Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N de...Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.展开更多
Al-Cu-Mn alloys are widely used to produce automobile components like cylinder heads and engine blocks because of their capability to retain excellent thermal and mechanical characteristics at high temperatures.Howeve...Al-Cu-Mn alloys are widely used to produce automobile components like cylinder heads and engine blocks because of their capability to retain excellent thermal and mechanical characteristics at high temperatures.However,the Al-Cu-Mn-based alloys demonstrate restricted fluidity,leading to casting defects such as shrinkage and incomplete filling.This research investigated the microstructure and fluidity of Al-4.7Cu-1.0Mn-0.5Mg(wt%)alloy with minor cerium(Ce)addition.The as-cast alloys predominantly compriseα-Al matrix,accompanied by the presence of Al_(2)Cu,Al_(6)Mn,and Al_(8)Cu_(4)Ce phases.The influence of adding Ce on the fluidity of the Al-4.7Cu-1.0Mn-0.5Mg alloy was investigated using a trispiral fluidity test mold in this research.The findings suggest that the addition of Ce within the range of 0.1 wt%to 0.5 wt%in the Al-4.7Cu-1.0Mn-0.5Mg alloy results in an enhancement in fluidity.Specifically,the alloy containing 0.4 wt%Ce exhibits a significant increase in fluidity distance,from 349.7 to 485.7 mm.This improvement can be attributed to the reduction in viscosity,the refinement of secondary dendrite arm spacing,and the modification of secondary phase particles.However,a higher concentration of Ce leads to a decrease in fluidity length,potentially due to the formation of Al_(8)Cu_(4)Ce.展开更多
The effect of Cr addition on nickel aluminium bronze(NAB)alloy microstructure,mechanical properties,and erosion-corrosion behaviour has been studied.The results show that Cr addition does not change the composition of...The effect of Cr addition on nickel aluminium bronze(NAB)alloy microstructure,mechanical properties,and erosion-corrosion behaviour has been studied.The results show that Cr addition does not change the composition of the precipitated phases,more Cr entered theκphase and a small amount of Cr solubilized in the matrix,which increase the hardness of theκand matrix and decrease the potential difference between theκand matrix.NAB alloy with Cr shows high erosion-corrosion resistance at high flow rate conditions,due to its lower phase potential difference and higher surface hardness.At the flow rate of 3 m·s^(-1),the corrosion rate is 0.076 mm·year^(-1),which is~20%lower than that of the unadded Cr sample.Moreover,the corrosion product film contains Cr_(2)O_(3)and Cr^(3+),which improves the densification of the film and raises alloy’s corrosion resistance with Cr addition.The combination of mechanical and corrosion resistant properties may qualify this alloy as a potential candidate material for sustainable and safe equipment.展开更多
In this paper,the property degradation micromechanism of Al-5.10Cu-0.65 Mg-0.8Mn(wt%)alloy induced by 0.5 wt%Fe minor addition was revealed by atomic-scale scanning transmission electron microscopy and energy-dispersi...In this paper,the property degradation micromechanism of Al-5.10Cu-0.65 Mg-0.8Mn(wt%)alloy induced by 0.5 wt%Fe minor addition was revealed by atomic-scale scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy coupled with first-principles calculations.The results show that the Fe minor addition to the Al-Cu-Mg-Mn alloy leads to a slight reduction of grain size and the formation of coarse Al7Cu2Fe constituent particles.Fe tends to segregate into the T-phase dispersoids,θ'-,and S-phase precipitates by preferentially occupying Cu or Mn sites in these phase structures.The apparent Fe segregation contributes to an increase in stiffness of the T-phase and S-phase but decreased stiffness of theθ'phase.Formation of the coarse Al7Cu2Fe constituent particles and decreased stiffness of main precipitatesθ'containing Fe result in the degraded strength of the Al-Cu-Mg-Mn-Fe alloy.Further study reveals that corrosion resistance degradation of the Al-Cu-Mg-Mn-Fe alloy is associated with the increased width of precipitation free zones and consecutive grain boundary precipitates.The obtained results have significant implications for the usage of recycled Al alloys and the potential design strategies of high-performance alloys containing Fe.展开更多
Rolling contact fatigue performance is among the most important issues for applications of bearing steels.In this work,a recently developed surface modification technique,surface mechanical rolling treatment,was appli...Rolling contact fatigue performance is among the most important issues for applications of bearing steels.In this work,a recently developed surface modification technique,surface mechanical rolling treatment,was applied on a rare-earth addition bearing steel.And rolling contact fatigue behavior of treated samples was compared with that of as-received counterparts at different contacting stresses.The results demonstrated that a 700μm-thick gradient nanostructured surface layer is produced on samples by surface mechanical rolling treatment.The grain size decreases while the microhardness increases gradually with decreasing depth,reaching~23 nm and~10.2 GPa,respectively,at the top surface.Consequently,the rolling contact fatigue property is significantly enhanced.The characteristic life of treated samples is~3.2 times that of untreated counterparts according to Weibull curves at 5.6 GPa.Analyses of fatigue mechanisms demonstrated that the gradient nanostructured surface layer might not only retard material degradation and microcrack formation,but also prolong the steady-state elastic response stage under rolling contact fatigue.展开更多
