高速动车齿轮箱反作用杆有限元分析

本文通过对反作用杆在不同工况下力的计算,应用Ansys有限元软件对其进行受力分析,计算出不同工况下反作用杆的载荷,为反作用杆的实际应用提供借鉴。

平衡悬架上反作用杆夹角设计初探

通过对中重型卡车平衡悬架反作用杆杆系在车辆运行各种工况下的受力分析,推导出上反作用杆夹角变化导致的受力情况变化。并利用ADAMS软件对计算结果进行验证。验证结论与计算值相符,进一步表明,合理地布置上反作用杆,使杆系受力分配更加合理,更适合具体整车的运行工况。

亲水作用色谱-三重四极杆串联质谱法测定化妆品中的牛磺酸和硫代牛磺酸

建立一种对化妆品中的牛磺酸和硫代牛磺酸进行直接测定的亲水作用色谱-三重四极杆串联质谱(HILIC-MS/MS)检测方法。样品用乙腈-水分散后超声提取、过滤后采用CAPCELL CORE PC色谱柱分离,以体积分数0.1%甲酸水溶液-乙腈为流动相进行洗脱,质谱在电喷雾离子源(ESI)、正离子扫描和多反应监测(MRM)模式下对牛磺酸和硫代牛磺酸进行定量测定。结果 :牛磺酸和硫代牛磺酸在5~1 000ng/mL质量浓度范围线性关系良好,相关系数R^(2)均大于0.994 0,方法检出限分别为0.015 mg/kg和0.02 mg/kg,定量限分别为0.05 mg/kg和0.07 mg/kg,回收率为82.7%~102.5%,相对标准偏差均低于7.0%。该方法具有样品处理简单快速、准确和灵敏度高等优点,可应用于化妆品中牛磺酸和硫代牛磺酸的直接测定。

亲水作用色谱-串联四极杆质谱测定液态奶中舒巴坦

建立了亲水作用色谱-串联四极杆质谱测定液态奶中微量舒巴坦的分析方法。样品经0.2%乙酸水溶液提取,HLB固相萃取柱净化、富集,以甲酸铵-乙腈为流动相,经Acquity UPLC BEH HILIC色谱柱分离后采用电喷雾质谱多反应监测方式(MRM)扫描,外标法定量。结果表明,舒巴坦的质量浓度在1～100μg/L范围内线性关系良好,r2大于0.99,定量下限为1.0μg/kg。加标水平在1.0～50.0μg/kg范围时,回收率为82%～102%,相对标准偏差(RSD)为1.6%～4.7%。该方法前处理简便快捷、灵敏度高、回收率和重现性良好,适用于液态奶中舒巴坦的测定。

铁路货车下作用式钩提杆座系列故障原因分析与防治

对铁路货车的钩提杆折断、钩提杆座折断、钩提杆座脱落和钩提杆扁平部位与钩提杆座的扁孔间隙大于3mm故障的原因进行分析,提出建议性防治措施,以保证铁路货车技术状态良好。

RFQ加速器中二极模稳定杆作用机理的研究(英文)

RFQ加速器中的二极模场给束流施加一个偏转力 ,导致束流损失在机器上 .因此 ,必须采取降低二极模场的措施 .人们提出采用二极模稳定杆使二极模频率远离四极工作模 .在一台RFQ冷模上开展的实验研究中 ,发现了一些与二极模稳定杆作用机理相关的新现象 ,本文报告这些实验结果 ,并对其进行分析解释 .根据这些结果 ,提出 ,利用非对称性地插入二极模稳定杆 ,可以降低非对称RFQ腔体中的二极模场分量 .

Research Application Progress on the Bacillus sp. in Plant Pathogenic Fungi Biocontrol

For about half a century, chemical control has played a major role in plant disease control. However, the long-term irrational use of chemical pesticide produces many problems. In nature, there exit extensive antagonistic microorganisms which are tightly concerned with plant pathogenic microbes, and biological pesticides can be researched to control related pathogenic microbes from its metabolites. It＇s an important research direction of new pesticide development. The Bacillus is the ideal and frequently studied object of bio-control bacteria, and it can produce some entospores with following characteristics such as heat-resistant, drought tolerance, antiultraviolet and organic solvent. In this article, the bio-control mechanism, problems and application prospects of the Bacillus were reviewed to promote the application in new biological pesticide.

