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牙轮钻机的发展趋势

国外金属矿山 1991年第10期16卷 90-94页

作者： B.l.霍金斯 l.e.霍尔沃斯李公照美国加德纳-丹佛采矿和建筑设备公司美国加德纳-丹佛采矿和建筑设备公司牙轮钻机生产经理总工程师

很早以前,许多露天矿的矿石都比较软,当时都是采用重型冲击式钻机穿凿较小直径的炮孔。第二次世界大战后,炸药的革新使之可以采用较大直径的炮孔。爆破技术的这一突破对当时生产率的迅猛提高起了刺激作用,同时,也满足了北美的汽车制造... 详细信息

很早以前,许多露天矿的矿石都比较软,当时都是采用重型冲击式钻机穿凿较小直径的炮孔。第二次世界大战后,炸药的革新使之可以采用较大直径的炮孔。爆破技术的这一突破对当时生产率的迅猛提高起了刺激作用,同时,也满足了北美的汽车制造业和建筑业对钢铁的迫切需求。最初,在软岩中装填这种新炸药的较大直径的炮孔,多半是由钢绳冲击式钻机穿凿的,这类钻机基本上是机械传动的钻机。机械传动或机械-液压传动的牙轮钻机是缓慢地进入采矿市场的,特别是进入矿石和剥离层很软的采矿市场尤为缓慢。配合当时的钻头和爆破技术。

关键词：牙轮钻机发展露天矿

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关联指令分区控制脉宽调制技术

中国电机工程学报 2000年第6期20卷 43-46页

作者：郑琼林郝荣泰北方交通大学机械与电气工程学院北京l00044

提出了一种新的脉宽调制 (PWM )方法———关联指令分区控制 (CRSC)方法。CRSC脉宽调制技术把 1个周期分成 6个区 ,在 1个分区内 ,其中 1个桥臂 (比如U相 )不调制 ,即开关状态不变 ,其它 2个桥臂 (比如V相和W相 )按照关联指令分别进行... 详细信息

提出了一种新的脉宽调制 (PWM )方法———关联指令分区控制 (CRSC)方法。CRSC脉宽调制技术把 1个周期分成 6个区 ,在 1个分区内 ,其中 1个桥臂 (比如U相 )不调制 ,即开关状态不变 ,其它 2个桥臂 (比如V相和W相 )按照关联指令分别进行调制。关联指令实质上是线电压指令 ,由需调制相的相指令和不调制相的相指令相减而得。对三相逆变器系统来说 ,与传统PWM方法相比 ,CRSC方法可使逆变器输出电压提高 15 .47% ,开关次数降低 1/ 3。仿真与实验验证了理论分析结果。

关键词：逆变器脉宽调制关联指令分区控制

红外辐射联合回火与冷激杀菌技术对胡萝卜粉品质的影响

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中国食品学报 2022年第2期22卷 190-199页

作者：郭建陈芹芹毕金峰吕莹张星杨忻瑞中国农业科学院农产品加工研究所/农业农村部农产品加工重点实验室北京100193

首先研究不同红外辐射温度(100,110,120℃)及辐射时间(2.5,5,10 min)对胡萝卜粉微生物及品质的影响,然后根据栅栏效应原理研究红外辐射-回火、红外辐射-冷激联合杀菌对胡萝卜粉微生物、色调值、类胡萝卜素含量等品质的影响。结果表明:10... 详细信息