Friction stir lap welding(FSLW)was adopted to join successfully dissimilar AZ31B Mg alloy and TC4 Ti alloy with Sn foil addition of 30μm thickness.Interfacial microstructure,tensile shear performances and bonding mec...Friction stir lap welding(FSLW)was adopted to join successfully dissimilar AZ31B Mg alloy and TC4 Ti alloy with Sn foil addition of 30μm thickness.Interfacial microstructure,tensile shear performances and bonding mechanism of the joints obtained using three different rotation speeds were studied.High-performance FSLW Mg/Ti dissimilar joints with maximum tensile shear strength of 593.3 N/mm were produced at 1180 r/min,and which was mainly attributed to ultrastrong reaction interlayer consisting of 125.9 nm thick(Mg_(2)Sn+Mg)transition layer and discontinuous(Ti_(6)Sn_(5)+Ti_(3)Al)IMCs layer with 6.58 nm thickness at the interface.The formation of the reaction interlayer was beneficial for high interfacial strength,resulting in significantly improving the joint strength.The fracture of all FSLW joints located on AZ31B Mg stirred zone adjacent to(Mg_(2)Sn+Mg)transition layer or along the crack propagation direction of the AZ31B/TC4 interface with different fracture mechanisms,and which could be consistent with interfacial microstructure.展开更多
The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-di...The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.展开更多
A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the aci...A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the acidic alumina surface effectively activate the carbonyl group ofα,β-unsaturated ketones,significantly enhancing the electrophilicity of theβ-carbon and thereby facilitating selective alkylation at the C3 position of imidazo[1,2-a]pyridines.This method demonstrates excellent functional group compatibility,mild reaction conditions,low reagent costs,and operational simplicity,providing a novel strategy for the efficient synthesis of alkylated imidazo[1,2-a]pyridine derivatives.展开更多
The asymmetric addition of aromatic organometallic compounds to the carbonyl group(C-3)of isatins,catalyzed by transition metals,has emerged as a remarkably efficient method for the synthesis of chiral 3-hydroxyoxindo...The asymmetric addition of aromatic organometallic compounds to the carbonyl group(C-3)of isatins,catalyzed by transition metals,has emerged as a remarkably efficient method for the synthesis of chiral 3-hydroxyoxindoles.Here,an exceptionally enantioselective approach was developed for the first time to achieve a catalytic NHK reaction of isatins with aromatic halides(both aryl and heteroaryl).Utilizing chiral cobalt complexes as catalysts,and the presence of a diboron reagent B_(2)nep_(2)as both a reducing agent and determinant in enantiocontrol,has resulted in the triumphantly achieved synthesis of enantioenriched products.Compared to reported strategies,this approach exhibits remarkable compatibility with substrates bearing sensitive functional groups,such as halides and borate esters,while also eliminating the need for organometallic reagents as required in previous strategies.Through experimental investigations,the presence of aryl-cobalt species during the addition process was confirmed,rather than in-situ generation of an arylboron reagent.Furthermore,the successful attainment of the R absolute configuration through aryl addition was demonstrated.展开更多
TiAl alloys were melted in BaZrO_(3)crucibles without and with Y addition at 1550℃for 5,10,and 15 min,respectively.The effect of the melting time and Y addition on the interaction between the crucibles and the alloys...TiAl alloys were melted in BaZrO_(3)crucibles without and with Y addition at 1550℃for 5,10,and 15 min,respectively.The effect of the melting time and Y addition on the interaction between the crucibles and the alloys was investigated.Results revealed that the interaction extent was intensified with the increasing melting time.However,it could be effectively suppressed by adding Y into the alloy due to the in situ generated Y_(2)O_(3)protection layer.The thickness of the interaction layer could be decreased from 95.6 to 25.1μm with Y addition at 1550°C for 15 min.In addition,a significant deoxidation effect was achieved by adding Y,and the O concentration of the alloy was decreased from 0.2 to 0.0561 wt.%.In comparison with Al_(2)O_(3),MgO,CaO,and Y_(2)O_(3)crucibles,BaZrO_(3)crucible combined with Y addition exhibited the lowest O contamination to the alloy melt.展开更多
AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus ...AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus at the first 3mo of follow-up.METHODS:In this prospective observational study,20 eyes of 20 keratoconus patients who underwent SLAK combined with CXL were included.The morphological indices in keratometry and elevation data were recorded from the Sirius at baseline and 1 and 3mo postoperatively.The mean values of maximum keratometry(K_(max)),flat keratometry(K_(1)),and steep keratometry(K_(2))at the central,3-mm,5-mm,and 7-mm areas were measured from the curvature map.The changes in anterior and posterior corneal elevation under the best-fit sphere(BFS)radius at seven points horizontally of the center,3-mm,5-mm,and 7-mm area from the center at both nasal(N)and temporal(T)side were measured from elevation map.RESULTS:For the front corneal curvature,K_(1),and K_(2) at 3-mm,5-mm,and 7-mm of the anterior corneal surface increased significantly 1mo postoperatively(all P<0.05)and remained unchanged until 3mo(P>0.05).For the back corneal curvature,K_(1) and K_(2) along the 3-mm back meridian significantly decreased after month 1(P=0.002,0.077,respectively).Posterior K_(2)-readings along the 5-mm and 7-mm did not change after surgery(P>0.05).Anterior BFS decreased 1mo(P<0.001)postoperatively but remained unchanged until 3mo after SLAK(P>0.05).There was no change in posterior BFS before and after the surgery(P>0.05).Anterior elevation at N5,N3,central,and T5 points and posterior elevation at central and T7 points shifted backward 1mo postoperatively(all P<0.05)and remained stable until 3mo(P>0.05).CONCLUSION:The myopic SLAK combined with CXL is an economical alternative for stabilizing the corneal surface in severe keraoconus.“Pseudoprogression”occurs in the early phase postoperatively,but it is not an indicator of keratoconus progression.展开更多
