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81.
82.
刘焱白 《湖南农业大学学报(自然科学版)》2010,(3):125-128
“诚”是儒家的一个重要哲学范畴,它集中反映了儒家高度弘扬个体道德主体性和道德自觉性的伦理精神。“诚”贯穿天人,不仅包含着天道向人道的下贯,而且包含着人道自觉地向天道的上达;当“诚”进入心性论领域,更是表现为主体最高的心灵境界、至善的心理态度以及择善固执的道德意志,而这恰恰为个体德性的形成和维系提供了心灵的根基。 相似文献
83.
对中、韩高校图书馆参考咨询服务的机构设置、服务形式、服务管理、服务对象及内容等方面进行了比较研究,并提出了发展我国参考咨询服务必须重视的几个问题:确立先进的服务理念、理顺业务流程以提高服务效率、引入营销理念以加大宣传力度、健全人才培养机制等。 相似文献
84.
对江苏省44所本科高校图书馆参考咨询工作开展情况进行了调研,分析了基本现状与存在问题,对未来江苏高校图书馆参考咨询工作的开展提出了建议。 相似文献
85.
86.
Valeriano Parravicini Simon F. Thrush Mariachiara Chiantore 《Biological conservation》2010,143(11):2435-2440
Two major concerns affect the way we perceive impacts: first, no ecosystem can still be considered pristine and second, stressors may interact. Untangling the effects of broad-scale anthropogenic stressors is complicated as appropriate unimpacted areas at relevant scales are usually unavailable for contrast with impacted regions. Although the perfect study design in the traditions of small-scale manipulative experiments may not always be possible, many human impacts and the mechanisms associated with ecosystem responses have been highlighted in literature allowing contrasting predictions on expected patterns to be tested. We applied such an approach to the Marine Protected Area of Bergeggi (Ligurian Sea, NW Mediterranean). Our study aimed at assessing the effects of recreational angling (a presumed chronic stress) on the recovery of epibenthic communities following historical date-mussel harvesting (an extreme disturbance) by making and testing alternative predictions on the structure of epibenthic communities that should be apparent depending on the importance of specific mechanisms. Effects of date-mussel harvesting were still visible 20 years after its cessation, mostly because recovery is hampered by persistent sea-urchin grazing. We hypothesized that fish biomass removal by angling favours high sea urchin abundance. Based on these premises, we assembled information on angling pressure, sea urchin abundance and substratum cover by different trophic guilds to test our predictions. Our study indicates that the interaction between date-mussel harvesting and angling produced a shift, from autotrophic-dominated to consumer-dominated communities as a consequence of cascading trophic effects. Such an outcome implies that chronic recreation fishing pressure is blocking recovery in locations previously impacted by date-mussel harvesting. Testing predictions proved efficient in describing the interaction among stressors when system history is known and represents a valuable approach to provide scientifically sound insight for improved conservation management. 相似文献
87.
郭学军 《农业图书情报学刊》2011,23(1):218-221,F0003
基于数字时代图书馆参考咨询馆员的作用,分析了参考咨询馆员应具有的素质与能力,提出了当前图书馆参考咨询馆员培养的内容和方式。 相似文献
88.
It is important to determine how well ETo can be estimated from easily observed Epan (free water evaporation measured by a pan) measurements and the other climatic data. Our objectives are to predict annual ETo with Epan data (with a calibrated kp (=ETo/Epan)) and with a 4-variable regression function method. The significance of the trends of Epan, ETo and kp series were detected. The whole data series (ETo, Epan, mean temperature, sunlight hours, relative humidity and wind speed) were divided into the early (L-5) years for calibrating kp and coefficients of a 4-variable function and the last 5 years for predicting ETo. From the results, significance of series trends decreased when using the modified Mann-Kendall (MMK) test compared to the Mann-Kendall (MK) method. For ETo, five out of six sites showed significant trends according to the MK statistic Z, and two sites were significant in trend combining with the MMK statistic Z*(j). For Epan, two sites were significant in trends according to Z, and zero sites were significant in trends combining with Z*(j). For kp, two sites were significant in trends according to Z, and no sites were significant in trends combining with Z*(j). Thus the calibrated kp can be treated as a constant when using the Epan method. The predicted annual ETo using the Epan and the multi-variable methods showed generally good agreements with the estimated annual ETo (based on monthly PM equation) with low relative errors (RE). Mean ETo values were well predicted by both methods. When using Epan method, RE ranged from −14.7 to −3.3% for Urumqi, from 17.6 to 21.7% for Xning, from 1.8 to 10.7% for Lanzhou, from 4.7 to 17.0% for Huhehaote, from −7.4 to 9.1% for Beijing, and from −8.6 to 2.3% for Changchun. RE of predicting annual ETo with 4-variable regression function were even lower compared to Epan method. The main error source of the predictions came from the deviation between calibrated kp and the actual kp of the predicted years when using Epan method and from random fluctuations of climatic data when using the 4-varible regression function. In conclusion, the MMK test was a robust method for trend detection because it considered serial time dependence. Insignificant trend of the kp series supports the choice of a mean value as the calibrated kp and for ETo predictions. The Epan method is recommended for prediction of annual ETo. 相似文献
89.
Despite the steadily increasing area under protected agriculture there is a current lack of knowledge about the effects of
the 30% black shading screen on microclimate and crop water requirements. Meteorological and lysimeter measurements inside
a screenhouse planted with sweet pepper were compared to external reference data. Irrigation water use efficiency (IWUE) was
calculated from yield records Y and water meter readings I
applied. Shading reduced mean global radiation R
G
by more than 40%, and the screen transmissivity τ
screen was shown to vary with solar elevation angle β. Wind speed inside the screenhouse u
in was reduced by more than 50%. Crop water requirements ET
c
were 38% lower than estimates for an open field crop, suggesting a significant water saving potential when using screenhouses.
However, the screen did not significantly modify maximum temperature T
max and daily vapor pressure deficit. The FAO-Penman–Monteith approach based on meteorological measurements in the screenhouse
accurately predicted daily crop evapotranspiration, and was in close agreement with lysimeter measurements. IWUE was relatively
high (10.7 kg m−3 in 2004 and 13.5 kg m−3 in 2005), but additional research is required to quantify the effect of shading on yield as well as to determine the water
saving potential of other commonly used screens.
Contribution no. 603/06 from the Agricultural Research Organization
An erratum to this article can be found at 相似文献
90.
《Journal Of Agricultural & Food Information》2013,14(3):47-63
ABSTRACT The purpose of this study was to develop a core list of journals for the field of agricultural economics. For this study, the holdings of members of the Agricultural Economics Reference Organization who represent agricultural economics libraries in the U.S. and Canada were surveyed. The resulting list of titles is compared to four similar lists, three in agricultural economics and the fourth in economics. Using any one list of journals is inadequate for collection development in agricultural economics. This survey list, along with other similar lists, can be used for decision making in selection and management of journal titles in the field. 相似文献