独立院校大学生学风监管机制研究

建立养成大学生优良学习习惯的学风监管机制,是高校学风建设的重要方法之一。马克思主义＂质量互变规律＂是建立大学生学风监管机制的理论基石,思想政治教育调控理论是建立大学生学风监管机制的实践运作原理。     

当归优质高效栽培技术

介绍了当归育苗、施肥、定植、田间管理、病虫害防治等栽培技术,以指导当归大田生产.     

Rhizosphere calcareous soil P-extraction at the expense of organic carbon from root-exuded organic acids induced by phosphorus deficiency in several plant species

The amount of organic acids in root exudates rapidly increases under phosphorus (P) deficiency. Loss of carbon from root-exuded organic acids, which are derived from plant net photosynthetic products, is generally considered negligible. The present study aimed to study the characteristics of root-exuded organic acids, extraction of phosphorus (P extraction) in calcareous soil and the expression of organic carbon from root-exuded organic acids in two woody Moraceae plants (Broussonetia papyrifera L. Vent and Morus alba L.) and two herbaceous cruciferous plants (Orychophragmus violaceus L. Schulz and Brassica napus L.) under two P levels (P-normal and P-deficient). P extraction and the amount of root-exuded organic acids simultaneously and disproportionately increased in the four plant species tested under P deficiency. The maximum P-extracting capability of the four plant species was observed after 40 days of treatment. Additionally, the response of root-exuded organic acids induced by P deficiency was species-specific. B. papyrifera extracted more P in calcareous soil, and expended less organic acid for the same P-extraction than M. alba. Similarly, O. violaceus extracted more P in calcareous soil, and consumed less organic acid for the same level of P-extraction than B. napus. Root-exuded oxalic and malic acids accounted for most of the increment of P extraction in woody Moraceae plants, while root-exuded citric acid accounted for most of the increment in P extraction in herbaceous cruciferous plants. B. papyrifera and O. violaceus exhibited the strongest P-extracting capability at lower expense of organic carbon over the treatment duration in the four plant species. O. violaceus had the most rapid response of root-exuded organic acids to P deficiency, while B. napus had the slowest response. Thus, rapid response with low organic carbon cost and high efficiency of extraction on P in calcareous soil may underlie the strong adaptability of B. papyrifera and O. violaceus to a Karst environment.     

The Leaching Behaviour and Balances of Nitrogen and Other Elements under Spring Wheat in Lysimeter Experiment 1985–92

Abstract

In a lysimeter study it was found that moderate rates of ammonium nitrate increased utilization percentages in spring wheat, and the leaching was 10% or less of added N. Over-optimal rates reduced utilization percentages and increased leaching to almost 50% of the highest doses. Late split application of calcium nitrate increased the percentage of N in grain. Furthermore, leaching of N was not reduced, but occurred somewhat later in the fall and winter seasons. Leaching of Cl^? was more rapid and that of SO₄ ^2- was delayed relative to the leaching of NO₃ ^?. Rather large negative N balances were obtained, also after over-optimal application rates, and total N content of the soil was reduced. Compared with the N₀ treatment, differences in soil N residues amounted to 15–25% of added N in seven years. Gaseous losses had apparently taken place both from the added N and from soil N according to the total-N analysis.     

Effects of bark mulch and npk fertilizer on yield,leaf nutrient status and soil mineral nitrogen during three years of strawberry production

The effects of bark mulch and NPK fertilizers on yield and leaf and soil nutrient status of ‘Korona’ strawberry plants (Fragaria×ananassa Duch.), were studied over a period of three years. A significant effect of mulching was found in the first harvest year, but additional fertilizer did not affect total yield. Bark mulch slightly decreased the level of leaf nitrogen, but increased the level of leaf phosphorus and potassium in all years. Bark had a significant, negative effect on soil nitrate and ammonium content in the two first seasons. Mulching increased the soil moisture content in all years.     

Investigations on the radioactive contamination of crop plants as a result of H-bomb detonation (Part 2) Root and foliage uptake of “Bikini ash”

The Foliar Uptake by Squash Plant

The radioactive ash for experimental use, hereafter referred to as “Bikini ash”, was prepared by igniting the heavily contaminated substances on board No. 5 Fukuryu Maru at about 650°C, followed by sifting through a 100 mesh sieve. On ignition some parts of the fission products, particularly iodine, ruthenium and tellurium would have possibly been lost to the air.     

泗阳县玉米测土配方施肥试验

为明确测土配方技术在泗阳地区玉米生产过程中的实际效果，通过田间试验对玉米生育期、产量构成和效益等进行了对比分析。试验结果显示：采用14.8-9-8的肥料配比能显著提升玉米肥料利用率，提高产量和收益。相较常规施肥，测土配方施肥对玉米生育期影响较小，但玉米穗粒数和千粒重提升效果显著，分别提升了1.88%和3.89%；测土配方施肥的氮、磷、钾肥利用率和养分平均利用率分别为40.77%、28.02%、51.18%，相较常规施肥分别提升了11.55%、4.07%、21.46%，养分平均利用率提升了12.36%；测土配方施肥籽粒产量为9535.04kg/ha，相较常规施肥增产429.99kg，增产率为4.72%，纯收益每公顷提升1269.60元。     

基于改进蚁群算法的服务组合研究

在服务计算过程中，服务组合问题是其中关键的技术之一。在原子候选服务数目巨大的情况下，经典的算法一般都是寻找问题的最优解，存在运算量大，运行时间长的缺点，蚁群算法并不是寻找服务组合问题的最优解，而是得到用户能够认同的可行解。为了能够更有效的为用户提供各种服务，在静态的服务组合建立过程中，以服务发现的候选原子服务集合中的服务质量为权重，将服务组合问题分解成一个有向无环图，在组合代价为最小的原则下，采用改进的蚁群算法为搜索方法，迭代一定的次数或者达到用户设定的服务质量为算法的终止条件，找到能够组合为用户需要的原子候选服务集合，进而快速、准确的得到用户期望的服务。