三个不同因子对滑菇产量的影响

研究了滑菇培养基中含水率、麦麸含量、石膏含量等3个因素对滑菇产量的影响。结果表明:当麦麸含量为17%,石膏含量为1%时,滑菇产量较高,这2个因素不同水平的平均产量差异显著,基质含水率各水平之间的差异不显著。当含水率在63%时,平均产量高于其它2个水平。通过正交试验得出的最佳麦麸含量为17%,石膏含量为1%,培养基中最佳含水率为63%。     

石膏纤维板生产技术

本文从产品性能,应用范围及生产特点等方面将石膏纤维板与传统的湿法纤维板、纸面石膏板进行了对比,并简要介绍了石膏纤维板的生产技术与市场前景。     

SALTIRSOIL: a simulation model for the mid to long‐term prediction of soil salinity in irrigated agriculture

The SALTIRSOIL model predicts soil salinity, sodicity and alkalinity in irrigated land using basic information on soil, climate, crop, irrigation management and water quality. It extends the concept of the WATSUIT model to include irrigation and crop management practices, advances in the calculation of evapotranspiration and new algorithms for the water stress coefficient and calculation of electrical conductivity. SALTIRSOIL calculates the soil water balance and soil solution concentration over the year. A second module, SALSOLCHEM, calculates the inorganic ion composition of the soil solution at equilibrium with soil calcite and gypsum at the soil’s CO₂ partial pressure. Results from comparing predicted and experimentally determined concentrations, observations and predictions of pH, alkalinity and calcium concentration in calcite‐saturated solutions agree to the second significant figure; in gypsum‐saturated solutions the standard difference between observations and predictions is <3% in absolute values. The algorithms in SALTIRSOIL have been verified and SALSOLCHEM validated for the reliable calculation of soil salinity, sodicity and alkalinity at water saturation in well‐drained irrigated lands. In simulations for horticultural crops in southeast Spain, soil solution concentration factors at water saturation, quotients of electrical conductivity (EC₂₅) at saturation to electrical conductivity in the irrigation water, and quotients of sodium adsorption ratio (SAR) are very similar to average measured values for the area.     

Influence of Macromolecule-type Retarders on the Hydration and Microstructure of Hardened Paste

Influence of one macromolecule-type retarder bone glue on the setting time, strength, ion concentration in liquid phase and supersaturation degree, crystal morphology of dehydrate and microstructure of hardened paste of building gypsum is investigated. Furthermore, internal cause of strength loss of building gypsum with addition of retarder is analyzed, The results indicate that bone glue could retard the hydration of building gypsum markedly, but its negative influence on the strength of building gypsum is far lower than that of low molecule-type retarders. Bone glue has a minor effect on crystal morphology of dehydrate and porosity of hardened paste, but it causes the large crystal size and coarsening of pore size distribution of hardened gypsum paste, which is the very intrinsic reason of strength loss of building gypsum.     

Effect of acid rain on sandstone: The Royal Palace and the Riddarholm church,Stockholm

The deterioration of two kinds of sandstone is discussed for two 18:th century buildings in central Stockholm: the Royal Palace, and the Royal Carolean Burial Chapel (Karolinska gravkoret) annexed to the mediaeval Riddarholm church. The facades of calcitic Gotland sandstone show many signs of serious decay, such as gypsum formation, pulverized surface, exfoliation, discolouration, and salt efflorescence. The socles are built of the more resistant quartzitic Roslagen sandstone, displaying some discolouration, cracks, and slight exfoliation. In total about 300 samples have been analysed. The surface concentration of sulphur is highest at ground level and at rain-sheltered positions. Chemical and sulphur isotope data indicate that the stone decay to a large part may be attributed to anthropogenic sources like acid deposition and car traffic.     

Amelioration of calcareous saline sodic soils through phytoremediation and chemical strategies

Abstract. The worldwide occurrence of saline sodic and sodic soils on more than half a billion hectares warrants attention for their efficient, inexpensive and environmentally acceptable management. These soils can be ameliorated by providing a source of calcium (Ca²⁺) to replace excess sodium (Na⁺) from the cation exchange sites. Although chemical amendments have long been used to ameliorate such soils, the chemical process has become costly during the last two decades in several developing countries. As a low‐cost and environmentally acceptable strategy, the cultivation of certain salt tolerant forage species on calcareous sodic and saline sodic soils, i.e. phytoremediation, has gained interest among scientists and farmers in recent years. In a field study conducted at three calcareous saline sodic sites (pH_s=8.1–8.8, EC_e=7.8–12.5 dS m^–1, SAR=30.6–76.1) in the Indus Plains of Pakistan, we compared chemical and phytoremediation methods. There were four treatments; two involved plants: Kallar grass (Leptochloa fusca (L.) Kunth), and sesbania (Sesbania bispinosa (Jacq.) W. Wight). The other two treatments were uncropped: soil application of gypsum and an untreated control. All treatments were irrigated with canal water (EC=0.22–0.28 dS m^–1). The plant species were grown for one season (5–6 months). Sesbania produced more forage yield (34 t ha^–1) than Kallar grass (23 t ha^–1). Phytoremediation and chemical treatments resulted in similar decreases in soil salinity and sodicity, indicating that phytoremediation may replace or supplement the more costly chemical approach. The soil amelioration potential of sesbania was similar to that of the Kallar grass, which suggests that moderately saline sodic calcareous soils can be improved by growing a forage legume with market value.     

腐殖酸强化脱硫石膏改良油污盐碱土壤的研究

以腐殖酸为表面活性剂进行了脱硫石膏改良油污盐碱土壤的土柱实验,研究了不同洗盐条件下土壤渗透性能、电导率和pH值的变化规律。研究结果表明,油污显著影响脱硫石膏改良盐碱土壤的效果,淋洗前后油污土壤的碱化度仅从42.78%下降到37.72%;而加入腐殖酸表面活性剂后,油污盐碱土壤碱化度由42.78%下降到23.20%,淋出液电导率值显著增高,且pH值有所变化,证明加入腐殖酸表面活性剂可显著强化脱硫石膏改良油污盐碱土壤。     

滨海吹填土快速脱盐技术的初步研究

针对滨海地区吹填土的高盐分和质地粘重,从改善物理性状和降低盐分入手,通过添加不同量的脱硫石膏进行不同处理的脱盐试验,结果显示:3个处理都能够改善吹填土粘重的物理性状,有效降低吹填土中有害离子(Cl-和Na+)的含量,脱盐后的吹填土无次生碱化现象。3个处理中5%脱硫石膏和5%有机肥较单纯施用脱硫石膏的处理脱盐显著,且改良后的碱化指标明显低于另两个单纯施用脱硫石膏的处理。