炼焦煤的煤岩特征对其结焦性质的影响

 随着煤岩测定技术的进步,炼焦煤的煤岩性质已在炼焦配煤中得到广泛应用。通过对多种单种煤和配合煤的煤岩特征以及对应的40 kg试验焦炉所炼焦炭的性质进行分析和比较,结果表明：单煤种的R0max在1.3%～15%间,所炼制焦炭的冷态机械强度（M40和M10）最好,其热性质（反应性CRI和反应后强度CSR）也较好;配合煤反射率分布图特征越接近正态分布,则所炼制的焦炭冷态机械强度（M40、M10）就较好,配合煤反射率分布图特征偏离正态分布越远,其焦炭热性质越差;40 kg试验焦炉所得焦炭的反应性CRI高,其反应后强度CSR较低,存在负相关线形关系。     

煤岩分析在煤场管理中的应用

为指导炼焦用煤的合理堆放,建立了与煤随机反射率有关的煤岩指标：离异值、分布图重叠度、煤堆反射率中心值、分布范围等煤岩参数,用堆放煤反射率分布图叠加形成的煤堆反射率分布图来判定来煤堆放是否合理,从而为有效利用煤场的有限空间提供技术参数,同时保证了炼焦用煤的质量,提高配煤的准确性。     

煤岩学在炼焦生产中的应用

 为了改善焦炭质量,降低配煤成本,鞍钢鲅鱼圈利用测定煤显微结构的镜质组反射率,并将其绘制成分布图的煤岩学方法监控来煤质量,建立了本企业的煤岩配煤方法,开展煤岩配煤的应用研究,有效地杜绝了复杂混煤入厂,优化了配煤结构,提高了焦炭质量。结果表明,应用该技术后鲅鱼圈焦炭的冷态性能M40、M10、热态性能CRI、CSR提高明显,分别从2011年的88.11%、6.75%、27.36%、62.20%,逐步改善到2014年的88.88%、6.26%、23.89%、66.26%,主焦煤配比从2011年的75%下降到目前的69%。     

6m焦炉配煤结构和工艺参数优化

6m焦炉投产初期焦炭质量有时处于失控状态。2005年6-9月，济钢通过采取6m焦炉的用煤结构研究、配煤控制参数标定及误差分析、焦炉控制参数最佳化的测试标定等措施，稳定并改善了焦炭质量，焦炭主要指标达到了1750m^3高炉M40≥84％、M10≤7．0％、CRI≤28％、CSR≥63％的用焦要求，为其提供了良好的物料条件，促进了炉况的稳定顺行。     

焦炭反射率与强度指标及反应性之间的相关性

通过控制偏光显微镜的起偏镜旋转角度可以实现焦炭气孔壁平均最大反射率Rˉmax和平均双反射率Rˉbi的自动测定。经回归分析发现,Rˉmax和焦炭反应性CRI,以及反应后强度CSR之间存在显著的相关关系,相关系数r分别达到－0.926和0.949。Rˉmax和焦炭机械强度DI 15015之间的相关性相对较弱,r为0.704。Rˉbi和焦炭各强度指标之间没有发现明显的相关关系。     

配合煤胶质层的最大厚度(Y值)和粘结指数(G值)相关性分析

在焦化化验工作中，配合煤胶质层的最大厚度(Y值)和粘结指数(G值)这两种数据问存存着一定的关联，Y值与G值具有相关性，在一定区域内能导出一元线性回归方程，并进行显著性检验。可以用已知的G值预测Y值，或用已知的Y值预测G值，对于检测化验数据的准确与否有着重要的意义。     

配合煤结焦特性与焦炭热态强度的关系

分析近年来昆钢新焦配合煤结焦特性指标变化对焦炭热态性能造成的影响，找到配合煤结焦特性指标与焦炭热态性能指标之间的关系，提出配合煤结焦特性值x、Y、G、b适宜的控制范围。     

