The technology based on the time domain reflectometry of the coaxial cable and its application

2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Power distance orientation alleviates the beneficial effects of empowering leadership on actors' work engagement via negative affect and sleep quality

Although many studies have explored the benefits of empowering leadership for followers, the beneficial effect of such behavior for actors who demonstrate empowering leadership has been overlooked. Applying conservation of resources theory, we propose and test a model that determines why and when empowering leadership benefits actors. We use an experience sampling survey to examine the effect of empowering leadership on actors’ daily work engagement. In particular, we focus on the moderating role of power distance orientation and the mediating roles of negative affect and sleep quality, which operate sequentially. The results based on responses from 160 supervisors in two Chinese organizations indicated that empowering leadership in the morning was negatively related to negative affect in the afternoon and positively related to sleep quality at night and next-day work engagement. The strength of this beneficial effect was moderated by power distance orientation, such that supervisors with a high degree of power distance orientation obtained fewer benefits from empowering leadership than those with a low degree of power distance orientation. The theoretical and practical implications of these findings for the leadership, affect, sleep, power distance, and conservation of resources literatures are discussed

Model-based assessment of chromate reduction and nitrate effect in a methane-based membrane biofilm reactor

© 2019 Zhejiang University Chromate contamination can pose a high risk to both the environment and public health. Previous studies have shown that CH4-based membrane biofilm reactor (MBfR) is a promising method for chromate removal. In this study, we developed a multispecies biofilm model to study chromate reduction and its interaction with nitrate reduction in a CH4-based MBfR. The model-simulated results were consistent with the experimental data reported in the literature. The model showed that the presence of nitrate in the influent promoted the growth of heterotrophs, while suppressing methanotrophs and chromate reducers. Moreover, it indicated that a biofilm thickness of 150 μm and an influent dissolved oxygen concentration of 0.5 mg O2/L could improve the reactor performance by increasing the chromate removal efficiency under the simulated conditions

Relationships of trace gases and aerosols and the emission characteristics at Lin'an, a rural site in eastern China, during spring 2001

We present measurements of trace gases and fine aerosols obtained from a rural site in eastern China during 18 February to 30 April 2001. The field program aimed to characterize the variations in aerosol and gaseous pollutant concentrations and the emission signatures from the inland region of eastern China in the spring season. The data included O3, CO, NO, NOy*, SO2, methane, C2-C8 nonmethane hydrocarbons (NMHCs), C 1-C2 halocarbons, and the chemical composition of PM2.5. The average hourly mixing ratios (±standard deviation) of CO, SO2, and NOy* were 677 (±315) ppbv, 15.9 (±14.6) ppbv, and 13.8 (±7.2) ppbv, respectively. The mean daytime ozone mixing ratio was 41 (± 19) ppbv. The most abundant NMHC was ethane (3189 ± 717 pptv), followed by ethyne (2475 ± 1395 pptv), ethene (1679 ± 1455 pptv), and toluene (1529 ± 1608 pptv). Methyl chloride was the most abundant halocarbon (1108 ± 653 pptv). The average concentrations of particulate organic matter (POM, as organic carbon, OC, times 1.4) and elemental carbon (EC) in PM2.5 were 21.5 (±7) μg/m3 and 2.5 (±0.7) μg/m3, respectively, and sulfate and nitrate levels were 17.3 (±6.6) and 6.5 (±4) μg/m3, respectively. CO showed moderate to good correlation with NOy* (r2 = 0.59), OC (r2 = 0.65), CH3Cl (r2 = 0.59), soluble potassium (r2 = 0.53), and many NMHCs, indicating contributions from the burning of biofuel/biomass. CO also correlated with an industrial tracer, C2Cl4, indicative of some influence from industrial sources. SO2, on the other hand, correlated well with EC (r2 = 0.56), reflecting the contribution from the burning of coal. Ammonium was sufficiently abundant to fully neutralize sulfate and nitrate, indicating that there were strong emissions of ammonia from agricultural activities. Silicon and calcium had poor correlations with iron and aluminum, revealing the presence of source(s) for Si and Ca other than from soil. Examination of C2H2/CO, C3H8/C 2H6, nitrate/(nitrate + NOy* , and sulfate/(SO2 + sulfate) suggested that relatively fresh air masses had been sampled at the study site in the spring season. Comparison of the observed ratios/slopes with those derived from emission inventories showed that while the observed SO2/NO y* ratio (1.29 ppbv/ppbv) in March was comparable (within 20%) to the inventory-derived ratio for the study region, the measured CO/NOy* slope (37 ppbv/ppbv) was about 200% larger. The observed slope of CO relative to NMHC (including ethane, propane, butanes, ethene, and ethyne) also indicated the presence of excess CO, compared to the ratios from the inventories. These results strongly suggest that emissions of CO in eastern China have been underrepresented. The findings of this study highlight the importance of characterizing trace gases and aerosols within source regions of the Asian continent. The springtime results were also compared with data previously collected at the site in 1999-2000 and with those obtained on the Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft and from a coastal site in South China for the same study period. Copyright 2004 by the American Geophysical Union

