mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Efficient production of biodiesel from both esterification and transesterification over supported SO_4~(2-)–MoO_3–ZrO_2–Nd_2O_3/SiO_2 catalysts

SO_4~(2-)–MoO_3–Zr O_2–Nd_2O_3/SiO_2(SMZN/SiO_2) catalysts for the production of biodiesel via both esterification and transesterification were prepared and characterized by N_2 adsorption-desorption isotherms,X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetry analysis(TGA),ammonia adsorption Fourier transform infrared spectra(NH_3-FTIR),and ammonia adsorption temperature programmed desorption(NH_3-TPD) to reveal the dependence of the stable catalytic activity on calcination time. The reason for catalyst deactivation was also studied. The calcination time remarkably affected the types of active centers on SMZN/SiO_2,and 4 h was found to be the optimal calcination time. SO_4 species bonded with small size Zr O_2 were found to be the stable active centers,where the leaching of SO_4~(2-) and the deposition of coke were inhibited. The deposition of coke was easier on large size Zr O_2 than on small size ones. Calcination in air flow could eliminate the deposited coke to recover the deactivated catalysts.
Kinetic and thermodynamic studies of the esterification of acidified oil catalyzed by sulfonated cation exchange resin

This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins(SCER). The effects of the mass ratio of methanol to acidified oil,reaction temperature,and catalyst loading were studied to optimize the conditions for maximum conversion of free fatty acids(FFAs). The results showed that the optimal conversion rate of FFAs was 91.87% at the mass ratio of methanol to acidified oil of 2.5:1.0,reaction temperature of 65.0 °C,catalyst loading of 5.0 g and reaction time of 8.0 h. The external and internal mass transfer resistances were negligible based on the experimental results and a pseudo-homogeneous kinetic model was proposed for the esterification. The activation energy and thermodynamic parameters including G,S and H were determined. The conversion rates of FFAs obtained from the established model were in good agreement with the experimental data.
Mass production of Li Fe PO_4/C energy materials using Fe–P waste slag

To effectively solve the agglomeration problems in the solid state reaction process,pre-adding glucose is adopted to the synthesis of Li Fe PO_4/C energy materials using Fe–P waste slag. The average particle & grain size of Li FeP O_4/C decreases,and the impurities in Li Fe PO_4/C composites reduce to a great extent. It makes great sense to the mass industrial production. The optimum synthesis conditions determined in this work are based on the orthogonal experiments. The samples synthesized in a scale of 500 g exhibit high purity,excellent electrochemical performance,high reaction activity,good reversibility,and low polarization level.The discharge capacities are 145,134,117,and 102 m Ah/g at the current densities of 0.1 C,0.2 C,0.5 C and1 C,respectively. This work puts forward a practical suggestion for mass producing environmental benign and low cost Li FeP O_4/C as cathode materials of lithium ion batteries.
Dormancy release and germination of Echinochloa crus-galli grains in relation to galactomannan-hydrolysing enzyme activity

Echinochloa crus-galli, one of the world's most serious weeds, influences seriously the yield and quality of cereal crop plant. It is well known that E. crus-galli grain is dormant, but its dormant type, as well as its dormancy release and germination in relation to galactomannan-hydrolysing enzyme activity were poorly understood. The cooperation of endo-β-mannanase (EC 3.2.1.78), β-mannosidase (EC 3.2.1.25) and α-galactosidase (EC 3.2.1.22) can hydrolyze the cell walls rich in mannan-based polymers. In the present paper, the mature grains are used as experimental materials, we investigated the water uptake of grains, the effect of removing partial endosperm, after-ripening, stratification and phytohormone on grain germination, and the change in endo-β-mannanase, β-mannosidase and α-galactosidase activities of grains during after-ripening and germination. The results showed that the freshly-collected grains were water-permeable and had only phase I and II of water uptake, while the grains after-ripened for 150 d had an obvious phase III of water uptake. In alternating photoperiod, the germination of grains freshly-collected was zero at 10–35°C, and that of half grains was 11% at 20°C only. The grain germination was notably promoted by after-ripening and stratification, but not by gibberellic acid and 6-benzyladenine at 0.0001–1 mmol L~(–1). β-Mannosidase activity increased during 0 to 300 d of after-ripening and then decreased. The activity of endo-β-mannanase and α-galactosidase of grains decreased with after-ripening. During grain germination, endo-β-mannanase and β-mannosidase activities obviously increased, while α-galactosidase activity decreased. Our data showed that E. crus-galli grain was a deep physiological dormant, the dormancy release by after-ripening was related to an increasing β-mannosidase activity, and its germination was closely associated with an increasing endo-β-mannanase and β-mannosidase activity; which have provided new knowledge to decrease the harm of E. crus-galli on production of cereal crop plant.
Design and application of electrical fire monitoring system in mining industry