Protein interaction network related to Helicobacter pylori infection response

AIM:To understand the complex reaction of gastric inflammation induced by Helicobacter pylori(H pylori) in a systematic manner using a protein interaction network. METHODS:The expression of genes significantly changed on microarray during H pylori infection was scanned from the web literary database and translated into proteins.A network of protein interactions was constructed by searching the primary interactions of selected proteins.The constructed network was mathematically analyzed and its biological function was examined.In addition,the nodes on the network were checked to determine if they had any further functional importance or relation to other proteins by extending them. RESULTS:The scale-free network showing the relationship between inflammation and carcinogenesis was constructed.Mathematical analysis showed hub and bottleneck proteins,and these proteins were mostly related to immune response.The network contained pathways and proteins related to H pylori infection,such as the JAK-STAT pathway triggered by interleukins.Activation of nuclear factor (NF)-κB,TLR4,and other proteins known to function as core proteins of immune response were also found. These immune-related proteins interacted on the network with pathways and proteins related to the cell cycle,cell maintenance and proliferation,andtranscription regulators such as BRCA1,FOS,REL,and zinc finger proteins.The extension of nodes showed interactions of the immune proteins with cancer- related proteins.One extended network,the core network,a summarized form of the extended network, and cell pathway model were constructed. CONCLUSION:Immune-related proteins activated by H pylori infection interact with proto-oncogene proteins.The hub and bottleneck proteins are potential drug targets for gastric inflammation and cancer.

Adsorption and Insecticidal Activity of Toxin from Bacillus thuringiensis on Rectorite

The adsorption and desorption of the toxin from Bacillus thuringiensis strain WG-001 on rectorite were studied at different toxin and/or rectorite concentrations, pH values and temperatures. The insecticidal activity of the adsorbed toxin was evaluated by determining the lethal concentration to kill 50% of the larvae of Heliothis armigera （LC50）. The adsorption of the toxin on rectorite in sodium carbonate buffer （pH 9） reached equilibrium within 0.5-1.0 h and the adsorption isotherm of the toxin followed the Langmuir equation （R^2 〉 0.99）. In the pH range from 9 to 11 （carbonate buffer）, the adsorbed toxin decreased with increasing pH. The adsorption amounts decreased with increasing rectorite：toxin ratio. The adsorption was not significantly affected by the temperature between 10 and 50 ℃. The X- ray diffraction analysis indicated occurrence of the intercalation of the rectorite by the toxin. The infrared absorption spectrum showed that the binding of the toxin did not alter its structure. The LC50 wlues of the adsorbed toxin were smaller than those of the free toxin. The rectorite protected the toxin from ultraviolet irradiation damage. The desorption of the adsorbed toxin in water ranged from 37.5% to 56.4% and from 27.4% to 41.8% in a carbonate buffer. The desorption percentage also decreased with increasing rectorite：toxin ratio.

Screening on Synergist of Bacillus thuringiensis Wettable Powder

[Objective] This study aimed to screen the best synergistic material for Bt wettable powder and evaluate their synergistic effect. [Method] The synergism of six different kinds of additives for Bacillus thuringiensis wettable powder （Bt WP） on the 2^nd instar larvae of Plutella xylostella was tested by method of leaf dipping in labora- tory. [Result] The mixtures of Bt with 0.1% ZnCl2, 0.5% ZnCl2, 1.0% ZnCl2, 1.0% MgCI2, 0.5% boric acid, 1.0% boric acid, 0.5% citric acid or 1.0% citric acid all ex- hibited synergistic effect, in which the synergistic effect of mixture containing 0.5% boric acid was the highest, with 17.2 synergistic ratio; followed by the mixture containing 1.0% ZnCl2, with 15.6 synergistic ratio. Moreover, addition of 0.5% boric acid could shorten the median lethal time of Bt wettable powder by about 10 h. After the mixtures of Bt with 0.5% boracic acid or 1.0% ZnCl2 was stored for 15 d at room temperature, toxicities of the two mixtures did not change significantly. [Conclusion] Boracic acid as the synergist of Bt wettable powder could not only increase insecti- cidal effect of Bt, but also accelerate its insecticidal rate. So, boracic acid could improve the disadvantages of Bt wettable powder such as poor insecticidal effect and slow insecticidal speed in a certain degree.

