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Contact fatigue life prediction of a bevel gear under spectrum loading

Pan JIA, Huaiju LIU, Caichao ZHU, Wei WU, Guocheng LU

《机械工程前沿（英文）》 2020年第15卷第1期页码 123-132 doi: 10.1007/s11465-019-0556-8

摘要： Rolling contact fatigue (RCF) issues, such as pitting, might occur on bevel gears because load fluctuation induces considerable subsurface stress amplitudes. Such issues can dramatically affect the service life of associated machines. An accurate geometry model of a hypoid gear utilized in the main reducer of a heavy-duty vehicle is developed in this study with the commercial gear design software MASTA. Multiaxial stress–strain states are simulated with the finite element method, and the RCF life is predicted using the Brown–Miller–Morrow fatigue criterion. The patterns of fatigue life on the tooth surface are simulated under various loading levels, and the RCF curve is numerically generated. Moreover, a typical torque–time history on the driven axle is described, followed by the construction of program load spectrum with the rain flow method and the Goodman mean stress equation. The effects of various fatigue damage accumulation rules on fatigue life are compared and discussed in detail. Predicted results reveal that the Miner linear rule provides the most optimistic result among the three selected rules, and the Manson bilinear rule produces the most conservative result.

关键词： bevel gear rolling contact fatigue (RCF) multiaxial fatigue criterion load spectrum damage accumulation rule

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交叉模态对结构随机振动疲劳损伤的贡献

朱学旺,刘青林

《中国工程科学》 2008年第10卷第10期页码 36-41

摘要：

以小阻尼简支梁为例，讨论了交叉模态对随机振动疲劳损伤累积的贡献；结构的响应分析采用模态叠加方法，随机振动疲劳损伤累积分析采用Miner线性疲劳损伤准则。数值模拟结果表明,即使是小阻尼稀疏模态结构，交叉模态对结构振动疲劳损伤累积的贡献也是不容忽视的。

关键词：交叉模态结构随机振动疲劳损伤累积随机振动响应模态叠加小阻尼稀疏模态系统

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确定性疲劳累积损伤理论进展

杨晓华,姚卫星,段成美

《中国工程科学》 2003年第5卷第4期页码 81-87

摘要：

著名的Miner-Palmgren线性累积损伤理论的提出已有70余年，但由于疲劳问题的复杂性，迄今为止还没有一个模型的工程应用价值能与该理论媲美。疲劳累积损伤理论仍在发展与完善中。文章根据疲劳损伤与疲劳累积损伤理论的特点，将确定性疲劳累积损伤理论分成两大类，即线性累积损伤理论和非线性累积损伤理论，并将主要的非线性累积损伤理论分成五类：a. 基于损伤曲线法的非线性累积损伤理论；b. 基于材料物理性能退化概念的非线性累积损伤理论；c. 基于连续损伤力学概念的非线性累积损伤理论；d. 考虑载荷间相互作用效应的非线性累积损伤理论；e. 基于能量法的非线性累积损伤理论。文章分析了每一类模型中有代表性模型的物理背景，回答了模型在疲劳累积损伤理论中存在的主要问题，简要评述了模型的优缺点，讨论了确定性疲劳累积损伤理论的几个关键问题。

关键词：疲劳线性与非线性累积损伤损伤力学能量

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Entity and relation extraction with rule-guided dictionary as domain knowledge

