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1.
Chlorine isotope analysis of chlorinated hydrocarbons like trichloroethylene (TCE) is of emerging demand because these species are important environmental pollutants. Continuous flow analysis of noncombusted TCE molecules, either by gas chromatography/isotope ratio mass spectrometry (GC/IRMS) or by GC/quadrupole mass spectrometry (GC/qMS), was recently brought forward as innovative analytical solution. Despite early implementations, a benchmark for routine applications has been missing. This study systematically compared the performance of GC/qMS versus GC/IRMS in six laboratories involving eight different instruments (GC/IRMS, Isoprime and Thermo MAT-253; GC/qMS, Agilent 5973N, two Agilent 5975C, two Thermo DSQII, and one Thermo DSQI). Calibrations of (37)Cl/(35)Cl instrument data against the international SMOC scale (Standard Mean Ocean Chloride) deviated between instruments and over time. Therefore, at least two calibration standards are required to obtain true differences between samples. Amount dependency of δ(37)Cl was pronounced for some instruments, but could be eliminated by corrections, or by adjusting amplitudes of standards and samples. Precision decreased in the order GC/IRMS (1σ ≈ 0.1‰), to GC/qMS (1σ ≈ 0.2-0.5‰ for Agilent GC/qMS and 1σ ≈ 0.2-0.9‰ for Thermo GC/qMS). Nonetheless, δ(37)Cl values between laboratories showed good agreement when the same external standards were used. These results lend confidence to the methods and may serve as a benchmark for future applications.  相似文献   
2.
Fertigation for minimizing environmental pollution by fertilizers   总被引:2,自引:0,他引:2  
Intensification of agriculture by irrigation and enhanced use of fertilizers may generate pollution by increased levels of nutrients in underground and surface waters. Most of the irrigation is by open systems having a relatively low efficiency of water application. A higher efficiency may be gained by pressurized irrigation systems. Drip irrigation generates a restricted root system requiring frequent nutrient supply that may be satisfied by applying fertilizers in irrigation water, i.e. by fertigation. Maximization of crop yield and quality and minimization of leaching below the rooting volume may be achieved by managing fertilizers concentrations in measured quantities of irrigation water, according to crop requirements.  相似文献   
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由于空间成像套刻(Overlay)技术的预算随集成电路(IC)设计规范的紧缩而吃紧,因此,Overlay测量技术准确度的重要意义也随之提高。通过对后开发(AfterDevelopDI)阶段和后蚀刻(AfterEtchFI)阶段的Overlay测量结果进行比较,研究了0.18μm设计规范下的铜金属双重镶嵌工艺过程中的Overlay准确度。在确保对同一个晶圆进行后开发(DI)阶段和后蚀刻(FI)阶段测试的条件下,我们对成品晶圆的5个工艺层进行了比较。此外,还利用CD-SEM(线宽-扫描电子显微镜)测量了某个工艺层(PolyGate)上的芯片内Overlay,并与采用分割线方法的光学Overlay测量结果进行了比较。发现对芯片内overlay的校准存在着严重的局限性,即在应用CD-SEM时缺乏合适的结构进行Overlay测量。我们还将继续为大家提供定量的比较结果,同时也会向大家推荐组合的CD-SEM测量结构,使其能够被应用到今后的光刻设计中。  相似文献   
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This study addressed the issue of team support and explored the role of structural factors, namely, job enrichment designs; the role of cultural factors, namely, individualism-collectivism and power distance; and the role of the leader's support, which served as support carrier in teams. With 56 nursing teams, the results demonstrated that whereas leader's support, collectivism, and low power distance facilitated team support, job enrichment designs placed constraints on the accessibility of support to team members. Additionally, leader's support and low power distance moderated the negative impact of job enrichment on team support. These findings suggest that support is not primarily a burst of altruism displayed by individuals, and they draw attention to the teams' contexts that most likely serve to encourage team members to engage in support. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
This study determined how youth (ages 17-21) and their parents jointly constructed and acted on goals and strategies pertinent to the transition to adulthood. Twenty parent-youth dyads were followed over an 8-month period using the qualitative action-project method. Data included their joint conversations, video recall of internal processes, self-monitoring logs, and researcher telephone monitoring. Detailed and repeated analysis of elements, functional steps, and goals resulted in the identification of an explicit joint project for each dyad that the participants saw as pertinent to the transition to adulthood. These projects referred broadly to the youth development of identity and social inclusion in the adult world and included the specific projects of career promotion, governance transfer, and parent-youth relational processes. The findings illustrate the complexity of the transition-to-adulthood process as well as its joint construction by parent and youth. Implications for practice include identifying and following the joint parent-youth transition project. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
Analysis of advertisements in Israeli newspapers over the past decade has shown that American symbols have been widely used to market an array of consumer goods. Products made in America, Israel, or other countries are marketed with some sort of American angle by invoking America's values, symbols, landscapes, or lifestyle. Using both qualitative and quantitative methods, we analyzed how central components of the nation-state/national sphere—language, flag, political leaders, borders, landscapes, and sights—are reflected in advertising. We attempt to show how social values metamorphose, shedding their "Israeliness" and taking on an American veneer. Using Israel as an example may provide a test case for the Americanization process in other societies at the turn of the millennium.  相似文献   
8.
Two clinical interventions to moderate negative responses to media exposure to terrorism were tested. Participants were 300 young Israeli adults randomly allocated to a terrorism or nonterrorism televised news clip and assigned to 1 of 3 preexposure intervention conditions--cognitive, emotional, or control. Emotional responses of anxiety and anger and attitudinal responses of stereotypes and enemy perception were measured prior and subsequent to manipulation. Results indicated higher posttest levels of anxiety, anger, stereotypes, and negative enemy perception in the terrorism versus nonterrorism media exposure. In the terrorism group, clinical interventions moderated anxiety and increased willingness for conflict resolution. Findings indicate contributions of preparatory interventions for the public in certain contexts of terrorism and its media coverage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
Modification of a glass support with triethoxy propylaminosilane yields an active interface for the assembly of Au colloids. The colloids are imaged by AFM using a low applied load (0.5–0.7 nN). The lateral Au-colloid dimensions, 33±3 nm, deviate from the particle dimensions determined by TEM (19±2 nm) and absorption spectroscopy (15 nm). This deviation is attributed to the intrinsic curvature of the AFM tip. Application of higher loads on the tip (3 nN) results in the sweeping of Au colloids from the monolayer. The Au colloid monolayer is etched in the presence of CN. The etching proceeds by the initial coincidental etching of Au particles followed by the kinetically favored etching of particles at the edges of the etched domains. This provides means for the micro machining and the chemical manipulation of Au colloids of controlled spatial arrangement.  相似文献   
10.
International Journal of Computer Vision - Machine learning models are known to perpetuate and even amplify the biases present in the data. However, these data biases frequently do not become...  相似文献   
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