To protect mining areas from electrical fire, it is very important to install electrical fire monitoring system to ensure safety in development of mineral resources and for buildings. In this paper, design for electrical fire monitoring and detection system with optional sensor modules has been proposed. In addition, necessity and suitability of electrical fire monitoring and detection system with optional sensor modules in mining areas have been reviewed. The designed electrical fire monitoring and detection system suitable for work environment of mining industry is composed by host-computer monitoring software and slave-computer detectors. Monitoring detectors are manufactured by using embedded technology. External shells deployed have superior enclosure performances and explosion-proof properties. It is easy to install and maintain the system. In general, the system has reached, or even exceeded standards specified in national standards for performances and appearances of such devices. Test results show application of electrical fire monitoring and detection system can effectively enhance monitoring intensity over the mining areas and provide reliable guarantee to ensure orderly development of mineral resources and to protect physical and property safety of citizens in these areas.
An evaluation of a perfluoromethylcyclohexane (PMCH) permeation plug release vessel (PPRV) in a controlled turbulent environment

The use of sulfur hexafluoride (SF_6) as a tracer gas for analyzing underground mine ventilation systems has been practiced for over 30 years. As a result, the methods used to release, sample, and analyze SF_6 are well accepted. As the complexity and size of underground mine ventilation networks increase, the ability of a SF_6 to function as a convenient and rapid means of analysis diminishes. The utilization of multiple tracer gases can mitigate this by removing the need to purge the background presence of a tracer before conducting another release and allowing for a more comprehensive evaluation using multi-zone techniques. Recent studies have identified perfluoromethylcyclohexane (PMCH) as a possible supplement for SF_6 in underground mine ventilation tracer studies. However, the deployment of PMCH remains a challenge because of this compounds physical properties. This paper evaluates a PMCH permeation plug release vessel (PPRV) under controlled turbulent conditions. The details of the experimental parameters used in the evaluation as well as a discussion regarding the performance of the PPRV are included.
Deformation tests and failure process analysis of an anchorage structure

In order to study the failure process of an anchorage structure and the evolution law of the body's deformation field, anchor push-out tests were carried out based on digital speckle correlation methods(DSCM). The stress distribution of the anchorage interface was investigated using the particle flow numerical simulation method. The results indicate that there are three stages in the deformation and failure process of an anchorage structure: elastic bonding stage, a de-bonding stage and a failure stage. The stress distribution in the interface controls the stability of the structure. In the elastic bonding stage, the shear stress peak point of the interface is close to the loading end, and the displacement field gradually develops into a "V" shape. In the de-bonding stage, there is a shear stress plateau in the center of the anchorage section, and shear strain localization begins to form in the deformation field. In the failure stage, the bonding of the interface fails rapidly and the shear stress peak point moves to the anchorage free end. The anchorage structure moves integrally along the macro-crack. The de-bonding stage is a research focus in the deformation and failure process of an anchorage structure, and plays an important guiding role in roadway support design and prediction of the stability of the surrounding rock.
Floor heave characteristics and control technology of the roadway driven in deep inclined-strata

Based on in-mine instrumentation and theoretical analysis of the unsymmetrical large-deformation that occurred in the roadway after excavation, Differential Floor Heave (DFH) was found to be the main reason for roadway failure. It needs to be pointed out that the specific roadway was driven in inclined rock strata. In addition, the factors that contribute to the occurrence of DFH are discussed in detail. It is believed that DFH is triggered by the unsymmetrical stress distribution in the floor and the different rock types encountered near the two floor corners. Hence, DFH control should be focused on the left floor corner where shearing failure occurs initially and the left floor surface where tensile failure is more severe. The proposed DFH control strategies include unsymmetrical grouting for the whole roadway, re-design of the roof and ribs support, reinforcement of the weak zones, and release of the concentrated stress in the earlier stage. Meanwhile, it is recommended that in the later stage, both bolts and cable bolts with higher strength and the backfilling technique using the coal measure rocks and concrete should be employed in the reversed-arch floor. The field instrumentation results, after using the proposed control strategies, indicate that large deformation in a DFH roadway has been successfully controlled.
Assessment of pot-hole subsidence risk for Indian coal mines

