供给侧视域大学生思想政治教育获得感:价值、困境及超越

大学生思想政治教育获得感是衡量实效的“标尺器”、提升质量的“助推剂”和话语转换的“凭证书”,其归根到底是思想政治教育供求平衡的产物。现阶段思想政治教育供给不平衡不充分同大学生需求之间矛盾减削获得感,思想政治教育供给要在把握以情动人、以理服人、以行化人的维度基础上,力求内容既高大上又接地气、形式既含温度又设尺度、氛围既横向搭又纵向建,实现优质供给与需求恰好适配,直接精准提升获得感。     

Effects of cover crop growth and decomposition on the distribution of aggregate size fractions and soil microbial carbon dynamics

Although the effects of cover crops (CC) on various soil parameters have been fully investigated, less is known about the impacts at different stages in CC cultivation. The objective of this study was to quantify the influence of CC cultivation stages and residue placement on aggregates and microbial carbon (C_mic). Additionally, the influence of residue location and crop species on CO₂ emissions and leached mineralized nitrogen (N_min) during the plant degradation period was also investigated. Within an incubation experiment, four CC species were sown in soil columns, with additional columns being kept plant‐free. After plant growth, the columns were frozen (as occurs in winter under field conditions) and then incubated with the plant material either incorporated or surface‐applied. With CC, concentrations of large and medium macroaggregates were twice that of the fallow, confirming positive effects of root growth. Freezing led to a decrease in these aggregate size classes. In the subsequent incubation, the large macroaggregates decreased far more in the samples with CC than in the fallow, leading to similar aggregate size distributions. No difference in C_mic concentration was found among the CC cultivation stages. CO₂ emissions were roughly equivalent to the carbon amounts added as plant residues. Comparison of columns with incorporated or surface‐applied residues indicated no consistent pattern of aggregate distribution, CO₂ emission or C_mic and N_min concentrations. Our results suggest that positive effects of CC cultivation are only short term and that a large amount of organic material in the soil could have a greater influence than CC cultivation.     

采用混合生物地理学算法的番茄种植规划研究

为解决番茄酱产季原料供应不均衡问题,在构建番茄种植规划的数学模型基础上,提出采用生物地理学算法对番茄种植规划模型的求解。利用余弦迁移模型、干扰迁移算子和基于高斯分布的变异算子对BBO算法进行适当改进,并与差分进化算法的变异算子结合,以增强生物地理学算法的全局搜索性能。以新疆某番茄酱厂为例对番茄种植规划问题进行计算,结果表明:采用该算法获得的种植方案能实现番茄原料产量与番茄酱厂生产能力之间的平衡。仿真结果验证了番茄种植规划数学模型的合理性。在求解番茄种植规划问题上,与其他智能优化算法相比,该算法具有较好的收敛性。     

几种利用乳中尿素氮浓度估测尿氮排泄量模型的评价

本文利用34组国内外报道的荷斯坦牛乳中尿素氮浓度和尿氮排泄量的实测数据，对目前提出的部分利用MUN估测尿氮排泄量的模型进行了比较。结果表明，Zhai（2005）提出的模型[UN（g/d）：10．1×MUN（mg／dL）＋47.3]预测效果较好（P〉0．05）。划分MUN浓度范围分别建立模型可能会提高预测的准确度。此外，根据34组数据做简单回归：UN（g/d）=12．78×MUN（mg/d1）＋28．15（n=34，R2=0．59）。     

风险厌恶下的供应链收益共享契约协调模型研究

收益共享契约是实现供应链系统绩效改善或完美协调的一种机制.考虑了零售商与供应商分别具有风险厌恶决策偏好情况下，在随机市场需求下建立了由单供应商和单零售商组成的二级供应链的收益共享契约模型，并对模型进行了分析，揭示了供应商和零售商的风险厌恶决策偏好对收益共享契约参数的影响.研究结果表明：当销售商（供应商）的风险厌恶控制在一定程度内时，通过调整收益共享契约参数，可以保证供应链的协调.     

某宾馆利用太阳能集中热水供应系统设计

随着人们生活水平的提高,对生活热水需求的激增促进了太阳能热水器的迅速发展。目前太阳能热水器的应用,主要还是以分户独立系统为主,未来太阳能热水系统的发展趋势是以集中式为主。针对该宾馆热水供应的要求和特点,为宾馆设计了利用太阳能提供热水的集中系统,进行了太阳能集热系统规划、设计计算和设备选型,为将来集中式太阳能热水系统的应用和发展提供参考。     

人口老龄化对中国劳动力供给的影响分析

通过对中国人口统计的一些数据分析,研究了人口老龄化对中国劳动力供给的影响.研究结果表明,老龄化造成劳动力供给数量减少,同时老龄化影响中国劳动力供给质量.可采取应对措施:一是提高科技水平和人口素质,二是充分开发和利用老年人力资本.     

