combined outcome of the binary variables was expressed as odds ratio(OR) and the combined outcome of the continuous variables waspresented in the form of standardized mean difference(SMD). RESULTS: Data from eleven randomized, controlled trials on 2143 patients were retrieved from the electronic databases. There was a trend towards the higher risk of surgical site infection(OR = 0.66; 95%CI: 0.44-1.00; z = 1.94; P < 0.05), higher risk of incomplete total mesorectal resection(OR = 0.62; 95%CI: 0.43-0.91; z = 2.49; P < 0.01) and prolonged length of hospital stay(SMD,-1.59; 95%CI:-0.86--0.25; z = 4.22; P < 0.00001) following OTME. However, the oncological outcomes like number of harvested lymph nodes, tumour recurrence and risk of positive resection margins were statistically similar in both groups. In addition, the clinical outcomes such as operative complications, anastomotic leak and all-cause mortality were comparable between both approaches of mesorectal excision.CONCLUSION: LTME appears to have clinically and oncologically measurable advantages over OTME in patients with primary rectal cancer in both short term and long term follow ups.
基金the Innovation Capability Support Program of Shaanxi Province(2023-JC-JQ-25)High-end Foreign Experts Recruitment Plan of China(G2021172006L and G2023172014L).
文摘Freeze‒thaw induced landslides(FTILs)in grasslands on the Tibetan Plateau are a geological disaster leading to soil erosion.These landslides reduce biodiversity and intensify landscape fragmentation,which in turn are strengthen by the persistent climate change and increased anthropogenic activities.However,conventional techniques for mapping FTILs on a regional scale are impractical due to their labor-intensive,costly,and time-consuming nature.This study focuses on improving FTILs detection by implementing image fusion-based Google Earth Engine(GEE)and a random forest algorithm.Integration of multiple data sources,including texture features,index features,spectral features,slope,and vertical‒vertical polarization data,allow automatic detection of the spatial distribution characteristics of FTILs in Zhidoi county,which is located within the Qinghai‒Tibet Engineering Corridor(QTEC).We employed statistical techniques to elucidate the mechanisms influencing FTILs occurrence.The enhanced method identifies two schemes that achieve high accuracy using a smaller training sample(scheme A:94.1%;scheme D:94.5%)compared to other methods(scheme B:50.0%;scheme C:95.8%).This methodology is effective in generating accurate results using only~10%of the training sample size necessitated by other methods.The spatial distribution patterns of FTILs generated for 2021 are similar to those obtained using various other training sample sources,with a primary concentration observed along the central region traversed by the QTEC.The results highlight the slope as the most crucial feature in the fusion images,accounting for 93%of FTILs occurring on gentle slopes ranging from 0°to 14°.This study provides a theoretical framework and technological reference for the identification,monitoring,prevention and control of FTILs in grasslands.Such developments hold the potential to benefit the management of grassland ecosystem,reduce economic losses,and promote grassland sustainability.