Ground subsidence induced by extraction of coal seam belowground brings about changes in surface environment leading to trough and pot-hole subsidence. Pot-hole subsidence is extremely hazardous and does not give any prior indication before its occurrence. In India, several pot-holes have occurred in the coal mines of South Eastern Coalfields Limited triggering the need for in-depth studies. In line with the requirement, literature review and field investigations were conducted to develop an in-depth understanding of various parameters influencing the occurrence of pot-holes. The critical parameters identified were rock to soil ratio, depth to height of extraction ratio, brittleness index of rock and rock density. Risk assessment of pot-hole subsidence has been done by developing an empirical rating approach named as pot-hole subsidence rating (PHSR), involving the critical parameters with suitable corrections for certain structural and mining conditions to obtain corrected PHSR (CPHSR). CPHSR was then applied for all the 34 pot-holes studied and it was found that all the pot-holes fall under Class I and Class II category of risk representing a very high to high risk class. An effort was made for the estimation of pot-hole depth utilizing the developed CPHSR in both the development and depillaring cases. The developed approach was found to yield consistent results in pot-hole depth prediction.
Optimal control of natural resources in mining industry

The paper focuses on the optimal control of natural resources in mining industry. The purpose is to propose an optimal extraction series of these resources during the lifetime of the Mine's maintenance. Following the proposed optimal control model, a sensitivity analysis has been performed that includes the interest rate impact on the optimal solution. This study shows that the increasing of the interest rate stimulates faster extraction of the resources. The discounting factor induces that the resource has to be extracted faster but this effect is counterbalanced by the diminishing returns of the annual cash flow. At higher parameters of "alpha" close to one of the power function about 80% from the whole resource will be extracted during the first 4 years of object/mine maintenance. An existence of unique positive root with respect to return of investment has been proposed and proved by two ways: by the "method of chords" and by using specialized software.
Hydrophilic characteristics of soft rock in deep mines

A series of water absorption tests on dried soft rock have been conducted by the intelligent testing system for water absorption tests in deep soft rock, including tests of water absorption with and without pressure. The results show that the water absorbing capacity of rock with a certain pressure is larger than that of rock without pressure; however, the relationship between the water absorbing percentage and the time can be expressed by w(t) = a(1 - e~(-bt)). In bi-logarithmic coordinates, the hydrophilic relationship with time in tests with pressure could be characterized by linearity, while they present concave or convex in tests without pressure. Based on the hypothesis that each influential factor is irrelevant and they have a linear correlation with the water absorbing capacity, we calculated the weight coefficient of each factor according to experimental results under different conditions. The calculations demonstrate that the effective porosity, content of smectite and kaolinite are all positively correlated with the water absorption capacity of rock; meanwhile, the fractal dimension of the effective pores presents a negative correlation with the water absorption capacity of rock. The water absorption capacity with pressure increases with increasing illite, chlorite and chlorite/smectite formation and a decrease in illite/smectite formation and the fractal dimension of the effective pores, while it is opposite in tests without pressure. The weight coefficient of smectite is smallest among positive factors, and the fractal dimension of the effective pores is the smallest amongst the negative factors.
斑点免疫金渗滤技术检测抗精子抗体的实验研究

抗精子抗体是由于精子或精浆中的抗原类物质刺激机体通过同种免疫或自身免疫而产生,包括IgA、IgG、IgM、IgE等类型,抗精子抗体可抑制精子活动、干扰精子的获能等多个环节,导致不孕不育的发生。近年来,免疫性因素导致的不孕不育已经成为困扰适龄生育人群的重要问题。有资料估计,临床上大约20%的不孕不育是由于免疫性因素导致的,其中抗精子抗体阳性导致的免疫性不孕被认为是导致不孕不育的重要原因之一。调查报告显示广东省初婚夫妇不孕症的发生率为14.7%,以珠江三角洲地区最高,而且发病率有逐年增高的趋势。因此,若能早期筛查和检测导致妇女不孕的抗精子抗体等自身抗体及其滴度,对提高婚前检查效率、早期预防、治疗及减低不育不孕发生具有重要的临床价值及社会意义。传统的ELSIA检测法检测抗精子抗体存在敏感性和精密度低,自动化程度较低,检测过程容易受环境和人为因素的影响,检测步骤繁杂、耗时长。建立快捷、简便、特异性、重复性和敏感性高的检查方法对于提高不孕妇女检查效率具有重要的临床价值。
交通伤后急性闭角型青光眼鉴定分析2例

