First application of plutonium in soil erosion research on terraces

The spatial distributions of ^(239+240)Pu and ^(137)Cs in soils from Longji Rice Terraces were investigated to evaluate soil erosion.The activity concentrations of ^(239+240)Pu and ^(137)Cs in the surface soils of the paddy fields were in the range of 0.089–0.734 and1.80–7.88 mBq/g,respectively.The activities of ^(239+240)Pu and ^(137)Cs showed very similar distribution trends,first increasing and then decreasing with increasing elevation.The 240Pu/239Pu atom ratios in the surface soils ranged from 0.162 to 0.232.The activities of ^(239+240)Pu and ^(137)Cs in the soil cores tended to be uniformly distributed within the plowed layer and declined exponentially below this depth.The mean soil erosion rates of Longji Rice Terraces estimated by ^(239+240)Pu and ^(137)Cs tracer methods were 5.44 t/(ha·a)and 5.16 t/(ha·a),respectively,which demonstrated that plutonium can replace ^(137)Cs as an ideal tracer for soil erosion research in the future.Landform features are the main factors affecting the distribution of plutonium and ^(137)Cs as well as soil erosion in the Longji Rice Terraces.

Atlas of dynamic spectra of fast radio burst FRB 20201124A

Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope(FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076.

湿法炼锌窑渣铁精矿中有价组分浸出行为及其机理（英文）

盐酸浸出-喷雾热分解法被认为是高效清洁回收湿法炼锌窑渣铁精矿中有价金属的新方法。系统研究了Ag、Pb、Cu、Fe、As、Zn、Si等元素在浸出过程中的行为。结果表明:采用6 mol/L HCl溶液,在液固比10:1、温度60°C、浸出120 min的条件下,Ag、Pb、Cu、Fe、As、Zn的浸出率分别为99.91%、99.25%、95.12%、90.15%、87.58%和58.15%。浸出过程中硅达到饱和,从溶液中析出无定型SiO_2,由于其对溶液中的金属离子产生吸附作用,从而对窑渣铁精矿中有价金属的浸出产生不利影响,所以控制SiO_2的析出对浸出过程至关重要。

Probiotics increase T regulatory cells and reduce severity of experimental colitis in mice

AIM:To investigate the effect of probiotics on regulating T regulatory cells and reducing the severity of experimental colitis in mice. METHODS:Forty C57/BL mice were randomly divided into four groups.Colitis was induced in the mice using 2,4,6-trinitrobenzene sulfonic acid(TNBS).After 10-d treatment with Bifico capsules(combined bifidobacterium,lactobacillus and enterococcus),body weight,colonic weight,colonic weight index,length of colon,and histological scores were evaluated.CD4+CD25+Foxp3+T cell in mesenteric lymph nodes were measured by flow cytometry,and cytokines in colonic tissue homogenateswere analyzed by a cytometric bead array. RESULTS:The colonic weight index and the colonic weight of colitis mice treated with Bifico were lower than that of TNBS-induced mice without treatment. However,colonic length and percent of body weight amplification were higher than in TNBS-induced mice without treatment.Compared with TNBS-induced mice without treatment,the level of CD4+CD25+Foxp3+T cells in mesenteric lymph nodes,the expression of interleukin(IL)-2,IL-4 and IL-10 in colonic tissues from colitis mice treated with Bifico were upregulated,and tumor necrosis factor-αand interferon-γwere downregulated. CONCLUSION:Probiotics effectively treat experimental colitis by increasing CD4+CD25+Foxp3+T cell and regulating the balance of Th1 and Th2 cytokines in the colonic mucosa.

