高层建筑热压中和面位置的确定

根据通风网络理论 ,结合建筑物各楼层门窗间的串并联关系 ,率先引入了能够反映建筑门窗结构和气密性特征的特征参量“风阻” ,并应用中和面上、下渗进渗出风量平衡的关系 ,得出了求解热压中和面位置的一元方程式 ,使建筑热压中和面的求解成为可能     

玉米抗低温助长剂田间试验研究

为防御东北玉米低温冷害,研制了一种新型的玉米抗低温助长剂,其抗低温效果已为人工温控试验所证实。本项研究采用分期播种、地理播种和田间多处理对比试验方法,检验该化学制剂在影响玉米发育、生物量及产量性状方面的实用效果,并探求其适宜的浓度配比和喷施期次。研究结果表明,该制剂具有促生长、促早熟和使作物高产的性能,可防御延迟型冷害。施用时以1：400倍液和在营养生长期内两次喷施为佳。     

钛合金ZrN耐磨抗冲蚀防护涂层

采用真空多弧镀设备在TC11钛舍金表面沉积超硬耐磨ZrN防护涂层,通过增压气流固体颗粒冲蚀实验评价ZrN涂层的耐磨抗冲蚀性能,划痕仪测试涂层与基体的结合力,SEM、X射线分析涂层组成及观察涂层冲蚀前后表面形貌,盐雾及电化学实验测试涂层耐腐蚀性能。结果表明,ZrN涂层成分主要为（111）择优取向的ZrN相;ZrN涂层不影响钛合金的耐腐蚀性能及疲劳性能;ZrN涂层与基体结合牢固．涂层大大提高了基体的耐磨抗冲蚀性能。     

钢管混凝土柱耐火性能和抗火设计的特点

简要论述了按ISO－834和GS9978－88规定的标准升温曲线升温作用下钢管混凝土柱耐火性能的特点,分析了影响钢管混凝土柱耐火极限的因素,说明了由于钢管和混凝土的共同工作且核心混凝土具有较好的吸热性能,从而使钢管混凝土柱具有较好的耐火性能。在进行钢管钢混凝土柱的抗火设计时,柱子外围只需进行适当的防火涂料保护,即可达到《高层用民建筑设计防火规范（GB50045－95）》对柱结构所要求的耐火极限。《高层用民建筑设计防火规范（GB50045－95）》中对钢结构柱防火保护层厚度的确定方法不适合于钢管混凝土。     

在超滤草浆黑液过程中膜阻力的分布

采用截留分子量30000,20000,10000和6000的超滤膜,对草浆黑液进行了超滤过程中膜阻力分布的研究.通过测定不同条件下膜样品的通量,对聚乙二醇标准物的截留率,指出在超滤黑液过程中各部分阻力的比例和超滤膜的分离特性的变化.各种膜样品的热重分析结果表明,膜污染是由微量有机物引起的污染.     

Importance of dispersal routes that minimize open‐ocean movement to the genetic structure of island populations

Islands present a unique scenario in conservation biology, offering refuge yet imposing limitations on insular populations. The Kimberley region of northwestern Australia has more than 2500 islands that have recently come into focus as substantial conservation resources. It is therefore of great interest for managers to understand the driving forces of genetic structure of species within these island archipelagos. We used the ubiquitous bar‐shouldered skink (Ctenotus inornatus) as a model species to represent the influence of landscape factors on genetic structure across the Kimberley islands. On 41 islands and 4 mainland locations in a remote area of Australia, we genotyped individuals across 18 nuclear (microsatellite) markers. Measures of genetic differentiation and diversity were used in two complementary analyses. We used circuit theory and Mantel tests to examine the influence of the landscape matrix on population connectivity and linear regression and model selection based on Akaike's information criterion to investigate landscape controls on genetic diversity. Genetic differentiation between islands was best predicted with circuit‐theory models that accounted for the large difference in resistance to dispersal between land and ocean. In contrast, straight‐line distances were unrelated to either resistance distances or genetic differentiation. Instead, connectivity was determined by island‐hopping routes that allow organisms to minimize the distance of difficult ocean passages. Island populations of C. inornatus retained varying degrees of genetic diversity (N_A = 1.83 – 7.39), but it was greatest on islands closer to the mainland, in terms of resistance‐distance units. In contrast, genetic diversity was unrelated to island size. Our results highlight the potential for islands to contribute to both theoretical and applied conservation, provide strong evidence of the driving forces of population structure within undisturbed landscapes, and identify the islands most valuable for conservation based on their contributions to gene flow and genetic diversity.     