The effects of trace cerium(Ce)addition on the microstructural and textural evolution and the dynamic recrystallization(DRX)of the ultrahigh-purity copper(Cu)containing small amounts of sulfur(S)were investigated usin...The effects of trace cerium(Ce)addition on the microstructural and textural evolution and the dynamic recrystallization(DRX)of the ultrahigh-purity copper(Cu)containing small amounts of sulfur(S)were investigated using a Gleeble-1500 thermal simulation tester at 600℃.The results show that with increasing Ce content,the grain size of the Cu-S(S2)alloy gradually decreases and the grain boundary embrittlement induced by S impurities is considerably inhibited.The addition of Ce promotes the DRX process of the S2 alloy and changes its DRX mechanism from discontinuous to continuous and twinning-induced DRX mechanisms.The texture component and intensity of the S2 alloy vary with the increase of Ce content.The addition of 120×10^(-6) Ce(mass fraction)is favorable for the grain orientation randomization,which is attributed to the promoted DRX.展开更多
The effects of Zr addition on the mechanical properties and in vitro degradation behavior of Mg-1.0Yb-xZr(x=0,0.2,1.0,and 1.53,wt.%)cast alloys were investigated.The results indicated that with increasing Zr addition,...The effects of Zr addition on the mechanical properties and in vitro degradation behavior of Mg-1.0Yb-xZr(x=0,0.2,1.0,and 1.53,wt.%)cast alloys were investigated.The results indicated that with increasing Zr addition,a much refined and homogeneous equiaxed grain structure was achieved from a typical columnar grain structure,in companion with the appearance and coarsening of Zr-rich particles.Subsequent electrochemical and immersion tests demonstrated that the corrosion of the alloy was Zr-addition dependent.A trace or excessive Zr addition caused severe localized corrosion attacks,whereas Zr-free and 1.0 Zr alloyed counterparts were generally corroded uniformly.The good combination of mechanical properties and corrosion resistance of the Mg-1.0Yb-1.0Zr alloy was resulted from the refined and homogeneous equiaxed grain structure and fine dispersed Zr-rich particles,thus improving the comprehensive mechanical properties by grain refinement and reducing corrosion rate by generating a more stable and compact passivation layer during long-term immersion.展开更多
Background Serial sarcomere number(SSN)critically influences muscle function and is hypothesized to protect against injury.While most evidence for SSN addition comes from non-human animal studies,eccentric exercise is...Background Serial sarcomere number(SSN)critically influences muscle function and is hypothesized to protect against injury.While most evidence for SSN addition comes from non-human animal studies,eccentric exercise is often proposed as a key stimulus due to its association with increased fascicle length in humans.However,the most efficient exercise stimuli and the effectiveness of eccentric training in increasing SSN remain unclear.The objective of this study was to provide a detailed historical overview of research exploring the mechanical factors regulating muscle/fiber length and its relationship with function,and to explore more recent evidence that eccentric muscle contractions might be an important stimulus for SSN regulation using a meta-analytic approach.Methods An extensive literature search with snowballing was conducted to build the historical review.A systematic review with random-effect meta analyses was performed to compare proposed types of fiber-lengthening exercises to control conditions.Results The historical review demonstrated that the application of forces at long fiber lengths,but not specifically the use of greater excursions,plays an important role in increasing SSN.Animal data showed changes in SSN exceeding 20%over several weeks with varied forms of activities.Nonetheless,the meta-analysis revealed a lack of effect of eccentric resistance training in animal models(Δ=1%;Cohen’s d=0.19(95%confidence interval:–0.29 to 0.67),p=0.449).Conclusion High active or passive muscle forces applied at long fiber lengths appear to be the key stimuli triggering sarcomerogenesis.Eccentric exercise does not seem to be a key promoter of SSN.Too few studies exist to draw conclusions as to the effect of eccentric exercise on SSN in humans.Understanding the mechanical triggers and physiological mechanisms involved in serial sarcomere addition could help in the development of exercise(and other)interventions to optimize muscle function and reduce injury risk.展开更多
The microstructure and magnetic properties of Fe_(40)Co_(40)Zr_(9)B_(10)Ge_(1)(Mo-free)and Fe_(40)Co_(40)Zr_(5)Mo_(4)B_(10)Ge_(1)(Mocontaining)nanocrystalline alloys,prepared using an amorphous crystallization method,...The microstructure and magnetic properties of Fe_(40)Co_(40)Zr_(9)B_(10)Ge_(1)(Mo-free)and Fe_(40)Co_(40)Zr_(5)Mo_(4)B_(10)Ge_(1)(Mocontaining)nanocrystalline alloys,prepared using an amorphous crystallization method,were investigated.Mo addition affects the crystallization of the Fe_(40)Co_(40)Zr_(9)B_(10)Ge_(1) amorphous alloy and decreases the grain size of theα-Fe(Co)phase below 650℃.For the Mo-free alloy annealed at 600℃ and the Mo-containing alloy annealed at 575℃,with a singleα-Fe(Co)crystallization phase and approximately similar crystallization volume fractions,the Mo-containing alloy showed smaller,more regularly shaped grains and a significantly narrower grain-size distribution than the Mo-free alloy.The Fe and Co contents in the nanograins of the two alloys also differed.For the Mo-free alloy,a higher concentration of Co distributed in the residual amorphous matrix.For the Mo-containing alloy,a higher concentration Co dissolved in the nanograins.The specific saturation magnetization and coercivity of the Mo-free alloy were 1.05-and 1.59-times higher than those of the Mo-containing alloy,respectively.展开更多
Spiro-cyclopropyl oxindoles are widely found in natural products and medicinal molecules.Herein,we report a highly stereo-and enantio–selective procedure for accessing this class of compounds via tertiary amine media...Spiro-cyclopropyl oxindoles are widely found in natural products and medicinal molecules.Herein,we report a highly stereo-and enantio–selective procedure for accessing this class of compounds via tertiary amine mediated cyclopropanation of ammonium ylides with the in-situ Heck reaction-generated 3-alkenyl indolones as the Michael receptors.This reaction features mild conditions,excellent enantioselectivity(up to 98%)and diastereoselectivity(up to 99:1),high atom-and step-economy,broad substrate scopes,and good functional group tolerance.Additionally,this scalable synthetic process could offer a novel strategy for the efficient synthesis of enantiopure spirocyclopropyl oxindoles.展开更多