Age-specific PSA reference ranges in Chinese men without prostate cancer

This study is to determine age-specific prostate-specific antigen （PSA） distributions in Chinese men without prostate cancer （PC） and to recommend reference ranges for this population after comparison with other studies. From September 2003 to December 2006, 9 374 adult men aged from 18 to 96 years agreed to participate in the study. After all cases of PC were excluded, 8 422 adult men participated in statistical analysis and were divided into five age groups. Simple descriptive statistical analyses were carried out and quartiles and 95th percentiles were calculated for each age group. The age-specific PSA reference ranges are as follows： 4049 years, 2.15 ng mLl; 50-59 years, 3.20 ng mLl; 60-9 years, 4.10 ng mL^-1; 70-79 years, 5.37 ng mL^-1. The results indicate that the ethnic differences in PSA levels are obvious. The currently adopted Oesterling＇s age-specific PSA reference ranges are not appropriate for Chinese men. The reference ranges of this study should be more suitable to Chinese men.

Relationship between serum sex hormones levels and degree of benign prostate hyperplasia in Chinese aging men

Benign prostatic hyperplasia （BPH） is one of the most common medical conditions in middle aged and older men. This study investigated the relationship between serum levels of sex hormones and measures of BPH in the aging male population of China. Prostate symptoms were assessed as part of a free health screening program for men ~40 years of age. The examination included digital rectal examination, determination of serum prostate-specific antigen levels, International Prostate Symptom Score （IPSS） and transrectal ultrasonography. Serum levels of total testosterone （TT）, sex hormone binding globulin （SHBG）, free testosterone （FT）, luteinizing hormone （LH）, follicle-stimulating hormone （FSH）, prolactin （PRL） and estradiol （E2） were evaluated. The men also completed a health and demographics questionnaire and received a detailed physical examination. The final study population consisted of 949 men with a mean age of 58.9 years. Pearson correlation analysis indicated that there were significant correlations between age and levels of all sex hormones except TT, and between age and prostate volume （PV; r=0.243; P〈0.01） or IPSS （r=0.263; P〈0.01）. Additional significant correlations were found between IPSS and serum levels of LH （r=0. 112; P〈0.01） and FSH （r=0.074; P〈0.05）, but there were no significant correlations between sex hormone levels and PV. Multivariate linear regression analysis showed significant correlations between age and body mass index （BMI） with PV （P〈0.0001）. In addition, there was a significant correlation between age and PV with IPSS （P〈0.0001）. Serum sex hormone levels did not correlate with PV or IPSS. The effects of endocrine changes on measures of BPH in aging men require further investigation in longitudinal and multicenter studies that include oatients with all severities of BPH.

Investigation of rheo-diecasting mold filling of semi-solid A380 aluminum alloy slurry

The rheo-diecasting mold filling capacity and the microstructure of the semi-solid A380 aluminum alloy slurry were investigated. The results show that the mold filling capacity was strengthened with increasing pouring temperature or increasing injection pressure. Under certain process parameters, the mold cavity was fully filled. However, the mold filling capacity decreased with increasing holding time. The mold filling capacity was improved with increasing shape factor of primary α(Al) grains; however, the solid fraction and the grain size significantly increased at the same time. In addition, the microstructures along the route of the spiral samples obviously differed. The grain size decreased gradually from the near-end to the far-end, whereas the shape factor increased gradually.

Stress corrosion cracking of X80 pipeline steel exposed to high pH solutions with different concentrations of bicarbonate

Susceptibilities to stress corrosion cracking （SCC） of X80 pipeline steel in high pH solutions with various concentrations of HC03 at a passive potential of-0.2 V vs. SCE were investigated by slow strain rate tensile （SSRT） test. The SCC mechanism and the effect of HC03 were discussed with the aid of electrochemical techniques. It is indicated that X80 steel shows enhunced susceptibility to SCC with the concentration of HCO3 increasing from 0.15 to 1.00 mol/L, and the susceptibility can be evaluated in terms of current density at -0.2 V vs. SCE. The SCC behavior is controlled by the dissolution-based mechanism in these circumstances. Increasing the concentration of HCO3 not only increases the risk of rupture of passive films but also promotes the anodic dissolution of crack tips. Besides, little susceptibility to SCC is found in dilute solution containing 0.05 mol/L HCO3 for X80 steel. This can be attributed to the inhibited repassivation of passive films, manifesting as a more intensive dissolution in the non-crack tip areas than at the crack tips.

