Colorless to black switching with high contrast ratio via the electrochemical process of a hybrid organic-inorganic perovskite

Colorless‐to‐black switching has attracted widespread attention for smart windows and multifunctional displays because they are more useful to control solar energy.However,it still remains a challenge owing to the tremendous difficulties in the design of completely reverse absorptions in transmissive and colored states.Herein,we report on an electrochemical device that can switch between colorless and black by using the electrochemical process of hybrid organic–inorganic perovskite MAPbBr_(3),which shows a high integrated contrast ratio of up to 73%from 400 to 800 nm.The perovskite solution can be used as the active layer to assemble the device,showing superior transmittance over the entire visible region in neutral states.By applying an appropriate voltage,the device undergoes reversible switching between colorless and black,which is attributed to the formation of lead and Br_(2)in the redox reaction induced by the electron transfer process in MAPbBr_(3).In addition,the contrast ratio can be modulated over the entire visible region by changing the concentration and the applied voltage.These results contribute toward gaining an insightful understanding of the electrochemical process of perovskites and greatly promoting the development of switchable devices.

Long-Term Prognosis of Different Reperfusion Strategies for ST-Segment Elevation Myocardial Infarction in Chinese County-Level Hospitals:Insight from China Acute Myocardial Infarction Registry

Objective To evaluate the long-term prognosis of patients with ST-segment elevation myocardial infarction(STEMI)treated with different reperfusion strategies in Chinese county-level hospitals Methods A total of 2,514 patients with STEMI from 32 hospitals participated in the China Acute Myocardial Infarction registry between January 2013 and September 2014.The success of fibrinolysis was assessed according to indirect measures of vascular recanalization.The primary outcome was 2-year mortality.Results Reperfusion therapy was used in 1,080 patients(42.9%):fibrinolysis(n=664,61.5%)and primary percutaneous coronary intervention(PCI)(n=416,38.5%).The most common reason for missing reperfusion therapy was a prehospital delay>12 h(43%).Fibrinolysis[14.5%,hazard ratio(HR):0.59,95%confidence interval(CI)0.44–0.80]and primary PCI(6.8%,HR=0.32,95%CI:0.22–0.48)were associated with lower 2-year mortality than those with no reperfusion(28.5%).Among fibrinolysistreated patients,510(76.8%)achieved successful clinical reperfusion;only 17.0%of those with failed fibrinolysis underwent rescue PCI.There was no difference in 2-year mortality between successful fibrinolysis and primary PCI(8.8%vs.6.8%,HR=1.53,95%CI:0.85–2.73).Failed fibrinolysis predicted a similar mortality(33.1%)to no reperfusion(33.1%vs.28.5%,HR=1.30,95%CI:0.93–1.81).Conclusion In Chinese county-level hospitals,only approximately 2/5 of patients with STEMI underwent reperfusion therapy,largely due to prehospital delay.Approximately 30%of patients with failed fibrinolysis and no reperfusion therapy did not survive at 2 years.Quality improvement initiatives are warranted,especially in public health education and fast referral for mechanical revascularization in cases of failed fibrinolysis.

Confirmation of the First Law of Thermodynamics in Theory and Extended Bernoulli Equation

The internal energy change of ideal gas does not depend on the volume and pressure. The internal energy change of real gas has not any relation with the volume and pressure, which had been proved. If the internal energy change had not any relation with the volume and pressure, we could confirm the first law of thermodynamics in theory. Simultaneously, the internal energy change is the state function that shall be able to be proved in theory. If the internal energy change depended on the volume and pressure, we could not prove that the internal energy change is the state function and the chemical thermodynamics theory is right. The extended or modified Bernoulli equation can be derived from the energy conservation law, and the internal energy change, heat, and friction are all considered in the derivation procedure. The extended Bernoulli equation could be applied to the flying aircraft and mechanical motion on the gravitational field, for instance, the rocket and airplane and so on. This paper also revises some wrong ideas, viewpoints, or concepts about the thermodynamics theory and Bernoulli equation.

