Observation of Arctic surface currents using data from a surface drifting buoy

During the 10th Chinese Arctic scientific expedition carried out in the summer of 2019,the surface current in the high-latitude areas of the Arctic Ocean was observed using a self-developed surface drifting buoy,which was initially deployed in the Chukchi Sea.The buoy traversed the Chukchi Sea,Chukchi Abyssal Plain,Mendeleev Ridge,Makarov Basin,and Canada Basin over a period of 632 d.After returning to the Mendeleev Ridge,it continued to drift toward the pole.Overall,the track of the buoy reflected the characteristics of the transpolar drift and Chukchi Slope Current,as well as the inertial flow,cross-ridge surface flow,and even the surface disorganized flow for some time intervals.The results showed that:(1)the transpolar drift mainly occurs in the Chukchi Abyssal Plain,Mendeleev Ridge,and western Canada Basin to the east of the ridge where sea ice concentration is high,and the average northward flow velocity in the region between 79.41°N and 86.32°N was 5.1 cm/s;(2)the average surface velocity of the Chukchi Slope Current was 13.5 cm/s,and while this current moves westward along the continental slope,it also extends northwestward across the continental slope and flows to the deep sea;and(3)when sea ice concentration was less than 50%,the inertial flow was more significant(the maximum observed inertial flow was 26 cm/s,and the radius of the inertia circle was 3.6 km).

Genetic polymorphisms in genes regulating cell death and prognosis of patients with rectal cancer receiving postoperative chemoradiotherapy

Objective:The identification of biomarkers for predicting chemoradiotherapy efficacy is essential to optimize personalized treatment.This study determined the effects of genetic variations in genes involved in apoptosis,pyroptosis,and ferroptosis on the prognosis of patients with locally advanced rectal cancer receiving postoperative chemoradiotherapy(CRT).Methods:The Sequenom MassARRAY was used to detect 217 genetic variations in 40 genes from 300 patients with rectal cancer who received postoperative CRT.The associations between genetic variations and overall survival(OS)were evaluated using hazard ratios(HRs)and 95%confidence intervals(CIs)computed using a Cox proportional regression model.Functional experiments were performed to determine the functions of the arachidonate 5-lipoxygenase(ALOX5)gene and the ALOX5 rs702365 variant.Results:We detected 16 genetic polymorphisms in CASP3,CASP7,TRAILR2,GSDME,CASP4,HO-1,ALOX5,GPX4,and NRF2 that were significantly associated with OS in the additive model(P<0.05).There was a substantial cumulative effect of three genetic polymorphisms(CASP4 rs571407,ALOX5 rs2242332,and HO-1 rs17883419)on OS.Genetic variations in the CASP4 and ALOX5 gene haplotypes were associated with a higher OS.We demonstrated,for the first time,that rs702365[G]>[C]represses ALOX5 transcription and corollary experiments suggested that ALOX5 may promote colon cancer cell growth by mediating an inflammatory response.Conclusions:Polymorphisms in genes regulating cell death may play essential roles in the prognosis of patients with rectal cancer who are treated with postoperative CRT and may serve as potential genetic biomarkers for individualized treatment.

Mechanical properties of gangue-containing aluminosilicate based cementitious materials

High performance aluminosilicate based cementitious materials were produced using calcined gangue as one of the major raw materials. The gangue was calcined at 500℃. The main constituent was calcined gangue, fly ash and slag, while alkali-silicate solutions were used as the diagenetic agent. The structure of gangue-containing aluminosilicate based cementitious materials was studied by the methods of IR, NMR and SEM. The results show that the mechanical properties are affected by the mass ratio between the gangue, slag and fly ash, the kind of activator and additional salt. For 28-day curing time, the compressive strength of the sample with a mass proportion of 2：1：1 （gangue： slag： fly ash） is 58.9 MPa, while the compressive strength of the sample containing 80wt% gangue can still be up to 52.3 MPa. The larger K^＋ favors the formation of large silicate oligomers with which AI（OH）4- prefers to bind. Therefore, in Na-K compounding activator solutions more oligomers exist which result in a stronger compressive strength of aluminosilicate-based cementitious materials than in the case of Na-containing activator. The reasons for this were found through IR and NMR analysis. Glauber＇s salt reduces the 3-day compressive strength of the paste, but increases its 7-day and 28-day compressive strengths.