文摘Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined effects of uterine, placental and embryo/fetal function. The number of living conceptuses that the uterus is capable of supporting is greater during early gestation compared to later gestation. Plots of log fetal weight versus log placental weight also indicate that fetal weights are less sensitive to reduced placental weight （and therefore reduced intrauterine space） in early gestation compared to late gestation. However, even in late gestation, mechanisms still exist that maintain fetal growth when the size of the placenta is reduced. One such mechanism is likely to be improved development of the folded placental-epithelial/maternal-epithelial bilayer. Fold depth, and therefore the maternal fetal interactive surface, increases as gestation advances and is greater in placenta from smal fetuses. On the fetal side of the placenta, the epithelial bilayer is embedded in stromal tissue. Glycosaminoglycans are major components of stroma, including hyaluronan and heparan sulfate. Hyaluronidases and heparanases are present within placental tissues, and likely play roles in modification of stromal components to facilitate fold development. Glycosaminoglycans are polymers of forms of glucose （glucosamine, glucuronic acid, iduronic acid） suggesting that glycosaminoglycan synthesis may compete with the glucose needs of the developing fetus. Pig conceptuses are fructogenic, such that a substantial portion of glucose transferred from mother to fetus is converted to fructose. Fructose is an intermediate product in the synthesis of glucosamine from glucose, and glucosamine is linked to regulation of trophoblast cell proliferation through regulation of mTOR. These findings suggest a link between glucose, fructose, glucosamine synthesis, GAG production, and placental morphogenesis, but the details of these i
基金support of the U.S.National Science Foundation(NSF grants CMMI-1824681,BCS-2121616,&CMMI-2211077)。
文摘The U.S.National Institute of Standards and Technology(NIST)published the Community Resilience Planning Guide in 2016.The NIST Guide advocates for a participatory process for developing a performance measurement framework for the jurisdiction’s resilience against a scenario hazard.The framework centers around tables of expected and desired recovery times for selected community assets,such as electricity,water,and natural gas infrastructures.The NIST Guide does not provide a method for estimating the expected recovery times.However,building high-fidelity computer models for such estimations requires substantial resources that even larger ju-risdictions cannot cost-justify.The most promising approach to recovery time estimation is to systematically use data elicited from people to tap into the wisdom of the(knowledgeable)crowd.This paper describes a novel research-through-design project to enable the computer-supported elicitation of recovery time series data.This work is the first in the literature to examine people’s ability to estimate recovery curves and how design in-fluences such estimations.Its main contribution to resilience planning is three-fold:development of a new elicitation tool called Restimate,understanding its potential user base,and providing insights into how it can facilitate resilience planning.Restimate is the first tool to enable evidence-based expert elicitation in any community with limited resources for resilience planning.Beyond resilience planning,those who facilitate high-stakes planning activities under large uncertainties(e.g.,mission-critical system design and planning)will benefit from a similar research-through-design process.
文摘The Permian Basin is one of the most prolific,and currently one of the most active,oil and gas basins in the USA.The Lower Permian strata in the Permian Basin have produced more than 14 billion barrels of oil(BBO),making it the largest volume of hydrocarbon in the basin.Sedimentation in the Midland Basin during late Leonardian through early Guadalupian(ca.272-269 Ma)resulted in progradation of shelf edge and ultimately closure of the basin by Middle Permian time.We analyzed a merged seismic survey covering parts of the Permian Basin(i.e.,Central Basin Platform and Midland Basin)in Andrews,Ector,and Midland Counties,Texas.The seismic survey and well logs show the presence of gently dipping(ca.1°)clinoforms in the Upper San Andres and Grayburg Formations on the eastern edge of the Central Basin Platform and western Midland Basin.The seismic attributes,curvature,and spectral decomposition identify low sinuosity slope channels oriented north-south,but such channels do not appear beyond the slope.The shelf edge shifts from north to south during deposition of the Upper San Andres and Grayburg Formations.We identify five basinward shifts noted by the migration of the shelf edge toward the basin center and the presence of channel features along the depositional slope.The petrophysical analysis indicates that channels cut into carbonate rocks and are filled by siliciclastic sediments;this interpretation is supported by the most negative curvature anomalies along the channel axes caused by the differential compaction between the carbonate and siliciclastic rocks.There are a few channels with a northwest-southeast strike,which matches the direction of the Concho Lineament observed by satellite data.Such observations are consistent with previous interpretations of the northern Midland Basin closure during Middle-Late Permian time.
文摘Mitochondrial dysfunction and neurodegeneration:Progressive neurodegenerative diseases affect a significant proportion of the population;in a single year,there are as many as 276 million disabilities and 9 million deaths as a result of neurological diseases.