急性闭角型青光眼(acute angle closure glaucoma, AACG)是一种以眼压急剧升高并伴有相应症状和眼前段组织改变为特征的眼病,常有远视,双眼先后或同时发病。眼部局部的解剖结构变异是其主要发病机理。随着年龄的增长,晶状体厚度增加,前房更浅,瞳孔阻滞加重,发病率增高。一旦周边虹膜与小梁网发生接触,房角即告关闭,眼压急剧升高,引起急性发作。除解剖因素外,一般认为AACG与血管神经的稳定性有关,情绪激动、精神创伤、过度劳累、气候突变以及暴饮暴食等常为AACG的诱因。此时血管神经调节中枢发生故障致使血管舒缩功能失调,睫状体毛细血管扩张,血管渗透性增加,房水增多,后房压力升高,并在有解剖因素的基础上,睫状体充血水肿使房角阻塞加重,眼压急剧升高,导致青光眼的急性发作。
临夏回族自治州撒拉族人群15个STR基因座遗传多态性

短串联重复序列(STR)是一类简单重复DNA,其重复序列通常为2?6bp。据临夏回族自治州第六次人口普査'全州共有撒拉族人口12047人(占全州人口总数的0.556%),主要聚居于积石山保安族东乡族撒拉族自治县境内的大河家镇。本研究应用Identi-filer~~? Plus试剂盒对聚居于甘肃省临夏回族自治州积石山县境内的245名撒拉族无关个体15个STR基因座遗传多态性进行调查,为我国西北地区少数民族人群法医学个人识别和亲权鉴定提供基础数据。
Adaptive backstepping finite-time sliding mode control of spacecraft attitude tracking

This paper investigates the finite-time attitude tracking problem for rigid spacecraft. Two backstepping finite-time sliding mode control laws are proposed to solve this problem in the presence of inertia uncertainties and external disturbances. The first control scheme is developed by combining sliding mode control with a backstepping technique to achieve fast and accurate tracking responses. To obtain higher tracking precision and relax the requirement of the upper bounds on the uncertainties, a second control law is also designed by combining the second order sliding mode control and an adaptive backstepping technique. This control law provides complete compensation of uncertainty and disturbances. Although it assumes that the uncertainty and disturbances are bounded, the proposed control law does not require information about the bounds on the uncertainties and disturbances. Finite-time convergence of attitude tracking errors and the stability of the closed-loop system are ensured by the Lyapunov approach. Numerical simulations on attitude tracking control of spacecraft are provided to demonstrate the performance of the proposed controllers.
Investigations on the Improving Aerodynamic Performances of Last Stage Steam Turbine and Exhaust Hood under Design and Off Design Conditions

The purpose of this paper is to improve the aerodynamic performances of the last stage turbine and the exhaust hood of a 600MW steam turbine under design and off design conditions. During operation, strong flow interactions between the turbine and the exhaust hood impose influences on the flow behavior in the hood and lead to the unsatisfactory aerodynamic performance of the turbine and exhaust hood. So the exhaust hood has the potential to be improved in terms of aerodynamic efficiency. Considering the flow interactions between the turbine and the exhaust hood, the profiles of the diffuser end-wall were optimized. The coupled model turbine and model exhaust hood calculations and experiments were carried out to validate the effects of the optimization. Model experiments show that the design modifications resulted in a substantial increase in the overall pressure recovery coefficient. The flow and aerodynamic performances of the full-scale last stage turbine and full-scale exhaust hood were simulated to explore the flow physics alterations to the modification of diffuser geometry. The wet steam was selected as the flow medium. The actual flow fields under different operation conditions were analyzed.
Dielectrophoresis Flow Control of Volatile Fluids in Microchannels

In recent years the microchannel heat exchangers have been applied in a great variety of technical areas. One of the problems, which exist in the microchannel technology is the flow instabilities, including fluid maldistribution in the microchannels array for the case of two-phase flow especially in micro-evaporators. One of the ways to solve this problem is flow rate control at the microchannel inlet. However, due to very small inlet to the array of microchannels the classic flow restriction device (with moving mechanical parts) will be difficult to apply. The new device for the flow rate control based on the dielectrophoresis force was presented in the paper. Experimental research results of using this device for refrigerant flow control was presented in the paper. The experimentally obtained relationships between applied voltages and frequencies and flow rates were presented showing opportunity for applying such method for refrigerants and other volatile fluids.
克林霉素导致瘫痪麻木2例

