Spin gap in quasi-one-dimensional S=3/2 antiferromagnet CoTi2O5

Quasi-one-dimensional(1D)antiferromagnets are known to display intriguing phenomena especially when there is a spin gap in their spin-excitation spectra.Here we demonstrate that a spin gap exists in the quasi-1D Heisenberg antiferromagnet CoTi2O5 with highly ordered Co2+/Ti4+occupation,in which the Co2+ions with S=3/2 form a 1D spin chain along the a-axis.CoTi2O5 undergoes an antiferromagnetic transition at TN~24 K and exhibits obvious anisotropic magnetic susceptibility even in the paramagnetic region.Although a gapless magnetic ground state is usually expected in a quasi-1D Heisenberg antiferromagnet with half-integer spins,by analyzing the specific heat,the thermal conductivity,and the spin-lattice relaxation rate(1/T1)as a function of temperature,we found that a spin gap is opened in the spin-excitation spectrum of CoTi2O5 around TN,manifested by the rapid decrease of magnetic specific heat to zero,the double-peak characteristic in thermal conductivity,and the exponential decay of 1/T1 below TN.Both the magnetic measurements and the first-principles calculations results indicate that there is spin-orbit coupling in CoTi2O5,which induces the magnetic anisotropy in CoTi2O5,and then opens the spin gap at low temperature.

Consensus on the digestive endoscopic tunnel technique

With the digestive endoscopic tunnel technique(DETT), many diseases that previously would have been treated by surgery are now endoscopically curable by establishing a submucosal tunnel between the mucosa and muscularis propria(MP). Through the tunnel, endoscopic diagnosis or treatment is performed for lesions in the mucosa, in the MP, and even outside the gastrointestinal(GI) tract.At present, the tunnel technique application range covers the following:(1)Treatment of lesions originating from the mucosal layer, e.g., endoscopic submucosal tunnel dissection for oesophageal large or circular early-stage cancer or precancerosis;(2) treatment of lesions from the MP layer, per-oral endoscopic myotomy, submucosal tunnelling endoscopic resection, etc.; and(3) diagnosis and treatment of lesions outside the GI tract, such as resection of lymph nodes and benign tumour excision in the mediastinum or abdominal cavity. With the increasing number of DETTs performed worldwide, endoscopic tunnel therapeutics, which is based on DETT, has been gradually developed and optimized. However, there is not yet an expert consensus on DETT to regulate its indications, contraindications, surgical procedure, and postoperative treatment.The International DETT Alliance signed up this consensus to standardize the procedures of DETT. In this consensus, we describe the definition, mechanism,and significance of DETT, prevention of infection and concepts of DETTassociated complications, methods to establish a submucosal tunnel, and application of DETT for lesions in the mucosa, in the MP and outside the GI tract(indications and contraindications, procedures, pre-and postoperative treatments, effectiveness, complications and treatments, and a comparison between DETT and other operations).

Generation process of FeS and its inhibition mechanism on iron mineral reduction in selective direct reduction of laterite nickel ore

Numerous studies have demonstrated that Na2SO4 can significantly inhibit the reduction of iron oxide in the selective reduction process of laterite nickel ore. FeS generated in the process plays an important role in selective reduction, but the generation process of FeS and its inhibition mechanism on iron reduction are not clear. To figure this out, X-ray diffraction and scanning electron microscopy analyses were conducted to study the roasted ore. The results show that when Na2SO4 is added in the roasting, the FeO content in the roasted ore increases accompanied by the emergence of FeS phase. Further analysis indicates that NaeS formed by the reaction of Na2SO4 with CO reacts with SiO2 at the FeO surface to generate FeS and Na2Si2Os. As a result, a thin film forms on the surface of FeO, hindering the contact between reducing gas and FeO. Therefore, the reduction of iron is depressed, and the FeO content in the roasted ore increases.