《工程管理前沿（英文）》页码 610-622 doi: 10.1007/s42524-022-0226-0

摘要： Entity and relation extraction is an indispensable part of domain knowledge graph construction, which can serve relevant knowledge needs in a specific domain, such as providing support for product research, sales, risk control, and domain hotspot analysis. The existing entity and relation extraction methods that depend on pretrained models have shown promising performance on open datasets. However, the performance of these methods degrades when they face domain-specific datasets. Entity extraction models treat characters as basic semantic units while ignoring known character dependency in specific domains. Relation extraction is based on the hypothesis that the relations hidden in sentences are unified, thereby neglecting that relations may be diverse in different entity tuples. To address the problems above, this paper first introduced prior knowledge composed of domain dictionaries to enhance characters’ dependence. Second, domain rules were built to eliminate noise in entity relations and promote potential entity relation extraction. Finally, experiments were designed to verify the effectiveness of our proposed methods. Experimental results on two domains, including laser industry and unmanned ship, showed the superiority of our methods. The F1 value on laser industry entity, unmanned ship entity, laser industry relation, and unmanned ship relation datasets is improved by +1%, +6%, +2%, and +1%, respectively. In addition, the extraction accuracy of entity relation triplet reaches 83% and 76% on laser industry entity pair and unmanned ship entity pair datasets, respectively.

关键词： entity extraction relation extraction prior knowledge domain rule

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Physiological functions and clinical implications of the N-end rule pathway

null

《医学前沿（英文）》 2016年第10卷第3期页码 258-270 doi: 10.1007/s11684-016-0458-7

摘要：

The N-end rule pathway is a unique branch of the ubiquitin-proteasome system in which the determination of a protein’s half-life is dependent on its N-terminal residue. The N-terminal residue serves as the degradation signal of a protein and thus called N-degron. N-degron can be recognized and modifed by several steps of post-translational modifications, such as oxidation, deamination, arginylation or acetylation, it then polyubiquitinated by the N-recognin for degradation. The molecular basis of the N-end rule pathway has been elucidated and its physiological functions have been revealed in the past 30 years. This pathway is involved in several biological aspects, including transcription, differentiation, chromosomal segregation, genome stability, apoptosis, mitochondrial quality control, cardiovascular development, neurogenesis, carcinogenesis, and spermatogenesis. Disturbance of this pathway often causes the failure of these processes, resulting in some human diseases. This review summarized the physiological functions of the N-end rule pathway, introduced the related biological processes and diseases, with an emphasis on the inner link between this pathway and certain symptoms.

关键词： N-end rule pathway Ate1 cardiovascular development neurogenesis spermatogenesis neurodegenerative disorders Johanson–Blizzard syndrome

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Genotype variations in accumulation of cadmium and lead in celery (

Kun ZHANG, Jianbing WANG, Zhongyi YANG, Guorong XIN, Jiangang YUAN, Junliang XIN, Charlie HUANG

《环境科学与工程前沿（英文）》 2013年第7卷第1期页码 85-96 doi: 10.1007/s11783-012-0399-3

摘要： To help reduce risks of heavy metal pollution, two pot experiments were conducted to investigate the variations, transfer potential, and stability of Cadmium (Cd) and Lead (Pb) accumulations in celery ( L.) and to screen for low Cd and Pb accumulative cultivars. The maximum differences in shoot Cd concentration were 4.7-fold under low-Cd exposure and 3.3-fold under high-Cd exposure. These genotype variations in Cd accumulation are sufficiently large to help reduce Cd contamination risk in soil by using the Low-Cd-Accumulative genotypes. Cd accumulation of the Low-Cd-Accumulative genotypes is significantly positive correlated with Pb accumulation. Evidence obtained proves that Cd and Pb accumulations in celery are stable and genotype-dependent at the cultivar level. The presence of high-Pb contamination in soil promoted Cd accumulation in shoots of celery. Celery is considered a species with high risks in Cd pollution and low risks in Pb pollution. Among the tested cultivars, cv. Shuanggangkangbing (SGKB) had the lowest shoot Cd and Pb accumulating abilities, and thus is the most important material for breeding of pollution-safe cultivars (PSCs) to minimize Cd and Pb accumulations in celery.