Synthesis,Crystal Structure and Luminescence of a Novel One-dimensional Silver(Ⅰ)Sulfonate Complex with Pyrazine Ligand

The title complex,[Ag 2 （L1） 2 （Pyr）·2.5H 2 O] 1 （L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine）,has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in triclinic,space group P1,with a=7.339（5）,b=13.105（5）,c=14.097（5）,α=84.377（5）,β=76.921（5）,γ=79.628（5）°,V=1296.7（11） 3,C 48 H 50 Ag 4 N 8 O 17 S 4,M r=1570.68,Z=1,D c=2.011 g/cm 3,μ=1.732 mm-1,F（000）=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections （I 2σ（Ⅰ））.Compound 1 shows a rare one-dimensional （1D） double chain,and the chains are further connected through secondary bonding,hydrogen bonds,and π-π interactions to generate a three-dimensional （3D） supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture.

Characterization of chromosome segment substitution lines reveals candidate genes associated with the nodule number in soybean

Soybean is one of the most important food crops worldwide.Like other legumes,soybean can form symbiotic relationships with Rhizobium species.Nitrogen fixation of soybean via its symbiosis with Rhizobium is pivotal for sustainable agriculture.Type Ⅲ effectors(T3Es)are essential regulators of the establishment of the symbiosis,and nodule number is a feature of nitrogen-affected nodulation.However,genes encoding T3Es at quantitative trait loci(QTLs)related to nodulation have rarely been identified.Chromosome segment substitution lines(CSSLs)have a common genetic background but only a few loci with heterogeneous genetic information;thus,they are suitable materials for identifying candidate genes at a target locus.In this study,a CSSL population was used to identify the QTLs related to nodule number in soybean.Single nucleotide polymorphism(SNP)markers and candidate genes within the QTLs interval were detected,and it was determined which genes showed differential expression between isolines.Four candidate genes(GmCDPK28,GmNAC1,GmbHLH,and GmERF5)linked to the SNPs were identified as being related to nodule traits and pivotal processes and pathways involved in symbiosis establishment.A candidate gene(GmERF5)encoding a transcription factor that may interact directly with the T3E NopAA was identified.The confirmed CSSLs with important segments and candidate genes identified in this study are valuable resources for further studies on the genetic network and T3Es involved in the signaling pathway that is essential for symbiosis establishment.

Economic Research on Ecological Environment of Frigid Region with Black Earth

Suihua City in Heilongjiang Province is located in the heart of the frigid region with black earth and it has created abundant green property resources. However,the environmental issue of this place has caused wide attention,so the government should make full use of various means to solve the environment problem and protect the ecology in this region. Among the measures taken by the government,the tax means is the most effective economic device to solve the environmental problem. Economic means supplemented by lawful and administrative measures should be adopted to solve the ecological environmental problems in the frigid region with black earth.

Disinfection Technology for Auricularia auricula in Bag Cultivation:Problems and Countermeasures

This article analyzes the problems existing in disinfection technology for Auricularia auricular in bag cultivation,introduces the concept of disinfection and sterilization technology and the technical status of humidification for disinfection of A.auricular in bag cultivation,analyzes the related problems caused by this type of technology and the reasons for the problems,and puts forward solutions to the technical problems.

Elite sd1 alleles in japonica rice and their breeding applications in northeast China