三峡库区不同植被覆盖对土壤氮的影响

不同植被类型影响着土壤养分的积累、分布与循环,而土壤氮素是植被生长的重要限制性元素。通过分析宜昌点军区3种植被类型(柏树地、橘树地、菜地)覆盖下土壤氮素的变化情况,研究了不同植被对土壤氮素各形态的影响。结果表明,土壤全氮、硝态氮和微生物氮都是柏树地显著大于菜地和橘树地,而菜地和橘树地之间无显著性的差异;土壤矿化氮和微生物氮/全氮的变化顺序是柏树地橘树地菜地。说明不同植被覆盖对土壤氮有显著的影响,柏树地更有利于土壤氮的积累,氮的有效性也最高,由此认为柏树长期生长有益于土壤氮的改善。     

1例藏獒三氮脒中毒的生化检验及治疗

用三氮脒以3.5 mg/kg的剂量对患有附红细胞体病的藏獒进行肌肉注射,隔日用同等剂量的三氮脒肌肉注射,24 h后,藏獒发生以神经症状为主的中毒现象,并表现出食欲废绝,后肢发软,四肢抽搐呈划水状,卧地不起,昏迷,体温正常临床症状。经血清生化检验,藏獒的尿素氮、肌酸激酶等的生化指标明显升高,血糖降低占病例的100%。经过5 d的药物治疗后,中毒藏獒基本恢复健康。     

Effects of soybean variety and Bradyrhizobium strains on yield,protein content and biological nitrogen fixation under cool growing conditions in Germany

Soybean (Glycine max (L.) Merr.) is able to fix atmospheric nitrogen in symbiosis with the bacteria Bradyrhizobium japonicum. Because these bacteria are not native in European soils, soybean seeds must be inoculated with Bradyrhizobium strains before sowing to fix nitrogen and meet their yield potential. In Central Europe soybean cultivation is still quite new and breeding of early maturing soybean varieties adapted to cool growing conditions has just started.Under these low temperature conditions in Central Europe the inoculation with different, commercially available Bradyrhizobium inoculants has resulted in unsatisfactory nodulation. The aim of this study was: (i) to test the ability of commercially available inoculants to maximize soybean grain yield, protein content and protein yield, (ii) to study the interaction of different inoculants with different soybean varieties for two different sites in Germany under cool growing conditions over three years and (iii) to determine the variability of biological nitrogen fixation. Field trials were set up on an organically managed site at the Hessische Staatsdomäne Frankenhausen (DFH) and on a conventionally managed site in Quedlinburg (QLB) for three consecutive seasons from 2011 to 2013. Three early maturing soybean varieties—Merlin, Bohemians, Protina—were tested in combination with four different Bradyrhizobium inoculants—Radicin No.7, NPPL-Hi Stick, Force 48, Biodoz Rhizofilm—and compared with a non-inoculated control. Effective inoculation with Bradyrhizobium strains increased grain yield, protein content and protein yield by up to 57%, 26% and 99%, respectively. Grain yield, protein content and protein yield were generally higher in DFH. Average grain yield was 1634 kg ha⁻¹ in QLB (2012–2013) and 2455 kg ha⁻¹ in DFH (2011–2013), average protein content was 386 g kg⁻¹ in QLB and 389 g kg⁻¹ in DFH and average protein yield was 650 kg ha⁻¹ in QLB and 965 kg ha⁻¹ in DFH. The percentage of nitrogen derived from air (Ndfa) ranged between 40% and 57%. Soybeans inoculated with Radicin No. 7 failed to form nodules, and crop performance was identical to the non-inoculated control. Biodoz Rhizofilm, NPPL Hi-Stick and Force 48 are suitable for soybean cultivation under cool growing conditions in Germany. Interactions between soybean variety and inoculant were significant for protein content and protein yield at both sites, but not for nodulation, grain yield, thousand kernel weight and Ndfa. The variety Protina in combination with the inoculant Biodoz Rhizofilm can be recommended for tofu for both tested sites, while Merlin and Protina in combination with Biodoz Rhizofilm are recommended for animal fodder production in DFH. Animal fodder production was not profitable in QLB due to low protein yields.