Introduction Gender and sex are related to important quality and safety issues in scientific,health,and clinical research.Sex refers to biological characteristics,while gender encompasses the sociocultural norms,ident...Introduction Gender and sex are related to important quality and safety issues in scientific,health,and clinical research.Sex refers to biological characteristics,while gender encompasses the sociocultural norms,identities,and relationships that shape communities and organizations,as well as influence actions,behaviors,contexts,and knowledge.Both gender and sex intersect with other social categories.In this context,in addition to sex or gender,the intersectionality refers to overlapping or interdependent systems of discrimination by more than one factor,such as age,disability,ethnicity,geographic location,socioeconomic status,and sexuality,among others.展开更多
Biodegradable magnesium alloys show promising potential for pancreatic duct stents,yet their degradation varies significantly across physiological environments.This study compared the corrosion rates of extruded Mg-2Z...Biodegradable magnesium alloys show promising potential for pancreatic duct stents,yet their degradation varies significantly across physiological environments.This study compared the corrosion rates of extruded Mg-2Zn-xMn(x=0,0.5,1.0,1.5 wt.%)alloys in human pancreatic fluid.The results revealed that the alloys undergo different corrosion mechanisms in human pancreatic fluid,emphasizing the necessity of conducting evaluations under physiologically relevant conditions.Further investigations into the degradation mechanism in pancreatic fluid indicated that the alkaline PH(8.3–8.7),high bicarbonate concentration,and enzymatic activity significantly influence the corrosion process.Electrochemical and immersion tests showed rapid initial corrosion due to Cl^(−)attack,followed by the formation of a protective Mg(OH)_(2),MgCO_(3),and Ca_(3)(PO_(4))_(2)layer that slowed degradation.However,digestive enzymes,particularly trypsin,disrupt passivation by interacting with organic components,leading to pitting and filiform corrosion.Among the investigated alloys,Mg-2Zn-1.0Mn exhibited the most favorable combination of corrosion resistance,mechanical performance,and cytocompatibility.This study highlights the critical impact of pancreatic fluid on magnesium alloy degradation and stresses the need for physiologically accurate evaluations.展开更多
Nitrogen and phosphorus (NP) deposition can change the nutrient input of forest ecosystems. The effects of NP deposition on soil aggregate need to be analyzed to propose effective environmental management strategies. ...Nitrogen and phosphorus (NP) deposition can change the nutrient input of forest ecosystems. The effects of NP deposition on soil aggregate need to be analyzed to propose effective environmental management strategies. In this study, representative Korean pine mixed forests and Korean pine plantations in northeastern China were selected. Soil samples were sieved to obtain four different particle sizes of soil aggregates (> 2, 2–0.25, 0.25–0.053, and < 0.053 mm). Four NP treatments were applied to simulate N and P deposition, and an indoor incubation experiment was conducted over a period of 360 d. Total nitrogen, microbial nitrogen, dissolved organic nitrogen, hydrolyzed nitrogen, NH_(4)^(+)–N, NO_(3)^(−)–N content, and extracellular enzyme activities of NAG, LAP, and AP were determined. Different fractions of N responded differently to NP addition. Lower NP addition had a greater promoting effect on aggregate N compared to higher NP addition. NAG was the main extracellular enzyme affecting N in both forest types. NP addition had a greater effect on the extracellular enzyme activities of the soil aggregates from the Korean pine plantations. These results enhance our understanding of the effects of NP addition on soil nitrogen within temperate forest ecosystems.展开更多
Highly crystalline perovskite absorbers with low defect-state densities minimizing nonradiative recombination losses are a critical prerequisite for fabricating state-of-the-art photovoltaics.Here,we use a tartaric ac...Highly crystalline perovskite absorbers with low defect-state densities minimizing nonradiative recombination losses are a critical prerequisite for fabricating state-of-the-art photovoltaics.Here,we use a tartaric acid(TA)molecule with two carboxyl and two hydroxyl groups as an additive to improve the performance and stability of the device simultaneously.The strong carboxyl-Pb2+coordination slows nucleation kinetics and passivates Pb-related traps,whereas hydroxyl-I-hydrogen bonding can modulate grain growth and stabilize the lattice structure,collectively enabling low-defect-density and high-quality perovskite films.Besides,we also conducted quantitively loss analysis and confirmed that the TA addition effectively reduces trap-assisted non-radiative recombination.Consequently,the champion efficiency of the n-i-p structure is up to 24.77% with outstanding operational and humidity stability.Remarkably,in the triple-cation perovskite system,the incorporation of the TA additive similarly enabled the fabrication of high-quality films,ultimately yielding a p-i-n configuration with a champion efficiency of 26.11%.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28110300)National Natural Science Foundation of China(No.U23A2004)+3 种基金Natural Science Foundation of Jilin Province,China(No.YDZJ202201ZYTS522)Science and Technology Cooperation Program between Jilin Province and Chinese Academy of Sciences(No.2023SYHZ0053)Innovation Team Program of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.2023CXTD02)the European Commission under Marie Sk?odowska-Curie(No.101034371)。
文摘Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.