The Green Revolution gene sd1 has been used extensively in modern rice breeding,especially in indica cultivars.However,elite sd1 alleles and related germplasm resources used for japonica rice breeding have not been identified,and extensive efforts are needed for japonica rice breeding to obtain new dwarfing sources.Data from MBKbase-Rice revealed seven sd1 haplotypes in indica and four in japonica rice.Two new sd1 alleles were identified in indica rice.In 295 japonica accessions from northeast Asia,except for the weak functional allele SD1-EQ,sd1-r was the major allele,reducing plant height in comparison with SD1-EQ.Japonica germplasm resources carrying reported sd1 alleles were identified by genotype searching and further verified by literature search,genealogical analysis,and d Caps markers.Pedigrees and geographic distribution showed that sd1-r is an excellent allele widely used in northern China and Tohoku in Japan,and sd1-j is commonly used in east China and Kyushu in Japan.Dongnong-and Xiushui-series cultivars carrying sd1-r and sd1-j,respectively,are essential branches of the backbone parents of Chinese japonica rice,Akihikari and Ce21,with the largest number of descendants and derived generations.In semi-dwarf japonica rice breeding,sd1-d was introgressed into Daohuaxiang 2(DHX2).Dwarf and semi-dwarf lines carrying sd1-d were selected and designated as 1279 and 1280,respectively,after withstanding typhoon-induced strong winds and heavy rains in 2020,and are anticipated to become useful intermediate materials for future genetic research and breeding.This work will facilitate the introduction,parental selection,and marker-assisted breeding,and provide a material basis for the next step in identifying favorable genes that selected together with the sd1 alleles in japonica backbone parents.

Innovative Ideas for the Teaching of Guzheng in Colleges and Universities based on the New Curriculum Reform

As a traditional musical instrument,the guzheng holds a very important status in the Chinese traditional culture.In recent years,with the increase of opportunities for exchanges and cooperation between the West and China,guzheng is rapidly favored in the foreign music circle.As the main institute for cultivating high-level talents in the society,the academic discipline of music in various universities should actively promote the education reform of gxizheng based on the new curriculum reform combined with innovations and modifications of the national instrumental music teaching model to efficiently teach guzheng.

Superhydrophilic nickel hydroxide ultrathin nanosheets enable high-performance asymmetric supercapacitors

Superhydrophilic surfaces have been applied for supercapacitor;however,during energy storage reaction,how the wettability affects the process of electrochemical reaction specifically is still unclear.Herein,we demonstrate superhydrophilic surface for promotion of electrochemical reactions by liquid affinity and further explain the mechanism,where the transition of the wettability state caused by the change in surface free energy is the main reason for the obvious increase in specific capacitance.Through citric acid assistance strategy,an intrinsically hydrophobic Ni(OH)_(2)thick nanosheets(HNHTNs,16 nm)can be transitioned into superhydrophilic Ni(OH)_(2)ultrathin nanosheets(SNHUNs,6.8 nm),where the water contact angle was 0°and the surface free energy increased from 8.6to 65.8 mN·m^(-1),implying superhydrophilicity.Compared with HNHTNs,the specific capacitance of SNHUNs is doubled:from 1230 F·g^(-1)(HNHTNs)to 2350 F·g^(-1)(2A·g^(-1))and,even at 20 A·g^(-1),from 833 F·g^(-1)(HNHTNs)to 1670 F·g^(-1).The asymmetric capacitors assembled by SNHUNs and activated carbon show 52.44 Wh·kg^(-1)at 160W·kg^(-1)and excellent stability with~90%retention after5000 cycles(~80%retention after 9500 cycles).The promotion of electrochemical performances is ascribed to the change of surface wettability caused by surface free energy,which greatly increase affinity of electrode to the surrounding liquid environment to reduce the interface resistance and optimize the electron transport path.

Atmospheric pollution of agriculture-oriented cities in Northeast China: A case in Suihua

Agriculture-oriented cities in Northeastern China have experienced frequent atmospheric pollution events.Deeper understandings of the pollution characteristics,haze causes and effects of management on local air quality are crucial for conducting integrated management approaches for the sustainable development of agriculture-oriented cities.Taking a typical agriculture-dominant city(i.e.,Suihua)in Northeast China,we analyzed in detail the characteristics and causes of atmospheric pollution and evaluated the straw-burning prohibition using multisource data.The results showed a clear temporal pattern of air quality index(AQI)on an annual scale(i.e.,2015-April 2019),with two typical pollution periods occurring in late autumn and early spring.The large areas of concentrated straw burning at local and regional scales accounted for the first period(i.e.,October and November),while dust emissions and farming disturbances comprised the second period.The interannual variation in pollution periods among these years was large,showing similar trends from 2015 to 2017 and the postponed late-autumn pollution period in 2018.Our evaluation has shown that the prohibition effect of straw burning significantly improved air quality in 2018,with a reduction of 59%±88%in the PM2.5 concentrations in October and November compared to 2015–2017.However,From October to April of the following year,the improvement effect was not significant due to postponement of straw burning to February or March.Our analysis also highlighted the roles of meteorological conditions,Therefore,combined with the promotion of straw utilization,scientifically prescribed burning considering the burning amount and location,meteorological conditions and regional transportation should be implemented.