对烟煤胶质层指数的认识

在焦化生产中，烟煤的胶质层指数能指导配煤炼焦生产，在测定胶质层指数的试验过程中影响因素较多，准确测定Y值，找出Y值与G值的相关关系，总结体积曲线与焦块技术特征的联系，对昆钢炼焦生产有实际的指导作用。     

煤岩分析在配煤生产中的应用

介绍了煤岩分析镜质组反射率分布图的原理及在生产中的应用情况,通过煤岩分析有效促进了单种煤管理和配合煤质量的改善。     

海洋平台用S355G10+M厚钢板的焊接性研究

按照EN10225标准要求,对75 mm厚度规格海洋平台用S355G10+M钢板进行了堆焊硬度试验(BOP)、可控热拘束试验(CTS)以及热输入50 k J/cm埋弧焊对接接头系列力学性能试验,研究了钢板焊接热影响区(HAZ)的淬硬倾向、HAZ冷裂纹敏感性、焊接接头各部位抗拉强度、冲击韧性和裂纹尖端张开位移(CTOD)值的变化情况。结果显示S355G10+M厚钢板的HAZ最高硬度、焊接钢板冷裂纹、埋弧焊对接接头抗拉强度、低温冲击功均值、CTOD值等各项性能指标良好,满足海洋平台的焊接生产要求。     

Sex differences in the relative contributions of nitric oxide and EDHF to agonist-stimulated endothelium-dependent relaxations in the rat isolated mesenteric arterial bed

1. We have used the isolated, buffer-perfused, superior mesenteric arterial bed of male and female rats to assess the relative contributions of nitric oxide (NO) and the endothelium-derived hyperpolarizing factor (EDHF) to endothelium-dependent relaxations to carbachol. 2. Carbachol caused dose-related relaxations of methoxamine-induced tone in mesenteric vascular beds from male rats described by an ED50(M) of 0.43+/-0.15 nmol and a maximum relaxation (Rmax(M) of 89.6+/-1.2% (n=28) which were not significantly different from those observed in mesenteries from female rats (ED50(F)=0.72+/-0.19 nmol and Rax(F)=90.7+/-0.9%; n=22). 3. In the males, the addition of 100 microM NG-nitro-L-arginine methyl ester (L-NAME) caused the dose-response curve to carbachol to be significantly (P<0.001) shifted to the right 15 fold (ED50(M)=6.45+/-3.53 nmol) and significantly (P<0.01) reduced Rmax(M) (79.7+/-2.8%, n=13). By contrast, L-NAME had no effect on vasorelaxation to carbachol in mesenteries from female rats (ED50(f)= 0.89+/-0.19 nmol, Rmax(F)=86.9+/-2.3%, n=9). 4. Raising tone with 60 mM KCl significantly reduced the maximum relaxation to carbachol in mesenteries from male rats 2 fold (Rmax(M)=40.3+/-9.2%, n=4; P<0.001) and female rats by 1.5 fold (Rmax(F)=55.3+/-3.3%, n=6; P<0.001), compared with methoxamine-induced tone. The potency of carbachol was also significantly reduced 1.2 fold in preparations from males (ED50(M)=0.87+/-0.26 nmol; P<0.01) but not the females (ED50(F)=4.04+/-1.46 nmol). In the presence of both 60 mM KCl and L-NAME, the vasorelaxation to carbachol was completely abolished in mesenteries from both groups. 5. The cannabinoid receptor antagonist SR141716A (1 microM), which is also a putative EDHF antagonist, had no significant effect on the responses to carbachol in mesenteries from males or females (ED50(M)=1.41+/-0.74 nmol, Rmax(M)=89.4+/-2.5%, n=7; ED50(F)=2.17+/-0.95 nmol, Rmax(F)=89.9+/-1.8%, n=9). In mesenteries from male rats, in the presence of 100 microM L-NAME, SR141716A significantly (P<0.05) shifted the dose-response curve to carbachol 8 fold further to the right than that seen in the presence of L-NAME alone (ED50(M)= 53.8+/-36.8 nmol) without affecting Rmax(M) (72.4+/-4.8%, n=10). In mesenteries from female rats, the combined presence of L-NAME and SR141716A, significantly (P < 0.01) shifted the dose-response curve to carbachol 7.5 fold, (ED50(F)=6.66+/-2.46 nmol), as compared to L-NAME alone and significantly (P<0.001) decreased Rmax(F) (70.1+/-5.5%, n=8). 6. Vasorelaxations to the nitric oxide donor sodium nitroprusside (SNP), to the endogenous cannabinoid, anandamide (a putative EDHF) and to the ATP-sensitive potassium channel activator, levcromakalim, did not differ significantly between male and female mesenteric vascular beds. 7. The continuous presence of sodium nitroprusside (SNP; 20-60 nM) had no effect on vasorelaxation to carbachol in mesenteries from either males or females. In the presence of L-NAME, SNP significantly (P<0.05) reduced the potency of carbachol 6 fold, without affecting the maximal relaxation in mesenteries from male rats (ED50(M)=40.9+/-19.6 nmol, Rmax(M)=79.4+/-2.5%, n=11). Similarly in mesenteries from female rats, the ED50(F) was also significantly (P<0.01) increased 7 fold (6.24+/-2.02 nmol), while the Rmax(F) was unaffected (81.9+/-11.0%; n=4). 8 The results of the present investigation demonstrate that the relative contributions of agonist-stimulated NO and EDHF to endothelium-dependent relaxations in the rat isolated mesenteric arterial bed, differ between males and females. Specifically, although both NO and EDHF appear to contribute towards endothelium-dependent relaxations in males and females, blockade of NO synthesis alone has no effect in the female. This suggests that EDHF is functionally more important in females; one possible explanation for this is that in the absence of NO, the recently identified ability of EDHF to compensate for the loss of NO, is functio     

