高性能混凝土抗硫酸盐侵蚀耐久寿命预测初探

根据南京地铁工程高性能混凝土在硫酸盐侵蚀环境下的试验研究结果,初步建立了基于混凝土衰变规律的抗硫酸盐侵蚀耐久寿命模型,并对该工程进行了寿命预测。     

碱茅营养元素吸收量与土壤含盐量的相关分析

碱茅(Puccinellia distans(L·)Parl.)是广大盐碱土地区发展人工草场的优良草种。本文用硫酸盐盐土不同含盐量对碱茅吸收营养元素量进行相关分析表明,碱茅对N、P、K、Na元素的吸收量和土壤中含盐量呈直线相关,r=0.982,0.898,0.968,0.969。对Ca的吸收量和土壤含盐量呈负相关,r=O.996。对Mg的吸收量变动很小,和土壤含盐量没有明显相关性。     

锌对平菇母种菌丝的生长效应

本文通过在高美施培养基中添加不同浓度的硫酸锌对三个供试平菇菌株的生理反应试验，证明锌是促进平菇菌丝生长发育和生物合成的微量元素之一；发现高美施对平菇母种菌丝吸收利用锌元素有增效作用；不同品种对锌营养的需求不同，200×10－6的硫酸锌是促进平菇菌丝生长发育所需的最佳锌营养条件。     

Effect of amending urea fertilizer with chemical additives on ammonia volatilization loss and nitrogen-use efficiency

 Effects of amending urea with pyrite (Py) or potassium chloride (KCl) alone and in combination with copper sulphate (CuSO₄) on NH₃ volatilization and N-use efficiency in an Alfisol were evaluated. NH₃ volatilization from surface-applied urea fertilizers was measured using a closed dynamic air flow system. Kinetics of NH₃ volatilization over a 10-day period showed that the peak rate of NH₃ loss was on day 3 with the unamended urea, whilst it occurred on day 4 with all amended urea fertilizers. Total NH₃ loss from the unamended urea was 48% of the applied N, which was reduced to 38 and 40% with U+Py and U+KCl, respectively. A further reduction in N loss was recorded with U+Py+CuSO₄ (34%) and U+KCl+CuSO₄ (36%). The inhibition of NH₃ with U+Py+CuSO₄ and U+KCl+CuSO₄ was markedly high, at 30 and 25%, respectively. As compared to urea, all amended urea fertilizers resulted in a significantly higher dry matter yield, N uptake and apparent N recovery (ANR) efficiency by sunflower. An increase of 28 and 24% units in ANR over urea could be obtained with U+Py+CuSO₄ and U+KCl+CuSO₄, respectively. Since the chemical additives also have a fertilizer value besides being effective in controlling NH₃ loss from urea and improving N-use efficiency, their use as amendment to urea could be a viable option. Received: 5 August 1999     

A chlorophyll-reduced seedling mutant in oilseed rape, Brassica napus, for utilization in F1 hybrid production

A mutant chlorophyll‐reduced (Cr) seedling with yellow‐green cotyledons and leaves was obtained from the Brassica napus inbred line 3529 induced by fast neutron and diethyl sulphate (DES). Genetic analysis revealed that the Cr seedling marker trait was controlled by a pair of recessive genes. A randomized complete block design was used to evaluate its agronomic performance. Results from 2 years of tests indicated that the seed yield of Cr lines was significantly lower than that of normal green plants; however, when the Cr gene was in the heterozygous condition, no deleterious effects on yield characteristics and disease resistance were observed. The Cr seedling marker trait was introduced into male‐sterile lines, and Cr male‐sterile lines revealed the same superior combining ability as normal chlorophyll (Nc) lines. The Cr trait can therefore be used as a marker to produce hybrid seed.     