Origin and evolution of ore-forming fluid for the Gaosongshan gold deposit, Lesser Xing’an Range:Evidence from fluid inclusions,H-O-S-Pb isotopes

Epithermal gold deposits are typical precious metal deposits related to volcanic and subvolcanic magmatism.Due to the lack of direct geological and petrographic evidences,the origin of the ore-forming fluid is deduced from the spatial diagenesis-mineralization relationship,chronological data,physicochemical characteristics of mineral fluid inclusions,mineral or rock elements and isotopic geochemical characteristics.By objectively examining this scientific problem via a geological field survey and petrographic analysis of the Gaosongshan epithermal gold deposit,we recently discovered and verified the following points:(1) Pyrite-bearing spherical quartz aggregates (PSQA) occur in the rhyolitic porphyry;(2) the mineralization is structurally dominated by WNW- and ENE-trending systems and occurs mostly in hydrothermal breccias and pyrite-quartz veins,and the ore types are mainly hematite-crusted quartz,hydrothermal breccia,massive pyrite-quartz,etc.;(3) the alteration types consist of prevalent silicification,sericitization,propylitization and carbonation,with local adularization and illitization.The ore minerals are mainly pyrite,primary hematite,native gold,and electrum,with lesser amounts of chalcopyrite,magnetite,sphalerite,and galena,indicating a characteristic epithermal low-sulfidation deposit.The ore-forming fluid may have been primarily derived from magmatic fluid exsolved from a crystallizing rhyolitic porphyry magma.Further zircon U-Pb geochronology,fluid inclusion,physicochemical and isotopic geochemical analyses revealed that (1) rhyolitic porphyry magmatism occurred at 104.6 ± 1.0 Ma,whereas the crystallization of the PSQA occurred at 100.8 ± 2.1 Ma;(2) the hydrothermal fluid of the pre-ore stage was an exsolved CO2-bearing H2O-NaCl magmatic fluid that produced inclusions mainly composed of pure vapor (PV),vapor-rich (WV) and liquid-rich (WL) inclusions with a small number of melt-(M) and solid-bearing (S) inclusions;mineralization-stage quartz contains WL and rare PV,WV and pure liquid (PL) inclusions characterized by the H2O-NaCl system with low formation temperatures and low salinities;(3) the characteristics of hydrogen,oxygen,sulfur,and lead isotopes and those of rare earth elements (REEs) provide insight into the affinity between PSQA and orebodies resulting from juvenile crust or enriched mantle.Combined with previous research on the mineralogenetic epoch (99.32 ± 0.01 Ma),we further confirm that the mineralization of the deposit occurred in the late Early Cretaceous,which coincides with the extension of the continental margin induced by subduction of the Pacific Plate beneath the Eurasian Plate.The formation of the ore deposit was proceeded by a series of magmatic and hydrothermal events,including melting of enriched juvenile crust,upwelling,the eruption and emplacement of the rhyolitic magma,the exsolution and accumulation of magmatic hydrothermal fluid,decompression,the cooling and immiscibility/boiling of the fluid,and mixing of the magmatic fluid with meteoric water,in association with water-rock interaction.