A comparison of EDHF-mediated and anandamide-induced relaxations in the rat isolated mesenteric artery

1. Relaxation of the methoxamine-precontracted rat small mesenteric artery by endothelium-derived hyperpolarizing factor (EDHF) was compared with relaxation to the cannabinoid, anandamide (arachidonylethanolamide). EDHF was produced in a concentration- and endothelium-dependent fashion in the presence of NG-nitro-L-arginine methyl ester (L-NAME, 100 microM) by either carbachol (pEC50 [negative logarithm of the EC50] = 6.19 +/- 0.01, Rmax [maximum response] = 93.2 +/- 0.4%; n = 14) or calcium ionophore A23187 (pEC50 = 6.46 +/- 0.02, Rmax = 83.6 +/- 3.6%; n = 8). Anandamide responses were independent of the presence of endothelium or L-NAME (control with endothelium: pEC50 = 6.31 +/- 0.06, Rmax = 94.7 +/- 4.6%; n = 10; with L-NAME: pEC50 = 6.33 +/- 0.04, Rmax = 93.4 +/- 6.0%; n = 4). 2. The selective cannabinoid receptor antagonist, SR 141716A (1 microM) caused rightward shifts of the concentration-response curves to both carbachol (2.5 fold) and A23187 (3.3 fold). It also antagonized anandamide relaxations in the presence or absence of endothelium giving a 2 fold shift in each case. SR 141716A (10 microM) greatly reduced the Rmax values for EDHF-mediated relaxations to carbachol (control, 93.2 +/- 0.4%; SR 141716A, 10.7 +/- 2.5%; n = 5; P < 0.001) and A23187 (control, 84.8 +/- 2.1%; SR 141716A, 3.5 +/- 2.3%; n = 6; P < 0.001) but caused a 10 fold parallel shift in the concentration-relaxation curve for anandamide without affecting Rmax. 3. Precontraction with 60 mM KCl significantly reduced (P < 0.01; n = 4 for all) relaxations to 1 microM carbachol (control 68.8 +/- 5.6% versus 17.8 +/- 7.1%), A23187 (control 71.4 +/- 6.1% versus 3.9 +/- 0.45%) and anandamide (control 71.1 +/- 7.0% versus 5.2 +/- 3.6%). Similar effects were seen in the presence of 25 mM K+. Incubation of vessels with pertussis toxin (PTX; 400 ng ml-1, 2 h) also reduced (P < 0.01; n = 4 for all) relaxations to 1 microM carbachol (control 63.5 +/- 7.5% versus 9.0 +/- 3.2%), A23187 (control 77.0 +/- 5.8% versus 16.2 +/- 7.1%) and anandamide (control 89.8 +/- 2.2% versus 17.6 +/- 8.7%). 4. Incubation of vessels with the protease inhibitor phenylmethylsulphonyl fluoride (PMSF; 200 microM) significantly potentiated (P < 0.01), to a similar extent (approximately 2 fold), relaxation to A23187 (pEC50: control, 6.45 +/- 0.04; PMSF, 6.74 +/- 0.10; n = 4) and anandamide (pEC50: control, 6.31 +/- 0.02; PMSF, 6.61 +/- 0.08; n = 8). PMSF also potentiated carbachol responses both in the presence (pEC50: control, 6.25 +/- 0.01; PMSF, 7.00 +/- 0.01; n = 4; P < 0.01) and absence (pEC50: control, 6.41 +/- 0.04; PMSF, 6.88 +/- 0.04; n = 4; P < 0.001) of L-NAME. Responses to the nitric oxide donor S-nitroso-N-acetylpenicillamine (SNAP) were also potentiated by PMSF (pEC50: control, 7.51 +/- 0.06; PMSF, 8.00 +/- 0.05, n = 4, P < 0.001). 