磷石膏的发展及其在石膏板中的应用

磷石膏是一种重要的磷化工固体废弃物,其处置技术与应用领域等得到了快速的发展。目前国内外在磷石膏的应用率在逐年上升,主要应用于建材、化工和农业等领域。由于磷石膏中含有多种杂质成分,在制备纸面石膏板中存在诸多问题。未来对于磷石膏的大规模利用,其预处理技术与生产工艺改进将是研究重点。

An improved least mean square/fourth direct adaptive equalizer for under-water acoustic communications in the Arctic

An improved least mean square/fourth direct adaptive equalizer(LMS/F-DAE)is proposed in this paper for underwater acoustic communication in the Arctic.It is able to process complex-valued baseband signals and has better equalization performance than LMS.Considering the sparsity feature of equalizer tap coefficients,an adaptive norm(AN)is incorporated into the cost function which is utilized as a sparse regularization.The norm constraint changes adaptively according to the amplitude of each coefficient.For small-scale coefficients,the sparse constraint exists to accelerate the convergence speed.For large-scale coefficients,it disappears to ensure smaller equalization error.The performance of the proposed AN-LMS/F-DAE is verified by the experimental data from the 9th Chinese National Arctic Research Expedition.The results show that compared with the standard LMS/F-DAE,AN-LMS/F-DAE can promote the sparse level of the equalizer and achieve better performance.

Optimization of Polysaccharide Extraction from Radix Glehniae Root Bark by Response Surface Methodology and Anti-immunosuppressive Activity Analysis

[ Objective ] This study aimed to establish and optimize the extraction technology of polysaccharides from Radix Glehniae root bark, and to explore the processing methods of Radix Glehniae in producing areas. [ Method ] Based on the single-factor experiment, with polysaccharide content and polysaccharide yield as indices, various factors affecting polysaccharide yield from Radix Glehniae root bark were investigated by central composite design-response surface method. Mo- reover, immune functions of cyclophosphamide-induced blood-deficient mice in various polysaccharide groups were compared to investigate the effects of root bark removal of Radix Glehniae on medicinal quality. [ Result] Ultrasonic extraction was the appropriate extraction technology of polysaccharides from Radix Glehniae root bark. The optimal ultrasonic extraction conditions were ultrasonic time 36 min, ultrasonic power 460 W, solid-liquid ratio 1： 10, ethanol concentration 80%, under which polysaccharide yield reached 16.08%. Polysaccharides extracted from Radix Glehniae root （ALP） and Radix Glehniae root bark （BLP） could effec- tively improve immune function of blood-deficient mice with no significant differences. [ Conclusion] Radix Glehniae could be used without removal of root bark. The optimized extraction process was stable and feasible, which laid a solid foundation for further comprehensive development and utilization of Radix Glehniae root bark.

Investigation and development on processing of Vietnamese lacquer

Vietnamese sap and lacquerware have a splendid history. In order to promote a sustainable Vietnamese lacquer value chain, this review was carried out for us to investigate at site Vietnamese lacquer cultivation and processing of lacquer sap, then introduce the chemical components, HPLC-MS characteristic, properity and polymerization mechanism, as well as processing techniques of Vietnamese lacquer sap. Combined with the experience of lacquer cultivation and processing of Chinese lacquer, key problems to restrict the development of lacquer value chain were analyzed in Vietnam, and some suggestions would also be proposed in this investigation.

