防空组网雷达“四抗”能力综合评估

为正确评估防空组网雷达"四抗"能力,结合雷达组网的因素分析,建立了组网雷达系统层次结构模型,并利用层次分析法确定了各因素的权重,用最优指标法得出指标层的得分值,提出了组网雷达"四抗"综合能力量化评估方法。其评估结果在一定程度上为组网雷达性能优化提供了决策依据。

基于D-S证据理论的组网雷达“四抗”能力评价

针对武器系统效能评估常忽略可信度分析的问题,基于证据理论给出了具体的组网雷达"四抗"能力的评价方法.通过对系统进行综合评价的实例计算,得到了合理的评价结果.该方法为制定和修改雷达组网方案提供了依据.

雷达“四抗”技术的发展思考

在当前高新技术的快速发展中，雷达在军事上的运用对于军事领域的变革具有重大意义。文中主要围绕雷达技术，分析了当前雷达所面临的威胁，进而对雷达“四抗”技术的发展趋向进行了深入探究。

雁探1“四高”井钻井液应用技术

雁探1井是中国石油天然气股份有限公司青海油田分公司的一口重点矿权保护井,是青海油田柴达木盆地一里坪地区落雁山构造一口四开直井型风险井,完钻井深为5 909.95 m,钻探主要目的是探索落雁山构造E32～N1含油气性;了解落雁山地区古-新近系暗色泥岩发育情况以及生烃能力,为下步盆地腹部大型区带热成因气勘探研究及部署提供依据。该井地质条件复杂,没有任何实钻参考资料,存在高温、高密度、高压盐水层、高浓度CO_2等叠加复杂因素,实际使用钻井液密度高达2.50 g/cm^3,井底实测温度高达205℃,CO_2侵高达100%,加之多层高压盐水存在,是一口典型的"四高"井,钻井施工难度极大。优选采用了BH-WEI钻井液体系,围绕高温稳定性、抗酸性气体污染、抗盐水污染、高密度流变性、滤失量与流变性矛盾等技术难点,精细调整钻井液配方及维护处理措施,较好地解决了一系列技术难题和矛盾,顺利钻至设计井深5 700 m,后加深钻进至5 909.95 m突遇设计外的异常高压盐水层,由于关井压井时间过长,事故完井。该井技术难点典型,积累了宝贵的现场施工经验,具有很好的借鉴指导意义。

组网雷达作战分析与几点思考

现代高科技武器的发展使雷达防空体系面临电磁干扰、反辐射导弹、低空入侵和隐身目标这"四大威胁"的严峻挑战。组网雷达作战系统以其特有的优势可有效解决这一问题。文章从组网雷达的基本概念、特点和作战任务出发,详细分析了其"四抗"能力,并结合实际作战需求对组网雷达作战系统的建设和发展提出了几点思考。

雷达组网技术研究

由于雷达“四大威胁”的存在，人们把目光转向雷达组网的方式。本文介绍了雷达组网技术及其发展趋势，表明雷达组网技术能够适应现代军事电子设备向系统化、一体化的发展需求，是未来雷达的发展方向。

Preparation of TiCl_4 with multistage series combined fluidized bed

In order to solve the agglomeration problem in TiCl4 preparation,a new test in a multistage series combined fluidized bed was studied on a pilot scale.The pilot plant can make full use of titanium slag with a high content of MgO and CaO as the feedstock.Several experimental parameters such as chlorine flow and reaction temperature were discussed and the morphology and components of reaction product were analyzed.According to the results,the conversion rate of TiO2 is up to 90%.It is found that the combined fluidized bed has good anti-agglomeration ability because the accumulation of MgCl2 and CaCl2 on the surface of unreacted slag was carried out of the reactor.

基于对海警戒雷达与无源监视雷达的对海协同探测系统

重点论述基于对海警戒雷达与无源监视雷达组网技术的对海协同探测系统,探讨该组合在雷达"四抗"方面的实现及其优势。

Electrochemical behaviors of tantalum in anhydrous ethanol containing hydrogen sulfate ions

The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate（TBAHS） ethanol solutions were studied using potentiodynamic polarization,cyclic voltammetry,potentiostatic current time transient and impedance techniques.The results revealed that no active-passive transition is presented in the cyclic voltammogram,and the anodic current density increases with the increase of solution temperature,TBAHS concentration,potential scan rate and water content.The apparent activation energy is about 43.389 kJ/mol and the dissolution process is diffusion-controlled.Potentiostatic measurements showed that the current density gradually decays to a steady value when the potential is low;however,when the potential is higher than a certain value,the current density initially declines to a minimum value and then increases gradually.The resistance of passive film decreases with increasing potential,and inductive loops are presented when the potential is higher than 2.0 V.