5. EDHF-mediated relaxation to carbachol was significantly attenuated by the K+ channel blocker tetraethylammonium (TEA; 1 mM) (pEC50: control, 6.19 +/- 0.01; TEA, 5.61 +/- 0.01; n = 6; P < 0.01). In contrast, TEA (1 mM) had no effect on EDHF-mediated relaxation to A23187 (pEC50: control, 6.47 +/- 0.04; TEA, 6.41 +/- 0.02, n = 4) or on anandamide (pEC50: control, 6.28 +/- 0.06; TEA, 6.09 +/- 0.02; n = 5). TEA (10 mM) significantly (P < 0.01) reduced the Rmax for anandamide (control, 94.3 +/- 4.0%; 10 mM TEA, 60.7 +/- 4.4%; n = 5) but had no effect on the Rmax to carbachol or A23187. 6. BaCl2 (100 microM), considered to be selective for blockade of inward rectifier K+ channels, had no significant effect on relaxations to carbachol or A23187, but caused a small shift in the anandamide concentration-response curve (pEC50: control, 6.39 +/- 0.01; Ba2+, 6.20 +/- 0.01; n = 4; P < 0.01). BaCl2 (1 mM; which causes non-selective block of K+ channels) significantly (P < 0.01) attenuated relaxations to all three agents (pEC50 values: carbachol, 5.65 +/- 0.02; A23187, 5.84 +/- 0.04; anandamide, 5.95 +/- 0.02; n = 4 for each). 7. Apamin (1mu M), a selective blocker of small conductance, Ca2+-activated, K+ channels (SKCa), 4-aminopyridine (1mM), a blocker of delayed rectifier, voltage-dependent, K+ channels (Kv), and ciclazindol (10mu M), an inhibitor of Kv and adenosine 5'-triphosphate (ATP)-sensitive K+ channels (KATP), significantly reduced EDHF-mediated relaxations to carbachol, but had no significant effects on A23187 or anandamide responses. 8. Glibenclamide (10mu M), a KATP inhibitor and charybdotoxin (100 or 300nM), a blocker of several K+ channel subtypes, had no significant effect on relaxations to any of the agents. Iberiotoxin (50nM), an inhibitor of large conductance, Ca2+-activated, K+ channels (BKCa), had no significant effect on the relaxation responses, either alone or in combination with apamin (1muM). Also, a combination of apamin (1muM) with either glibenclamide (10muM) or 4-aminopyridine (1mM) did not inhibit relaxation to carbachol significantly more than apamin alone. Neither combination had any significant effect on relaxation to A23187 or anandamide. 9. A combination of apamin (1muM) with charybdotoxin (100nM) abolished EDHF-mediated relaxation to carbachol, but had no significant effect on that to A23187. Apamin (1muM) and charybdotoxin (300nM) together consistently inhibited the response to A23187, while apamin (1muM) and ciclazindol (10muM) together inhibited relaxations to both carbachol and A23187. None of these toxin combinations had any significant effect on relaxation to anandamide. 10. It was concluded that the differential sensitivity to K+ channel blockers of EDHF-mediated responses to carbachol and A23187 might be due to actions on endothelial generation of EDHF, as well as its actions on the vascular smooth muscle, and suggests care must be taken in choosing the means of generating EDHF when making comparative studies. Also, the relaxations to EDHF and anandamide may involve activation of cannabinoid receptors, coupled via PTX-sensitive G-proteins to activation of K+ conductances. The results support the hypothesis that EDHF is an endocannabinoid but relaxations to EDHF and anandamide show differential sensitivity to K+ channel blockers, therefore it is likely that anandamide is not identical to EDHF in the small rat mesenteric artery.     

