社区图书馆实行多元化的建设模式

探讨了城市社区图书馆建设的重要性和意义，借助我国全面推进体制改革的机遇，坚持不懈地争取政府对图书馆事业管理体制的改革支持，根据我国国情，谋求现行体制下的事业发展。阐述了要加快社区图书馆建设的步伐，走多元化办馆之路是必然选择。     

基于用水总量控制与定额管理相结合的用水制度探讨——以重庆市铜梁县为例

以铜梁县为例,针对铜梁县资源性、工程性、水质性缺水较为严重的现状,以及铜梁县为全国第二批节水型社会建设试点地区的特殊性,从总量控制和定额管理相结合制度方案的制订思路、方法、经验等方面,探讨如何实现二者的有机结合,落实"三条红线",建立节水型社会,解决区域缺水难题。     

普通丝瓜褐变度概率分级与总酚的回归分析

为运用概率分级和回归分析方法揭示普通丝瓜褐变度与总酚含量之间的相互关系,从而建立普通丝瓜基于褐变度正态分布的分级标准,研究测定38份普通丝瓜的褐变度和总酚含量。采用X-1.2818S、X-0.5246S、X+0.5246S和X+1.2818S 4个点将丝瓜褐变度概率分为5级,即极低(1级)、低(2级)、中(3级)、高(4级)、极高(5级),并将其与总酚含量进行线性回归分析。普通丝瓜果肉褐变度变化范围为2.17~9.60,平均值为6.211,变异系数为29.77%,经K-S正态性检验符合正态分布,建立褐变度和总酚含量的线性回归方程y=3.559x-2.837,两者之间存在显著的线性关系。普通丝瓜果肉褐变度与总酚含量呈显著正相关。     

大豆总DNA导入花生的研究Ⅰ.大豆总DNA的提取

花生是一种重要的蛋白食用作物。进一步提高花生蛋白质含量，对增强我国花生的出口竞争力，更好地满足消费者的需要，具有重要意义。大豆、花生同为豆科作物，但大豆子仁蛋白质含量高于花生。如有的大豆资源蛋白质含量高达40％以上，远高于一般花生(26％左右)。这为选育高蛋白花生品种提供了优异的基础材料。本研究的目的在于建豆适宜大豆的DNA提取流程，并将大豆总DNA通过一定方法导入花生，研究导入后代内外性状变异，探讨大豆总DNA导入对花生主要品质指标的影响。本文报道高盐低pH法提取大豆总DNA的效果。     

What the soil reveals: Potential total ecosystem C stores of the Pacific Northwest region, USA

How much organic C can a region naturally store in its ecosystems? How can this be determined, when land management has altered the vegetation of the landscape substantially? The answers may lie in the soil: this study synthesized the spatial distribution of soil properties derived from the state soils geographic database with empirical measurements of old-growth forest ecosystem C to yield a regional distribution of potential maximum total-ecosystem organic C stores. The region under consideration is 179,000 square kilometers extending from the southern Oregon border to the northern Washington border, and from the Pacific Ocean to the east side of the Cascade Mountains. Total ecosystem organic C (TEC) was measured in 16 diverse old-growth forests encompassing 35 stands and 79 pedons to a depth of 100 cm. The TEC ranged between 185 and 1200 Mg C ha⁻¹. On an average, 63% of TEC was in the vegetation, 13% in woody detritus, 3% in the forest floor, 7% in the 0–20 cm mineral soil, and 13% in 20–100 cm mineral soil. The TEC was strongly related to soil organic C (SOC) in the 0–20 cm mineral soil, yielding a monotonically increasing, curvilinear relation. To apply this relation to estimate the TEC distribution throughout the region, 211 map units of the state soils geographic database (STATSGO) were used. The SOC in the 0–20 cm mineral soil of the map units was consistent with values from previously measured pedons distributed throughout the region. Resampling of 13 second-growth forests 25 years after initial sampling indicated no regional change in mineral SOC, and supported the use of a static state soils map. The SOC spatial distribution combined with the quantitative old-growth TEC–SOC relation yielded an estimate of potential TEC storage throughout the region under the hypothetical condition of old-growth forest coverage. The area-weighted TEC was 760 Mg C ha⁻¹. This is 100 Mg C ha⁻¹ more than a previous estimate based on a coarser resolution of six physiographic provinces, and 400 Mg C ha⁻¹ more than current regional stores. The map of potential TEC may be useful in forecasting regional C dynamics and in land-management decisions related to C sequestration.     

