Curcuminoids Inhibit Botrytis cinerea and Colletotrichum gloeosporioides

The growth rate method was adopted to measure the inhibitory effect of curcumin,tetrahydrocurcumin,demethoxycurcumin,and bisdemethoxycurcumin on the mycelial growth of Botrytis cinerea and Colletotrichum gloeosporioides.The results showed that the four curcuminoids inhibited the mycelial growth of the two pathogens in a concentration-dependent manner.Bisdemethoxycurcumin at 600 mg/L exerted the strongest inhibitory effect on the mycelial growth of B.cinerea and C.gloeosporioides,with the relative inhibition rates of 98.19%and 100%,respectively;followed by demethoxycurcumin;curcumin exerted the worst inhibitory effect.Toxicity test results also showed that four curcuminoids all had a certain toxicity to B.cinerea and C.gloeosporioides,among which,bisdemethoxycurcumin exhibited the strongest toxicity,with the EC_(50)of 131.125 and 122.235 mg/L,respectively;while curcumin had the lowest toxicity,with the EC_(50)of 273.143 and 194.943 mg/L,respectively.

某含炭低品位铜矿石浮选试验

针对某矿山硫化铜矿含炭高、有用矿物嵌布粒度细、铜及伴生银矿物回收率低,精矿质量差等问题,本试验采用硫化钠做活化剂,铁铬盐木质素作为炭质矿物的抑制剂,丁基黄药与FZ-9538做组合捕收剂进行铜(银)硫混浮-铜硫分离,且经过闭路试验获得了铜精矿中铜品位22.23%、回收率81.05%,银品位2010.85 g/t、回收率69.80%,硫精矿硫品位36.28%、回收率42.02%的良好的选矿指标。

Mechanism study of organic antioxidant and inorganic salt on suppressing coal oxidation

The advantages and disadvantages of organic antioxidant and inorganic salt on suppressing coal oxidation were analyzed on the basis of the theory that coal oxidation mechanisms can be attributed to the free radical chain-type reaction mechanism. The inhibition curves on suppressing coal oxidation of the different type and different concentration of organic antioxidant and inorganic salt were given through experimental study and data processing. Then some conclusions can be gained from the experimental study combining with theoretical analysis. First the inhibition mechanism of the organic antioxidant and inorganic salt is different. The former is that the chemical action is the dominant position. It can be called as the chain termination theory because the free radical is captured during coal oxidation. And the later is that the physical effect is the dominant position. It can be called as the decreasing-temperature theory because the liquid membrane which was formed by the inorganic salt can make coal body be the state of wetness and prevent oxygen from coal surface. Second the inhibition effect of the organic antioxidant is higher than the inorganic salt in the later period. But it is lower in the early period.

Experimental study on performance that carbon dioxide inhibits coal oxidation and spontaneous combustion

Adopting oil-bath temperature programming experiment and gas chromatography, CO2＇s inhibitory performance on spontaneous combustion of Tingnan Coal Mine sample was analyzed. Through temperature rise rate test experiment, the accuracy, stability and reliability of the improved oil-bath temperature programming system applied in this experiment was proved to be superior to the traditional system. Spontaneous combustion characters parameters test of coal sample in pure air was carried out with this system and offered comparison standard for research in next stage. Temperature programming to coal sample was further conducted in oil-bath with different concentration of CO2. Testing results are compared with parameters of concentration of CO, O2, temperature, CO generation rate and O2 consumption rate tested and calculated in previous experiment in pure air. Methods of proportioning between concentration of CO and O2, CO concentration and temperature, CO generation rate and O2 consumption rate were applied to eliminate obstructions from certain external factors such as inlet of CO2; meanwhile influences of CO2 of different concentrations to coal oxidation and spontaneous combustion were investigated. Also CO2 inhibition technique was used in spontaneous combustion prevention in workface No. 106 of Tingnan Coal Mine, data collected from which indicate that CO2 performs well in inhibiting coal oxidation and spontaneous combustion.

Inhibition mechanism between sodium(Na3AlF6)and sulfur on coke reactivity

Inhibition mechanism between sodium （NaaAlF6） and sulfur on coke reactivity was investigated by simulating petroleum coke with low-impurity pitch coke and by impurity doping. The mechanism was discussed by scanning electron microscopy, energy-dispersive spectrometry, and X-ray powder diffraction. Results show that Na effectively inhibited S catalysis during carbon-air/CO2 reactions, and S inhibited the catalysis of Na during carbon- air reaction to a certain extent. A stable structure with a Na-to-S atomic ratio of 1.4 and a cyclic reaction system of ＂Na2SO3→ Na2S→Na2CO3→ Na2SO3＂ were likely the keys to producing this mutual inhibition.

A new theory of chemical method to prevent spontaneous combustion of coal

In order to prevent spontaneous combustion of coal from the source,based onthe study on the mechanism of spontaneous combustion of coal,especially the process ofcoal to self-ignite and different activate structures have different activation for oxidization,the new theory and mechanism with chemical inhibition that can change the tendency ofspontaneous combustion of coal and let the activate structures deactivate were broughtforward.Therefore,coal was not self-ignited under a certain temperature when beingchemically inhibited.

Study of the Action Mode of Wickerhamomyces anomalus against Colletotrichum gloeosporioides

Colletotrichum gloeosporioides is the causal agent of anthracnose disease in fruits and vegetables, representing a global problem. The use of biocontrol agents has proved effective against fungal diseases in a wide variety of products. In this work, the antifungal activity of Wickerhamomyces anomalus against C. gloeosporioides isolated from contaminated avocados was evaluated. The antagonism and volatile compound inhibition were measured on Petri dishes. In the mixed cultures, the mycelia damage was observed by scanning electron microscope （SEM）. Chitinase and glucanase production by the antagonism was quantified by the reducing sugars method, and biofilm formation was evaluated with 1% crystal violet. The yeast W. anomalus could reduce the growth of C. gloeosporioides up to 65% by direct antagonism and 10% by volatile compounds. The antagonist did not allow the conidia germination and mycelia growth in any of the tested formulations. SEM showed mycelial damage caused by W. anomalus. The antagonist showed adhesion to the mycelium by a polysaccharide biofilm. The presence of mycelium stimulated the hydrolytic enzyme production with the maximal activity of 21.4 U/mg for chitinases at 24 h and 10 U/mg for glucanases at 60 h. These results showed that W. anomalus used together different mechanisms to express its antifungal activity against C. gloeosporioides. This study might be the first report for this phytopathogen isolated from avocado fruits, which could represent an opportunity to establish biocontrol of diseases for this agricultural product.