Propofol increases in vitro proliferation of cultured rat hippocampal precursor cells inhibited by corticosterone

BACKGROUND： Previous studies have shown that propofol enhances proliferation of cultured hippocampal precursor cells in vitro and increases proliferation of cultured hippocampal precursor cells inhibited by corticosterone. Because gamma-aminobutyric acid A （GABA-A） receptor is the functional target for propofol, the proliferative effects of propofol are thought to take place through GABA-A receptor. OBJECTIVE： To determine whether propofol enhances proliferation of rat hippocampal precursor cells inhibited by corticosterone by upregulating expression of GABA-A receptor. DESIGN, TIME AND SETTING： A comparative, observational, in vitro experiment was performed at the Beijing Institute of Pharmacology and Toxicology from April 2005 to April 2006. MATERIALS： Propofol was purchased from AstraZeneca, italy; corticosterone was purchased from Sigma, USA; bicuculline was purchased from Alexis, Switzerland. METHODS： Hippocampal precursor cells were isolated from newborn Wistar rats and cultured in vitro. The second passage of precursor cells was grouped according to the various drugs added to the culture medium： 0.5 μmol/L propofol; 2.5 pmol/L propofol; 100 μmol/L corticosterone; 10 μmol/L bicuculline; 100 μmol/L corticosterone and 0.5 μmol/L propofol; 100 μmol/L corticosterone and 2.5 μmol/L propofol; 100 μmol/L corticosterone, 10 μmol/L bicuculline, and 0.5 μmol/L propofol; 100 μmol/L corticosterone, 10 μmol/L bicuculline, and 2.5 μmol/L propofol; 100 μmol/L corticosterone and 10 pmol/L bicuculline. The cells were cultured for 24 hours with medium containing the respective concentration of drug. The control group consisted of precursor cells absent of drug treatment. MAIN OUTCOME MEASURES： The MTT and ^3H-TdR incorporation assays were used to detect proliferative effects of propofol and bicuculline on cultured rat hippocampal precursor cells inhibited by corticosterone. Immunocytochemistry was used to detect GABA-A receptor expression. Enzyme-linked irnmunosorbent assay was used to quantify GABA-A receptor expression. RESULTS： Propofol, at a concentration of 0.5 and 2.5 μmol/L, increased proliferation of cultured rat hippocampal precursor cells inhibited by corticosterone, while bicuculline antagonized the effects of propofol （P 〈 0.05 or P 〈 0.01 ）. Corticosterone （100μmol/L） decreased expression of GABA-A receptor in the hippocampal precursor cells （P〈 0.05）, and GABA-A receptor expression was upregulated when propofol （2.5μmol/L） was added to the culture medium （P〈 0.05）. CONCLUSION： Low concentrations of propofol increased expression of GABA-A receptor. These results suggest that GABA-A receptor is involved in increased proliferation of cortisone-inhibited rat hippocampal precursor cells in vitro.

ICA Based Identification of Time-Varying Linear Causal Model

Recently, several approaches have been proposed to discover the causality of the time-independent or fixed causal model. However, in many realistic applications, especially in economics and neuroscience, causality among variables might be time-varying. A time-varying linear causal model with non-Gaussian noise is considered and the estimation of the causal model from observational data is focused. Firstly, an independent component analysis(ICA) based two stage method is proposed to estimate the time-varying causal coefficients. It shows that, under appropriate assumptions, the time varying coefficients in the proposed model can be estimated by the proposed approach, and results of experiment on artificial data show the effectiveness of the proposed approach. And then, the granger causality test is used to ascertain the causal direction among the variables. Finally, the new approach is applied to the real stock data to identify the causality among three stock indices and the result is consistent with common sense.

