基于不等距灰预测模型的变频调速设备故障预测

灰色预测模型具有要求样本数据少、计算方便、预测精度较高并且可对结果进行校验等优点,因此被广泛应用于设备的故障诊断中。本文针对在数据采集过程中出现的不等距数据无法用一般等距模型来预测的情况,建立了一般累加生成差分灰预测模型UGM(1,1)的改进模型,将其用于变频调速设备的状态监测实践中。结果表明该预测模型能使预测精度提高了10%以上,同时计算量并未明显增加。该方法还可以广泛应用于工业企业、医疗卫生等行业各种设备的故障诊断。

灰色数列预测应用分析

对灰色理论与统计分析在装备经济管理工作中的实用性分别以模型机理、模型数据处理复杂性和模型结果精度三方面进行了比较分析 ,着重指出在某些情况下灰色模型具有小样本而精度高的特点 。

Acid mine drainage activation mechanism on lime-depressed pyrite flotation from copper sulfide ore

The lime-depressed pyrite from Cu differential flotation tailings with acid mine drainage(AMD)as a natural activator was recovered.The effect of AMD on lime-depressed pyrite flotation was investigated by a series of laboratory flotation tests and surface analytical techniques.Flotation test results indicated that AMD could effectively activate the pyrite flotation with a sodium butyl xanthate(SBX)collector,and a high-quality sulfur concentrate was obtained.Pulp ion concentration analysis results indicated that AMD facilitated desorption of Ca~(2+)and adsorption of Cu~(2+)on the depressed-pyrite surface.Adsorption measurements and contact angle analysis results confirmed that adding AMD improved the adsorption amount of SBX collector on the pyrite surface and increased the contact angle by 31°.Results of Raman spectroscopy and X-ray photoelectron spectroscopy analysis indicated that AMD treatment promoted the formation of hydrophobic species(S~0 hydrophobic entity and copper sulfides)and the removal of hydrophilic calcium and iron species on the pyrite surface,which reinforced the adsorption of collector.The findings of the present research provide important theoretical basis and technical support for a cleaner production of copper sulfide ores.

A new grey forecasting model based on BP neural network and Markov chain

A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is equivalent to the time response model, was proved by analyzing the features of grey forecasting model（GM（1,1））. Based on this, the differential equation parameters were included in the network when the BP neural network was constructed, and the neural network was trained by extracting samples from grey system＇s known data. When BP network was converged, the whitened grey differential equation parameters were extracted and then the grey neural network forecasting model （GNNM（1,1）） was built. In order to reduce stochastic phenomenon in GNNM（1,1）, the state transition probability between two states was defined and the Markov transition matrix was established by building the residual sequences between grey forecasting and actual value. Thus, the new grey forecasting model（MNNGM（1,1）） was proposed by combining Markov chain with GNNM（1,1）. Based on the above discussion, three different approaches were put forward for forecasting China electricity demands. By comparing GM（1, 1） and GNNM（1,1） with the proposed model, the results indicate that the absolute mean error of MNNGM（1,1） is about 0.4 times of GNNM（1,1） and 0.2 times of GM（I, 1）, and the mean square error of MNNGM（1,1） is about 0.25 times of GNNM（1,1） and 0.1 times of GM（1,1）.

Nitrogen Forms in Humic Substances

In this paper,the nitrogen forms in newly-formed humic substances,including humic acid (HA),fulvic acid (FA) and humic acid in humin (HAI),were studied by using the ^15N CP-MAS NMR technique in combination with chemical approaches.Results show that the majority of nitrogen in HA,FA and HAI was in the amide form with some presented as aliphatic and/ or aromatic amines and some as pyrrole type nitrogen,although the contents of nonhydrolyzable nitrogen in them differed greatly from each other (15-55%).

使篩糠工作自動化、密閉化

在安全生產和節約粮食的号召下,泉州市生教院加工廠技工謝彼得在現有設備的基礎上鑽研技術,想办法改進吸糠机的風筒並加密閉化,結果大大減少人工篩糠,根絕糠灰滿車間飛揚現象,據現有生產水平初步統計,每年可為国家增加四千一百九十四元五角的收入,且减少五百一十九元九角的開支。