Helicobacter pylori eradication: Sequential therapy and Lactobacillus reuteri supplementation

AIM:To evaluate the role of sequential therapy and Lactobacillus reuteri (L. reuteri ) supplementation, in the eradication treatment of Helicobacter pylori (H. pylori ). METHODS:H. pylori infection was diagnosed in 90 adult dyspeptic patients. Patients were excluded if previously treated for H. pylori infection or if they were taking a proton pump inhibitor (PPI), H2-receptor antagonist or antibiotics. Patients were assigned to receive one of the following therapies:(1) 7-d triple therapy (PPI plus clarithromycin and amoxicillin or metronidazole) plus L. reuteri supplementation dur- ing antibiotic treatment; (2) 7-d triple therapy plus L. reuteri supplementation after antibiotic treatment; (3) sequential regimen (5-d PPI plus amoxicillin therapy followed by a 5-d PPI, clarithromycin and tinidazole) plus L. reuteri supplementation during antibiotic treatment; and (4) sequential regimen plus L. reuteri supplementation after antibiotic treatment. Successful eradication therapy was defined as a negative urea breath test at least 4 wk following treatment. RESULTS:Ninety adult dyspeptic patients were en- rolled, and 83 (30 male, 53 female; mean age 57 ± 13 years) completed the study. Nineteen patients were administered a 7-d triple treatment:11 with L. reuteri supplementation during and 8 after therapy. Sixty-four patients were administered a sequential regimen:32 with L. reuteri supplementation during and 32 after therapy. The eradication rate was significantly higher in the sequential group compared with the 7-d triple regimen (88% vs 63%, P = 0.01). No difference was found between two types of PPI. No difference in erad- ication rates was observed between patients submitted to L. reuteri supplementation during or after antibiotic treatment. Compliance with therapy was excellent in all patients. No difference in adverse effects was observed between the different antibiotic treatments and between patients submitted to L. reuteri supplementation during and after antibiotic treatment. There was a low incidence of adverse effects in all groups of patients with sequential therapy, probably due to the presence of the L. reuteri supplementation. CONCLUSION:The sequential treatment regimen achieved a significantly higher eradication rate of H. pylori compared with standard 7-d regimen. L. reuteri supplementation could reduce the frequency and the intensity of antibiotic-associated side-effects.

Screening, identification and desilication of a silicate bacterium

The strain Lv（1- z） isolated from the Henan bauxite was characterized by morphological observation, biochemical and physiological identification, and 16S rDNA sequence analysis. The influences of temperature, initial pH value, the volume of medium, shaking speed and illite concentration on the desilicating ability of the strain Lv（1- z） were investigated. The results show that the bacterium is a Gram-negative rod-shaped bacterium with oval endspores and thick capsule, but without flagellum. The biochemical and physiological tests indicate that the strain Lv（1- z） is similar to Bacillus rnucilaginosus. In GenBank the 16S rDNA sequence similarity of the strain Lv（1- z） and the B. rnucilaginosus YNUCC0001（AY571332） is more than 99%. Based on the above results, the strain Lv（1- z） is identified as B. rnucilaginosus. The optimum conditions for the strain L（1- z） to remove silicon from illite are as follows., temperature is 30℃ ;initial pH value is 7.5; medium volume in 200 mL bottle is 60 mL; shaking speed of rotary shaker is 220 r/m ; illite concentration is 1%.

Effective extraction of elastase from Bacillus sp. fermentation broth using aqueous two-phase system

This paper presents the evaluation of an aqueous two-phase system （ATPS） for extracting elastase produced by Bacillus sp. EL31410. The elastase and cell partition behavior in polyethylene glycol （PEG）/salt systems was investigated. The suitable system for elastase extraction was PEG/KHEPO4-KEHPO4, in which elastase is mainly partitioned into the PEG-rich phase, while the cells remained in the other phase. The influence of defined system parameters （e.g. PEG molecular mass, pH, NaCl addition） on the partitioning behavior of elastase is described. The concentration of phase forming components, PEG and KHEPO4-KEHPO4, was optimized for elastase recovery by means of response surface methodology, and it was found that they greatly influenced extraction recovery. The optimal ATPS was 23.1% （w/w） PEG 2000 and 11.7% （w/w） KHEPO4-KEHPO4. The predicted recovery was about 89.5%, so this process is suggested to be a rapid and convenient method for elastase extraction.