The influence of endogenous hormones on the formation of buds from stems of bitter melon (Momordıca charantıa L.)

Stems of bitter melon (Momordica charantia L.) cv. Dabai were used to establish in vitro cultures. The endogenous hormone concentrations (indoleacetic acid [IAA], abscisic acid [ABA], gibberellins 3 [GA3], zeatin [ZT]) of the calluses were determined by means of high pressure liquid chromatography (HPLC). The endogenous ZT was higher in the stem calluses that had formed buds, and there was a higher IAA/ZT ratio and GA3/ZT ratio in the calluses having no capacity for buds formation. The results showed that addition of plant growth regulator influences endogenous hormone status and it will be helpful for in vitro propagation of bitter melon.Key words: Endogenous phytohormones, high pressure liquid chromatography, in vitro culture, bitter melon (Momordica charantia L.)

Optimized system for plant regeneration of watermelon (Citrullus lanatus Thumb.)

The objective of this study was to establish an efficient and reproducible in vitro plant regeneration for Citrullus lanatus cv. Zaojia. To achieve optimal conditions for adventitious shoot induction, five explants (entire cotyledons, distal cotyledons, proximal cotyledons, cotyledonary node A and cotyledonary node B) were tested on MS medium supplemented with different concentrations and combinations of growth regulators (0 to 0.2 mg/L IAA and 1.0 to 5.0 mg/L BA), the results showed that entire cotyledons cultured in MS + BA (2.0mg/L) + IAA(0.2mg/L) achieved the highest regenerated rate (89.67%) and the optimal protocol screened in this experiment had 7.69 ± 0.10 shoots per explants. Adventitious shoots were able to elongate both on MS medium with 0.2 mg/L KT and 0.2 mg/L NAA; IBA 0.3mg/L was found to be effective in the production of root. Acclimatized plantlets transferred to pot resumed growth, and their stems and leaves elongated and expanded in one month.Key words: Watermelon (Citrullus lanatus Thumb.), optimized system, regeneration, cotyledon explants, cotyledonary node

Smad3 promotes cancer progression by inhibiting E4BP4-mediated NK cell development

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Tellurium quantum dots: Preparation and optical properties

Herein, we report an effective and simple method for producing Tellurium Quantum dots (TeQDs), zero-dimensional nanomaterials with great prospects for biomedical applications. Their preparation is based on the ultrasonic exfoliation of Te powder dispersed in 1-methyl-2-pyrrolidone. Sonication causes the van der Waals forces between the structural hexagons of Te to break so that the relatively coarse powder breaks down into nanoscale particles. The TeQDs have an average size of about 4 nm. UV-Vis absorption spectra of the TeQDs showed an absorption peak at 288 nm. Photoluminescence excitation (PLE) and photoluminescence (PL) are used to study the optical properties of TeQDs. Both the PLE and PL peaks revealed a linear relationship against the emission and excitation energies, respectively. TeQDs have important potential applications in biological imaging and catalysis as well as optoelectronics