Operational optimization of copper flotation process based on the weighted Gaussian process regression and index-oriented adaptive differential evolution algorithm

Concentrate copper grade(CCG)is one of the important production indicators of copper flotation processes,and keeping the CCG at the set value is of great significance to the economic benefit of copper flotation industrial processes.This paper addresses the fluctuation problem of CCG through an operational optimization method.Firstly,a density-based affinity propagationalgorithm is proposed so that more ideal working condition categories can be obtained for the complex raw ore properties.Next,a Bayesian network(BN)is applied to explore the relationship between the operational variables and the CCG.Based on the analysis results of BN,a weighted Gaussian process regression model is constructed to predict the CCG that a higher prediction accuracy can be obtained.To ensure the predicted CCG is close to the set value with a smaller magnitude of the operation adjustments and a smaller uncertainty of the prediction results,an index-oriented adaptive differential evolution(IOADE)algorithm is proposed,and the convergence performance of IOADE is superior to the traditional differential evolution and adaptive differential evolution methods.Finally,the effectiveness and feasibility of the proposed methods are verified by the experiments on a copper flotation industrial process.

Meiotic nuclear divisions 1 suppresses the proliferation and invasion of pancreatic cancer cells via regulating H2A.X variant histone

Introduction:Among all malignant tumors of the digestive system,pancreatic carcinoma exhibits the highest mortality rate.Currently,prevention and effective treatment are urgent issues that need to be addressed.Methods:The study focused on meiotic nuclear divisions 1(MND1),integrating data from the Gene Expression Profiling Interactive Analysis(GEPIA)database with prognostic survival analysis.Simultaneously,experiments at cellular level were employed to demonstrate the effect of MND1 on the proliferation and migration of PC.The small-molecule inhibitor of MND1 was used to suppress the migration of PC cells by knocking down MND1 using small interfering RNA(siRNA)in Patu-8988 and Panc1 cell lines.Results:The results of Cell Counting Kit-8 indicated that the suppression of MND1 resulted in a decrease in cell proliferation.Wound healing and Transwell assays revealed that MND1 knockdown reduced cell migration and invasion.Flow cytometry revealed that inhibiting MND1 hindered the cell cycle.Furthermore,MND1 could stimulate the proliferation,migration,and invasion of Patu-8988 and Panc1 cells by increasing the expression of MND1.Notably,MND1 had a positive effect on H2AFX expression in PC cells.Elevated MND1 expression suggests the low overall survival rate of individuals diagnosed with PC.Conclusion:These findings suggest that MND1 has the potential to be a gene with the ability to accurately diagnose and treat PC.

蜀汉正统视域下的诸葛亮七擒孟获

三国历史上的诸葛亮七擒七纵孟获,深切地展示了诸葛亮建构华夏正统在仁德而不在地理的努力。在对待以孟获为代表的南中民族问题上,诸葛亮审慎地反思汉代的德柔和威服民族政策,有意识地区别于曹魏政权的武力震慑民族政策,改而采用攻心的以德怀远民族政策,树立起“恢复汉室”和“蜀汉正统”的旗帜。

Co@CoO:An efficient catalyst for the depolymerization and upgrading of lignocellulose to alkylcyclohexanols with cellulose intact

The depolymerization and upgrading of lignin from raw biomass,while keeping cellulose intact is important in biorefinery and various metal-based catalysts have been used in reductive catalytic fractionation,a key method in"lignin-first"strategy,Recently,we found that a core-shell structured Co@CoO catalyst with CoO shell as the real active site had excellent performance in the hydrogenolysis of 5-hydromethylfurfural to 2,5-dimethylfuran due to its unique ability to dissociate H_(2)and yield active H^(δ-)species(Xiang et al.,2022).In this work,we report a one-pot depolymerization and upgrading of lignocellulose to alkylcyclohexanols,a flavour precursor,with intact cellulose over this unique core-shell structured catalyst,Co@CoO.Lignin model compounds(β-O-4,4-O-5,α-O-4)were first used to clarify the activity of Co@CoO catalyst.Then,the one-pot conversion of various organosolv lignin(birch,pine and poplar)to alkylcyclohexanols was realized with the mass yield of alkylcyclohexanols up to25.8 wt%from birch lignin under the reaction condition of 210℃,1 MPa H_(2),16 h.Finally,the corresponding woody sawdusts were used as feedstocks and found that the Co@CoO catalyst indeed preferentially depolymerized and upgraded the lignin part and obtained the same alkylcyclohexanols products with the retention of cellulose-rich pulp.The collected alkylcyclohexanols were further esterified to obtain valueadded esters,which can be used as flavors.This work will inspire the design of new efficient metal oxide catalysts in lignin fractionation and depolymerization to high-value-added chemicals with intact cellulose.