基金financial support from the National Key Research and Development Program of China (2017YFC0403303)the Shanxi Agricultural University of Science and Technology Innovation Fund, China (2016YJ07 and 2016007)
文摘Excessive use of nitrogen (N) fertilizers in agricultural systems increases the cost of production and risk of environmental pollution. Therefore, determination of optimum N requirements for plant growth is necessary. Previous studies mostly established critical N dilution curves based on aboveground dry matter (DM) or leaf dry matter (LDM) and stem dry matter (SDM), to diagnose the N nutrition status of the whole plant. As these methods are time consuming, we investigated the more rapidly determined leaf area index (LAI) method to establish the critical nitrogen (Nc) dilution curve, and the curve was used to diagnose plant N status for winter wheat in Guanzhong Plain in Northwest China. Field experiments were conducted using four N fertilization levels (0, 105, 210 and 315 kg ha?1) applied to six wheat cultivars in the 2013–2014 and 2014–2015 growing seasons. LAI, DM, plant N concentration (PNC) and grain yield were determined. Data points from four cultivars were used for establishing the Nc curve and data points from the remaining two cultivars were used for validating the curve. The Nc dilution curve was validated for N-limiting and non-N-limiting growth conditions and there was good agreement between estimated and observed values. The N nutrition index (NNI) ranged from 0.41 to 1.25 and the accumulated plant N deficit (Nand) ranged from 60.38 to –17.92 kg ha?1 during the growing season. The relative grain yield was significantly affected by NNI and was adequately described with a parabolic function. The Nc curve based on LAI can be adopted as an alternative and more rapid approach to diagnose plant N status to support N fertilization decisions during the vegetative growth of winter wheat in Guanzhong Plain in Northwest China.
文摘Healthy soils are important to ensure satisfactory crop growth and yield. Poultry litter (PL), as an organic fertilizer, has proven to supply the soil with essential macro and micronutrients, enhance soil fertility, and improve crop productivity. Integrating this treatment has the potential to improve soil physical and biological properties by increasing soil carbon, C. However, rapid decomposition and mineralization of PL, particularly in the hot and humid southeastern U.S., resulted in losing C and reduced its effect on soil health. Biochar and lignite have been proposed to stabilize and mitigate C loss through application of fresh manure. However, their combined effects with PL on C sequestration and soil health components are limited. A field experiment was conducted on Leeper silty clay loam soil from 2017 to 2020 to evaluate the combined effect on soil properties when applying biochar and lignite with PL to cotton (Gossypium hirsutum L.). The experimental design was a randomized complete block involving nine treatments replicated three times. Treatments included PL and inorganic nitrogen, N, fertilizer with or without biochar and lignite, and an unfertilized control. Application rates were 6.7 Mgkg⋅ha−1</sup> for PL, 6.7 Mgkg⋅ha−1</sup></sup> for biochar and lignite and 134 kg⋅ha−1</sup><sup></sup> for inorganic N fertilizer. Integration of PL and inorganic fertilizer with biochar and lignite, resulted in greater soil infiltration, aggregate stability, plant available water, reduced bulk density and penetration resistance as compared to the sole applications of PL and inorganic fertilizer.
基金supported by the National Research Foundation,Prime Minister’s Office,Singapore,under its Competitive Research Programme(CRP Award No.NRF-CRP15-2015-03)supported by the National Research Foundation,Prime Minister’s Office,Singapore,under its Competitive Research Programme(CRP Award No.NRFCRP15-2015-01)+2 种基金supported by the Institute of Materials Research and Engineering(IMRE)and the Agency for Science,Technology and Research(A*STAR)under Grants 1521480031 and 1527000014support from ERC Advance grant(TWISTS)the Onehundred-person Project of the Chinese Academy of Sciences for its support.
文摘Quantum entanglements between integer-order and fractional-order orbital angular momentums(OAMs)have been previously discussed.However,the entangled nature of arbitrary rational-order OAM has long been considered a myth due to the absence of an effective strategy for generating arbitrary rational-order OAM beams.Therefore,we report a single metadevice comprising a bilaterally symmetric grating with an aperture,creating optical beams with dynamically controllable OAM values that are continuously varying over a rational range.Due to its encoded spiniform phase,this novel metagrating enables the production of an average OAM that can be increased without a theoretical limit by embracing distributed singularities,which differs significantly from the classic method of stacking phase singularities using fork gratings.This new method makes it possible to probe the unexplored niche of quantum entanglement between arbitrarily defined OAMs in light,which could lead to the complex manipulation of microparticles,high-dimensional quantum entanglement and optical communication.We show that quantum coincidence based on rational-order OAM-superposition states could give rise to low cross-talks between two different states that have no significant overlap in their spiral spectra.Additionally,future applications in quantum communication and optical micromanipulation may be found.