荒漠绿洲土壤抗生素抗性基因分布特征及驱动机制

荒漠绿洲农田生态系统是干旱区环境下人类活动显著的复合生态系统.土壤微生物抗生素抗性与人类健康和生态平衡关系密切.研究荒漠绿洲环境不同土地利用类型模式下土壤抗生素抗性基因的多样性、分布特征和影响因素,对于评估干旱区土壤环境健康风险,促进绿洲农业生态的发展具有重要意义.采用高通量测序和高通量定量PCR技术对荒漠绿洲土壤微生物的群落结构和抗生素抗性基因多样性开展了研究,旨在探究干旱区土壤抗性基因的分布特征及其驱动机制.结果表明,从沙漠边缘到绿洲,荒漠沙生植物土壤、棉花地土壤、玉米地土壤、芦苇地土壤和湖泊沉积物中抗生素抗性的种类和丰度显著增加,与土地利用变化关系密切,农田土壤是抗性基因的重要存储库;荒漠绿洲土壤微生物群落与抗生素抗性基因显著相关,硫杆菌属(Thiobacillus)、沙漠细菌属(Pontibacter)、诺卡氏菌属(Nocardioides)、耐盐微杆菌属(Salinimicrobium)、土壤红杆菌属(Solirubrobacter)和链霉菌属(Streptomyces)等是各类抗性基因重要的潜在携带者;干旱区土壤中重(类)金属元素和可移动基因元件,与微生物群落共同塑造了抗生...     

Function of arsATorf7orf8 of Bacillus sp. CDB3 in arsenic resistance

Bacillus sp. CDB3 isolated from an arsenic contaminated cattledip site possesses an uncommon arsenic resistance (ars) operon bearing eight genes in the order of arsRYCDATorf7orf8. We investigated the functions of arsA, arsT, orf7 and orf8 in arsenic resistance using a plasmid-based gene knockout approach in the ars genedeficient Escherichia coli strain AW3110. The CDB3 arsA genewas shown to play a significant role in resistance, suggesting that the encoded ArsA may couplewith the arsenite transporter, forming an ArsAY complex that can enhance arsenite extrusion efficiency. Thedisruption of either arsT or orf7was not observed to affect arsenic resistance in the heterologous E. coli host, but their involvement in arsenic resistance can not be excluded. The orf8 gene is predicted to encode a putativedual-specificity protein phosphatasewhich also shares certain homology to arsenate reductases. The function loss of orf8 resulted in a remarkabledecrease in resistance to arsenate, though not arsenite. To examine if this effectwasdue to the reduction of arsenate by orf8, the arsC genewithin the 8-gene operonwasdisrupted. The resulting abolishment of arsenate resistance suggests that the involvement of orf8 in arsenic resistance is not via reductase activity.     

步兵轻武器新型夜瞄复合荧光材料耐腐蚀性能研究

采用自制的复合荧光粉体和化学载体成分,研制出一种步兵轻武器新型夜瞄复合荧光材料。采用酸溶液、碱溶液和盐溶液浸泡腐蚀的方法,研究了针对有关武器表面处理的酸性和碱性环境以及海水浸泡环境下材料的耐腐蚀性能。试验结果表明,研制的新材料具有良好的耐酸、耐碱、耐盐腐蚀性能,可满足步兵轻武器夜间瞄准需求。     

高垦殖丘陵区不同类型农用地土壤中抗生素抗性基因分布特征

为揭示高垦殖丘陵区不同类型农用地土壤中抗生素抗性基因分布特征,分析了抗生素抗性基因在菜地、果园和耕地土壤中的丰度和多样性.结果表明,所有土壤样品中共检出70种抗生素抗性基因和4种可移动基因元件,其中β-内酰胺类cphA-01抗性基因是农用地土壤中相对丰度最高的耐药基因.在菜地和果园土壤中,主要的抗性基因亚型为cphA-01和cmx（A）,而耕地土壤以mexF和aacC基因为主.土壤中抗生素抗性基因的相对丰度和多样性均表现为：耕地<菜地<果园,这与不同农用地土壤的养分条件差异有关.类似地,土壤中可移动基因元件的相对丰度和多样性均以耕地土壤为最低,而其最高值分别出现在菜地和果园样品中.高垦殖丘陵区农用地土壤环境中可移动基因元件与抗生素抗性基因丰度呈显著正相关关系（P<0.05）,表明基因水平迁移可能促进抗生素抗性基因在高垦殖丘陵区农用地土壤环境中扩散.