Natural variation in SlSOS2 promoter hinders salt resistance during tomato domestication

Increasing soil salinization seriously impairs plant growth and development,resulting in crop loss.The Salt-Overly-Sensitive(SOS)pathway is indispensable to the mitigation of Na+toxicity in plants under high salinity.However,whether natural variations of SOS2 contribute to salt tolerance has not been reported.Here a natural variation in the SlSOS2 promoter region was identified to be associated with root Na+/K+ratio and the loss of salt resistance during tomato domestication.This natural variation contains an ABI4-binding cis-element and plays an important role in the repression of SlSOS2 expression.Genetic evidence revealed that SlSOS2 mutations increase root Na+/K+ratio under salt stress conditions and thus attenuate salt resistance in tomato.Together,our findings uncovered a critical but previously unknown natural variation of SOS2 in salt resistance,which provides valuable natural resources for genetic breeding for salt resistance in cultivated tomatoes and other crops.

Analysis of Genetic Variation of VP2 Gene in 6 FPV Strainsin China

In order to understand the variation of FPV strains in the Jinan area, Shandong Province, China, the VP2 gene of 6 FPV strains was sequenced, and the analysis of the genetic relationship, evolution and main functional site variation was carried out. It was found that FPV-XY2, FPV-XY3 and FPV-XY6 were the same strain with 100% homology, and also close to FPV-XY1, and the homology between FPV-XY4 and FPV-XY5 was close. The homology between the reference strain and the test strain was over 99.3%. According to the evolutionary analysis, the genetic relationship among FPV-XY1, FPV-XY2, FPV-XY3, FPV-XY6 was close, and the genetic relationship between FPV-XY4 and FPV-XY5 was close, and the result was similar to the homologous result. Compared with the VP2 amino acid sequence of the standard strain FPV-CU4, the VP2 protein of all the test strains changed from I to t on the 101st Amino acid, this may be the cause of immune failure in these 6 cases;the change of a to s in the 91st amino acid position of FPV-XY1, FPV-XY2, FPV-XY3, FPV-XY6 may be the cause of enhanced virulence of FPV. This study provides a reference for exploring the epidemic law of FP in the Jinan area, the standard of FP treatment plan and the research and development of FPV subunit vaccine.

社会排斥与毒品亚文化:青少年群体吸毒的双重诱因及其消解路径

毒品已经成为困扰全球的严重社会问题,我国毒品形势也不容乐观,特别是青少年群体吸毒问题尤需重视。论文以"推力-拉力"为分析维度,将资源禀赋薄弱的弱势青少年群体吸毒的双重诱因,划分为社会排斥视角下主流社会的经济排斥、制度排斥、社会关系排斥和文化排斥四种"推力"因素,以及毒品亚文化中价值观念的契合、社会互动的需求、文化压力的强化三方面"拉力"因素,以此来剖析其吸毒行为的生成逻辑。最后,论文以社会融合为目标,分别从社会支持网络的支撑路径与宣传教育的化解路径,提出消解青少年吸毒群体"反推力-反拉力"的综合模式。

专栏导语:青少年吸毒的发生逻辑与治理路径

2014年7月6日,中共中央、国务院在印发的《关于加强禁毒工作的意见》中将禁毒工作上升到国家安全战略和平安中国、法治中国建设的高度,并提出到2020年禁毒工作要在全民禁毒意识提升、戒毒康复体系完善、走私与制贩毒活动整治、禁毒工作社会化格局形成,以及禁毒的专业化队伍建设和法律法规制定等各个方面取得显著成效,切实掌握禁毒斗争主动权。党的十九大报告指出,我国社会主要矛盾已经转化为“人民日益增长的美好生活需要和不平衡不充分的发展之间的矛盾”.

