Design and Application of an S-band Fast Radio Bursts Search Pipeline for the Nanshan 26 m Radio Telescope

Fast radio bursts(FRBs)are among the most studied radio transients in astrophysics,but their origin and radiation mechanism are still unknown.It is a challenge to search for FRB events in a huge amount of observational data with high speed and high accuracy.With the rapid advancement of the FRB research process,FRB searching has changed from archive data mining to either long-term monitoring of the repeating FRBs or all-sky surveys with specialized equipments.Therefore,establishing a highly efficient and high quality FRB search pipeline is the primary task in FRB research.Deep learning techniques provide new ideas for FRB search processing.We have detected radio bursts from FRB 20201124A in the L-band observational data of the Nanshan 26 m radio telescope(NSRT-26m)using the constructed deep learning based search pipeline named dispersed dynamic spectra search(DDSS).Afterwards,we further retrained the deep learning model and applied the DDSS framework to S-band observations.In this paper,we present the FRB observation system and search pipeline using the S-band receiver.We carried out search experiments,and successfully detected the radio bursts from the magnetar SGR J1935+2145and FRB 20220912A.The experimental results show that the search pipeline can complete the search efficiently and output the search results with high accuracy.

Senegenin suppresses hepatocellular carcinoma by regulating O-GlcNAcylation

BACKGROUND Based on current knowledge,hepatocellular carcinoma(HCC)is a condition with numerous etiologies and risk factors.However,the pathogenesis of HCC remains unclear.AIM To investigate the roles of senegenin and O-GlcNAcylation in the growth and metastasis of HCC.METHODS The levels of O-linked N-acetylglucosamine transferase(OGT)and O-GlcNAcylation in HCC cells and tissues were detected using western blot analysis.The effects of senegenin and O-GlcNAcylation on the proliferation of HCC cells were investigated in vitro using cell counting kit-8 and clonogenic assays.The potential effects of senegenin and O-GlcNAcylation on HCC metastasis were examined using the transwell migration assay.O-GlcNAcylation levels were altered via drug treatment and lentiviral infection,and western blot analysis was used to detect proteins involved in various pathways.RESULTS Western blot analysis revealed that OGT and O-GlcNAcylation levels were significantly elevated in HCC tissues and cells.O-GlcNAcylation levels in HCC cells were significantly altered by drug treatment and lentiviral infection.An increase in the glycosylation level was linked to enhanced proliferation,invasiveness,clonogenicity,and metastatic potential of cancer cells.O-GlcNAcylation induced by senegenin was found to slow the proliferation and migration of HCC cells.The levels of proteins involved in nuclear factor-kappa B(NF-κB)and c-Jun N-terminal kinase(JNK)pathways,which are associated with endoplasmic reticulum stress,were altered.CONCLUSION Senegenin lowers O-GlcNAcylation levels,decreases OGT expression,and inhibits cancer cell growth and metastasis by regulating proteins involved in NF-κB and JNK pathways.

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.

Influence of rheo-diecasting processing parameters on microstructure and mechanical properties of hypereutectic Al-30%Si alloy

The effects of pouring temperature,vibration frequency,and the number of curves in a serpentine channel,on themicrostructure and mechanical properties of Al-30%Si alloy processed by rheo-diecasting(RDC)were investigated.The semisolidAl-30%Si alloy slurry was prepared by vibration serpentine channel pouring(VSCP)process in the RDC process.The results showthat the pouring temperature,the vibration frequency,and the number of the curves strongly affect the microstructure and mechanicalproperties of Al-30%Si alloy.Under experimental conditions of a pouring temperature of850°C,a twelve-curve copper channel anda vibration frequency of80Hz,the primary Si grains are refined into fine compact grains with average grain size of about24.6μm inthe RDC samples assisted with VSCP.Moreover,the ultimate tensile strength(UTS),elongation and hardness of the RDC sample are296MPa,0.87%and HB155,respectively.It is concluded that the VSCP process can effectively refine the primary Si grains.Therefinement of primary Si grains is the major cause for the improvement of the mechanical properties of the RDC sample.

Leaching of iron concentrate separated from kiln slag in zinc hydrometallurgy with hydrochloric acid and its mechanism

It is taken as a novel prospective process to treat iron concentrate from hydrometallurgical zinc kiln slag forcomprehensive utilization of valuable metals by a hydrochloric acid leaching-spray pyrolysis method.The leaching mechanism ofdifferent valuable metals was studied.The results revealed that the leaching rates of Ag,Pb,Cu,Fe,As and Zn were99.91%,99.25%,95.12%,90.15%,87.58%and58.15%,respectively with6mol/L HCl and L/S ratio of10:1at60°C for120min.The actionof SiO2in leaching solution was also studied.The results showed that the precipitation and settlement of SiO2(amorphous)adsorbedpart of metal ions in solution,which greatly inhibited the leaching of Cu,Fe,As and Zn,so it is crucial to control the precipitation ofamorphous SiO2.

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.

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.

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.

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.

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.

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.

Overexpression of transglutaminase 4 and prostate cancer progression： a potential predictor of less favourable outcomes

Transglutaminase 4 has been shown to enhance various biological properties of prostate cancer cells, e.g., cell-matrix adhesion, invasiveness and the epithelial-mesenchymal transition. The objectives of this study were to investigate the associations between transglutaminase 4 expression and the established features and biochemical recurrence of prostate cancer. Transglutaminase 4 immunostaining was performed on a tissue microarray. The expression of transglutaminase 4 was evaluated by a scoring method based on the intensity and extent of staining. The clinical and pathological information was obtained through a review of medical records. Follow-up data were obtained by consulting the hospital medical records and the prostate cancer database of our department and by contacting patients or family members. We then compared the transglutaminase 4 expression levels between the prostate cancer tissues and the paracarcinoma tissues and evaluated the correlation of transglutaminase 4 expression with the clinical parameters and biochemical recurrence of prostate cancer. Our results indicated that the transglutaminase 4 staining was significantly higher in tumour tissue than in paracarcinoma tissue （P^O.O01） and was positively associated with higher Gleason score （P^O.O01） and higher prostate-specific antigen level （P=0.005）. Patients with transglutaminase 4 overexpression experienced shorter biochemical recurrence-free survival after surgery （P=0.042） in the univariate analysis but not in the multivariate analysis （P=0. 139）, which indicated that transglutaminase 4 may serve as a potential predictor of biochemical recurrence of prostate cancer.

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.