基金Project supported by the National Natural Science Foundation of China (52171030)the Key Basic Research Project of the Basic Strengthen Program (2021-JCJQ-ZD-043-00)the National Key Research and Development Program of China (2018YFA0702903)。
文摘Al-Cu-Mn alloys are widely used to produce automobile components like cylinder heads and engine blocks because of their capability to retain excellent thermal and mechanical characteristics at high temperatures.However,the Al-Cu-Mn-based alloys demonstrate restricted fluidity,leading to casting defects such as shrinkage and incomplete filling.This research investigated the microstructure and fluidity of Al-4.7Cu-1.0Mn-0.5Mg(wt%)alloy with minor cerium(Ce)addition.The as-cast alloys predominantly compriseα-Al matrix,accompanied by the presence of Al_(2)Cu,Al_(6)Mn,and Al_(8)Cu_(4)Ce phases.The influence of adding Ce on the fluidity of the Al-4.7Cu-1.0Mn-0.5Mg alloy was investigated using a trispiral fluidity test mold in this research.The findings suggest that the addition of Ce within the range of 0.1 wt%to 0.5 wt%in the Al-4.7Cu-1.0Mn-0.5Mg alloy results in an enhancement in fluidity.Specifically,the alloy containing 0.4 wt%Ce exhibits a significant increase in fluidity distance,from 349.7 to 485.7 mm.This improvement can be attributed to the reduction in viscosity,the refinement of secondary dendrite arm spacing,and the modification of secondary phase particles.However,a higher concentration of Ce leads to a decrease in fluidity length,potentially due to the formation of Al_(8)Cu_(4)Ce.
基金supported by Beijing Nova Program(No.20230484371)the National Key Research and Development Program of China(No.2021YFB3700700).
文摘The effect of Cr addition on nickel aluminium bronze(NAB)alloy microstructure,mechanical properties,and erosion-corrosion behaviour has been studied.The results show that Cr addition does not change the composition of the precipitated phases,more Cr entered theκphase and a small amount of Cr solubilized in the matrix,which increase the hardness of theκand matrix and decrease the potential difference between theκand matrix.NAB alloy with Cr shows high erosion-corrosion resistance at high flow rate conditions,due to its lower phase potential difference and higher surface hardness.At the flow rate of 3 m·s^(-1),the corrosion rate is 0.076 mm·year^(-1),which is~20%lower than that of the unadded Cr sample.Moreover,the corrosion product film contains Cr_(2)O_(3)and Cr^(3+),which improves the densification of the film and raises alloy’s corrosion resistance with Cr addition.The combination of mechanical and corrosion resistant properties may qualify this alloy as a potential candidate material for sustainable and safe equipment.
基金supported by the National Natural Science Foundation of China(Nos.U20A20274 and 52061003)the Natural Science Foundation of Yunnan Province(No.202301AT070209)the Science and Technology Major Project of Yunnan Province(No.202102AG050017).
文摘In this paper,the property degradation micromechanism of Al-5.10Cu-0.65 Mg-0.8Mn(wt%)alloy induced by 0.5 wt%Fe minor addition was revealed by atomic-scale scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy coupled with first-principles calculations.The results show that the Fe minor addition to the Al-Cu-Mg-Mn alloy leads to a slight reduction of grain size and the formation of coarse Al7Cu2Fe constituent particles.Fe tends to segregate into the T-phase dispersoids,θ'-,and S-phase precipitates by preferentially occupying Cu or Mn sites in these phase structures.The apparent Fe segregation contributes to an increase in stiffness of the T-phase and S-phase but decreased stiffness of theθ'phase.Formation of the coarse Al7Cu2Fe constituent particles and decreased stiffness of main precipitatesθ'containing Fe result in the degraded strength of the Al-Cu-Mg-Mn-Fe alloy.Further study reveals that corrosion resistance degradation of the Al-Cu-Mg-Mn-Fe alloy is associated with the increased width of precipitation free zones and consecutive grain boundary precipitates.The obtained results have significant implications for the usage of recycled Al alloys and the potential design strategies of high-performance alloys containing Fe.
基金The financial supports by the Chinese Academy of Sciences(Nos.XDC04030300 and XDB0510303)CAS-HK Joint Laboratory of Nanomaterials and MechanicsShenyang National Laboratory for Materials Science are acknowledged.
文摘Rolling contact fatigue performance is among the most important issues for applications of bearing steels.In this work,a recently developed surface modification technique,surface mechanical rolling treatment,was applied on a rare-earth addition bearing steel.And rolling contact fatigue behavior of treated samples was compared with that of as-received counterparts at different contacting stresses.The results demonstrated that a 700μm-thick gradient nanostructured surface layer is produced on samples by surface mechanical rolling treatment.The grain size decreases while the microhardness increases gradually with decreasing depth,reaching~23 nm and~10.2 GPa,respectively,at the top surface.Consequently,the rolling contact fatigue property is significantly enhanced.The characteristic life of treated samples is~3.2 times that of untreated counterparts according to Weibull curves at 5.6 GPa.Analyses of fatigue mechanisms demonstrated that the gradient nanostructured surface layer might not only retard material degradation and microcrack formation,but also prolong the steady-state elastic response stage under rolling contact fatigue.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52005240,52164045)Young Talent Program of Major Disciplines of Academic and Technical Leaders in Jiangxi Province(No.20212BCJ23028)Outstanding Youth Foundation in Jiangxi Province(No.20224ACB214012).