Flow-accelerated corrosion behavior of 13Cr stainless steel in a wet gas environment containing CO_2

This work investigated the flow-accelerated corrosion （FAC） behavior of 13Cr in a wet CO2-containing environment at different flowing gas velocities mid impinging mlgles, with the natural-gas pipeline environment simulated by a self-assembled impingement jet sys- tem. Surface molphology determination, electrochemical measurements, mid hydromechaziics numerical analysis were cmlied out to study the FAC behavior. The results demonstrate that pitting corrosion was the primary mode of corrosion in 13Cr stainless steel. High-flow-rate gas destroyed the passive film mid decreased the pitting potential, resulting in more serious corrosion. The corrosion degree witk various im- pact mlgles showed the following order： 90~ 〉 60~ 〉 45~. The shear force and the electrolyte from the flowing gas were concluded to be the determinm^t factors of FAC, whereas the shear force was the main factor responsible for destroying the passive film.

Refinement of primary Si grains in Al–20%Si alloy slurry through serpentine channel pouring process

In this study, a serpentine channel pouring process was used to prepare the semi-solid A1-20%Si alloy slurry and refine primary Si grains in the alloy. The effects of the pouring temperature, number of curves in the serpentine channel, and material of the serpentine channel on the size of primary Si grains in the semi-solid A1-20%Si alloy slurry were investigated. The results showed that the pouting temperature, number of the curves, and material of the channel strongly affected the size and distribution of the primary Si grains. The pouring tempera- ture exerted the strongest effect, followed by the number of the curves and then the material of the channel. Under experimental conditions of a four-curve copper channel and a pouring temperature of 701℃, primary Si grains in the semi-solid A1-20%Si alloy slurry were refined to the greatest extent, and the lath-like grains were changed into granular grains. Moreover, the equivalent grain diameter and the average shape coefficient of primary Si grains in the satisfactory semi-solid A1-20%Si alloy slurry were 24.4 μm and 0.89, respectively. Finally, the re- finement mechanism and distribution rule of primary Si grains in the slurry prepared through the serpentine channel pouring process were analyzed and discussed.

Refinement of primary Si grains of A390 alloy slurry through serpentine channel pouring process

In this paper, the serpentine channel pouring process for preparing a semi-solid A390 alloy slurry and refining the primary Si grains of the A390 alloy, was used. The effects of the pouring temperature, the cooling water flow and the number of the curves on the size of the primary Si grains in the semi-solid A390 alloy slurry were investigated. The results show that the pouring temperature, the cooling water flow and the number of the curves have a major effect on the size and the distribution of primary Si grains. Under the experimental condition of the four-curve copper channel whose cooling water flow was 500 L·h-1 and the pouring temperature was 690 oC, the primary Si grains of the semi-solid A390 alloy slurry were refined to the greatest extent and the lath-like grains were changed into granular ones. Additionally, the equivalent grain diameter and the average shape factor of the primary Si grains of the satisfactory semi-solid A390 alloy slurry are 18.6 μm and 0.8, respectively. Further, the refinement mechanism of the primary Si grains through the serpentine channel pouring process was analyzed and discussed. In summary, the primary Si nuclei could be easily precipitated due to the chilling effect of the channel inner wall, thus the primary Si grains were greatly refined. Meanwhile, the subsequent alloy melt fluid also promoted the separation of primary Si grains from the inner wall, further refining the primary Si grains.

Corrosion behavior and characteristics of the product film of API X100 steel in acidic simulated soil solution

The short-term corrosion behavior of API X100 steel in an acidic simulated soil was investigated by electrochemical measurements and soaking experiments,followed by corrosion morphology observations and X-ray photoelectron spectroscopy analyses.The results show that X100 steel exhibits an obvious pitting susceptibility in an acidic soil environment.Pits nucleate after approximately 10 h of immersion.Along with the nucleation and growth of the pits,the charge-transfer resistance and open-circuit potential first increase sharply,then decrease slowly,and eventually reach a steady state.The maxima of the charge-transfer resistance and open-circuit potential are attained at approximately 10 h.The evolution of the electrochemical process is confirmed by the analysis of the product film.The product film exhibits a porous and loose structure and could not protect the substrate well.The product film is primarily composed of ferrous carbonate and ferrous hydroxide（Fe（OH）2）.The concentration of Fe（OH）2 in the product film increases from the inside to the outside layer.