Cooperative interception with fast multiple model adaptive estimation

For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang-bang evasive maneuver with a random switching time.Combined Fast multiple model adaptive estimation(Fast MMAE)algorithm,the cooperative guidance law takes detection configuration affecting the accuracy of interception into consideration.Introduced the detection error model related to the line-of-sight(LOS)separation angle of two interceptors,an optimal cooperative guidance law solving the optimization problem is designed to modulate the LOS separation angle to reduce the estimation error and improve the interception performance.Due to the uncertainty of the target bang-bang maneuver switching time and the effective fitting of its multi-modal motion,Fast MMAE is introduced to identify its maneuver switching time and estimate the acceleration of the target to track and intercept the target accurately.The designed cooperative optimal guidance law with Fast MMAE has better estimation ability and interception performance than the traditional guidance law and estimation method via Monte Carlo simulation.

A method for calibrating the confocal volume of a confocal three-dimensional micro-x-ray fluorescence setup

The measurement of the confocal volume of a confocal three-dimensional micro-x-ray fluorescence(3D-XRF)setup is a key step in the field of confocal 3D-XRF analysis.With the development of x-ray facilities and optical devices,3D-XRF analysis with a micro confocal volume will create a great potential for 2D and 3D microstructural analysis and accurate quantitative analysis.However,the classic measurement method of scanning metal foils of a certain thickness leads to inaccuracy.A method for calibrating the confocal volume is proposed in this paper.The new method is based on the basic content of the textbook,and the theoretical results and the feasibility are given in detail for the 3D-XRF mono-chromatic x-ray condition and the poly-chromatic x-ray condition.We obtain a set of experimental confirmation using the poly-chromatic x-ray tube in the laboratory.It is proved that the sensitivity factor of the 3D-XRF can be directly and accurately obtained in a real calibration process.

Properties of Certain Subclasses of Analytic Functions Involving q-Poisson Distribution

By using the basic(or q)-Calculus many subclasses of analytic and univalent functions have been generalized and studied from different viewpoints and perspectives.In this paper,we aim to define certain new subclasses of an analytic function.We then give necessary and sufficient conditions for each of the defined function classes.We also study necessary and sufficient conditions for a function whose coefficients are probabilities of q-Poisson distribution.To validate our results,some known consequences are also given in the form of Remarks and Corollaries.

X-ray focusing using an x-ray lens composed of multi-square polycapillary slices

A new type of x-ray lens composed of multi-square polycapillary slices(ASPXRL)used in focusing parallel x-ray beam was presented in this paper.Compared with conventional x-ray polycapillary lens,ASPXRL can provide smaller and brighter focus.The effects of the manufacturing imperfections on focusing quality of ASPXRL were evaluated with the values of transmission efficiency and discussed.It is suggested that ASPXRL has application prospects as a condenser lens for x-ray microscopy and flux collectors for x-ray analytical instruments.

Integrated chemical and transcriptomic analyses unveils synthetic characteristics of different medicinal root parts of Angelica sinensis

Objective:Why are different medicinal parts including heads,bodies and tails of Angelicae Sinensis Radix(ASR)distinct in pharmaceutical activities?Here we explored their discrepancy in chemical constituents and transcriptome.Methods:ASR were separated into three medicinal parts:heads(rootstocks with petiole traces of ASR),bodies(taproots of ASR)and tails(lateral roots of ASR),and chemical and transcriptomic analyses were conducted simultaneously.Results:High performance liquid chromatography(HPLC)fingerprint results showed that five widely used active ingredients(ferulic acid,senkyunolide H,senkyunolide A,n-butylphathlide,and ligustilide)were distributed unevenly in the three ASR medicinal parts.Partial least squares-discriminant analysis(PLS-DA)demonstrated that the heads can be differentiated from the two other root parts due to different amounts of the main components.However,the content of ferulic acid(a main quality marker)was significantly higher in tails than in the heads and bodies.The transcriptome analysis found that 25,062,10,148 and 29,504 unigenes were specifically expressed in the heads,bodies and tails,respectively.WGCNA analysis identified 17 co-expression modules,which were constructed from the 19,198 genes in the nine samples of ASR.Additionally,we identified 28 unigenes involved in two phenylpropanoid biosynthesis(PB)pathways about ferulic acid metabolism pathways,of which 17 unigenes(60.7%)in the PB pathway were highly expressed in the tails.The expression levels of PAL,C3 H,and CQT transcripts were significantly higher in the tails than in other root parts.RT-q PCR analysis confirmed that PAL,C3 H,and CQT genes were predominantly expressed in the tail parts,especially PAL,whose expression was more than doubled as compared with that in other root parts.Conclusion:Chemical and transcriptomic analyses revealed the distribution contents and pivotal transcripts of the ferulic acid biosynthesis-related pathways.The spatial gene expression pattern partially explained the discrepancy of integral medicinal activities of three medicinal root parts.