Chemoselective hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol over Ir-MoO_x/SiO_2 catalyst

In this work, MoOx promoted Ir/SiO2 catalysts were prepared and used for the selective hydrogenolysis of tetrahydrofurfuryl alcohol(THFA)to 1,5-pentanediol in a continuous flow reactor. The effects of different noble metals(Ir, Pt, Pd, Ru, Rh), supports and Ir contents were screened.Among the investigated catalysts, 4 wt%Ir-MoOx/SiO2 with a Mo/Ir atomic ratio of 0.13 exhibited the best catalytic performance. The synergy between Ir particles and the partially reduced isolated MoOx species attached on them is essential for the excellent catalytic performance of Ir-MoOx/SiO2. The catalyst exhibited a better hydrogenolysis efficiency of THFA with the selectivity of 1,5-pentanediol of 65%–74% at a conversion of THFA of 70%–75% when the initial THFA concentration is ranging from 20 wt% and 40 wt%. And higher system pressure was also in favor of the conversion of THFA. During a stability test, the conversion of THFA and 1,5-pentanediol yield over Ir-MoOx/SiO2 decreased with reaction time, which can be explained by the leaching of Mo species during the reaction.

Effect of electrode Pt-loading and cathode flow-field plate type on the degradation of PEMFC

The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this study, membrane electrode assemblies with different Pt-loadings were prepared, and PEMFCs were assembled using those membrane electrode assemblies with traditional solid plate and water transport plate as cathode flow-field plates, respectively. The performance and electrochemical surface area of cells were characterized to evaluate the membrane electrode assemblies degradation after rapid currentvariation cycles. Scanning electron microscope and transmission electron microscope were used to investigate the decay of catalyst layers and Pt/C catalyst. With the increase of Pt-loading, the performance degradation of membrane electrode assemblies will be mitigated. But higher Pt-loading means thicker catalyst layer, which leads to a longer pathway of mass transfer, and it may result in carbon material corrosion in membrane electrode assemblies. The decay of Pt/C catalyst in cathode is mainly caused by the corrosion of carbon support, and the degradation of anode Pt/C catalyst is a consequence of migration and aggregation of Pt particles. And using water transport plate is beneficial to alleviating the age of cathode Pt/C catalyst.

Dehydration of xylose to furfural over niobium phosphate catalyst in biphasic solvent system

Phosphoric acid treated niobic acid(NbP)was used for the dehydration of xylose to furfural in biphasic solvent system,which was found to exhibit the best performance among the tested catalysts.The excellent performance of NbP could be explained by the better synergistic cooperation between Bro¨nsted and Lewis acid sites.Moreover,NbP showed good stability and no obvious deactivation or leaching of Nb could be observed after six continuous recycles.

QTL mapping for grain number per spikelet in wheat using a high-density genetic map

Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from which the reference genome assembly of bread wheat was obtained.Both parents and the recombinant inbred lines were genotyped using the wheat 55K single nucleotide polymorphism(SNP) array.A high-density genetic map containing 21,197 SNPs was obtained.These markers covered each of the 21 chromosomes with a total linkage distance of 3792.71 c M.Locations of these markers in this linkage map were highly consistent with their physical locations in the genome assembly of Chinese Spring.The two parents and the whole RIL population were assessed for GNS in two consecutive years at two different locations.Based on multi-environment phenotype data and best liner unbiased prediction values,three quantitative trait loci (QTL) for GNS were identified.One of them located on chromosomes 2B and the other two on 2D.Phenotypic variation explained by these loci varied from 3.07%to26.57%.One of these QTL,QGns.sicau-2D-2,was identified in each of all trials conducted.Based on the best linear unbiased prediction values,this locus explained 19.59%–26.57%of phenotypic variation.A KASP(Kompetitive Allele-Specific PCR) marker closely linked with this locus was generated and used to validate the effects of this locus in three different genetic backgrounds.The identified QTL and the KASP marker developed for it will be highly valuable in fine-mapping the locus and in exploiting it for markerassisted selection in wheat breeding programs.

PpERF3 positively regulates ABA biosynthesis by activating PpNCED2/3 transcription during fruit ripening in peach

The plant hormone ethylene regulates ripening in climacteric fruits.The phytohormone abscisic acid(ABA)affects ethylene biosynthesis,but whether ethylene influences ABA biosynthesis is unknown.To explore this possibility,we investigated the interactions between the ABA biosynthesis genes PpNCED2/3 and the ethylene response transcription factor PpERF3 in peach fruit.The ABA content increased during fruit maturation and reached a peak at stage S4 III.The increase was greatly inhibited by the ethylene inhibitor 1-MCP,which also suppressed PpERF3 expression.PpERF3 shared a similar expression profile with PpNCED2/3,encoding a rate-limiting enzyme involved in ABA biosynthesis,during fruit ripening.A yeast one-hybrid assay suggested that the nuclear-localized PpERF3 might bind to the promoters of PpNCED2/3.PpERF3 increased the expression of PpNCED2/3 as shown by dual-luciferase reporters,promoter-GUS assays and transient expression analyses in peach fruit.Collectively,these results suggest that ethylene promotes ABA biosynthesis through PpERF3’s regulation of the expression of ABA biosynthesis genes PpNCED2/3.