焦炭常温强度对锰铁高炉冶炼指标的影响

根据新钢生产实践，运用数理统计方法分析了焦炭常温指标Ｍ４０和Ｍ１０对锰铁高炉利用系数和入炉焦比的数量关系，认为焦炭Ｍ１０对锰铁高炉利用系数、入炉焦比的显著性和敏感度均好于焦炭Ｍ４０，是影响高炉产量和消耗的主要因素。焦炭Ｍ４０、Ｍ１０对产量的影响不如对焦比的影响显著，说明焦炭Ｍ４０、Ｍ１０主要影响焦比。     

SUS304不锈钢点状缺陷对研磨性能的影响

通过市场调查和缺陷分析认为:影响酒钢研磨质量的主要缺陷是点状缺陷,点状缺陷分为两类,一类为设备原因造成的周期性缺陷;第二类为研磨抛光后出现的点状缺陷,通过SEM和晶相分析,缺陷不是晶间腐蚀和夹杂物引起。研磨抛光后出现的点状缺陷是热轧氧化铁皮结构与酸洗工艺的影响导致Rmax提高,较大的Rmax经过轧制,带钢表面凹凸点相互挤压覆盖使带钢表面平滑,在后续研磨中凸点挤压覆盖凹点处研磨脱落所产生。     

Surgical simulation and virtual reality: the coming revolution

The present study was designed to define whether maximal removal rate of indocyanine green (ICG Rmax), plasma cyclic 3',5'-adenosine monophosphate (cAMP) response to exogenous glucagon (peak to basal ratio of cAMP level: P/B cAMP) and plasma half-life of galactose (t1/2 galactose) can measure the hepatic functional reserve of fatty liver prepared in rats fed choline-deficient (9 weeks), 2% cholesterol (2 weeks) or 0.25% DL-ethionine (2 weeks) diet. Although changes in cholesterol and phospholipid values in serum during feeding periods differed among the models, histopathologic examinations in the liver of almost all animals revealed intermediate to severe fatty liver with or without fibrosis at each termination. ICG Rmax and P/B cAMP were significantly decreased in rats fed choline-deficient or DL-ethionine diet, implying reductions in hepatic functional mass and disturbances in hepatic cAMP production. Meanwhile, t1/2 galactose showed no change in any of the models, suggesting that glucose metabolisms in the models used may be preserved. These findings demonstrate that ICG Rmax and P/B cAMP can apply to measurement of hepatic surviving reserve of fatty liver with fibrosis.     