关键词： cadmium (Cd) accumulation lead (Pb) accumulation celery genotype variation food safety

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Novel slack-based robust scheduling rule for a semiconductor manufacturing system with uncertain processing

Juan LIU, Fei QIAO, Yumin MA, Weichang KONG

《工程管理前沿（英文）》 2018年第5卷第4期页码 507-514 doi: 10.15302/J-FEM-2018045

摘要：

The NP-hard scheduling problems of semiconductor manufacturing systems (SMSs) are further complicated by stochastic uncertainties. Reactive scheduling is a common dynamic scheduling approach where the scheduling scheme is refreshed in response to real-time uncertainties. The scheduling scheme is overly sensitive to the emergence of uncertainties because the optimization of performance (such as minimum make-span) and the system robustness cannot be achieved simultaneously by conventional reactive scheduling methods. To improve the robustness of the scheduling scheme, we propose a novel slack-based robust scheduling rule (SR) based on the analysis of robustness measurement for SMS with uncertain processing time. The decision in the SR is made in real time given the robustness. The proposed SR is verified under different scenarios, and the results are compared with the existing heuristic rules. Simulation results show that the proposed SR can effectively improve the robustness of the scheduling scheme with a slight performance loss.

关键词： semiconductor manufacturing system uncertain processing time dynamic scheduling slack-based robust scheduling rule

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关联规则挖掘算法综述

毕建欣,张岐山

《中国工程科学》 2005年第7卷第4期页码 88-94

摘要：

介绍了关联规则挖掘算法的基本原理，并按照挖掘中涉及到的变量数目（维数）、数据的抽象层次和处理变量的类别（布尔型和数值型），依次对关联规则挖掘算法的研究进行综述，并对一些典型的算法进行分析和比较，最后展望了关联规则挖掘算法的研究方向。

关键词：数据挖掘关联规则算法综述

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Comparison of growth and lipid accumulation properties of two oleaginous microalgae under different nutrient

Qiao ZHANG,Yu HONG

《环境科学与工程前沿（英文）》 2014年第8卷第5期页码 703-709 doi: 10.1007/s11783-014-0649-x

摘要： This study compared the growth and lipid accumulation properties of two oleaginous microalgae, namely, sp. LX1 and sp. HQ, under different nutrient conditions. Both algal species obtained the highest biomass, lipid content and lipid yield under low-nutrient conditions (mBG11 medium). The biomass, lipid content and lipid yield of sp. LX1 were 0.42 g·L , 22.5% and 93.8 mg·L , respectively. These values were relatively higher than those of sp. HQ (0.30 g·L , 17.1% and 51.3 mg·L , respectively). These algae were then cultivated in an SE medium that contained more nutrients; as a result, the biomass and lipid yield of sp. LX1 reduced more significantly than those of sp. HQ. Opposite results were observed in lipid and triacylglycerols (TAGs) contents. The cell sizes of both algal species under low-nutrient conditions were larger than those under high-nutrient conditions. sp. HQ cells did not aggregate, but sp. LX1 cells flocculated easily, particularly under low-nutrient conditions. In summary, low-nutrient conditions favour the growth and lipid production of both algae, but sp. LX1 outperforms sp. HQ.

关键词： Scenedesmus sp. LX1 Chlorella sp. HQ growth rate algal biomass lipid accumulation triacylglycerols (TAGs)

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Erratum to: Meter-scale variation within a single transect demands attention to taxon accumulation curves

《环境科学与工程前沿（英文）》 2022年第16卷第6期 doi: 10.1007/s11783-022-1560-5

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Meter-scale variation within a single transect demands attention to taxon accumulation curves in riverine

《环境科学与工程前沿（英文）》 2022年第16卷第5期 doi: 10.1007/s11783-022-1543-6

摘要：

● Riverine microbiomes exhibited hyperlocal variation within a single transect.

关键词： Microbiome Freshwater Taxon accumulation curve Community assembly

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Study on the NOx release rule along the boiler during pulverized coal combustion

JIN Jing, ZHANG Zhongxiao, LI Ruiyang

《能源前沿（英文）》 2007年第1卷第1期页码 91-95 doi: 10.1007/s11708-007-0009-7

摘要： Numerical simulation and experimental study on NO release along the boiler during pulverized coal combustion have been conducted. With the increase of temperature the NO emission increased and the peak value of NO release moved forward. But when the temperature increased to a certain degree, NO emission began to reduce. NO emission increased with the increase of nitrogen content of coal. The peak value of NO release moved backwards with the increase of coal rank. NO emission increased obviously with the increase of stoichiometric ratio. There existed a critical average diameter of the pulverized coal (). If "d, NO emission reduced with the decrease of pulverized coal size. If >, NO emission reduced with the increase of the pulverized coal size. The results showed that the simulation results are in agreement with the experimental results for concentration distribution of NO along the axis of the furnace.

