非对称开采条件下工作面“多向应力”变化特征研究

在非对称开采条件下,工作面受上覆岩层自重应力、超前支承应力、采空区侧向支承应力和回风巷煤柱应力等“多向应力”叠加影响,使得工作面应力呈“非对称”性。为研究非对称开采条件下工作面“多向应力”变化特征,基于微震监测、应力在线监测和理论计算,对母杜柴登煤矿30202工作面回采过程中所形成的非对称开采条件下的应力变化进行分析;并基于工作面所受应力条件和围岩体结构条件,分析了“多向应力”叠加显现机理。结果表明:30202工作面回采期间,煤柱支承应力沿走向分为应力升高区、应力明显降低区、应力缓慢降低区和应力稳定区,其应力峰值主要集中在工作面前方40 m左右,应力集中系数平均为1.61;在非对称开采阶段,在走向方向工作面超前支承应力影响范围较回采初期增加了100 m左右;在不考虑垂直应力影响的情况下,相邻工作面采空区的侧向应力对30202工作面倾向方向的影响范围为44 m,应力最大值为56.1 MPa。在“多向应力”耦合作用下工作面在回采过程中产生能量集聚,并在采动扰动下发生能量释放,满足了大能量事件发生的基本应力条件;同时在扰动条件下采空区发生高位顶板错动,以及围岩支护薄弱为大能量事件的发生提供了围岩结构条件。研究结果可为工作面非对称开采条件下采场矿压显现规律研究、顶板控制和巷道支护设计提供指导。     

An interpersonal perspective of perceived stress: Examining the prosocial coping response patterns of stressed managers

We adopt an interpersonal perspective and examine the adaptive effects of managers' perceived stress on their behavior towards subordinates. Drawing from the transactional model of stress (Lazarus & Folkman, 1984), we advance a model that highlights the propensity for stressed managers to engage in prosocial coping behaviors towards their employees, which in turn are related to lower levels of turnover and higher levels of job performance. We tested our predictions in a sample of 281 employees and their 53 managers working in a clothing retailer in Turkey. Consistent with predictions, we found positive effects of managers' perceived stress on their prosocial coping behaviors and employee outcomes. Managers' perceived stress was positively related to sharing credit with employees for managers who held positive implicit prototypes about employees. Results also indicated that managers' perceived stress was positively related to sharing knowledge with their subordinates regardless of implicit follower prototypes. Both sharing credit and sharing knowledge, in turn, were related to turnover intentions and actual turnover, and sharing credit was related to job performance. This study extends past work by adopting an interpersonal perspective of stress and demonstrating that managerial stress can have positive effects on employee outcomes via prosocial coping behaviors.     

丛枝菌根对盐胁迫的响应及其与宿主植物的互作

丛枝菌根真菌(Arbuscular Mycorrhizae Fungi,AMF)作为陆地生态系统的组成部分之一,在促进宿主植物对土壤养分和水分的吸收、提高植物生物量生产、调节种群和群落的结构、维持生态系统的稳定性等方面发挥了重要作用。其中,盐渍化是自然生态系统中广泛存在的一种胁迫生境条件,全球盐渍化土地约占耕地总面积的10%,因而探讨AM菌根在此胁迫生境下对宿主植物生长的影响具有重要意义。从以下几个方面,围绕盐胁迫条件、AM菌根和宿主植物三者之间的关系对当前国际上相关领域的研究进展进行了综述:1)AM真菌对盐胁迫的响应,包括菌根共生体形成、菌根侵染率、AM真菌的分布、菌丝体生长发育、孢子的形成和分布等;2)盐胁迫条件下AM菌根对宿主植物的效应,包括AM菌根促进宿主植物对P、N等元素的吸收、降低植物体内Na 的含量、提高光合作用能力,进而提高植物的生物量和对植物的群落结构产生影响等;3)AM菌根提高宿主植物耐盐性的机理,分别从植物根系形态的改变、水分吸收能力的加强、细胞内营养物质的平衡,以及细胞生理代谢的调节等方面对AM菌根促进植物抗盐性的机理进行了剖析。     

机械振荡对猕猴桃愈伤组织的生理效应

通过机械振荡处理中华猕猴桃（Actinidia chinensis planch)茎段的愈伤组织，研究模拟振荡方式的力学刺激对木本植物愈伤组织生长分化的生理生化效应。结果表明，猕猴桃对机械振荡的应激效应与本实验室此前对草本植物非洲雏菊（Gerbera jamesonii acrocarpous)的研究有相似的结果。即适度的机械振荡（频率2-3Hz)可促进猕猴桃愈伤组织的生长，使胞内可溶性蛋白质含量升高，SOD活性升高，而IAA氧化酶活性质膜的通透性降低；但当振动强度超过一定范围（3Hz)后，愈伤组织的生长受到明显的抑制，可溶性蛋白质含量下降，SOD活性降低，而IAA氧化酶活性升高，同时细胞膜的封闭和完整性受到损伤，透性增大，研究显示植物对外界应力刺激的响应（应激效应）是很明显的图1表2参17。     

