全文获取类型
收费全文 | 49篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 4篇 |
环保管理 | 8篇 |
综合类 | 16篇 |
基础理论 | 3篇 |
污染及防治 | 2篇 |
评价与监测 | 3篇 |
社会与环境 | 1篇 |
灾害及防治 | 1篇 |
出版年
2020年 | 2篇 |
2019年 | 1篇 |
2016年 | 2篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 6篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有51条查询结果,搜索用时 218 毫秒
41.
Polythene sheeting is a major litter component on estuarine beaches and river banks. Sanitary towel backing strips, which
are one of the commonest items of sewage related debris found on beaches, enter the riverine system via combined sewer overflows.
Investigations on these items, positioned at natural riverine stranding levels, showed that after an initial rapid breakdown
little further loss of tensile strength occurred. Experiments carried out on backing strips, buried in the bank suspended
from a tree and tethered to the bank, showed significant change. Buried samples retained the greatest tensile strength retention,
dropping no lower than 90 %, the other samples showed similar retention rates at 80%. The difference is probably due to photodegradation
as biodegradation effects were minimal. Probably, the longevity of such plastics is a major reason for their abundance and
widespread distribution both on river banks and beaches. 相似文献
42.
结构振动疲劳加速试验技术研究 总被引:3,自引:3,他引:0
目的提出一种用于评估随机振动环境下工程结构长期耐久性和疲劳可靠性的加速试验技术。方法通过开展一系列高斯和非高斯振动疲劳对比试验,系统研究影响结构振动疲劳寿命的各种因素,包括随机振动激励的均方根值、功率谱密度、带宽和峭度值等。结果非高斯随机振动激励的带宽和峭度值对结构振动疲劳寿命也有明显影响。结论当结构振动激励呈现明显的非高斯特征时,设计随机振动疲劳加速试验方案必须综合考虑振动激励的带宽和峭度值。 相似文献
43.
44.
电器实验室在对电器产品实施安全性能检测的过程中,实验室本身存在着安全和环境污染问题。如何对实验室的日电器实验室在对电器产品实施安全性能检测的过程中,实验室本身存在着安全和环境污染问题。如何对实验室的日常运作进行安全和环境的有效监控,对于保护实验室仪器设备和生命财产安全,以及试验人员的健康,具有重要的意义。
电器实验室安全和环境问题涉及但不限于防火、防烫伤、防暴、防触电、防机械伤害、防淋水、防盗、限制区域的禁入、仪器设备的保护、试验负荷控制、环境温度、湿度、电网电压、谐波畸变、噪音、有毒有害气体、电磁渡污染等诸多方面。本文针对电器实验室存在的一些主要安全和环境问题,从经济和技术可行性方面研究有效解决方法,并提出一种利用现代科技实现远程综合监控的方案。 相似文献
45.
46.
介绍了测试舱的研制意义、测试舱构造和温度控制部分,以及空气交换、循环控制,空气净化装置和温度、湿度、流速显示装置等.通过实验,对测试舱的温度控制,空气净化系统检验,空气交换、循环的检验,释放甲醛平衡点的快速判断和测试舱的比对等运行技术指标进行了论证、优化.结果表明,简易的室内装饰装修材料测试舱对主要运行参数可以自动运行与控制,运行情况满足国家标准方法的技术指标要求,与同类商品化测试舱相比,误差在2%左右. 相似文献
47.
R. A. Tatara S. Suraparaju K. A. Rosentrater 《Journal of Polymers and the Environment》2007,15(2):89-95
With the rapid growth in the ethanol fuel industry in recent years, considerable research is being devoted to optimizing the
use of processing coproducts, such as distillers dried grains with solubles (DDGS), in livestock diets. Because these residues
contain high fiber levels, they may be amendable to incorporation into bio-based composites. Thus, the goal of this study
was to demonstrate the viability of using corn-based DDGS as a biofiller with phenolic resin, in order to produce a novel
biomaterial. DDGS was blended with phenolic resin at 0, 10, 25, 50, 75, and 90%, by weight, and then compression molded at
51 MPa (3.7 tons/in2) and 174 °C (345°F). Molded specimens were then tested for tensile strength. Tensile yield strengths ranged from 32 MPa (4,700 psi)
to 7.6 MPa (1,100 psi), while the engineering strain ranged from 0.6% to 1.25%. Results indicate that DDGS concentrations
between 25% and 50% retained sufficient mechanical strength and thus represent reasonable inclusion values. Additionally,
data were similar to those from other studies that have investigated biofillers. Follow-up studies should quantify the effects
of altering molding parameters, including molding pressure, temperature, and time, as well as pretreatment of the DDGS. Additionally,
strength of the DDGS composites should be optimized through the use of coupling agents or other additives.
Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the United
States Department of Agriculture and does not imply approval of a product to the exclusion of others that may be suitable. 相似文献
48.
材料以及产品的环境试验方法 总被引:1,自引:1,他引:1
本文主要分析了各环境因素及其引起的失效模式,介绍了环境试验方法以及环境试验设计过程中应当注意的问题等基础知识,还给出了一些常用的环境试验标准. 相似文献
49.
分別采用1mol L~(-1) NH_4OAC淋洗法,0.1mol L~(-1)BaCl_2捕掳交换法,6.667×10~(-3)mol L~(-1)Co(NH_3)_6Cl_3提取法以及电荷测定法测定了南方几种不同性质的土壤的阳离子交换性质。结果表明,酸性土壤的阳离子交换量具有不定性,NH_4OAC法的结果很高,而其它方法的结果显著偏低,但方法间仍存在显著差异。不过,各法对微酸性、中性土壤的测定结果无显著差异。与NH_4OAC法相比,BaCl_2法得到较多的Ca,而Co法则交换出较少的K。各法的浸提液pH间虽存在差异,但彼此间有良好的统计相关性。Co法测定的CEC值与交换性阳离子总和较为吻合,其浸提液pH与pH_(KCl)、pH_(CaCl_2)有良好的线性关系。看来,不同方法对酸性土壤阳离子交换量的测定差异主要来自測定过程中介质pH条件及离子强度不同所浸出的交换性酸的多寡。本文认为,Co(NH_2)_6Cl_3法可以作为这些土壤阳离子交换性质测定的例行方法。 相似文献
50.
A Study of Physicomechanical and Morphological Properties of Starch/Poly(vinylalcohol) Based Films 总被引:2,自引:0,他引:2
Dipa Ray Papri Roy Suparna Sengupta Siba Prasad Sengupta Amar K. Mohanty Manjusri Misra 《Journal of Polymers and the Environment》2009,17(1):56-63
Starch/Poly(vinylalcohol) blends in two different ratios (60:40 and 50:50) were prepared with glycerol as a plasticizer. Films
were cast by a solution casting method. One set of films were filled with 10 wt% of unmodified bentonite clay and another
set of films were crosslinked with epichlorohydrin in an alkaline medium. The prepared film samples were subjected to X-ray
diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), mechanical characterization and scanning electron microscope
(SEM). Significant changes in the tensile properties were observed depending on the different chemical constituents of the
films. The presence of clay and crosslinking with epichlorohydrin were both found to have considerable effect on the morphology
and mechanical property of the films. The SEM investigations, XRD analysis and FTIR studies revealed the interaction between
the various chemical components of the films. 相似文献