Influence of moisture content on shearing strength of unsaturated undisturbed quaternary system middle pleistocene

The unsaturated undisturbed quaternary system middle pleistocene loess,a typical unsaturated soil,often occurs in the implementation of western development strategy.To obtain the shearing strength characteristics of this unsaturated undisturbed loess,based on the analysis of mineral composition,the triaxial shear test of undisturbed quaternary system middle pleistocene loess under different moisture contents is conducted with the specialized triaxial instrument for unsaturated soil.The test results show that the mainly mineral composition of undisturbed quaternary system middle pleistocene loess is quartz and albite.Under the same confining pressure,the matric suction increases with the decrease of moisture content.The smaller the moisture content,the larger the matric suction;the higher the moisture content,the lower the matric suction.Under the same moisture content,the matric suction increases with the confining pressure and reaches a maximum when the confining pressure is 100 kPa,and then decreases with the increase of confining pressure.This phenomenon is closely related to the grain contact tightness of soil mass under high confining pressure.According to the triaxial test of loess,the sample of loess experiences 4 stages from loading to failure:1) compaction stage;2) compression stage;3) microcrack developing stage;4) shear failure stage.The test sample is of brittle failure(weak softening)under low moisture content and confining pressure.With the decrease of matric suction and the increase of consolidated confining pressure,the stress-strain curve changes from softening type to ideal plastic type.In the shearing strength parameters of unsaturated undisturbed loess,the influence of moisture content on internal friction angle is small,but that on cohesive force is obvious.Therefore,the shearing strength of unsaturated undisturbed loess is higher than that of saturated undisturbed loess and varies with the moisture content.

四季抗病毒合剂治疗小儿普通型手足口病40 例临床观察

目的观察四季抗病毒合剂治疗小儿普通型手足口病的临床疗效。方法选取2018年5月至2019年5月在陕西中医药大学附属医院儿科门诊治疗的普通型手足口病患儿80例,按确诊的先后顺序分为单号和双号,单号为治疗组,双号为对照组,各40例。对照组口服利巴韦林片,治疗组口服四季抗病毒合剂,1周后统计2组的临床疗效、症状和体征消失时间及不良反应发生情况。结果对照组总有效率为90.0%(36/40),治疗组为100.0%(40/40),2组比较,差异有统计学意义(P<0.05)。治疗组热退时间、手足疱疹消失时间、口腔溃疡消失时间均短于对照组,2组比较,差异有统计学意义(P<0.05)。对照组出现白细胞减少1例,腹泻1例,血小板计数减少1例,不良反应发生率为7.5%(3/40);治疗组出现腹泻1例,呕吐2例,不良反应发生率为7.5%(3/40)。2组不良反应发生率比较,差异无统计学意义(P>0.05)。结论四季抗病毒合剂治疗小儿普通型手足口病疗效显著,能明显缩短患儿临床症状、体征消失时间,且安全性高,值得临床推广应用。

Hepatoprotective effects of Nigella sativa L and Urtica dioica L on lipid peroxidation, antioxidant enzyme systems and liver enzymes in carbon tetrachloride-treated rats

AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups： A （CCl4-only treated）, B （CCl4＋UD treated）, C （CCl4＋NS treated） and D （CCl4＋UD＋NS treated）, each containing 14 animals. All groups received CCl4 （0.8 mL/kg of body weight, sc, twice a week for 60 d）. In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS： The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment （alone or combination） for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION： NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.

Procedure for preparing peptide-major histocompatibility complex tetramers for direct quantification of antigen-specific cytotoxic T lymphocytes

AIM： To establish a simplified method for generating peptide-major histocompatibility complex （MHC） class I tetramers.METHODS： cDNAs encoding the extracellular domain of human lymphocyte antigen （HLA）-A＊0201 heavy chain （A2） and β2-microglobulin （132m） from total RNA extracted from leukocytes of HLA-A2＋ donors were doned into separate expression vectors by reverse transcription-polymerase chain reaction. The recombinant A2 and 132m proteins were expressed in ~/a oo/i^uain BL21（DE3） and recovered from the inclusion body fraction. Soluble A2 proteins loaded with specific antigen peptides were refolded by dilution from the heavy chain in the presence of light chain 132m and HLA-A2-restricted peptide antigens. The refolded A2 monomers were biotinylated with a commercial biotinylation enzyme （BirA） and purified by low pressure anion exchange chromatography on a Q-Sepharose （fast flow） column.The tetramers were then formed by mixing A2 monomers with streptavidin-PE in a molar ratio of 4：1. Flow cytometry was used to confirm the expected tetramer staining of CD8^＋ T cells.RESULTS： Recombinant genes for HLA-A＊0201 heavy chain （A2） fused to a BirA substrate peptide （A2-BSP） and mature β2m from HLA-A2＋ donor leukocytes were successfully doned and highly expressed in E. coli, Two soluble monomeric A2-peptide complexes were reconstituted from A2-BSP in the presence of 132m and peptides loaded with either human cytomegalovirus pp65495-503 peptide （NLVPMVATV,NLV; designated as A2-NLV） or influenza virus matrix protein Mp58-66 peptide （GILGFVFTL, GIL; designated as A2-GIL）. Refolded A2-NLV or A2-GIL monomers were biotinylated and highly purified by single step anion exchange column chromatography. The tetramers were then formed by mixing the biotinylated A2-NLV or A2-GIL monomers with streptavidin-PE, leading to more than 80% multiplicationas revealed by SDS-PAGE under non-reducing, unboiled conditions. Flow cytometry revealed that these tetramers could specifically bind to CD8^＋ T cells from a HLA-A2^＋ donor,but failed to bind to those from a HLA-A2- donor.CONCLUSION： The procedure is simple and efficient for generating peptide-MHC tetramers.