A Green Strategy to Synthesize Ag/Ag3PO4/Chitosan Composite Photocatalysts and Their Photocatalytic Degradation Performance under Visible Light Irradiation

In this work, the plasmonic Ag/Ag3PO4/chitosan(Ag/Ag3PO4/CS) composite photocatalyst was prepared by a low-temperature strategy. Environmentally friendly CS plays triple vital roles in this composite. First, it was devoted to in situ reducing metallic silver from silver ions of Ag3PO4. Also, as the carrier of Ag/Ag3PO4 nanoparticles,CS can effectively prevent aggregation. Furthermore, benefitting from the settlement of hydrophilic CS, the prepared composite could be easily separated and recovered from the solution system. X-ray diffraction(XRD), the scanning electron microscope, energy-dispersive X-ray spectroscopy(EDS), ultraviolet-visible(UV-vis) diffused reflectance spectroscopy, and X-ray photoelectron spectroscopy(XPS) were employed to characterize the properties of materials. The results of photo-decomposition testing showed that the Ag/Ag3PO4/CS composite possessed good activity for the decomposition of Rhodamine B(Rh B) under visible light.

Observations of interplanetary scintillation with a single-station mode at Urumqi

The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation （IPS） observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. We discuss one mode of ground-based single-station observations： Single-Station Single-Frequency （SSSF） mode. To study the SSSF mode, a new system has been established at Urumqi Astronomical Observatory （UAO）, China, and a series of experimental observations were successfully carried out from May to December, 2008.

Observations of Giant Pulses of the Crab Pulsar

The Crab Pulsar was observed at 1540MHz with the 25m radio telescope at Urumqi with a filterbank de-dispersion backend. A total of 2436 giant pulses with pulse energies larger than 4300 Jy μs were detected in two observing sets. All of these giant pulses are located in the main pulse （MP） and inter pulse （IP） windows of the average profile of the Crab Pulsar. The ratio of the numbers of giant pulses detected in the IP and MP windows is about 0.05. Our results show that, at 1540MHz, the emission in the IP is contributed by giant and normal pulses, while that in the MP is almost dominated by giant pulses. The distribution of energy of the 2436 giant pulses at 1540 MHz can be described by a power-law with index α = 3.13 ± 0.09. The intrinsic threshold of giant pulse energy in the MP window is about 1400Jy μs at 1540MHz.

Energetics and diffusion of point defects in Au/Ag metals:A molecular dynamics study

To reveal the potential aging mechanism for self-irradiation in Pu-Ga alloy,we choose Au-Ag alloy as its substitutional material in terms of its mass density and lattice structure.As a first step for understanding the microscopic behavior of point defects in Au-Ag alloy,we perform a molecular dynamics(MD)simulation on energetics and diffusion of point defects in Au and Ag metal.Our results indicate that the octahedral self-interstitial atom(SIA)is more stable than the tetrahedral SIA.The stability sequence of point defects for He atom in Au/Ag is:substitutional site>octahedral interstitial site>tetrahedral interstitial site.The He-V cluster(Hen Vm,V denotes vacancy)is the most stable at n=m.For the mono-vacancy diffusion,the MD calculation shows that the first nearest neighbour(1 NN)site is the most favorable site on the basis of the nudged elastic band(NEB)calculation,which is in agreement with previous experimental data.There are two peaks for the second nearest neighbour(2 NN)and the third nearest neighbour(3 NN)diffusion curve in octahedral interstitial site for He atom,indicating that the 2 NN and 3 NN diffusion for octahedral SIA would undergo an intermediate defect structure similar to the 1 NN site.The 3 NN diffusion for the tetrahedral SIA and He atom would undergo an intermediate site in analogy to its initial structure.For diffusion of point defects,the vacancy,SIA,He atom and He-V cluster may have an analogous effect on the diffusion velocity in Ag.