基金the Rural&Environment Science&Analytical Services(RESAS)Division of the Scottish Government(JHI-B1-1)the Biotechnology and Biological Sciences Research Council(BBSRC,BB/S015663/1)+3 种基金the Royal Society(NAF\R1\201061)the National Natural Science Foundation of China(32061130211,32372558)AK was supported through a Research Leaders 2025 fellowship funded by European Union’s Horizon 2020 Research and Innovation Programme under Marie Sklodowska-Curie Grant Agreement(754380)The authors acknowledge the Research/Scientific Computing teams at The James Hutton Institute and NIAB for providing computational resources and technical support for the‘‘UK’s Crop Diversity Bioinformatics HPC”(BBSRC Grant BB/S019669/1),use of which has contributed to the results reported within this paper.
文摘More than 170 years after causing the potato famine in Ireland,late blight is still considered one of the most devastating crop diseases.Commercial potato breeding efforts depend on natural sources of resistance to protect crops from the rapidly evolving late blight pathogen,Phytophthora infestans.We have identified and mapped a novel broad-spectrum disease resistance gene effective against P.infestans from the wild,diploid potato species Solanum bulbocastanum.Diagnostic resistance gene enrichment sequencing(dRenSeq)was used to confirm the uniqueness of the identified resistance.RenSeq and GenSeq-based mapping of the resistance,referred to as Rpi-blb4,alongside recombinant screening,positioned the locus responsible for the resistance to potato chromosome 5.The interval spans approximately 2.3 Mb and corresponds to the DM reference genome positions of 11.25 and 13.56 Mb.
基金This review was supported by the Department of Psychology and Neurosciences,Leibniz-Institut fiir Arbeitsforschung Ministry of Science,Research and Technology,Deputy of Scholarship and Students Affairs,Iran(95000171)the German Ministry of Research and Education(German Center for Brain Stimulation grant number 01EE1403C).
文摘Transcranial direct current stimulation(tDCS)is a promising method for altering cortical excitability with clinical implications.It has been increasingly used in neurodevelopmental disorders,especially attention-deficit hyperactivity disorder(ADHD),but its efficacy(based on effect size calculations),safety,and stimulation parameters have not been systematically examined.In this systematic review,we aimed to(1)explore the effectiveness of tDCS on the clinical symptoms and neuropsychological deficits of ADHD patients,(2)evaluate the safety of tDCS application,especially in children with ADHD,(3)model the electrical field intensity in the target regions based on the commonly-applied and effective versus less-effective protocols,and(4)discuss and propose advanced tDCS parameters.Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach,a literature search identified 14 empirical experiments investigating tDCS effects in ADHD.Partial improving effects of tDCS on cognitive deficits(response inhibition,working memory,attention,and cognitive flexibility)or clinical symptoms(e.g.,impulsivity and inattention)are reported in10 studies.No serious adverse effects are reported in 747 sessions of tDCS.The left and right dorsolateral prefrontal cortex are the regions most often targeted,and anodal tDCS the protocol most often applied.An intensity of 2 mA induced stronger electrical fields than 1 mA in adults with ADHD and was associated with significant behavioral changes.In ADHD children,however,the electrical field induced by 1 mA,which is likely larger than the electrical field induced by 1 mA in adults due to the smaller head size of children,was sufficient to result in significant behavioral change.Overall,tDCS seems to be a promising method for improving ADHD deficits.However,the clinical utility of tDCS in ADHD cannot yet be concluded and requires further systematic investigation in larger sample sizes.Cortical regions involved in ADHD pathophysiology,stimulation parameters(e.g.intensity,durati
