基于U-Net的海上风场模式数据订正

我国沿海地区生产生活受海上风场的影响较大,目前海上高分辨网格化数据为模式数据,其主要通过物理数值模型推算得出,对于初值敏感,且无法准确描述近地面和海面的风速信息。需要考虑用浮标、船舶等实况参考数据订正,而传统订正方法只能订正参考数据附近的格点值。本文提出一种基于U-Net网络的风场数据订正算法。利用U-Net网络通过站点参考数据对整个目标区域进行订正,降低目标海洋区域订正后风速误差。实验结果表明海洋目标区域10 m风速平均订正误差RMSE值为1.96 m/s,比模式数据的平均误差降低了16.8%,U-Net网络模型可以有效订正模式数据,为后续数据融合等研究提供高质量数据支持。

Ultrafast dynamics in photo-excited Mott insulator Sr_(3)Ir_(2)O_7 at high pressure

High-pressure ultrafast dynamics,as a new crossed research direction,are sensitive to subtle non-equilibrium state changes that might be unresolved by equilibrium states measurements,providing crucial information for studying delicate phase transitions caused by complex interactions in Mott insulators.With time-resolved transient reflectivity measurements,we identified the new phases in the spin–orbit Mott insulator Sr_(3)Ir_(2)O_7 at 300 K that was previously unidentified using conventional approaches such as x-ray diffraction.Significant pressure-dependent variation of the amplitude and lifetime obtained by fitting the reflectivity?R/R reveal the changes of electronic structure caused by lattice distortions,and reflect the critical phenomena of phase transitions.Our findings demonstrate the importance of ultrafast nonequilibrium dynamics under extreme conditions for understanding the phase transition of Mott insulators.

Integrated design and performance optimization of three-electrode sliding discharge plasma power supply

The three-electrode sliding dielectric barrier discharge(TES-DBD) plasma actuator significantly enhances the ionization rate and momentum exchange between charged particles and neutral particles by incorporating a parallel DC electrode into the standard DBD design. This design improves the body force and induced jet velocity while allowing flexible control of the induced jet angle, overcoming the limitations of discharge extension and uncontrollable direction in traditional DBD plasma actuators. An integrated plasma power supply has been designed specifically for TES-DBD plasma actuators, streamlining the power supply management. The methodology involves designing the circuit topology for the TES-DBD power supply, followed by simulating and validating its operating principles using Multisim software. The operational performance of the power supply is evaluated through a comprehensive analysis of its electrical,thermal, and aerodynamic properties specific to TES-DBD plasma actuation.

Unveiling a novel metal-to-metal transition in LuH_(2):Critically challenging superconductivity claims in lutetium hydrides

Following the recent report by Dasenbrock-Gammon et al.[Nature 615,244–250(2023)]of near-ambient superconductivity in nitrogendoped lutetium trihydride(LuH_(3-δ)N_(ε)),significant debate has emerged surrounding the composition and interpretation of the observed sharp resistance drop.Here,we meticulously revisit these claims through comprehensive characterization and investigations.We definitively identify the reported material as lutetium dihydride(LuH_(2)),resolving the ambiguity surrounding its composition.Under similar conditions(270–295 K and 1–2 GPa),we replicate the reported sharp decrease in electrical resistance with a 30%success rate,aligning with the observations by Dasenbrock-Gammon et al.However,our extensive investigations reveal this phenomenon to be a novel pressure-induced metal-to-metal transition intrinsic to LuH_(2),distinct from superconductivity.Intriguingly,nitrogen doping exerts minimal impact on this transition.Our work not only elucidates the fundamental properties of LuH_(2)andLuH_(3),but also critically challenges the notion of superconductivity in these lutetium hydride systems.These findings pave the way for future research on lutetium hydride systems,while emphasizing the crucial importance of rigorous verification in claims of ambient-temperature superconductivity.