Acoustic Emission Characteristics of Different Bamboo and Wood Materials in Bending Failure Process

The acoustic emission(AE)technique can perform non-destructive monitoring of the internal damage development of bamboo and wood materials.In this experiment,the mechanical properties of different bamboo and wood(bamboo scrimber,bamboo plywood and SPF(Spruce-pine-fir)dimension lumber)during four-point loading tests were compared.The AE activities caused by loadings were investigated through the single parameter analysis and K-means cluster analysis.Results showed that the bending strength of bamboo scrimber was 3.6 times that of bam-boo plywood and 2.7 times that of SPF dimension lumber,respectively.Due to the high strength and toughness of bamboo,the AE signals of the two bamboo products were more abundant than those of SPF dimension lumber.However,the AE evolution trend of the three materials was similar,which all experienced three stages,including gentle period,steady period and steep period,and the area of rupture precursor characteristics could be recognized before the specimen destroyed.Due to the bottom layer was first tensile failure,the main structure of bamboo plywood was destroyed after the stress redistribution.The rupture precursor characteristics could be observed before each peak.Findings put in evidence a good correlation between AE clusters of two bamboo products,while the amplitude and energy of wood signals were lower than those of bamboo.The amplitude and energy from the propagation and aggregation of cracks were greater than those related to micro-cracks initiation.

Natural gas consumption forecasting model based on coal-to-gas project in China

Natural gas is widely used because it is environmentally friendly,particularly in reducing carbon emission and improving the Air Quality Index(AQI)around densely populated cities.China has initiated a coal-to-gas project(CGP)to improve the air quality in northern China.As a subcompany of China National Petroleum Corporation,PetroChina Natural Gas Marketing North Company has been focusing on natural gas resource allocation while considering numerous issues such as ensuring the bottom line of livelihood requirements in winter and the performance of economic indicators for an entire calendar year in the northern part of China.Therefore,the accurate prediction of natural gas consumption is important to PetroChina Natural Gas Marketing North Company.It has become a challenge to forecast natural gas consumption because the natural gas market has changed considerably because of the CGP.Natural gas consumption cannot be forecasted using conventional models.This study analyzes the characteristics of the CGP based on the data obtained from rural individual users and company users.Based on the analysis,the gas consumption in winter is predicted using two different forecasting approaches.The methods presented in this paper provide a basis for formulating effective measures for natural gas scheduling in the northern part of China.

First-Principles Study of Lithium and Sodium Atoms Intercalation in Fluorinated Graphite

The structure evolution of fluorinated graphite(CFx) upon the Li/Na intercalation has been studied by firstprinciples calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been calculated. The better cycling performance of Na intercalation into the CF cathode, comparing to that of Li intercalation, is attributed to the different strength and characteristics of the Li-F and Na-F interactions. The interactions between Li and F are stronger and more localized than those between Na and F. The strong and localized Coulomb attraction between Li and F atoms breaks the C—F bonds and pulls the F atoms away, and graphene sheets are formed upon Li intercalation.

Current management of chemotherapy-induced neutropenia in adults:key points and new challenges

Chemotherapy-induced neutropenia(CIN)is a potentially fatal and common complication in myelosuppressive chemotherapy.The timing and grade of CIN may play prognostic and predictive roles in cancer therapy.CIN is associated with older age,poor functional and nutritional status,the presence of significant comorbidities,the type of cancer,previous chemotherapy cycles,the stage of the disease,specific chemotherapy regimens,and combined therapies.There are many key points and new challenges in the management of CIN in adults including:(1)Genetic risk factors to evaluate the patient’s risk for CIN remain unclear.However,these risk factors urgently need to be identified.(2)Febrile neutropenia(FN)remains one of the most common reasons for oncological emergency.No consensus nomogram for FN risk assessment has been established.(3)Different assessment tools[e.g.,Multinational Association for Supportive Care in Cancer(MASCC),the Clinical Index of Stable Febrile Neutropenia(CISNE)score model,and other tools]have been suggested to help stratify the risk of complications in patients with FN.However,current tools have limitations.The CISNE score model is useful to support decision-making,especially for patients with stable FN.(4)There are still some challenges,including the benefits of granulocyte colony stimulating factor treatment and the optimal antibiotic regimen in emergency management of FN.In view of the current reports,our group discusses the key points,new challenges,and management of CIN.