文摘Friction stir lap welding(FSLW)was adopted to join successfully dissimilar AZ31B Mg alloy and TC4 Ti alloy with Sn foil addition of 30μm thickness.Interfacial microstructure,tensile shear performances and bonding mechanism of the joints obtained using three different rotation speeds were studied.High-performance FSLW Mg/Ti dissimilar joints with maximum tensile shear strength of 593.3 N/mm were produced at 1180 r/min,and which was mainly attributed to ultrastrong reaction interlayer consisting of 125.9 nm thick(Mg_(2)Sn+Mg)transition layer and discontinuous(Ti_(6)Sn_(5)+Ti_(3)Al)IMCs layer with 6.58 nm thickness at the interface.The formation of the reaction interlayer was beneficial for high interfacial strength,resulting in significantly improving the joint strength.The fracture of all FSLW joints located on AZ31B Mg stirred zone adjacent to(Mg_(2)Sn+Mg)transition layer or along the crack propagation direction of the AZ31B/TC4 interface with different fracture mechanisms,and which could be consistent with interfacial microstructure.
文摘The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.
文摘A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the acidic alumina surface effectively activate the carbonyl group ofα,β-unsaturated ketones,significantly enhancing the electrophilicity of theβ-carbon and thereby facilitating selective alkylation at the C3 position of imidazo[1,2-a]pyridines.This method demonstrates excellent functional group compatibility,mild reaction conditions,low reagent costs,and operational simplicity,providing a novel strategy for the efficient synthesis of alkylated imidazo[1,2-a]pyridine derivatives.
基金the National Key R&D Program of China(No.2022YFA1503200)the National Natural Science Foundation of China(Nos.22025104,22171134,and 21972064)the Fundamental Research Funds for the Central Universities(No.020514380254)is greatly appreciated.
文摘The asymmetric addition of aromatic organometallic compounds to the carbonyl group(C-3)of isatins,catalyzed by transition metals,has emerged as a remarkably efficient method for the synthesis of chiral 3-hydroxyoxindoles.Here,an exceptionally enantioselective approach was developed for the first time to achieve a catalytic NHK reaction of isatins with aromatic halides(both aryl and heteroaryl).Utilizing chiral cobalt complexes as catalysts,and the presence of a diboron reagent B_(2)nep_(2)as both a reducing agent and determinant in enantiocontrol,has resulted in the triumphantly achieved synthesis of enantioenriched products.Compared to reported strategies,this approach exhibits remarkable compatibility with substrates bearing sensitive functional groups,such as halides and borate esters,while also eliminating the need for organometallic reagents as required in previous strategies.Through experimental investigations,the presence of aryl-cobalt species during the addition process was confirmed,rather than in-situ generation of an arylboron reagent.Furthermore,the successful attainment of the R absolute configuration through aryl addition was demonstrated.
基金supported by the National Key Research and Development Program(Nos.2022YFB3404501 and 2022YFB3404500)National Natural Science Foundation of China(Nos.52025041,U2341267,52374360,52174294,52450003,52472031,12305374 and 52104305).
文摘TiAl alloys were melted in BaZrO_(3)crucibles without and with Y addition at 1550℃for 5,10,and 15 min,respectively.The effect of the melting time and Y addition on the interaction between the crucibles and the alloys was investigated.Results revealed that the interaction extent was intensified with the increasing melting time.However,it could be effectively suppressed by adding Y into the alloy due to the in situ generated Y_(2)O_(3)protection layer.The thickness of the interaction layer could be decreased from 95.6 to 25.1μm with Y addition at 1550°C for 15 min.In addition,a significant deoxidation effect was achieved by adding Y,and the O concentration of the alloy was decreased from 0.2 to 0.0561 wt.%.In comparison with Al_(2)O_(3),MgO,CaO,and Y_(2)O_(3)crucibles,BaZrO_(3)crucible combined with Y addition exhibited the lowest O contamination to the alloy melt.
基金Supported by the Social Development Grant of Shaanxi Province(No.2022SF-404)the Science and Technology Program of Xi’an,China(No.23YXYJ0010,No.23YXYJ0037)+1 种基金the Research Project of Xi’an Health Commission(No.2024ms05)the Technology Innovation Supporting Program of Shaanxi(No.2024RS-CXTD-11).
文摘AIM:To investigate the response of the anterior and posterior corneal surface in femtosecond laser-assisted convex stromal lenticule addition keratoplasty(SLAK)combined with cross-linking(CXL)for treating keratoconus at the first 3mo of follow-up.METHODS:In this prospective observational study,20 eyes of 20 keratoconus patients who underwent SLAK combined with CXL were included.The morphological indices in keratometry and elevation data were recorded from the Sirius at baseline and 1 and 3mo postoperatively.The mean values of maximum keratometry(K_(max)),flat keratometry(K_(1)),and steep keratometry(K_(2))at the central,3-mm,5-mm,and 7-mm areas were measured from the curvature map.The changes in anterior and posterior corneal elevation under the best-fit sphere(BFS)radius at seven points horizontally of the center,3-mm,5-mm,and 7-mm area from the center at both nasal(N)and temporal(T)side were measured from elevation map.RESULTS:For the front corneal curvature,K_(1),and K_(2) at 3-mm,5-mm,and 7-mm of the anterior corneal surface increased significantly 1mo postoperatively(all P<0.05)and remained unchanged until 3mo(P>0.05).For the back corneal curvature,K_(1) and K_(2) along the 3-mm back meridian significantly decreased after month 1(P=0.002,0.077,respectively).Posterior K_(2)-readings along the 5-mm and 7-mm did not change after surgery(P>0.05).Anterior BFS decreased 1mo(P<0.001)postoperatively but remained unchanged until 3mo after SLAK(P>0.05).There was no change in posterior BFS before and after the surgery(P>0.05).Anterior elevation at N5,N3,central,and T5 points and posterior elevation at central and T7 points shifted backward 1mo postoperatively(all P<0.05)and remained stable until 3mo(P>0.05).CONCLUSION:The myopic SLAK combined with CXL is an economical alternative for stabilizing the corneal surface in severe keraoconus.“Pseudoprogression”occurs in the early phase postoperatively,but it is not an indicator of keratoconus progression.