克林霉素抗菌谱比较广，并且抗菌效力较强，对革兰阳性菌和厌氧菌具有很好的杀菌作用，临床应用时又不需要做皮试，故而在临床上获得广泛的应用，同时，其不良反应也日渐增多，其常见的不良反应为：胃肠道反应如恶心、呕吐、腹痛、腹泻以及二重感染等；过敏反应；肝肾功能的损害，特别是肾功能衰竭与血尿；神经系统以及血液系统的反应。现将我院收治的2例使用克林霉素导致瘫痪、麻木的患者的临床特点及预后分析报道如下。
内陆及近岸二类水体透明度的遥感研究进展

自1865年，意大利天文学家Pietro Angelo Secchi发明塞克盘(Secchi disk)以来，使用塞克盘测量水体透明度迄今已有近150 a的历史。透明度(Secchi disk depth)是指放入水中的塞克盘能够看得见的最大深度。它是描述水体光学性质的基本参数之一，也是水质调查中的一个重要指标，反映了水体的透光能力。在军事上是确定潜艇潜没深度和布设水雷的重要参数。在海洋水质监测中，它是一种直观的指示参数，可以评估水体的富营养化程度。水体透明度的变化会严重影响沉水植被的生长以及依靠可见光捕食的鱼类和水鸟等水生动物的生存。此外，水体透明度可估算水体固有光学参数、叶绿素 a 浓度甚至是初级生产力。因此，水体透明度的研究对水环境变化、水体光学参数、水生生态系统以及初级生产力的深入研究具有重要意义。然而，尽管传统透明度测量方法操作简单，但要实现监测大面积水体透明度的时空变化，显然是不现实的。遥感技术具有快速、大面积、动态覆盖等优势，能弥补传统测法耗时长且费用高的缺陷，尤其是能监测人员较难到达的区域，因而逐渐成为监测水体透明度的重要且有效的手段之一。
Stability and local bifurcation of parameter-excited vibration of pipes conveying pulsating fluid under thermal loading

The parametric excited vibration of a pipe under thermal loading may occur because the fluid is often transported heatedly. The effects of thermal loading on the pipe stability and local bifurcations have rarely been studied. The stability and the local bifurcations of the lateral parametric resonance of the pipe induced by the pulsating fluid velocity and the thermal loading are studied. A mathematical model for a simply supported pipe is developed according to the Hamilton principle. Two partial differential equations describing the lateral and longitudinal vibration are obtained. The singularity theory is utilized to analyze the stability and the bifurcation of the system solutions. The transition sets and the bifurcation diagrams are obtained both in the unfolding parameter space and the physical parameter space, which can reveal the relationship between the thermal field parameter and the dynamic behaviors of the pipe. The frequency response and the relationship between the critical thermal rate and the pulsating fluid velocity are obtained. The numerical results demonstrate the accuracy of the single-mode expansion of the solution and the stability and local bifurcation analyses. It also confirms the existence of the chaos. The presented work can provide valuable information for the design of the pipeline and the controllers to prevent the structural instability.
Residual tree damage along skidding trails in beech stands in Greece

We studied the damage caused to unfelled trees during skidding operations in four beech stands of northern and central Greece that were managed under differing harvesting systems. After timber was harvested we recorded and analyzed all damage to a width of 2 m along both sides of the skid trails. The percentage of damaged residual trees was 17–28 %. Higher numbers of saplings were uprooted or destroyed in parts of the stands with high natural regeneration. Most damaged trees suffered 1.33–1.90 wounds that were inflicted up to a height of 1 m above ground level. At all sites mean wound sizes were large, 89–1190 cm~2, and caused elevated risk of future fungal infection. The damage caused by skidding during timber harvesting can be minimized by better planning the harvest operations, and training forest workers in reduced impact logging.
Properties of paper mill sludge-wood fiber-HDPE composites after exposure to xenon-arc weathering

We used paper mill sludge (PMS) to substitute for part of the wood fibers (WF) used to reinforce high density polyethylene (HDPE). The resulting composites were subjected to xenon-arc weathering. The composite filled with limited PMS (under 10 %) had mechanical properties and aging resistance similar to those without PMS. The composites containing more PMS faded and cracked more readily than those without PMS. Based on the carbonyl index, crystallinity, and wood index, PMS appeared to accelerate the degradation of composites during weathering. Adding PMS to WF–HDPE composites reduced the weathering resistance, and this reduction was not significant if the PMS content did not exceed 20 % of the wood fibers. Therefore, PMS could be used as a reinforcement in wood-plastic composites at levels less than 20 % of the wood fiber content.