Consistency analysis of accelerated degradation mechanism based on gray theory

A fundamental premise of an accelerated testing is that the failure mechanism under elevated and normal stress levels should remain the same. Thus, verification of the consistency of failure mechanisms is essential during an accelerated testing. A new consistency analysis method based on the gray theory is pro- posed for complex products. First of all, existing consistency ana- lysis methods are reviewed with a focus on the comparison of the differences among them. Then, the proposed consistency ana- lysis method is introduced. Two effective gray prediction models, gray dynamic model and new information and equal dimensional （NIED） model, are adapted in the proposed method. The process to determine the dimension of NIED model is also discussed, and a decision rule is expanded. Based on that, the procedure of ap- plying the new consistent analysis method is developed. Finally, a case study of the consistency analysis of a reliability enhancement testing is conducted to demonstrate and validate the proposed method.

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination.[Methods]The L9(34)orthogonal test was carried out,the comprehensive scores of ginsenoside Rb1 content,notoginsenoside R1 content,tanshinone I content and saikosaponin A content in the compound extract were used as evaluation indicators to explore the effects of water addition,the water addition,decoction time and decoction times on the water extraction process,and verification tests were carried out.[Results]The optimized water extraction process was as follows:adding 9 times of water in the first extraction,and extracting for 90 min;adding 7 times of water in the second extraction,and extracting for 60 min;adding 7 times of water in the third extraction,and extracting for 60 min.[Conclusions]The optimized water extraction process is stable and feasible,and can be used for the extraction of various herbs in Compound Man Gan Ning.It can also provide experimental basis for the formulation development of Compound Man Gan Ning sustained release tablet.

Extraction Process and Content Determination of Total Flavonoids in Lonicera japonica

[Objectives]To optimize the extraction process of total flavonoids of Lonicerae japonica and establish a method for its extraction and content determination.[Methods]The total flavonoids of L.japonica were extracted by reflux extraction method.Through a single factor experiment,the effects of extraction method,extraction solvent concentration,extraction volume and extraction time on the total flavonoids content of medicinal materials were investigated to select the optimal extraction process of the total flavonoids of L.japonica.[Results]The optimal extraction process of the total flavonoids of L.japonica was 70%ethanol,1∶30 of solid-to-liquid ratio,and 1.0 h of reflux extraction time.[Conclusions]This method can effectively determine the content of total flavonoids in L.japonica and is expected to provide a certain scientific basis for the study of the quality standard of L.japonica.This method has high reproducibility.It is stable and feasible in extraction of total flavonoids from L.japonica.

Study on the Effect of Aqueous Extract of Houttuynia cordata on Serum TNF-αand IL-6 Content in Mice Infected with Five Common Pathogenic Bacteria

[Objectives]To observe the effect of aqueous extract of Houttuynia cordata on the content of serum TNF-αand IL-6 in mice with abdominal infection caused by Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa,Proteus vulgaris and Klebsiella pneumoniae,so as to investigate the antibacterial effect of aqueous extract of Houttuynia cordata in vivo.[Methods]A total of 72 KM mice were randomly divided into six groups:model group,blank group,cefdinir dispersible tablet group(0.25 g/kg),high,medium and low dose groups of aqueous extract of Houttuynia cordata(40,20,10 g/kg crude drug).There were 12 mice in each group,half male and half female,continuously given intragastric administration for three days,once a day.The blank group and the model group were intragastrically infused with normal saline,and the other groups were given corresponding drugs with a volume of 0.02 mL/g.After 30 min of administration on the third day,the mice were injected intraperitoneally with 0.5 mL of bacterial suspension to make bacterial infection.The mice in the blank group were intraperitoneally injected with the same amount of normal saline,followed by intragastric administration 6 h after intraperitoneal injection and intragastric administration again after 24 h.The mice were observed for three days,and the changes of body weight before and after infection were recorded.On the fourth day of infection,eyeball blood was taken,serum was separated,and the concentration of inflammatory factors TNF-αand IL-6 in serum was determined.[Results]Compared with the model group,the high,medium and low dose groups of H.cordata aqueous extract had protective effects on mice with abdominal infection caused by S.aureus,E.coli,P.aeruginosa,P.vulgaris and K.pneumoniae,and decreased the content of TNF-αand IL-6 in serum.[Conclusions]The aqueous extract of H.cordata had a certain antibacterial effect on acute abdominal infection caused by S.aureus,E.coli,P.aeruginosa,P.vulgaris and K.pneumoniae,and its mechanism was related to TNF-αand IL-6.