An Integrated Quantitative Trait Locus Map of Oil Content in Soybean,Glycine max(L.) Merr.,Generated Using a Meta-Analysis Method for Mining Genes

Soybean is a major cash crop in the world, and its oil content was one of the very important traits. Therefore, the study of gene mapping for oil content in soybean is very important for breeding application. At present, at least 130 QTL loci for soybean oil content have been published; however, the mapping results of oil content were dispersed and a coalescent public map should be established to integrate the published QTLs, and to more efficiently mine genes based on the meta- analysis method of the bioinformatics tools. This study was to construct an integrated map of QTLs for soybean oil content and accelerate the application of bioinformation resource related to oil content improvement in the practice of soybean breeding. We collected information of 130 QTLs reported over the past 20 yr for soybean oil content and used the Software BioMercator 2.1 to project QTLs from their own maps onto a reference map, which was an early-integrated map constructed by Song （2004） for oil-content quantitative trait loci （QTLs） in soybean. Gene mining was performed based on the meta-analysis by running the local ver. GENSCAN and InterProScan. The confidence interval of QTLs was efficaciously narrowed using the meta-analysis method, and 25 consensus QTLs were mapped on the reference map. Using a local version of GENSCAN, 12 805 sequences in the consensus QTL intervals were predicted. With BLAST, these predicted sequences were aligned to gene sequences from the International Protein Index database using InterProScan locally. Thirteen predicted genes were in the class of the geme ontology （GO） accession （0006631）, which were involved in the fatty acid metabolic process. These genes were analyzed using BLAST at the NCBI website to examine whether they were related to oil content. Six genes were found in the oil-synthesis pathway. Twenty-five consensus QTLs and six genes were found in the oil-synthesis pathway. These results would lay the foundation for marker-assisted selection and mapping QTL precisely, and these genes will facilitate the researches on the gene mining of oil synthesis and molecular breeding in soybean.

Genetic Variation Dissection of Rice Blast Resistance Using an Indica Population

Rice blast disease,caused by fungus pathogen Magnaporthe oryzae,is one of the most destructive diseases that impact rice farming.In the worldwide,rice harvests lose 10%to 30%of the total production because of blast infection,which is estimated to be enough for feeding 60 million people(Skamnioti and Gurr,2009).

Research on DSP-Based Automatic Excitation Regulator in Small Rural Hydropower Station

Excitation regulator has played an important role to ensure that generator run safely and stably. However, in some remote areas, the rural small generator excitation control system is very backward, and it has hindered the development of Chinese agriculture and the pace of new countryside construction. This paper introduced a kind of structure and basic principle of DSP-based automatic excitation regulator, which was applied to rural small generator. We chose TMS320LF2407A chip as the core of regulator control system; the regulator adjusted PWM based on PID control strategy to control the exciting current. The theoretical analysis showed that the regulator had the characteristics of simplicity and reliability, well dynamic and static characteristics, and it could also adjust its own state quickly. The result was applicable to small rural hydropower station.

Boundary Value Problems for Second-order Integro-differential Equations in Banach Spaces

This paper investigates the maximal and minimal solutions of initial value problems for second order nonlinear integro-differential equations of Volterra type on a finite interval in a Banach space by establishing a comparison result and using the monotone iterative technique.

Comparative Analysis of Higher Education Between China and the United States

It is well-known that the United States,a highly developed country whether in high-tech.or higher education,is in a leading position in the world.Based on the comparison and analysis of higher education between China and the U.S.,this article highly affirms the advantages of American higher education,offers an objective comment on China's higher education reform in recent years,and earnestly indicates that China's higher education needs to be improved in order to facilitate greater development.

Several Suggestions on the Climate Change and Its Studies

According to the abundant studies,the relevant information and comprehensive analysis of the climate changes,several important problems on the climate changes and its studies were proposed.Based on the temporal distribution of the meteorological disaster of agriculture,the wave theory was expounded so as to draw people’s attention on climate changes and to be objective,just and careful about the study.

Research of Rural Power Network Reactive Power Optimization Based on Improved ACOA

In view of the serious reactive power loss in the rural network, improved ant colony optimization algorithm （ACOA） was used to optimize the reactive power compensation for the rural distribution system. In this study, the traditional ACOA was improved in two aspects： one was the local search strategy, and the other was pheromone mutation and re-initialization strategies. The reactive power optimization for a county＇s distribution network showed that the improved ACOA was practicable.