硫酸钠对肉仔鸡早期增重的影响

肉仔鸡全价饲料中添加３ｇ／ｋｇ硫酸钠．探讨硫酸钠对肉仔鸡增重的影响。试验结果表明,试验组增重比对照组高,差异极显著（Ｐ＜０．０１）,试验组饲料转化率比对照组高,但差异不显著（Ｐ＞０ ．０５）。试验组较对照组增重成本降低３．０５％。     

叶面喷施硫酸钾镁肥对不同部位烟叶镁、钾、钙吸收的影响

[目的]在云南省曲靖市植烟土壤交换性钙镁比超过20的缺镁烟区,通过土壤镁肥施用和叶面喷施进行钙镁比调控,了解其对烤烟钾、钙、镁吸收的影响,为曲靖市缺镁烟区烤烟的平衡施肥技术提供理论依据和生产指导。[方法]通过田间小区试验,采用完全随机区组设计,以不施镁肥作为对照,分别设3个叶面喷施硫酸钾镁肥处理和2个根层施镁＋叶面喷施处理。采集根、茎、上部叶、中部叶和下部叶5个部位进行烘干称重,并且粉碎制样,测定钾、钙、镁含量;每个小区从初烤烟叶中选取上部（B2F）、中部（C3F）、下部（X2F）样品,分析烟叶全钾、钙、镁含量。[结果]从不同部位来看,叶面喷施及土壤施用和叶面喷施配合调控钙镁比提高了中、下部烟叶对镁、钾的吸收以及下部烟叶对钙的吸收,但降低了上部烟叶对镁、钾、钙的吸收以及中部烟叶对钙的吸收。烟叶不同部位镁、钾、钙的累积分配量比较表现为中部叶〉下部叶〉上部叶;从不同部位来看,中、上部烟叶钙镁比、钾镁比降低,下部烟叶钙镁比增加,而下部烟叶钾镁比处理之间没有差异。[结论]叶面喷施及土壤施用和叶面喷施配合调控对烟叶钙镁比、钾镁比的影响,主要是通过影响镁的吸收。     

高硫废水厌氧消化中硫酸盐抑制解除方法的研究

本文采用物理化学和砂氧消化等手段，对含以有机废水厌氧消化中硫酸盐抑制的解除方法进行了研究。采用投加以铁盐为主手复合脱硫剂ＨＳ－１，糖蜜酒精废水厌氧处理小试运行结果为，有朵负荷稳定在８．０ｇＣＯＤ／（Ｌ．ｄ）以上，容积产气率在３Ｌ／Ｌ．ｄ）以上，ＣＯＤ去除率为７５－７８％，达到稳定运行的效果。沿气中Ｈ２Ｓ含量在１０ｍｇ／ｍ＾２以下，低于城市用煤气标准（２０ｍｇ／ｍ＾２）。     

Short-term variation in the concentration of selected ions within individual tropical rainstorms

Rainwater was collected at the campus of the University of Brunei Darussalam in Bandar Seri Begawan, Brunei Darussalam, using a funnel-in-bottle sampler. Polypropylene bottles were changed at intervals during rainstorm events. The pH and conductivity were determined immediately after collection on aliquots of the sample. Samples were refrigerated at 5°C for subsequent chemical analysis. Analyses for Na, Mg, Ca, Zn and Fe were carried out by means of inductively coupled plasma atomic emission spectroscopy (ICP-AES); Cu and Mn were analysed by graphite furnace atomic absorption spectroscopy (GFAAS); K was analysed using flame atomic emission spectroscopy (FAES); and Cl^–, NO₃ ^– and SO₄ ^2– were analysed by ion chromatography (IC). Concentration versus time profiles are reported for three rainstorm events. All ions exhibited a decrease in concentration during the rainstorm. The first sample contained the highest concentration of ions, consistent with a first-flush effect. The contribution of the initial stages of the shower to the total quantity of ion deposited during the entire rainstorm is quite overwhelming; in many cases 20 to 30% of the mass was deposited in less than 5% of rainstorm duration. On the other hand, the pH and conductivity variation during rainstorms did not exhibit a consistent pattern.     

Effects of herbicides on three vesicular-arbuscular fungi associated with winter wheat (Riticum aestivum L.)

Summary We studied the effects of field application rates of four herbicides (Avenge, Ceridor, Dicurane, and Harrier) on spore germination and infection of wheat roots by three species of Glomus grown under conditions of low P availability. Low concentrations of Ceridor (bifenox, mecoprop) and Harrier (mecoprop, ioxynil, clopyralid) inhibited spore germination while higher concentrations were stimulatory. Avenge (difenzoquat methyl sulphate) prevented spore germination completely, while Dicurane (chlortoluron) had no effect. The herbicide applications had no significant effect on the infection rates of any of the three fungi except Harrier on G. geosporum. The herbicide treatments did, however, affect plant growth and ear yields. Ceridor and Harrier increased ear yields, while Dicurane showed marked phytotoxic effects.