Extraction Process of Total Flavonoids from Eucommiae Cortex and Its in vitro Antioxidant Activity

[Objectives]To optimize the extraction process of total flavonoids from Eucommiae Cortex,establish the extraction and content determination methods of its medicinal materials,and study its in vitro antioxidant activity.[Methods]The total flavonoids from Eucommiae Cortex were extracted by reflux extraction method,and the effects of extraction method,extraction solvent concentration,extraction volume,and extraction time on the total flavonoids content of the medicinal materials were explored through the single factor experiment.Orthogonal experiment was carried out to optimize the extraction process conditions,and the optimal extraction process for total flavonoids from Eucommiae Cortex was screened out.The total antioxidant capacity index was used to determine the free radical scavenging ability of the total flavonoids from Eucommiae Cortex.[Results]The optimal extraction process of total flavonoids from Eucommiae Cortex was 50%ethanol,1∶40 solid-to-liquid-ratio,and 1.5 h reflux extraction time.Through the antioxidant experiment in vitro,it is found that the total flavonoids from Eucommiae Cortex have a higher scavenging ability for the total antioxidant capacity,and there is a certain positive correlation with the mass concentration of total flavonoids.[Conclusions]This method can effectively determine the total flavonoids content of Eucommiae Cortex medicinal material,and provide a certain scientific basis for the quality standard research of the medicinal material.The total flavonoids from Eucommiae Cortex have good in vitro antioxidant activity.And the method for extracting total flavonoids from Eucommiae Cortex medicinal material in this experiment has good repeatability,high stability and feasibility.

Enhanced photocatalytic ammonia oxidation activity and nitrogen selectivity over Ag/AgCl/N-TiO_(2) photocatalyst

The removal of ammonia(NH_(3))emitted from agricultural and industrial activities is of great significance to protect human health and ecological environment.Photocatalytic NH_(3)oxidation to N2under mild conditions is a promising strategy.However,developing visible light photocatalysts for NH_(3)oxidation is still in its infancy.Here,we fabricate N-TiO_(2)and Ag/AgCl/N-TiO_(2)photocatalysts by sol-gel and photodeposition methods,respectively.The introduction of N not only endows TiO_(2)with visible light response(absorption edge at460 nm)but also results in the formation of heterophase junction(anatase and rutile).Thus,N-TiO_(2)shows 2.0 and 1.8 times higher than those over anatase TiO_(2)and commercial TiO_(2)for NH_(3)oxidation under full spectrum irradiation.Meanwhile,surface modification of Ag can simultaneously enhance visible light absorption(generating localized surface plasmon resonance effect)and charge separation efficiency.Therefore,the photocatalytic activity of Ag/AgCl/N-TiO_(2)is further improved.Furthermore,the presence of N and Ag also enhances the selectivity of N2product owing to the change of reaction pathway.This work simultaneously regulates photocatalytic conversion efficiency and product selectivity,providing some guidance for developing highly efficient photocatalysts for NH_(3)elimination.