爱茉莉

女友爱茉莉,平日嬉皮或朋克装束,大花布裙,中分直发,有时候描烟灰熏的眼影。像所有流落在北京艺术圈的女子,浑身散发不知归宿的桀骜气息。无数场潮来潮去的恋爱,虚假繁荣背后,被这个城市的浑浊气流吞噬,年华日渐老去,已经三十又三。口口声声说,很想结婚,很想生孩子,但所有的朋友都不相信她。不相信她找不到可以结婚的男人,或者不相信她能找到可以结婚的男人。因为身边的男人来去太快太热闹。她的寂寞,似乎被理所当然地视作一场自作自受的戏剧。虽然她总是这样的光彩夺目,令人爱慕。

橙金色雏菊物语

一、二人三足认认颜然缘于我的一次受伤。事情起因是这样的:我是校体育队队员,放学后如常练习跨栏,体育老师吹哨前三秒钟,我视线里闪进两个熟悉的身影,他们并肩而行。哨声响起,心神恍惚的我起跑慢了。

Trace element composition in tuite decomposed from natural apatite in high-pressure and high-temperature experiments

Tuite has been suggested as a potential reservoir for trace elements in the deep mantle,but no evidence confirms this supposition.By using a natural apatite as starting material,the trace-element-bearing tuite large crystals were obtained under highpressure and high-temperature conditions(15 GPa and 1800 K).X-ray diffraction pattern and Micro-Raman spectrum of the run product confirm that tuite was synthesized.The concentrations of trace elements in tuite crystals were analyzed by laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS).The rare earth element patterns of tuite show enrichment of light rare earth elements relative to heavy rare earth elements.Tuite shows high concentrations of Th and Sr,and negative anomalies of Rb,Nb,and Hf.The results show that tuite can accommodate a large amount of trace elements.Tuite might be an important host to accommodate trace elements if there is much apatite subducted into the deep mantle.

Geothermal regime and hydrocarbon kitchen evolution in the Jianghan Basin

The present geothermal gradient and terrestrial heat flow was calculated of 18 wells in the Jianghan Basin.Thermal gradient distribution of the Jianghan Basin was obtained based on data of systematical steady-state temperature and oil-test temperature.The basin-wide average thermal gradient in depth interval of 0-4000 m is 33.59℃/km.We report nine measured terrestrial heat flow values based on the data of detailed thermal conductivity and systematical steady-state temperature.These values vary from 41.9 to 60.9 mW/m 2 with a mean of 52.3±6.3 mW/m 2.However,thermal history analyses based on vitrinite reflectance(VR) and apatite fission track(AFT) data indicate that thermal gradient in the northern and southern Qianbei Fault reached its peak of ～36 and ～39℃/km respectively in the Middle Jurassic and the Oligocene,and it descended during the early Miocene to the present-time value.Furthermore,tectonic subsidence analysis reveals that the tectonic subsidence of the Jianghan Basin in the Cretaceous to early Miocene was characterized by synrift initial subsidence followed by the subsequent thermal subsidence.The thermal history and tectonic subsidence history of Jianghan Basin are of great significance to petroleum exploration and hydrocarbon source assessment,because they bear directly on issues of petroleum source rock maturation.Based on the thermal history and tectonic subsidence history,with the combination of geochemical and thermal parameters,the maturation and the hydrocarbon generation intensity evolution history of the P2d source rocks are modeled.The results show that the P2d source rocks are in a higher degree of maturation at present,and the Yuan'an and Herong sags are the two most important kitchens in the Late Jurassic,Xiaoban Sag is another most important kitchen during the Late Cretaceous to late Paleogene,and the Zhijiang and Mianyang sags are other two important hydrocarbon kitchens in the Late Cretaceous.The Mianyang Sag and Yichang Ramp are the favorable exploration targets in the future.This study may provide new insight for the understanding of the oil and gas exploration potential for the Jianghan Basin.

Diet of the Assamese macaque Macaca assamensis in lime- stone habitats of Nonggang, China

To enhance our understanding of dietary adaptations in macaques we studied the diet of the Assamese macaque Macaca assamensis in limestone seasonal rain forests at Nonggang Nature Reserve, China from September 2005 to August 2006. Our results show that although macaques fed on many plant species, 85.2% of the diet came from only 12 species, of which a bamboo species, Indocalamus calcicolus contributed to 62% of the diet. Young leaves were staple food items （74.1% of the diet） for Assamese macaques at Nonggang, and constituted the bulk of monthly diets almost year-round, ranging from 44.9% （July） to 92.9% （May）. Young parts of Indocalamus calcicolus unexpanded leaves contributed to a large proportion of the young leaf diet in most months. Fruit accounted for only 17.4% of the diet, with a peak of consumption in July. We suggest that this highly fo- livorous diet may be related to the long lean season of fruit availability in limestone habitats as well as the utilization of cliffs of low fruit availability