Investigation into Spatter Particles and Their Effect on the Formation Quality During Selective Laser Melting Processes

During the selective laser melting process,a high-energy laser beam acts on the powder,a molten pool is rapidly generated and the characteristic parameters are constantly changing.Among them,temperature is one of the important parameters in the forming process.Due to the generation of splash particles,there will be defects in the microstructure,which will seriously affect the formation quality of the prepared parts.Therefore,it is necessary to study the relationships between the splash behavior,molten pool characteristics and product quality.The finite element simulation of the transient temperature field was performed by ANSYS software.Time-series images at different frame rates were obtained with a high-speed camera,and the dynamic process of splashing was observed.Using IN718 alloy powder,the influence of the laser energy density on the light intensity of the molten pool was studied.The appearance of splash particles and the deviation of the powder chemical elements caused by the splash were analyzed.The results show that the transient temperature field with drastic change is easy to cause spatter,which is consistent with the experimental results.There are large differences in the splash at different shooting frame rates.Increasing the frame rate can allow the observation of details such as the shape,size and number of splash particles,which is beneficial for studying the process of splash formation.At the moment when the splash occurs,the light intensity of the molten pool always first increases and then decreases,depending on the energy input.The higher the energy input is,the more intense the light intensity of the molten pool and the higher the peak interval distribution.Compared with fresh powder,the contents of Al and Ti in powder reused 5 times were reduced by 0.15%and 0.02%,respectively.The increases of these two elements in the splash were 16.18%and 29.62%,respectively,and the content of Nb even exceeded the standard range.When the energy density decreased from 229.17 J/mm3 to 130.95 J/mm3,the relative density of the part increased from 91.82%to 99.83%.This shows that reducing the energy input can reduce the splash to suppress the generation of defects,along with the weakening of the overall light intensity of the molten pool.These results can provide a basis for feature extraction of the molten pool,which is of great significance for real-time monitoring and online control in manufacturing processes and ensuring product quality.

Research on prediction model of formation temperature of ammonium bisulfate in air preheater of coal-fired power plant

Ammonium bisulfate(ABS)is a viscous compound produced by the escape NH_(3) in the NO reduction process and SO_(3) in the flue gas at a certain temperature,which can cause the ash corrosion of the air preheater in coal-fired power plants.Therefore,it is essential to study the formation temperature of ABS to prevent the deposition of ABS in air preheaters.In this paper,the SO_(3) reaction kinetic model is used to analyze the SO_(3) generation process from coal combustion to the selective catalytic reduction(SCR)exit stage,and the kinetic model of NO reduction is used to analyze the NH_(3) escape process.A prediction model for calculating the ABS formation temperature based on the S content in coal and NO reduction parameters of the SCR is proposed,solving the difficulty of measuring SO_(3) concentration and NH_(3) concentration in the previous calculation equation of ABS formation temperature.And the reliability of the model is verified by the actual data of the power plant.Then the influence of S content in coal,NH_(3)/NO_(x) molar ratio,different NO_(x) concentrations at SCR inlet,and NO removal efficiency on the formation temperature of ABS are analyzed.

Influence of Aspect Ratio on Rolling Shear Properties of Fast-Grown Small Diameter Eucalyptus Lumber

Eucalyptus is a major fast-grown species in South China,which has the potential for producing structural wood products such as cross-laminated timber(CLT).Aspect ratio(board width vs.board thickness)of eucalyptus lumbers is small due to the small diameter of fast-grown eucalyptus wood.To evaluate its rolling shear modulus and strength for potential CLT applications,three-layer hybrid CLT shear block specimens with different aspect ratios(2,4,6),were tested by planar shear test method.Digital image correlation(DIC)was employed to measure the rolling shear strain distribution and development during the planar shear tests.The mean values of rolling shear modulus and strength of eucalyptus lamination were 260.3%and 88.2%higher than those of SPF(Spruce-pine-fir)lamination with the same aspect ratio of 4,respectively.The rolling shear properties of eucalyptus laminations increased as the aspect ratio increased.Aspect ratio had a significant influence on rolling shear modulus compared to rolling shear strength.The high shear strain regions were primarily found around the gaps between segments of cross layer.The quantity of high shear strain regions increased as the aspect ratio of lamination decreased.Other high shear strain regions also occurred around the pith and along the glue line.The sudden failure of specimen occurred in the high strain region.In conclusion,the rolling shear strength and modulus of fast-grown eucalyptus laminations exceed the respective characteristic values for softwoods in the current standard by roughly factors of 3 and 8,indicating great potential for fast-grown eucalyptus wood cross-layers in CLT.