首先研究不同红外辐射温度(100,110,120℃)及辐射时间(2.5,5,10 min)对胡萝卜粉微生物及品质的影响,然后根据栅栏效应原理研究红外辐射-回火、红外辐射-冷激联合杀菌对胡萝卜粉微生物、色调值、类胡萝卜素含量等品质的影响。结果表明:100℃、10 min的红外辐射处理使细菌和真菌分别降低了1.9 lg(CFU/g)和2.32 lg(CFU/g),110℃、5 min的红外辐射处使细菌和真菌分别降低了1.58 lg(CFU/g)和2.57 lg(CFU/g)。在上述两种处理条件下胡萝卜粉的水分活度从0.238分别降至0.123和0.147,胡萝卜粉中总类胡萝卜素含量从308.8μg/g降至227.8μg/g和238.8μg/g,色差值(Δe)为9.11和7.89。与红外辐射单独作用相比,联合回火后的处理没有显著影响细菌数目,处理后保持在5.40~5.80 CFU/g,霉菌、酵母数却在处理过程中显著减少,然而减少量较低,总数仍不低于4.5 lg(CFU/g)。红外辐射-冷激联合处理相比红外辐射单独处理,100℃、10 min联合冷激7 d处理可将细菌数量降低0.25 lg(CFU/g),可将霉菌与酵母数量降低0.28 lg(CFU/g),110℃、5 min联合冷激7 d处可将细菌数量降低0.26 lg(CFU/g),可将霉菌、酵母数量降低0.40 lg(CFU/g),且这些处理下胡萝卜粉的色调值、水分活度、类胡萝卜素含量变化不显著。本试验结果表明,红外辐射-冷激处理具有协同效应,且处理过程中胡萝卜粉的色调值及总类胡萝卜素含量不受影响,这为低水分粉体食品红外辐射联合杀菌提供了参考。

关键词：红外辐射胡萝卜粉杀菌类胡萝卜素

1980—2000年贝拉勒士地区儿童死亡模式

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世界核心医学期刊文摘（儿科学分册） 2006年第2期2卷 17-18页

作者： Gruber l.e. Mahoney M.C. lawvere S. 朱新菊 Division of Cancer Prevention and Population Sciences Roswell Park Cancer Institute-Carlton 307 Elm and Carlton Streets Buffalo NY 14263 United States

The public health infrastructure of the former Soviet Union was impacted by both the Chernobyl disaster in 1986 and the Soviet breakup in 1991. This paper examines mortality patterns among children aged 1-14 years within the Mogilev region of Belarus between 1980 and 2000. This study utilized a regional cohort design that included all childhood deaths (ages 1-14 years) occurring among persons residing within the Mogilev oblast of Belarus between 1980 and 2000. Patterns of death and death rates were examined across three intervals: 1980-1985 (pre-Chernobyl), 1986-1991 (post-Chernobyl and pre-Former Soviet Union (FSU) breakup) and 1992-2000 (post-Chernobyl and post-FSU breakup) based upon administrative death files. Annual death rates among children aged 1-4 years declined between 1980 and 2000, while mortality rates among children aged 5-9 years and 10-14 years remained steady over this time period. Average annual mortality rates among males aged 5-9 years and 10-14 years increased significantly between 1986 and 1991. Compared to the baseline interval, mortality among both males and females aged 1-4 years was significantly decreased during 1986-1990 and 1992-2000. In general, mortality rates among males were 24% -95% greater compared to females. Injuries and poisonings accounted for the largest proportion of deaths across all age and gender groups examined. Subsequent to the Chernobyl disaster, significant decreases were noted in mortality rates among children aged 1-4 years while mortality rates among children aged 5-9 and 10-14 remained stable. Conclusion: Similar to the findings in other countries, injuries and poisonings predominated as the leading cause of death among Belarussian children.

关键词：儿童死亡率死亡模式年度死亡率切尔诺贝利 0~14岁儿童公共卫生组织前苏联时间段下降灾难

Sources and significance of variation in basal,summit and maximal metabolic rates in birds

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Current Zoology 2010年第6期56卷 741-758页

作者： Andrew e. MCKeCHNIe David l. SWANSON DST/NRF Centre of excel.e.ce at the Percy FitzPatrick Institute Department of Zoology and EntomologyUniversity of Pretoria Department of Biology University of South Dakota