基金financially supported by the National Natural Science Foundation of China(Nos.52071133,U21A2051)the Henan Province Science and Technology Tackling Key Problems Project,China(No.222102230001)+2 种基金the Zhongyuan Scholar Workstation Funded Project,China(No.224400510025)the Henan Key Research and Development Project,China(No.221111230600)Luoyang Major Science and Technology Innovation Special Project,China(No.2201017A)。
文摘The effects of trace cerium(Ce)addition on the microstructural and textural evolution and the dynamic recrystallization(DRX)of the ultrahigh-purity copper(Cu)containing small amounts of sulfur(S)were investigated using a Gleeble-1500 thermal simulation tester at 600℃.The results show that with increasing Ce content,the grain size of the Cu-S(S2)alloy gradually decreases and the grain boundary embrittlement induced by S impurities is considerably inhibited.The addition of Ce promotes the DRX process of the S2 alloy and changes its DRX mechanism from discontinuous to continuous and twinning-induced DRX mechanisms.The texture component and intensity of the S2 alloy vary with the increase of Ce content.The addition of 120×10^(-6) Ce(mass fraction)is favorable for the grain orientation randomization,which is attributed to the promoted DRX.
基金the financial supports from the China Scholarship Council(No.201808505057)。
文摘The effects of Zr addition on the mechanical properties and in vitro degradation behavior of Mg-1.0Yb-xZr(x=0,0.2,1.0,and 1.53,wt.%)cast alloys were investigated.The results indicated that with increasing Zr addition,a much refined and homogeneous equiaxed grain structure was achieved from a typical columnar grain structure,in companion with the appearance and coarsening of Zr-rich particles.Subsequent electrochemical and immersion tests demonstrated that the corrosion of the alloy was Zr-addition dependent.A trace or excessive Zr addition caused severe localized corrosion attacks,whereas Zr-free and 1.0 Zr alloyed counterparts were generally corroded uniformly.The good combination of mechanical properties and corrosion resistance of the Mg-1.0Yb-1.0Zr alloy was resulted from the refined and homogeneous equiaxed grain structure and fine dispersed Zr-rich particles,thus improving the comprehensive mechanical properties by grain refinement and reducing corrosion rate by generating a more stable and compact passivation layer during long-term immersion.
文摘Background Serial sarcomere number(SSN)critically influences muscle function and is hypothesized to protect against injury.While most evidence for SSN addition comes from non-human animal studies,eccentric exercise is often proposed as a key stimulus due to its association with increased fascicle length in humans.However,the most efficient exercise stimuli and the effectiveness of eccentric training in increasing SSN remain unclear.The objective of this study was to provide a detailed historical overview of research exploring the mechanical factors regulating muscle/fiber length and its relationship with function,and to explore more recent evidence that eccentric muscle contractions might be an important stimulus for SSN regulation using a meta-analytic approach.Methods An extensive literature search with snowballing was conducted to build the historical review.A systematic review with random-effect meta analyses was performed to compare proposed types of fiber-lengthening exercises to control conditions.Results The historical review demonstrated that the application of forces at long fiber lengths,but not specifically the use of greater excursions,plays an important role in increasing SSN.Animal data showed changes in SSN exceeding 20%over several weeks with varied forms of activities.Nonetheless,the meta-analysis revealed a lack of effect of eccentric resistance training in animal models(Δ=1%;Cohen’s d=0.19(95%confidence interval:–0.29 to 0.67),p=0.449).Conclusion High active or passive muscle forces applied at long fiber lengths appear to be the key stimuli triggering sarcomerogenesis.Eccentric exercise does not seem to be a key promoter of SSN.Too few studies exist to draw conclusions as to the effect of eccentric exercise on SSN in humans.Understanding the mechanical triggers and physiological mechanisms involved in serial sarcomere addition could help in the development of exercise(and other)interventions to optimize muscle function and reduce injury risk.
基金Project supported by the Natural Science Foundation of Jilin Province,China(Grant No.YDZJ202201ZYTS319)the Fund from Sinoma Institute of Materials Research(Guangzhou)Co.,Ltd.(SIMR)for assisting with the TEM characterization。
文摘The microstructure and magnetic properties of Fe_(40)Co_(40)Zr_(9)B_(10)Ge_(1)(Mo-free)and Fe_(40)Co_(40)Zr_(5)Mo_(4)B_(10)Ge_(1)(Mocontaining)nanocrystalline alloys,prepared using an amorphous crystallization method,were investigated.Mo addition affects the crystallization of the Fe_(40)Co_(40)Zr_(9)B_(10)Ge_(1) amorphous alloy and decreases the grain size of theα-Fe(Co)phase below 650℃.For the Mo-free alloy annealed at 600℃ and the Mo-containing alloy annealed at 575℃,with a singleα-Fe(Co)crystallization phase and approximately similar crystallization volume fractions,the Mo-containing alloy showed smaller,more regularly shaped grains and a significantly narrower grain-size distribution than the Mo-free alloy.The Fe and Co contents in the nanograins of the two alloys also differed.For the Mo-free alloy,a higher concentration of Co distributed in the residual amorphous matrix.For the Mo-containing alloy,a higher concentration Co dissolved in the nanograins.The specific saturation magnetization and coercivity of the Mo-free alloy were 1.05-and 1.59-times higher than those of the Mo-containing alloy,respectively.