Occurrence,leaching behavior,and detoxification of heavy metal Cr in coal gasification slag

Coal gasification slag(CGS)is a type of solid waste produced during coal gasification,in which heavy metals severely restrict its resource utilization.In this work,the mineral occurrence and distribution of typical heavy metal Cr in CGS is investigated.The leaching behavior of Cr under different conditions is studied in detail.Acid leaching-selective oxidation-coprecipitation method is proposed based on the characteristics of Cr in CGS.The detoxification of Cr in CGS is realized,and the detoxification mechanism is clarified.Results show that Cr is highly enriched in CGS.The speciation of Cr is mainly residual fraction(74.47%-86.12%),which is combined with amorphous aluminosilicate.Cr^(3+)and Cr^(6+)account for 90.93%-94.82%and 5.18%-9.07%of total Cr,respectively.High acid concentration and high liquid-solid ratio are beneficial to destroy the lattice structure of amorphous aluminosilicate,thus improving the leaching efficiency of Cr,which can reach 97.93%under the optimal conditions.Acid leaching-selective oxidation-coprecipitation method can realize the detoxification of Cr in CGS.Under the optimal conditions,the removal rates of Fe^(3+)and Cr^(3+)in the leaching solution are 80.99%-84.79%and 70.58%-71.69%,respectively,while the loss rate of Al^(3+)is only 1.10%-3.35%.Detoxification slag exists in the form of Fe-Cr coprecipitation(Fe_(1-x)Cr_xOOH),which can be used for smelting.The detoxification acid leaching solution can be used to prepare inorganic polymer composite coagulant poly-aluminum chloride(PAC).This study can provide theoretical and data guidance for detoxification of heavy metal Cr in CGS and achieve resource utilization of coal gasification solid waste.

Reconstruction and recovery of anatase TiO_(2) from spent selective catalytic reduction catalyst by Na OH hydrothermal method

The improper disposal of spent selective catalytic reduction (SCR) catalysts causes environmental pollution and metal resource waste.A novel process to recover anatase titanium dioxide (TiO_(2)) from spent SCR catalysts was proposed.The process included alkali (NaOH) hydrothermal treatment,sulfuric acid washing,and calcination.Anatase TiO_(2) in spent SCR catalyst was reconstructed by forming Na_(2)Ti_(2)O_(4)(OH)_(2) nanosheet during NaOH hydrothermal treatment and H_(2)Ti_(2)O_(4)(OH)_(2) during sulfuric acid washing.Anatase TiO_(2) was recovered by decomposing H_(2)Ti_(2)O_(4)(OH)_(2) during calcination.The surface pore properties of the recovered anatase TiO_(2) were adequately improved,and its specific surface area (SSA) and pore volume (PV) were 85 m^(2)·g^(-1)and 0.40 cm^(3)·g^(-1),respectively.The elements affecting catalytic abilities(arsenic and sodium) were also removed.The SCR catalyst was resynthesized using the recovered TiO_(2) as raw material,and its catalytic performance in NO selective reduction was comparable with that of commercial SCR catalyst.This study realized the sustainable recycling of anatase TiO_(2) from spent SCR catalyst.

Preparation of mesoporous activated carbons from coal liquefaction residue for methane decomposition

Mesoporous activated carbons were prepared from direct coal liquefaction residue （CLR） by KOH activation method, and the experiments were carried out to investigate the effects of KOH/CLR ratio, solvent for mixing the CLR and KOH, and carbonization procedure on the resultant carbon texture and catalytic activity for catalytic methane decomposition （CMD）. The results showed that optimal KOH/CLR ratio of 2 ： 1; solvent with higher solubility to KOH or the CLR, and an appropriate carbonization procedure are conductive to improving the carbon pore structure and catalytic activity for CMD. The resultant mesoporous carbons show higher and more stable activity than microporous carbons. Additionally, the relationship between the carbon textural properties and the catalytic activity for CMD was also discussed.

Extranodal involvement in young patients with diffuse large B-cell lymphoma： distribution, prognostic value and treatment options

Objective： Extranodal involvement represents a peculiar presentation of diffuse large B-cell lymphoma（DLBCL）. Previous studies have suggested that older patients are more prone to extranodal involvement. This study retrospectively addressed the distribution, prognostic value and treatment options of extranodal involvement in young patients with DLBCL.Methods： A total of 329 patients were enrolled according to the inclusion requirements. The effects of gender,extranodal involvement, age-adjusted international prognostic index（aa IPI）, rituximab infusion and radiotherapy on patient outcomes were evaluated.Results： Among these patients, 59% presented extranodal involvement in 16 anatomic sites. More than one instance was linked to many poorer clinical characteristics and poorer survival compared with either nodal disease or one instance. In patients with one extranodal lesion, multivariate analysis revealed that the site of extranodal involvement, but not the aa IPI or rituximab infusion, was independently related to the outcome, and radiotherapy had a negative influence on survival.Conclusions： Extranodal involvement is common in younger patients and exhibits a ubiquitous distribution.The site of extranodal involvement is of strong prognostic significance. Radiotherapy for extranodal lesions does not improve patient outcomes.