Shape formation of closed-cell aluminum foam in solid–liquid–gas coexisting state

The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid–liquid–gas coexisting state was realized through cell wall deformation and cell movement caused by primary α-Al grains that slid,rotated,deformed,and ripened within cell walls.During formation,characteristic parameters of closed-cell aluminum foam were almost unchanged.Under proper forming conditions,shaped products of closed-cell aluminum foam could be fabricated through mold pressing.

Co-oxidation of arsenic(Ⅲ) and iron(Ⅱ) ions by pressurized oxygen in acidic solutions

The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200℃ and an oxygen pressure up to 2.0 MPa. Fe(Ⅱ) ions in the solutions did have a catalysis effect on the oxidation of As(Ⅲ), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH ) and Fe(Ⅳ) in the oxidation process of Fe(Ⅱ). The effects of such factors as the initial molar ratio of Fe(Ⅱ)/As(Ⅲ), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(Ⅲ) and Fe(Ⅱ) were studied. It was found that the oxidation of As(Ⅲ) was limited in the co-oxidation process due to the accumulation of the As(Ⅲ) oxidation product, As(Ⅴ), in the solutions.

转谷氨酰胺酶4在前列腺癌进展及预后中的作用

转谷氨酰胺酶4（TGM4）在前列腺癌组织和正常组织中差异表达，且与前列腺癌细胞的多种生物学特性相关，如前列腺癌细胞间质化，细胞侵袭性和细胞基质粘附等。本研究主要探索TGM4表达水平与前列腺癌病理特征及前列腺癌生化复发之间的关系。取160名接受前列腺癌根治术患者的石蜡标本构建组织芯片，进而利用组织芯片行TGM4免疫组织化学染色；TGM4的表达情况采用染色范围与染色强度相结合的方式来评价。通过查阅病历获得患者的临床及病理信息；随访信息通过查阅病历、调用我院前列腺癌随访数据库和电话随访等多种方式获得。进而，我们比较了TGM4在癌和癌旁组织中的表达差异情况，及TGM4不同表达水平与前列腺癌病理特征和生化复发之间的关系。同癌旁组织相比，TGM4在前列腺癌组织中明显高表达（P〈0．001），并且其表达水平与Gleason评分（P〈0．001）和PSA水平（P=0．005）呈明显正相关。单变量分析提示TGM4高表达是前列腺癌生化复发的高危因素（P=0．042），但多变量分析并不支持TGM4高表达是前列腺癌生化复发的高危因素（P=0．139）。TGM4在前列腺癌中高表达，其表达水平与Gleason评分和PSA水平呈正相关，TGM4高表达可能作为前列腺癌生化复发的潜在预测因子。

Targeted Search for Fast Radio Bursts with Nanshan 26m Radio Telescope

Fast radio bursts(FRBs)are radio transients that are bright and have short duration,with their physical mechanism not being fully understood.We conducted a targeted search for bursts from FRB 20201124A between 2021 June 2and July 20.High time-resolution data were collected for 104.5 hr using the ROACH2-based digital backend.We introduce the details of our FRB search pipeline which is based on HEIMDALL and FETCH.Testing of the injected mock FRBs search could help us better understand the performance of the pipelines,and improve the search algorithms and classifiers.To study the efficiency of our pipeline,5000 mock FRBs were injected into the data and searched using the pipeline.The results of the mock FRB search show that our pipeline can recover almost all(?90%)the injected mock FRBs above a signal-to-noise ratio(S/N)threshold of 15,and the performance is still acceptable(?80%)for injected S/Ns from 10 to 15.The recovery fraction displays relations with S/N,dispersion measure and pulse width.No bursts were detected from FRB 20201124A in the middle of 2021.The non-detection of FRB 20201124A may be due to its quiet phase window or no emission above the threshold of the Nanshan telescope.