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Experimental study of nitrite accumulation in pre-denitrification biological nitrogen removal process

WU Xuelei, CHEN Lunqiang, PENG Yongzhen, WANG Pu, WANG Yayi

《环境科学与工程前沿（英文）》 2008年第2卷第2期页码 236-240 doi: 10.1007/s11783-008-0008-x

摘要： The effect of dissolved oxygen (DO) concentration on nitrite accumulation was investigated in a pilot-scale pre-denitrification process at room temperature for 100 days. In the first 10 days, due to the instability of the system, the DO concentration fluctuated between 1.0 and 2.0 mg/L. In the next 14 days, the DO concentration was kept at 0.5 mg/L and nitrite accumulation occurred, with the average nitrite accumulation rate at 91%. From the 25th day, the DO concentration was increased to 2.0 mg/L to destroy the nitrite accumulation, but nitrite accumulation rate was still as high as 90%. From the 38th day the nitrite accumulation rate decreased to 15%–30% linearly. From the 50th day, DO concentration was decreased to 0.5 mg/L to resume nitrite accumulation. Until the 83rd day the nitrite accumulation rate began to increase to 80%. Dissolved oxygen was the main cause of nitrite accumulation, taking into account other factors such as pH, free ammonia concentration, temperature, and sludge retention time. Because of the different affinity for oxygen between nitrite oxidizing bacteria and ammonia oxidizing bacteria when DO concentration was kept at 0.5 mg/L, nitrite accumulation occurred.

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Simultaneous denitrifying phosphorus accumulation in a sequencing batch reactor

YUAN Linjiang, HAN Wei, WANG Lei, YANG Yongzhe, WANG Zhiying

《环境科学与工程前沿（英文）》 2007年第1卷第1期页码 23-27 doi: 10.1007/s11783-007-0004-6

摘要： In order to achieve simultaneous nitrogen and phosphorus removal in the biological treatment process, denitrifying phosphorus accumulation (DNPA) and its affecting factors were studied in a sequencing batch reactor (SBR) with synthetic wastewater. The results showed that when acetate was used as the sole carbon resource in the influent, the sludge acclimatized under anaerobic/aerobic operation had good phosphorus removal ability. Denitrifying phosphorus accumulation was observed soon when fed with nitrate instead of aeration following the anaerobic stage, which is a vital premise to DNPA. If DNPA sludge is fed with nitrate prior to the anaerobic stage, the DNPA would weaken or even disappear. At the high concentration of nitrate fed in the anoxic stage, the longer anoxic time needed, the better the DNPA was. Induced DNPA did not disappear even though an aerobic stage followed the anoxic stage, but the shorter the aerobic stage lasted, the higher the proportions of phosphorus removal via DNPA to total removal.

关键词： SBR synthetic wastewater Induced DNPA resource removal ability

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基于非关联流动法则的滑移线场及上限法研究

郑颖人,邓楚键,王敬林

《中国工程科学》 2010年第12卷第8期页码 56-69

摘要：

当前岩土材料的滑移线场理论及上限法中都广泛采用经典塑性理论中的关联流动法则，由此得出应力特征线与速度滑移线一致的结论。而试验得知，岩土材料并不服从关联流动法则，因而应力特征线与速度滑移线不可能重合。文章分析了基于关联流动法则的滑移线场及上限法中存在的问题，根据广义塑性理论推导了基于非关联流动法则的滑移线场及上限法，消除了现行滑移线场理论及上限法理论中的种种矛盾。

关键词：滑移线场上限法关联流动法则非关联流动法则广义塑性理论