Effects of dietary supplementation of carotenoids on survival, growth, pigmentation, and antioxidant capacity of characins, Hyphessobrycon callistus

This study aimed to find out if dietary carotenoid (CD) supplement could make differences in survival, growth, pigmentation, and antioxidant capacity of characins Hyphessobrycon callistus, an ornamental fish. Two types of CD and its combination (AX — astaxanthin, BC — β-carotene, MX — 1:1 combination of AX and BC) at three concentrations (10, 20, and 40 mg/kg) were used resulting in nine pigmented diets. A diet without CD supplement served as control. No differences in growth and survival of the fish among treatments were found after 8 weeks rearing. Disregarding the types of dietary CD, AX dominated (> 98%) the body CD, indicating that this fish converted most dietary BC into body AX for storage. Body AX and BC content increased with increasing dietary CD concentration. Body AX in BC-fed fish was lower than that in both AX- and MX-fed fish. No difference in body AX was found between AX- and MX-fed fish, and in body BC in all pigmented fish. Serum total antioxidant status [TAS], serum antioxidant enzymes (superoxide dismutase [SOD], glutathione peroxidases [GPx]) and serum transaminases (alanine aminotransferase [ALT], aspartate aminotransferase [AST]) were chosen as indices of fish antioxidant capacity. Antioxidant activities changed with dietary CD type and concentration. Pigmented fish had lower SOD, GPx and ALT than control fish; dietary CD types only affected SOD and ALT in fish. AX-fed fish had the lowest SOD. Dietary AX had more numbers of negative correlations with antioxidant parameters in fish than BC.     

The effect of various flooring materials on performance and foot health of early-weaned pigs

The effects of various flooring materials on the performance and foot health of early-weaned piglets were evaluated in seven trials using 728 pigs. Pigs housed on galvanized flattened expanded metal, plastic-coated expanded metal, perforated galvanized panels, galvanized woven wire and plastic-coated woven wire had similar average daily gains, average daily feed intakes and feed/gain ratios. Foot pad scores were lower (less cuts, cracks and abrasions) for plastic-coated expanded metal, plastic-coated woven wire and perforated galvanized panels than for galvanized expanded metal and galvanized woven wire. While foot pad scores varied among flooring materials, none of the flooring materials produced lesions that resulted in any visible discomfort or inhibition of locomotion of the pigs. Correlation coefficients between individual pig body weight and foot pad scores were positively related indicating that body weight may be a factor contributing to lesion severity. Although foot pad lesions were common in the weanling pigs, with some variation due to flooring materials, there were no differential effects among the flooring materials evaluated on performance or visible comfort of the pigs.     

植株中全硼测定方法的研究

以硝酸-高氯酸为湿灰化法的氧化剂,不同植物材料为试验对象,干灰化法的测试结果为参比,探讨研究湿灰化法测定植株全硼的可行性。结果表明:湿灰化法测定植株全硼含量与干灰化法的结果基本一致,利用湿灰化法进行样品消解是可行的,这为批量测试植株中的全硼含量提供了有益的探索。     

Screening sorghum genotypes for salinity tolerant biomass production

Genetic improvement of salt tolerance is of high importance due to the extent and the constant increase in salt affected areas. Sorghum [Sorghum bicolor (L.) Moench] has been considered relatively more salt tolerant than maize and has the potential as a grain and fodder crop for salt affected areas. One hundred sorghum genotypes were screened for salinity tolerance in pots containing Alfisol and initially irrigated with a 250-mM NaCl solution in a randomized block design with three replications. Subsequently 46 selected genotypes were assessed in a second trial to confirm their responses to salinity. Substantial variation in shoot biomass ratio was identified among the genotypes. The performance of genotypes was consistent across experiments. Seven salinity tolerant and ten salinity sensitive genotypes are reported. Relative shoot lengths of seedlings were genetically correlated to the shoot biomass ratios at all stages of sampling though the relationships were not close enough to use the trait as a selection criterion. In general, the whole-plant tolerance to salinity resulted in reduced shoot Na⁺ concentration. The K⁺/Na⁺ and Ca²⁺/Na⁺ ratios were also positively related to tolerance but with a lesser r ². Therefore, it is concluded that genotypic diversity exists for salt tolerance biomass production and that Na⁺ exclusion from the shoot may be a major mechanism involved in that tolerance.     

生物炭对水稻土Olsen-P的影响

生物炭如何影响土壤磷素的有效性目前尚不清楚。本研究以稻草和白杨树枝为原料,采用室内培养方法,研究了300℃、450℃和600℃制备的生物炭在5、15和40g/kg施用量下对水稻土Olsen-P的影响。与树枝炭相比,稻草炭显著提高了水稻土Olsen-P含量;3种温度制备的稻草炭对水稻土Olsen-P的影响不存在显著差异;3种施用量稻草炭均显著提高了水稻土Olsen-P含量。生物炭制备原料和施用量均显著影响土壤磷素的有效性,不同温度制备的生物炭对土壤磷素的有效性影响不显著。