Epidemiologically characteristics of human brucellosis and antimicrobial susceptibility pattern of Brucella melitensis in Hinggan League of the Inner Mongolia Autonomous Region,China

Background:Hinggan League is located in the Northeast of the Inner Mongolia Autonomous Region,the historically endemic area of animal and human brucellosis.In this study,the epidemiological characteristics of human brucellosis were analyzed,and the genotypic profile and antimicrobial susceptibilities of Brucella melitensis strains isolated from humans in Hinggan League were investigated.Methods:The epidemic characteristics were described using case number,constituent ratio,and rate.The 418 human blood samples were collected and tested by bacteriology,and suspect colonies were isolated and identified by conventional biotyping assays,the VITEK 2.0 microbial identification system,and AMOS(Brucella abortus,B.melitensis,B.ovis,and B.suis)-PCR.Subsequently,all strains were genotyped using multiple-locus variable-number tandem repeat analysis(MLVA)assays,and the antimicrobial susceptibility pattern of Brucella strains against the 10 most commonly used antibiotics was determined by microdilution method.Results:A total of 22848 cases of human brucellosis were reported from 2004 to 2019,with an annual average incidence of 87.2/100000.The incidence rates in developed areas of animal husbandry(Horqin Youyi Qianqi[161.2/100000]and Horqin Youyi Zhongqi[112.1/100000])were significantly higher than those in forest areas(Arxan[19.2/100000])(χ2=32.561,P<0.001).In addition,peak morbidity occurred during May–August,accounting for 72.6%(16582/22848)of cases.The highest number of cases occurred in the 40+age group,accounting for 44.4%(10137/22484)of cases,and morbidity in males was significantly higher than that in females in all age groups(χ2=299.97,P<0.001),the most common occupation was farmers.A total of 54 B.melitensis strains were divided into 37 genotypes(GT1–37)with 80–100%genetic similarity.All 25 strains were sensitive to seven tested antibiotics,phenotypic resistance to cotrimoxazole and azithromycin was observed in 5(20%)and 25(100%)of the isolates,respectively.Conclusions:Human brucellosis exhibited a significant increasing trend and B.melitensis is the main pathogen responsible for human brucellosis in this region.Improved surveillance of infected animals(sheep)and limiting their transfer and trade are optional strategies for decreasing the incidence of this disease.

Effect of Sodium Sulfate on Direct Reduction of Beach Titanomagnetite for Separation of Iron and Titanium

The effect of sodium sulfate on direct reduction of beach titanomagnetite,followed by magnetic separation,to separate iron and titanium was investigated. Direct reduced iron（ DRI） with a high Fe content,low TiO_2 content and low iron recovery was obtained after adding sodium sulfate. When the sodium sulfate dosage was increased from 0 to 10 mass%,the Fe content of the DRI increased from 90. 00 mass% to 93. 55 mass% and the TiO_2 content decreased from 1. 27 mass% to 0. 70 mass%. The reduction mechanism of sodium sulfate was investigated by X-ray diffraction（ XRD） and scanning electron microscopy（ SEM） with energy dispersive spectrometer（ EDS）. Results revealed that the metallic iron grains in the reduced ore with sodium sulfate were larger than those in the ore without sodium sulfate. Sodium sulfate promoted the migration of iron as well as the accumulation and growth of metallic iron grains by low-melting-point carnegieite and troilite formed in the redox system. Low-melting-point carnegieite decreased the melting point of the system and then promoted liquefaction. Troilite could decrease the surface tension and melting point of metallic iron grains.