Forecast of Consumption and Emission of HFC-134a Used in the Mobile Air-conditioner Sector in China

HFC-134a is the most important alternative to CFC-12 used in the mobile air-conditioner sector in China. The con- sumption of HFC-134a has been increasing rapidly in recent years. It becomes the most consumed HFC in the sector. Selecting 2005 as the base line year, future consumption and emission amounts of HFC-134a are estimated through an analysis of a combined scenario： 1） replacement by non-HFC-134a blends, 2） good practice in servicing, 3） technology promotion, and 4） government policies on control of HFC-134a emissions. The analysis shows that HFC-134a consumption and emissions will continue to increase in the next 10 years. The projected HFC-134a consumption will approach 20,150 t and 34,875 t in 2010 and 2015 respectively, while the estimated emission amounts will reach 16,065 t and 30,186 t （i.e., 21 Mt CO2-eq and 39 Mt CO2-eq emissions） correspondingly. Compared with the business-as-usual scenario, the expected emission reductions in 2010 and 2015 will range between 6.7 Mt CO2-eq and 13.0 Mt CO2-eq.

Numerical investigation of air-entrainment in skimming flow over stepped spillways

As a widely used flood energy dissipator, the stepped spillway can significantly dissipate the kinetic or hydraulic energy due to the air-entrainment in skimming flow over the steps. The free-surface aeration involves the sharp deformation of the free surface and the complex turbulent shear flows. In this study, the volume of fluid （VOF）, mixture, and Eulerian methods are utilized to simulate the air-entrainment by coupling with the Reynolds-averaged Navier-Stokes/large eddy simulation （RANS/LES） turbulence models. The free surface deformation, air volume fraction, pressure, and velocity are compared for the three different numerical methods. Only the Eulerian＋RANS method fails to capture the free-surface aeration. The air volume fraction predicted by the VOF＋LES method best matches the experimental measurement, while the mixture＋LES method predicts the inception point of the air entrainment more accurately.

胶州市畜禽粪污综合利用情况调研报告

做好畜禽粪污处理和资源化利用工作,是贯彻畜牧业绿色发展理念的必然要求,也是全面实施乡村振兴战略、打造生态宜居环境的重要举措。近年来,胶州市强化责任,坚持指导与服务、监管与联动相结合,在畜禽粪污处理和资源化利用工作中实现新突破。

Occurrence and Damage and Pathogene of Potato Early Blight in Winter in Yunnan Province,China

[Objectives]The paper was to understand the species and pathogenicity of the pathogen causing potato early blight in winter.[Methods]The occurrence of potato early blight was investigated in 5 winter potato growing areas in Yunnan Province.The disease samples were collected from two locations(Zhutang Village and Zhanai Village,Pu'er City)where the occurrence of early blight was severe.The pathogen was isolated and purified in laboratory and identified by morphological characteristics and phylogenetic analysis of ITS gene sequence.And it was further verified via re-inoculation by Koch's rules.The growth characteristics and pathogenicity of isolates in different seasons were analyzed with 4 strains of Alternaria isolated in spring(EYZ,EYAX,TA1 and TAC)as controls.[Results]Early blight occurred in varying degrees in the 5 winter potato growing areas,and the incidence of early blight was up to 100%in some plots in Lancang County,Pu'er City.A total of 35 strains of Alternaria were isolated from plots with high incidence,which were divided into two types according to colony morphology.The first type was round colonies with smooth edges and gray white fronts,and the second type was round colonies with rough edges and gray black fronts.Three strains LC1,LC2,LC3 of the first type and two strains ZT3 and ZT8 of the second type were selected and identified as Alternaria alternata through morphological and molecular identification.Re-inoculation test further confirmed that the pathogen was A.alternata.Meantime,it was found that the growth rate of colonies isolated in winter was relatively slow,and there was no significant difference between the pathogenicity of LC1 and TA1,but the pathogenicity of strains isolated in winter was generally higher than that isolated in spring.[Conclusions]It is confirmed that the pathogen causing potato early blight in winter is A.alternata in Yunnan Province.The results will lay a foundation for the research of pathogenesis,occurrence regularity and disease control of A.alternata in winter potato.