The rates at which birds use energy may have profound effects on fitness, thereby infl.e.cing physiology, behavior, ecology and evolution. Comparisons of standardized metabolic rates （e.g., lower and upper limits of metabolic power output） present a method for elucidating the effects of ecological and evolutionary factors on the interface between physiology and life history in birds. In this paper we review variation in avian metabolic rates [basal metabolic rate （BMR; minimum normothermic metabolic rate）, summit metabolic rate （Msum; maximal thermoregulatory metabolic rate）, and maximal metabolic rate （MMR; maximal.e.ercise metabolic rate）], the factors associated with this variation, the evidence for functional links between these metabolic traits, and the ecological and evolutionary significance of avian metabolic diversity. Both lower and upper limits to metabolic power production are phenotypically flexible traits, and vary in association with numerous ecological and evolutionary factors. For both inter- and intraspecific comparisons, lower and upper limits to metabolic power production are generally upregulated in response to energetically demanding conditions and downregulated when energetic demands are relaxed, or under conditions of energetic scarcity. Positive correlations have been documented between BMR, Msum and MMR in some, but not all studies on birds, providing partial support for the idea of a functional link between lower and upper limits to metabolic power production, but more intraspecific studies are needed to determine the robustness of this conclusion. Correlations between BMR and field metabolic rate （or daily energy expenditure） in birds are variable, suggesting that the linkage between these traits is subject to behavioral adjustment, and studies of the relationship between field and maximal metabolic rates are lacking. Our understanding of avian metabolic diversity would benefit from future studies of：（1） the functional and mechanistic li

关键词： Phenotypic flexibility Reaction norms Basal metabolic rate Maximal metabolic rate Birds

CT三维重建改良R.e.N.A.l.评分系统在50例腹腔镜肾部分切除术中的应用

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山东大学学报（医学版） 2020年第9期58卷 52-57页

作者：高沛毛昌琳陈峰何维管勇吕家驹李善军丁森泰山东大学附属山东省立医院泌尿外科山东济南250021 山东第一医科大学附属省立医院泌尿外科山东济南250021

目的探讨基于CT三维重建技术改良R.e.N.A.l.评分系统在腹腔镜肾部分切除术中的应用价值。方法选取山东大学附属山东省立医院泌尿外科2018年9月至2019年11月间进行的T1期肾细胞癌腹腔镜肾部分切除术50例,所有纳入患者术前均行CT三维重建... 详细信息

目的探讨基于CT三维重建技术改良R.e.N.A.l.评分系统在腹腔镜肾部分切除术中的应用价值。方法选取山东大学附属山东省立医院泌尿外科2018年9月至2019年11月间进行的T1期肾细胞癌腹腔镜肾部分切除术50例,所有纳入患者术前均行CT三维重建,并分别按照传统R.e.N.A.l.评分系统以及CT三维重建改良R.e.N.A.l评分系统进行术前评分,结果与手术实际难度进行比较,并利用Spearman秩相关分析改良R.e.N.A.l.评分系统与患者手术时间、住院天数、术中热缺血时间(WIT)、术后血红蛋白下降、术后血肌酐及术后血尿素氮水平之间的相关性。结果 CT三维重建改良R.e.N.A.l评分与患者的手术时间、WIT以及术后血红蛋白下降程度之间呈正相关(r_s分别为0.570、0.802、0.903,Pe.N.A.l评分系统的灵敏度、特异度以及约登指数均明显优于传统R.e.N.A.l.评分系统。结论 CT三维重建改良R.e.N.A.l.评分系统对患者的手术难度的评估较传统R.e.N.A.l.评分系统更加准确,同时对患者围手术期指标有预测作用。

关键词： CT三维重建 R.e.N.A.l.评分系统 CT三维重建改良R.e.N.A.l.评分系统瘤径比肾部分切除术

二十碳五烯酸对大鼠脾脏自然杀伤细胞活性的影响及其机理

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中国药理学与毒理学杂志 1993年第3期7卷 186-189页

作者：张克坚田村泰中国医学科学院药物研究所北京100050 日本千叶大学医学部

本文观察了二十碳五烯酸(ePA)对大鼠脾脏天然杀伤(NK)细胞活性的影响,并对其可能的作用机理进行了探讨,结果表明,ePA乙酯(ePA-e)ig可明显降低脾脏NK细胞活性和白三烯B_4(lTB_4)的产生从脾细胞中除去粘附性细胞后,ePA-e对NK细胞活性的抑... 详细信息