Enhanced photocatalytic performance of Bi_(4)O_(5)Br_(2)with threedimensionally ordered macroporous structure for phenol removal

Herein,a series of three-dimensionally ordered macroporous(3DOM)Bi_(4)O_(5)Br_(2)photocatalysts with different macropore sizes were successfully fabricated via a polymethyl methacrylate(PMMA)template method.The photocatalytic activity for phenol degradation over 3DOM Bi_(4)O_(5)Br_(2)first increased and then decreased with the rise in macropore size.Specifically,3DOM Bi_(4)O_(5)Br_(2)-255(macropore diameter ca.170 nm)exhibits the best photocatalytic activity in the static system,which is about 4.5,7.3,and 11.9 times higher than those of bulk Bi_(4)O_(5)Br_(2),Bi_(2)WO_(6),and g-C_(3)N_(4),respectively.Meanwhile,high phenol conversion(75%)is also obtained over 3DOM Bi_(4)O_(5)Br_(2)-255 in the flow system under full spectrum irradiation.Furthermore,3DOM Bi_(4)O_(5)Br_(2)-255 also shows strong mineralization capacity owing to the downward shift of valance band position(0.15 V)as compared with Bi_(4)O_(5)Br_(2).Total organic carbon(TOC)removal rate over 3DOM Bi_(4)O_(5)Br_(2)-255(62%)is much higher than that of Bi_(4)O_(5)Br_(2)(17%).The enhancement in photocatalytic performance of 3DOM Bi_(4)O_(5)Br_(2)-255 is attributable to its better phenol adsorption,O_(2)activation,and charge separation and transfer abilities.This work combines the advantages of 3D structure and surface dangling bonds,providing new possibilities for designing highly efficient photocatalysts for pollutants removal.

Ce-promoted Mn/ZSM-5 catalysts for highly efficient decomposition of ozone

Manganese oxides supported by ZSM-5 zeolite(Mn/ZSM-5) as well as their further modified by Ce promoter were achieved by simple impregnation method for ozone catalytic decomposition. The yCe20Mn/ZSM-5–81 catalyst with 8% Ce loading showed the highest catalytic activity at relative humidity of 50% and a space velocity of 360 L/(g × hr), giving 93% conversion of 600 ppm O_(3) after 5 hr. Moreover, this sample still maintained highly activity and stability in humid air with 50%–70% relative humidity. Series of physicochemical characterization including X-ray diffraction, temperature-programmed technology(NH_3-TPD and H_(2)-TPR), X-ray photoelectron spectroscopy and oxygen isotopic exchange were introduced to disclose the structure-performance relationship. The results indicated that moderate Si/Al ratio(81) of zeolite support was beneficial for ozone decomposition owing to the synergies of acidity and hydrophobicity. Furthermore, compared with 20 Mn/ZSM-5-81, Ce doping could enhance the amount of low valance manganese(such as Mn^(2+) and Mn^(3+)). Besides, the Ce^(3+)/Ce^(4+) ratio of 8Ce20Mn/ZSM-5-81 sample was higher than that of 4Ce_(2)0 Mn/ZSM-5-81. Additionally, the synergy between the MnO_x and CeO_(2) could easily transfer electron via the redox cycle, thus resulting in an increased reducibility at low temperatures and high concentration of surface oxygen. This study provides important insights to the utilization of porous zeolite with high surface area to disperse active component of manganese for ozone decomposition.

复合材料层合板的颤振特性及振动抑制研究

研究了超声速流中压电复合材料层合板的颤振特性及振动抑制方法.采用一阶活塞理论计算了超声速流场中的气动压力,基于经典层合板理论和Hamilton原理推导了压电复合材料层合板的动力学模型,设计了滑模观测器以减少观测溢出,通过Lyapunov方法证明观测器的稳定性,应用观测状态设计了LQR控制器,讨论了几何参数、铺设角度对压电复合材料层合板颤振特性的影响,利用SIMULINK仿真求解了层合板的脉冲响应,验证了控制器的有效性.结果表明,合理规划层合板的几何参数和铺设角度可提高系统颤振稳定性,滑模观测器能够较为准确地追踪原始系统且具有良好的鲁棒性,LQR控制可以在一定范围内消除层合板的颤振点,并且能够有效地控制压电复合材料层合板在颤振边界处的振动,Q矩阵越大,振动控制效果越好,压电层厚度越大,LQR控制效果越好.