Lactobacillus plantarum inhibits epithelial barrier dysfunction and interleukin-8 secretion induced by tumor necrosis factor-a

AIM： To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-α （TNF-α） on intestinal epithelial cells. METHODS： Caco-2 cells were incubated with TNF-α alone or in the presence of L. plantarum. Transepithelial electrical resistance was used to measure epithelial barrier function. Interleukin 8 （IL-8） secretion by intestinal epithelial cells was measured using an ELISA. Cellular lysate proteins were immunoblotted using the anti-extracellular regulated kinase （ERK）, anti-phospho- ERK and anti-IκB-α. RESULTS： A TNF-α-induced decrease in transepithelial electrical resistance was inhibited by L. plantarum. TNF- α-induced IL-8 secretion was reduced by L. plantarum. L. plantarum inhibited the activation of ERK and the degradation of IκB-α in TNF-a-treated Caco-2 cells. CONCLUSION： Induction of epithelial barrier dysfunction and IL-8 secretion by TNF-α is inhibited byL. plantarum. Probiotics may preserve epithelial barrier function and inhibit the inflammatory response by altering the signal transduction pathway.

UHILIC-MS/MS同时测定栝楼桂枝颗粒中22个氨基酸的含量

目的建立一种超高效亲水作用色谱串联三重四极杆质谱法(UHILIC-MS/MS)对栝楼桂枝颗粒中22个氨基酸类成分(亮氨酸、苯丙氨酸、色氨酸、异亮氨酸等)进行含量测定。方法采用超高效亲水作用色谱串联三重四极杆质谱法,正离子多反应监测(MRM)模式进行含量测定。色谱条件:采用亲水作用色谱柱,Acquity BEH(2.1 mm×100 mm,1.7μm)色谱柱,以(0.25%甲酸+2 mmol·L^(-1)甲酸铵)水(A)和乙腈(B)为流动相,梯度洗脱,进样量:1μL;流速:0.4 mL·min^(-1),柱温:45℃。结果在所设定的色谱条件下,6 min内完成对栝楼桂枝颗粒中上述22个成分的含量测定,在考察的浓度范围内呈良好的线性关系(r>0.9953),回收率和RSD分别在96.12~103.93%和1.49%~2.94%范围内,精密度、重复性、稳定性考察均符合分析要求。3批样品含量测定结果发现22个氨基酸中,瓜氨酸(Cit)、γ-氨基丁酸(GABA)、脯氨酸(Pro)、天冬酰胺(Asn)、精氨酸(Arg)含量较高,达到0.3 mg·g^(-1)以上。结论超高效亲水作用色谱串联三重四极杆质谱法定量分析方法简便、快捷、准确,分离效果较好,为揭示栝楼桂枝颗粒中氨基酸类成分的物质基础奠定实验依据。

Implications of anti-parietal cell antibodies and anti-Helicobacter pylori antibodies in histological gastritis and patient outcome

AIM： To develop a serum or histological marker for early discovery of gastric atrophy or intestinal metaplasia. METHODS： This study enrolled 44 patients with gastric adenocarcinoma, 52 patients with duodenal ulcer, 14 patients with gastric ulcer and 42 consecutive healthy adults as controls. Each patient received an endoscopy and five biopsy samples were obtained. The degrees of histological parameters of gastritis were categorized following the Updated Sydney System. Anti-parietal cell antibodies （APCA） and anti- Helicobacter pylori （ H pylori） antibodies （AHPA） were analyzed by immunoassays. Hpyloriinfection was diagnosed by rapid unease test and histological examination. RESULTS： Patients with gastric cancer and gastric ulcer are significantly older than healthy subjects, while also displaying higher frequency of APCA than healthy controls. Patients with positive APCA showed higher scores in gastric atrophy and intestinal metaplasia of corpus than patients with negative APCA. Patients with positive AHPA had higher scores in gastric atrophy, intestinal metaplasia, and gastric inflammation of antrum than those patients with negative AHPA. Elderly patients had greater prevalence rates of APCA. Following multivariant logistic regression analysis, the only significant risk factor for antral atrophy is positive AHPA, while that for corpus atrophy is positive APCA. CONCLUSION： The existence of positive APCA correlates with glandular atrophy in corpus and the presence of positive AHPA correlates with glandular atrophy in antrum. The existence of serum APCA and AHPA betokens glandular atrophy and requires further examination for gastric cancer.