不同精子数输精对里岔黑猪母猪繁殖性能的影响

对母猪采取人工授精,使用不同精子数会影响母猪繁殖性能。试验选择里岔黑猪经产母猪为实验对象,按照随机分组原则进行组合测试。实验结果显示,使用精子数20亿和40亿的母猪情期受胎率、分娩率、平均产仔猪数、平均产活仔猪数、仔猪平均初生重差异不显著(P>0.05)。

Novel Synthesis of Noble Metal-based Alloy Nanoparticles and Their Electrocatalytic Activities

Noble metal nanoparticles are attractive catalytic materials on account of their novel optical,electrical and magnetic properties compared with bulk solids.Nanosized alloys attract considerable attentions due to the increasing demands,and outstanding chemical and physical properties via cooperative interactions for high performance catalysts.In this research,carbon-supported

不同腹腔镜手术治疗胆囊结石合并胆总管结石的疗效及并发症对比

目的研究“一步法”与序贯“二步法”腹腔镜手术治疗胆囊结石合并胆总管结石患者的整体疗效及术后并发症对比。方法纳入2020年5月至2022年5月期间收治的103例胆囊结石合并胆总管结石患者,根据治疗方法将其分为一步法组(n=48)与二步法组(n=55),一步法组实施腹腔镜胆总管探查术(LCBDE)联合腹腔镜胆囊切除术(LC)治疗;二步法组实施内镜逆行胰胆管造影(ERCP)与内镜十二指肠乳头括约肌切开取石术(EST)联合LC治疗。将所有患者数据进行倾向性匹配评分(卡钳值为0.02)排除基线资料混杂因素影响,两组各获得46例基线资料可比的患者。数据采用SSPS 24.0软件分析,计数资料以[例(%)]表示,采用χ^(2)检验;计量资料以x±s表示,采用配对t检验或者LSD-t检验。P<0.05表示差异有统计学意义。结果两组患者手术期间一次性结石清除率(93.5% vs. 91.3%)、中转开腹率(0.0% vs. 2.2%)、结石残留率(6.5% vs. 8.7%)比及胃肠道功能比较,差异均无统计学意义(P>0.05),两组患者术后胃肠道功能改善用时比较差异无统计学意义(P>0.05);一步法组镇静剂使用率及住院时间均显著低于二步法组(P<0.05);两组患者手术期间并发症发生率(8.7% vs. 10.9%),差异无统计学意义(P>0.05)。结论LCBDE联合LC治疗胆囊结石合并胆总管结石,术后恢复更快,适用于年轻患者或结石较大患者,但对于老年患者或重度梗阻性黄疽患者,则可以采选ERCP/EST+LC治疗,因此临床应根据患者实际情况选择合适的微创治疗方案。

Spatiotemporal evolution laws of sector-shaped dielectric-barrier-discharge plasma actuator

Dielectric barrier discharge(DBD)plasma actuators are widely used in active flow control due to their simple design and rapid responsiveness.However,they need more effectiveness and discharge extension.To overcome these limitations,a sector-shaped dielectric barrier discharge(SS-DBD)plasma actuator with an adjustable jet angle was developed to enhance flow control effectiveness.The flow field dynamics induced by the SS-DBD plasma actuator were quantitatively analyzed using particle image velocimetry(PIV).Experimental investigations showed that precise adjustments to the actuation voltage can modulate the maximum velocity of the induced jet.Furthermore,a quasi-linear relationship between the sector-shaped angles of the SS-DBD and the deflected jet angles was established,indicating that changes in the sector-shaped angles directly influence the direction of the deflected jet.This correlation enables precise control over jet angles,significantly enhancing flow control by adjusting the SS-DBD-PA's sector-shaped angle.

Toward learning steelmaking-A review on machine learning for basic oxygen furnace process

Basic oxygen furnace(BOF)steelmaking is the most widely used process in global steel production today,accounting for around 70%of the industry's output.Due to the physical,mechanical,and chemical complexities involved in the process,conventional monitoring and control methods are often pushed to their limits.The increasing global competition has created a demand for new methods to monitor and control the BOF steelmaking process.Over the past decade,Machine Learning(ML)techniques have garnered substantial attention,offering a promising pathway to enhance efficiency and suitability of steel production.This paper presents the first comprehensive review of ML applications in the BOF steelmaking process.We provide an introduction to both fields:an overview of the BOF steelmaking process and ML.We analyze the existing work on ML applications in BOF steelmaking and synthesize common concepts into categories,supporting the identification of common use cases and approaches.This analysis concludes with the elaboration of challenges,potential solutions,and a future outlook for further research directions.