土壤水分对沙棘成活率及抗逆生理特性的影响

为提高沙棘在滩涂区，半干旱区造林的成活率，对不同土壤水分下沙棘的生理学特性进行了分析。结果表明：（1）在不同土壤水分处理下，随土壤含水量降低及处理时间的延长，沙棘叶片脯氨酸（Pro)含量升高，POD活性增强，可溶性糖含量升高；水淹情况下，沙棘叶片Pro含量明显上升，POD活性增强，可溶性糖含量升高。（2）土壤含水量在15%-30%之间，沙棘苗木成活率最高（100%），生长最好；35%和40%处理下，沙棘苗木成活率较高（66.7%)，生长良好；5%，10%处理水平和水淹情况下，沙棘苗木成活率低（33.3%)，生长不良，（3）不同处理下，随土壤含水量的降低，沙棘叶片的相对电导度增大，沙棘受伤害的程度加剧，且淹水对沙棘的伤害最重。     

苗期玉米根叶对干旱胁迫的生理响应

采用人工控制水分的方法,研究了干旱胁迫下苗期玉米(ZeamaysL.)根系和叶片的生理指标,用以明确苗期玉米根系和叶片对干旱的生理响应。研究结果表明,苗期中度干旱胁迫处理条件下,玉米根系和叶片均表现出对干旱胁迫的生理响应,并各具特点。与对照相比,干旱胁迫使玉米根系和地上部的生物量降低,叶片中的叶绿素含量显著降低、叶片光合面积减小,根冠比增大。干旱胁迫使玉米根系比表面积增大,根系氧化活力和还原活力增强。干旱胁迫导致玉米叶片的光合功能降低,初始荧光升高,初始光系统Ⅱ(PSⅡ)的原初光能转换效率、PSⅡ潜在活性、潜在光合作用活力均受到抑制。干旱胁迫下玉米叶片和根系脂质过氧化作用增强,根系和叶片中的游离脯氨酸含量升高。     

Microorganisms for remediation of cadmium-contaminated soils

An alternative to the cleaning-up of agricultural soil contaminated by heavy metals is to avoid their transfer from soil to plant by inoculating soil with selected microorganisms able to biosorb heavy metals. Here, four bacteria species and a fungus isolated from contaminated soils revealed their ability to grow in the presence of high cadmium level. We tested their growth capacity related to pH and Cd concentration on synthetic and soil extract media. The comparison of their growth rate, the biosorbed cadmium rate and the specific biosorption allowed to select the most efficient microorganism to be used in bioremediation.     

低磷胁迫下不同水稻品种根系吸收能力差异的生理与遗传本质

在低磷（1mg L-1)和适磷水平（10mg L^-1)下，分别以混合培养方式研究了粳稻京系17（Oryza sativa ssp.japonica)(JX17)和粘稻窄叶青8号（Oryza sativa ssp.indica)(ZYQ8)对磷营养的反应。结果表明，低磷胁迫下，JX17较ZYQ8吸收更多磷素，干物重也显著增加。相反，ZYQ8则受到更强的磷胁迫，吸磷量和干物重降低，主要是因为JX17具有较高的吸磷速度，单位根长吸磷量大，即根系高亲和力磷酸盐转运蛋白表达强，最大限度地吸收可能利用的磷素，从而改善植株营养状况，同时又有较多的磷被分配到根系，使根第，根表面积和根干重相应提高，进一步增加了其在低磷胁迫条件下的竞争磷营养的优势。图3表2参17     

Cu and Cd removal from wastewater by a microalloyed aluminium composite

We studied the removal of cadmium and copper from industrial wastewaters by a microalloyed aluminium composite. The composite was highly efficient, resulting in water concentrations of cadmium and copper below the maximal allowed concentrations for drinking water. Moreover, our results show that the removal mechanism is mainly based on reduction and coprecipitation, since Cd and Cu were removed from the wastewater in reduced forms as metals and hydroxides.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organised by Dr. Branimir Jovancicevic     

SO2和O3动态胁迫烟草致病的暴露试验

ＳＯ_２和Ｏ_３动态胁迫烟草致病的暴露试验陈锦云，兰志斌，苏珍山，曾军，王阳青（福建龙岩地区烟科所龙岩３６４０００）关键词Ｓ）_２和Ｏ_３；烟草；气候斑点病，动态胁迫暴露ＴＨＥＤＹＮＡＭＩＣＳＴＲＥＳＳＥＸＰＯＳＵＲＥＴＥＳＴＯＮＴＯＢＡＣＣＯＢＬＡＤＥ...