Robust force tracking control via backstepping sliding mode control and virtual damping control for hydraulic quadruped robots

In order to improve the force tracking performance of hydraulic quadruped robots in uncertain and unstructured environments,an impedance-based adaptive reference trajectory generation scheme is used.Secondly,in order to improve the robustness to environmental changes and reduce the contact force errors caused by trajectory tracking errors,the backstepping sliding mode controller is combined with the adaptive reference trajectory generator.Finally,a virtual damping control based on velocity and pressure feedback is proposed to solve the problem of contact force disappearance and stall caused by sudden environmental change.The simulation results show that the proposed scheme has higher contact force tracking accuracy when the environment is unchanged;the contact force error can always be guaranteed within an acceptable range when the environment is reasonably changed;when the environment suddenly changes,the drive unit can move slowly until the robot re-contacts the environment.

Oxaliplatin,Fluorouracil and Leucovorin (FOLFOX) as First-line Chemotherapy for Metastatic or Recurrent Colorectal Cancer Patients

OBJECTIVE To investigate the efficiency and safety of the oxaliplatin, fluorouracil （5-FU） and leucovorin regimen （FOLFOX）in previously untreated patients with metastatic or recurrent colorectal cancer. METHODS Previously untreated patients with metastatic or recurrent colorectal cancer received 100 mg/m^2 of oxaliplatin intravenously （Ⅳ） over 2 h on day 1, and Ⅳ 400 mg/m^2 of leucovorin over 2 h followed by a bolus of 400 mg/m^2 of 5-FU. Then 2,600-3,000 mg/m^2 of 5-FU was administered by continuous infusion over 46 h. RESULTS An evaluated response rate was determined for 97 of 105 treated patients. The overall response rate was 35.1%, 9 patients （9.3%） had a complete response and 25 patients （25.8%） a partial response. Thirtytwo patients （33.0%） developed stable disease and 32.0% of the patients progressed. The median time to progression （TTP） was 7.7 months and the median overall survival 20.5 months. One and 2-year survival rates were 68% and 32%. Toxic effects based on the National Cancer Institute-Common Toxicity Criteria （NCI-CTC）, reaching grade 3/4 were： neutropenia 12.3%, anemia 11.3%, vomiting 4.1% and diarrhea 7.2%. Grade 3 neuropathy was 5.1%. The overall survival rate of patients who had received a radical resection was superior to the patients who had not received a operation, or had received a palliative resection （P=0.0658）. The serum levels of CEA, ALP and LDH had no relationship with survival （P〉0.05）. CONCLUSION The FOLFOX regimen containing oxaliplatin, 5-FU plus leucovorin was an efficacious regimen with good tolerability in previously untreated metastatic or recurrent colorectal cancer patients.

Isolation and pharmacological activities of bromophenols from Rhodomela confervoides

Four bromophenols were isolated from the extract of marine red alga, Rhodomela confervoides by column chromatography and HPLC methods. By means of spectroscopic methods including IR, MS, 1D, and 2D-NMR techniques, their structures were elucidated as (1) 3-bromo-4,5-dihydroxy benzoic acid methyl ester; (2) bis (2,3-dibromo-4,5-dihydroxybenzyl) ether; (3) 3,4-dibromo-5-(methoxymethyl)-1,2-benzenediol and (4) 3-bromo-4,5-dihydroxy-benzaldehyde. Compound 1 was first isolated from the algae in nature, and 1, 4 were found to have selective cytotoxic activities against KB, Bel 7402 and A549 cells, 2 showed powerful antibacterial activities against Staphylococcus aurens and Pseudomonas aeruginosa.