Integrated(de)multiplexer for orbital angular momentum fiber communication

The quickly increasing data transfer load requires an urgent revolution in current optical communication. Orbital angular momentum(OAM) multiplexing is a potential candidate with its ability to considerably enhance the capacity of communication. However, the lack of a compact, efficient, and integrated OAM(de)multiplexer prevents it from being widely applied. By attaching vortex gratings onto the facets of a few-mode fiber, we demonstrate an integrated fiber-based OAM(de)multiplexer. A vortex grating fabricated on the fiber facet enables the direct multiplexing of OAM states at one port and the demultiplexing of OAM states at the other port. The measured bit error rate of the carrier signal after propagating through a 5-km few-mode fiber confirms the validity and effectiveness of the proposed approach. The scheme offers advantages in future high-capacity OAM communication based on optical fiber.

Review of characterization and modeling of polymer electrolyte fuel cell catalyst layer： The blessing and curse of ionomer

Ionomer impregnation represents a milestone in the evolution of polymer electrolyte fuel cell （PEFC） catalyst layers. Ionomer acts as the binder, facilitates proton transport, and thereby drastically improves catalyst utilization and effectiveness. However, advanced morpho- logical and functional characterizations have revealed that up to 60% of Pt nanoparticles can be trapped in the micropores of carbon support particles. Ionomer clusters and oxygen molecules can hardly enter into micropores, leading to low Pt utilization and effectiveness. Moreover, the ionomer thin-films covering Pt nanoparticles can cause significant mass transport loss especially at high current densities. Ionomer-free ultra-thin catalyst layers （UTCLs） emerge as a promising alternative to reduce Pt loading by improving catalyst utilization and effectiveness, while theoretical issues such as the proton conduction mechan- ism remain puzzling and practical issues such as the rather narrow operation window remain unsettled. At present, the development of PEFC catalyst layer has come to a crossroads： staying ionomer-impregnated or going iono- mer-free. It is always beneficial to look back into the past when coming to a crossroads. This paper addresses the characterization and modeling of both the conventional ionomer-impregnated catalyst layer and the emerging ionomer-free UTCLs, featuring advances in characterizing microscale distributions of Pt particles, ionomer, support particles and unraveling their interactions; advances in fundamental understandings of proton conduction and flooding behaviors in ionomer-free UTCLs; advances in modeling of conventional catalyst layers and especially UTCLs; and discussions on high-impact research topics in characterizing and modeling of catalyst layers.

Estimated HCFC-142b emissions in China: 2000–2050

1-Chloro-1,1-difluoroethane(HCFC-142b)was both ozone depleting substance under restriction of the Montreal Protocol on Substances that Deplete the Ozone Layer(Montreal Protocol)and potent greenhouse gas with high GWP.Controlling its emissions in China will contribute to both mitigating climate change and protecting ozone.A national emission inventory of HCFC-142b for China during 2000–2012 was established and projected to2050 based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Montreal Protocol,showing that(i)in contrast to the downward trend revealed by existing researches,HCFC-142b emissions kept increasing from 0.1 kt/y in 2000 to the peak of 14.4 kt/y in2012,making China a crucial contributor to global HCFC-142b emissions and(ii)for future emission projections,a continuous increase from 14.9 kt/y in 2013 to 97.2 kt/y in2050 was anticipated under the business-as-usual(BAU)scenarios,while a reduction of about 90%of the projected BAU emissions would be obtained by fulfilling the Montreal Protocol,namely an accumulative mitigation of 1578kt HCFC-142b from 2013 to 2050,equal to 103 kt ODP and 3504 Tg CO2emissions.Emissions from each province in 2012 were also estimated to identify key emission areas.Among the 31 mainland provinces in China(Hong Kong,Macao,and Taiwan were not included),Jiangsu,Zhejiang,Shandong,and Guangdong had the highest emission ratesin 2012(2.06,1.85,1.52,and 1.04 kt/y,respectively);Zhejiang,Jiangsu,and Shanghai exhibit the strongest emission strength(0.83,0.59,and 0.54 t/km2,respectively),much higher than the average national level of 0.33t/km2.