本文观察了二十碳五烯酸(ePA)对大鼠脾脏天然杀伤(NK)细胞活性的影响,并对其可能的作用机理进行了探讨,结果表明,ePA乙酯(ePA-e)ig可明显降低脾脏NK细胞活性和白三烯B_4(lTB_4)的产生从脾细胞中除去粘附性细胞后,ePA-e对NK细胞活性的抑制作用消失,而这种非粘附脾细胞几乎没有产生lTB_4的能力,另外,外源性lTB_4可部分恢复ePA-e抑制的NK细胞活性。

关键词：二十碳五烯酸天然杀伤细胞

2002—2004年间与接种天花疫苗相关的神经系统不良事件

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世界核心医学期刊文摘(神经病学分册) 2006年第4期 1-2页

作者： Sejvar J.J. labutta R.J. Chapman l.e. 张平 Division of Viral and Rickettsial Diseases National Center for Infectious Diseases Centers for Disease Control and Prevention 1600 Clifton Rd Atlanta GA 30333 United States.Dr

Context: Neurologic ill.e.s is an infrequent but severe adverse event associated with smallpox vaccination. The reinstatement of smallpox vaccination in the United States in response to possible bioterrorism renewed concerns about vaccine-related adverse neurologic events. Objective: To determine rates and describe the clinical features of neurologic events associated with smallpox vaccination. Design and Setting: We assessed reports of adverse events obtained through active case reporting and review of data reported to the Vaccine Adverse event Reporting System among 665 000 persons vaccinated against smallpox by the Departments of Defense (n=590 400)and Health and Human Services (n=64 600) during the 2002- 2004 US Smallpox Vaccination Program. Main Outcome Measure: Adverse neurologic events temporally associated with smallpox vaccination. Results: Between December 16, 2002, and March 11, 2004, 214 neurologic adverse events temporally associated with smallpox vaccination were reported; 111 reports invol.e. Department of Health and Human Services and 103 invol.e. Department of Defense vaccinees. Fifty-four percent of these events occurred within 1 week of vaccination, and 53% were among primary vaccinees. The most common neurologic adverse event was headache (95 cases), followed by nonserious limb paresthesias (n=17) or pain (n=13) and dizziness or vertigo (n=13). Serious neurologic adverse events included 13 cases of suspected meningitis, 3 cases of suspected encephalitis or myelitis, 11 cases of Bell palsy, 8 seizures (including 1 death), and 3 cases of Guillain-Barré syndrome. Among these 39 events, 27 (69% ) occurred in primary vaccinees and all but 2 occurred within 12 days of vaccination. Conclusions: During the 2002- 2004 smallpox vaccination campaign, reported neurologic events were generally mild and selflimited, and no neurologic syndrome was identified at a rate above baseline estimates. Serious neurologic adverse events, such as postvaccinal.e.cephalitis

关键词：天花疫苗神经系统

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结核导致的左侧结肠狭窄

世界核心医学期刊文摘（儿科学分册） 2005年第3期1卷 45-46页

作者： De Jesus l.e. Marques A.M. Rocha M.S. 李丹 Hospital Municipal Jesus Rio de Janeiro Brazil

作者报道了1例10岁患儿,其肠结核仅累及左侧结肠并由此导致严重的营养不良、腹痛及并发肠梗阻。所有这些临床表现特征都被诊断为儿童肠结核。仅累及结肠的肠结核非常罕见,而且与克罗恩病的鉴别诊断也很困难。手术并发症发生频率很高,尤... 详细信息

作者报道了1例10岁患儿,其肠结核仅累及左侧结肠并由此导致严重的营养不良、腹痛及并发肠梗阻。所有这些临床表现特征都被诊断为儿童肠结核。仅累及结肠的肠结核非常罕见,而且与克罗恩病的鉴别诊断也很困难。手术并发症发生频率很高,尤其是肠梗阻,但大多数病例可以通过切除受累的肠管节段,然后进行一期吻合来治疗。

关键词：肠狭窄克罗恩病管节鉴别诊断