风选调湿技术对炼焦煤焦化性能的影响

采用炼焦煤风选调湿技术,对混合煤进行了风选分级,并通过煤样分析、堆密度试验和40 kg焦炉炼焦试验,分析了风选调湿分级粉碎后粒度分布与湿度对焦化性能的影响。对炼焦煤样按分级粉碎与不分级粉碎处理,并在此基础上进行选择性筛分和细度调整,按6种粒度分布进行对比试验。结果表明,采用分级粉碎焦炭的抗碎强度M40提高1.9%～5.8%,耐磨强度M10改善0.1%～0.3%;煤样的粉碎细度从73.0%提高到84.0%,焦炭的抗碎强度提高2.4%～4.1%,焦炭的耐磨强度改善0.5%～0.7%;筛除部分小于1 mm颗粒的煤样堆密度提高,焦炭的耐磨强度改善。煤样的堆密度随着煤样水分的增加而逐渐减小,当煤样水分大于8%时逐渐趋于稳定。给出了堆密度与煤样水分的非线性回归方程,进行了中位径、煤样水分对堆密度影响的双因素方差分析。研究结果有利于风选调湿技术的工程优化设计改进。     

国内外合金化热镀锌汽车外板表面粗糙度对比分析

对国内外合金化热镀锌汽车外板的表面粗糙度指标Ra,PPI,Rmax和Wca值进行了详细的对比分析,指出国内合金化板表面粗糙度控制的不足之处,并给出了一些改进措施.分析发现,国外合金化板的粗糙度沿板面横向分布得比较均匀,而且总体Ra、Rmax和Wca值都低于国内板,PPI值高于国内板,并且O5面粗糙度指标较非O5面要好,这对最终产品的涂装和鲜映性非常有利.     

Comparison of three methods of estimating the parameters of the Naka-Rushton equation

The Naka-Rushton equation empirically describes the amplitude R of the dark-adapted electroretinogram b-wave, as a function of stimulus luminance L, as R/Rmax = Ln/(Ln + Kn). Estimating the three parameters Rmax, n, and K of this function from electroretinogram data is of both experimental and clinical interest. Several different approaches have been developed to accomplish this analysis, but these approaches may derive different estimates of the three parameters. To examine this possibility, we compared the results of three methods of fitting the Naka-Rushton equation to data sets obtained from 30 normal subjects. Two methods were nonlinear curve-fitting programs; the third method involved fitting a regression line to transformed data. The results indicate that solutions provided by these methods have consistent differences, which may be an important consideration when comparing results reported in studies that used different curve-fitting methods.     

Isolation of pathogenic bacteria from induced sputum from hospitalized children with pneumonia in Bangladesh

A high-performance liquid chromatographic system, combining solid-phase extraction and automated precolumn derivatization is described for the routine determination of methotrexate in human plasma. The sample extraction and elution onto the analytical column were performed automatically and concomitantly using the column-switching technique and a protein-coated precolumn. Cerium (IV) trihydroxyhydroperoxide (CTH) was introduced as a packed oxidant before the analytical column for the conversion of methotrexate into highly fluorescent products. The oxidative-cleavage of methotrexate occurs during the flow of 0.04 M phosphate buffer (pH 3.5) containing plasma sample through CTH column with a flow rate of 0.5 mL/min at 40 degrees C. The fluorescent products were transferred to the protein-coated precolumn, which was then flushed with the same buffer for clean-up and enrichment from plasma sample. The trapped substances were desorbed from the precolumn and eluted onto the ODS/TM analytical column by isocratical elution with a mobile phase containing 0.05 M phosphate buffer, pH 6.6 and acetonitrile (90-10, v/v) for subsequent separation. The fluorescent products were detected fluorimetrically at excitation and emission wavelengths of 367 and 463 nm, respectively. The complete analysis was achieved within 15 min per sample. The calibration graph was linear in the range of 50-500 ng/mL of methotrexate and there was no interference from endogenous components.