Bactericidal and anti-adhesive properties of culinary and medicinal plants against Helicobacter pylori

AIM： To investigate the bactericidal and anti-adhesive properties of 25 plants against Helicobacter pylori （H pylon）. METHODS： Twenty-five plants were boiled in water to produce aqueous extracts that simulate the effect of cooking. The bactericidal activity of the extracts was assessed by a standard kill-curve with seven strains of H pylori. The anti-adhesive property was assessed by the inhibition of binding of four strains of FITC-labeled Hpylori to stomach sections. RESULTS： Of all the plants tested, eight plants, including Bengal quince, nightshade, garlic, dill, black pepper, coriander, fenugreek and black tea, were found to have no bactericidal effect on any of the isolates. Columbo weed, long pepper, parsley, tarragon, nutmeg, yellow-berried nightshade, threadstem carpetweed, sage and cinnamon had bactericidal activities against Hpylori, but total inhibition of growth was not achieved in this study. Among the plants that killed H pylori, turmeric was the most efficient, followed by cumin, ginger, chilli, borage, black caraway, oregano and liquorice. Moreover, extracts of turmeric, borage and parsley were able to inhibit the adhesion of H pylori strains to the stomach sections. CONCLUSION： Several plants that were tested in our study had bactericidal and/or anti-adhesive effects on Hpylori. Ingestion of the plants with anti-adhesive properties could therefore provide a potent alternative therapy for H pylori infection, which overcomes the problem of resistance associated with current antibiotic treatment.

Role of E. coli DNA in systemic inflammatory response syndrome

Objective: To investigate whether bacterial DNA involving in the pathogenesis of systemic inflammatory response syndrome (SIRS) and possible mechanism. Methods: Escherichia coli DNA (EC DNA) was extracted from Escherichia coli 25922 with alkaline lysis method. The mice mortality was observed after EC DNA was injected into mice via caudal vein. The changes of serum TNF-α and IL-6 levels in rats were measured with ELISA after rats were given EC DNA. Calf thymus DNA and lipopolysaccharide (LPS) were used as the control, respectively. Results: EC DNA led mice to death with notable dose-effect relationship (LD50=11.51 mg/kg), but CT DNA didn't. The peak level of TNF-αwas lower in EC DNA group than in LPS group (P＜0. 05), though the former reaching the peak I h earlier than the latter. However, they had coordinate ability to induce IL-6 release in rats, and no significant difference was seen in serum IL-6 peak level between 2 groups. Conclusion: EC DNA leads mice to death, and induces the increases of serum TNF-αand IL-6 levels in rats. EC DNA has the effect equal to LPS in inducing SIRS by triggering cytokines cascade.

在大型数控车床上加工深孔类零件的夹紧和定位装置

为解决细长深孔类零件的加工问题,设计了一种在大型数控车床上加工大长径比深孔类零件的夹紧和定位装置,所加工的零件可以大部分放入主轴孔内,零件的一端用卡盘夹紧,另一端由定位装置顶紧,使零件加工时不会产生振动。

Study on gob-side entry retaining in fully-mechanized longwall with top-coal caving and its application

Based on the engineering background of gob-side entry retaining in fully-mechanized longwall with top coal caving(GER-FLTC) on N2105 working face of Yuwu coal mine, by adopting the methods of theoretical analysis and numerical calculation, the control techniques of surrounding rocks in GER-FLTC working face are studied in this paper. The two main difficulties of stability of surrounding rocks at gob-side retained entry in fully-mechanized longwall working face are the stability control of top coal and control of large deformation of GER-FLTC working face. Interaction mechanical model between roofing and roadside backfilling in GER-FLTC is established and the equations for the calculation of roof-cutting resistance of roadside backfilling are derived. Results of numerical calculation show that the damage zones of top coal can be categorized into the delaminating zone of top coal above the backfilling, tensile damage zone of top coal above the retained roadway and shear damage zone of the upper rib of the solid coal. Stability control of top coal is the critical part to success of GER-FLTC. With consideration of large deformation of surrounding rocks of gob-side retained entry in fully-mechanized longwall, the support technique of‘‘roofing control and wall strengthening'' is proposed where high strength and highly prestressed anchor rods and diagonal tensile anchor cables support are used for top coal, high strength and highly prestressed yielding anchor rod support is used for solid coal and roadside prestressed load-carrying backfilling is constructed by high-water material, in order to maintain the integrity of the top coal, transfer load, high resistance yielding load-carrying of solid coal, roof-cutting of roadside backfilling and support,and to achieve GER-FLTC. Results from this study are successfully applied in engineering practice.