Effects of anaerobic composting on tetracycline degradation in swine manure

Oxytetracycline(OTC) and tetracycline(TC) are the most common TC antibiotics used in human and veterinary medicine.Residual amounts of these antibiotics in manure pose a potential threat to public and ecological health as a result of the potential for them to be released to the environment following land application of manure from animals treated with antibiotics.We investigated the degradation of OTC and TC during anaerobic composting.We tested the effects of temperature and antibiotic concentration on degradation rates in a control and in manure spiked with TCs.We examined changes in p H,biological degradation material(BDM),and moisture corresponding with antibiotic degradation of TCs in the swine manure.Results showed that the OTC and TC concentrations decreased by between 68.54% and 95.50% in all nine treatments following 14 days of anaerobic composting,and the highest removal ef ficiencies were observed at an incubation temperature of 55°C and initial concentrations of 10.36 μg·g^(-1),and 5.96 μg·g^(-1) of OTC and TC,respectively,which were degraded by 95.50%,and 90.06%.During composting at 55 °C and at added concentrations of 5 μg·g^(-1),OTC decreased rapidly,and the time required for50% and 90% degradation was 4.1 and 9.8 days,respectively;for TC,these values were 4.4 and 14.0 days,respectively.Removal ef ficiencies for all TCs correlated well with moisture content of the manure.These results show that composting may be a practical and useful means to reduce concentrations of OTC and TC in swine manure prior to its land application.

Effect of Lead Toxicity on Germination and Enzymatic Activity of Durum Wheat Triticum durum Desf.

The aim of this work is to identify the effect of lead on germinal parameters and the antioxidant enzyme activities （lipase, peroxidase and catalase） in durum wheat Triticum durum Desf. cv （waha, vitron and gta） exposed to the concentrations of 0, 0.15, 0.25 and 0.3 g/L of Pb （NO3）2 during germination process. The obtained results showed that lead reduced the germination, root and aerial biomass. The concentration of 0.3 g/L inhibited completely the germination of the three varieties. It also slowed lipase activity, the degradation of lipids of the seed＇s reserves and disrupted the metabolism of peroxidase and catalase. Concerning the behavior of the three varieties studied, it appears that the Vitron is the best predisposed variety to stand against lead stress by its strong antioxidant defense system.

Construction of HLA/Peptide Tetramer with Peptide-Linked β_2 Microglobulin

Analysis of the frequency of antigen-specific cytotoxic T lymphocytes (CTLs) ex vivo is largely dependent on the use of MHC/peptide tetramers. However, the latter reagents have not been widely available, most likely because of their costly and time-consuming production. In this report we utilized an economic strategy to construct HLA/peptide tetramers with recombinant peptide-linked β2 microglobulin (β2m). The HLA-A2-restricted, melanoma antigen MARTI-derived pep- tide MART127-35( AAGIGILTV) was fused to the N terminus of human β2m through a 15-amino acid (aa)-long linker before being refolded with the recombinant biotinylated HLA-A2 heavy chain ectodomain. The resulted 2-component (2C) monomer was then tetramerized with phycoerythin-labeled streptavidin. The experimental result showed that the 2C HLA-A2/ MART127-35 monomer was shown to bind to the HLA class complex-specific monoclonal antibody W6/32 and the HLA-A2/ MART127-35 complex-specific single chain antibody fragment (scFv) 8.3, suggesting the correctness of its specificity. Fur- thermore, the 2C HLA-A2/MART127-35 tetramer detected a specific CD8+ T cell population in HLA-A2-restricted melanoma infiltrating lymphocytes as the conventional 3C HLA-A2/MART127-35 tetramer. The yield of 2C HLA-A2/MART127-35 monomer was 2. 5 times more than that of the conventional 3C monomer. Taken together, these data indicate that the HLA-A2/ MART127-35 tetramer can be generated conveniently through the use of MART127-35 peptide-β2 m fusion proteins, which can fa- cilitate the monitoring of HLA-A2-restricted, MART1-specific CTL responses in patients with melanoma.

Risk Assessment of Veterinary Drug Residues： The Dietary Exposure Assessment of Benzylpenicillin and Tetracycline Residues in Pork Consumed on Filipino Market

Biological, physical and chemical agents, recognized as food safety hazards, cause potential risks in modem food productions. Although the use of antibiotics in intensive animal productions is impossible to avoid the presence and remaining amount of their residues in food, it is possible to reduce them by using the principles of good veterinary, good manufacturing practices, and continuous control of food and risk assessment approach. This study was conducted to determine exposure risk to antibiotic drug residues in pork consumed in the Philippines and aimed to estimate dietary exposure of benzylpenicillin and tetracycline residues by age and gender groups. Dietary modeling, validated method used, combines food consumption data with food chemical concentration data to estimate dietary exposure to food chemicals. The results had shown that the dietary exposure of benzylpenicillin and tetracycline residues for children from 1 to 〈 3 years old had the highest exposure followed by adolescents, adults and infants while males were significantly lower than females （P 〈 0.05）. This is the initial study to determine risk assessment of dietary exposure to antibiotic residue of different population of Filipino groups.