文摘Spiro-cyclopropyl oxindoles are widely found in natural products and medicinal molecules.Herein,we report a highly stereo-and enantio–selective procedure for accessing this class of compounds via tertiary amine mediated cyclopropanation of ammonium ylides with the in-situ Heck reaction-generated 3-alkenyl indolones as the Michael receptors.This reaction features mild conditions,excellent enantioselectivity(up to 98%)and diastereoselectivity(up to 99:1),high atom-and step-economy,broad substrate scopes,and good functional group tolerance.Additionally,this scalable synthetic process could offer a novel strategy for the efficient synthesis of enantiopure spirocyclopropyl oxindoles.
基金funded by the European Union's Horizon 2020 Research and Innovation Programme under grant No.896932(TTV guide TX project)and grant No.824087(EOSC-Life)。
文摘Introduction Gender and sex are related to important quality and safety issues in scientific,health,and clinical research.Sex refers to biological characteristics,while gender encompasses the sociocultural norms,identities,and relationships that shape communities and organizations,as well as influence actions,behaviors,contexts,and knowledge.Both gender and sex intersect with other social categories.In this context,in addition to sex or gender,the intersectionality refers to overlapping or interdependent systems of discrimination by more than one factor,such as age,disability,ethnicity,geographic location,socioeconomic status,and sexuality,among others.
基金supported by China National Natural Science Foundation of China(52225101)Graduate Research and Innovation Foundation of Chongqing(CYB240017)+1 种基金National Natural Science Foundation of China(82373128)Natural Science Foundation of Chongqing,China(2024MSXM174)for Shixiang Guo.
文摘Biodegradable magnesium alloys show promising potential for pancreatic duct stents,yet their degradation varies significantly across physiological environments.This study compared the corrosion rates of extruded Mg-2Zn-xMn(x=0,0.5,1.0,1.5 wt.%)alloys in human pancreatic fluid.The results revealed that the alloys undergo different corrosion mechanisms in human pancreatic fluid,emphasizing the necessity of conducting evaluations under physiologically relevant conditions.Further investigations into the degradation mechanism in pancreatic fluid indicated that the alkaline PH(8.3–8.7),high bicarbonate concentration,and enzymatic activity significantly influence the corrosion process.Electrochemical and immersion tests showed rapid initial corrosion due to Cl^(−)attack,followed by the formation of a protective Mg(OH)_(2),MgCO_(3),and Ca_(3)(PO_(4))_(2)layer that slowed degradation.However,digestive enzymes,particularly trypsin,disrupt passivation by interacting with organic components,leading to pitting and filiform corrosion.Among the investigated alloys,Mg-2Zn-1.0Mn exhibited the most favorable combination of corrosion resistance,mechanical performance,and cytocompatibility.This study highlights the critical impact of pancreatic fluid on magnesium alloy degradation and stresses the need for physiologically accurate evaluations.
基金the Fundamental Research Funds for the Central Universities(Grant No.2572021DT04)the National Natural Science Foundation of China(Grant No.31770656).
文摘Nitrogen and phosphorus (NP) deposition can change the nutrient input of forest ecosystems. The effects of NP deposition on soil aggregate need to be analyzed to propose effective environmental management strategies. In this study, representative Korean pine mixed forests and Korean pine plantations in northeastern China were selected. Soil samples were sieved to obtain four different particle sizes of soil aggregates (> 2, 2–0.25, 0.25–0.053, and < 0.053 mm). Four NP treatments were applied to simulate N and P deposition, and an indoor incubation experiment was conducted over a period of 360 d. Total nitrogen, microbial nitrogen, dissolved organic nitrogen, hydrolyzed nitrogen, NH_(4)^(+)–N, NO_(3)^(−)–N content, and extracellular enzyme activities of NAG, LAP, and AP were determined. Different fractions of N responded differently to NP addition. Lower NP addition had a greater promoting effect on aggregate N compared to higher NP addition. NAG was the main extracellular enzyme affecting N in both forest types. NP addition had a greater effect on the extracellular enzyme activities of the soil aggregates from the Korean pine plantations. These results enhance our understanding of the effects of NP addition on soil nitrogen within temperate forest ecosystems.
基金funding support from the National Key Research and Development Program of China(2022YFE0137400)the National Natural Science Foundation of China(62274040)+3 种基金funding support from the National Natural Science Foundation of China(62304046)the National Key Research and Development Program of China(2022YFB2802802)the Key Laboratory of Rare Earths,Ganjiang Innovation Academy,Chinese Academy of Sciencessupport from the Shanghai Science and Technology Innovation Action Plan 2023 Special Project for Supporting Carbon Peak Carbon Neutrality Project(23DZ1200400)。
文摘Highly crystalline perovskite absorbers with low defect-state densities minimizing nonradiative recombination losses are a critical prerequisite for fabricating state-of-the-art photovoltaics.Here,we use a tartaric acid(TA)molecule with two carboxyl and two hydroxyl groups as an additive to improve the performance and stability of the device simultaneously.The strong carboxyl-Pb2+coordination slows nucleation kinetics and passivates Pb-related traps,whereas hydroxyl-I-hydrogen bonding can modulate grain growth and stabilize the lattice structure,collectively enabling low-defect-density and high-quality perovskite films.Besides,we also conducted quantitively loss analysis and confirmed that the TA addition effectively reduces trap-assisted non-radiative recombination.Consequently,the champion efficiency of the n-i-p structure is up to 24.77% with outstanding operational and humidity stability.Remarkably,in the triple-cation perovskite system,the incorporation of the TA additive similarly enabled the fabrication of high-quality films,ultimately yielding a p-i-n configuration with a champion efficiency of 26.11%.
