Antisepsis and Fresh-keeping Effects of Natamycin Coating Compounds Treatment on Red Global Grape

The aim was to research fresh-keeping effects of natamycin on cold-pre- served grape. Red globe grapes were processed with compound coating liquid of chitosan with mass fraction at 1% and natamycin with mass fractions at 0.20% （T1）, 0.40% （T2） and 0.60% （T3）, respectively. Grapes processed with water （CK3） and 1% chitosan （CK2） were taken as control groups. Rotten rate, seed shattering rate, mass loss rate, respiratory intensity and related physiological quality in test and control groups were compared. The results indicated that respiratory intensity, mass loss rate, rotten rate and seed shattering rate in CK1 were all higher than those in CK2. In addition, T1, T2 and T3 were lower in the indices than CK1 and CK2, but still kept at a high level in fruit hardness. Furthermore, mass fractions of Vc and titratable acid declined more slowly in T1, T2 and T3, compared with CK1 and CK2. Natamycin better preserved grapes and prolonged storage period. In general, natamycin with mass fraction at 0.4% proved best in fresh-keeping.

Effects of Nine Kinds of Household Vase Solutions on Fresh-keeping Effect of Lilium Cut Flowers

[Objective]The paper was to study the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers.[Method]Using Lilium"Sorbonne"as the material,nine kinds of household vase solutions were prepared by edible white granulated sugar,white vinegar,akafen powder and vitamin C tablets,respectively.The morphological and physiological indexes of Lilium cut flowers,including vase life,ornamental grade,flower diameter,fresh weight of flower branches,water balance value,soluble protein content and MDA content of petals,were observed,and the effects of nine kinds of household vase solutions on fresh-keeping effect of Lilium cut flowers were studied.[Result]The household vase solution F8(20 g/L white granated sugar+1 packet/L acafen powder+2 tablets/L vitamin C tablets)had the best fresh-keeping effect on Lilium cut flowers,which was beneficial to prolong the vase life and improve the ornamental value of Lilium cut flowers.[Conclusion]The household vase solution of Lilium cut flowers is optimized,which is not only environmentally friendly but also convenient for ordinary families.

Fresh-keeping Effects of Different Concentrations of 6-BA and B9 on Carnation Cut Flower

Using sucrose, citric acid and vitamin C as the basic liquid, different concentrations of 6-BA and B9 preservatives were added, and the carnation variety ＇ Master＇ was treated. The results showed that the formula of 3% sucrose ＋ 50 mg/L citric acid ＋ 600 mg/L vitamin C ＋ 20 mg/L 6-BA could effectively maintain the water balance of the cut flower, prolong the vase life of the cut flower to 16.4 d, and maximize the flower diameter and the crown height.

Kiwi Fruit Fresh-keeping Technology

The vitamin C rich-kiwi fruit-the king of fruits-is good to taste but hard to store. Only a few countries can prevent mildew on the fruit stalk during the storage process. The fresh-keeping technology developed by the Shaanxi Teachers University has enabled China to catch up with the advanced countries in this field.

Effect of reagent films on coupling relationship between glass surface and particles

The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significantly changed by the reagent films. There were no evident rules between the average size of particles and sampling time interval, the placing angle and reagent concentration. The average particle size on the surface coated by composite reagent （2-3 μm） was smaller than that on the single reagent coated surface, while the largest particle size （4-5 μm） was observed on the surface coated with the Tween 60. The experiment also demonstrated that the best adhesive performance was obtained on the surface which was coated with 0.5% SDBS and 0.5% fluorocarbon composite reagents. The experiment results indicated that each reagent had a certain optimum adhesive range to the particle. The composite reagents with different proportion of single reagents exhibited some particular physical and chemical properties, which could effectively change the adhesive performance between the solid surface and the particles.

芬顿试剂(Fenton's reagent法降解对苯二酚和工业废水

可溶性亚铁盐和H2O2的组合称为芬顿试剂(Fenton’s reagent),是一种氧化能力很强的氧化剂,常用于废水的净化处理。本文以对苯二酚为代表物,探讨用Fenton试剂氧化的反应条件,并用最佳的实验条件处理工业废水,90分钟工业废水的COD去除率可达71.6％。

Preparation of ZnO Nanoparticles and Photocatalytic H2 Production Activity from Different Sacrificial Reagent Solutions

ZnO nanoparticles were synthesized via a direct precipitation method followed by a hetero- geneous azeotropic distillation and calcination processes, and then characterized by X-ray power diffraction, scanning electron microscopy, transmission electron microscopy, and ni- trogen adsorption-desorption measurement. The effects of Pt-loading amount, calcination temperature, and sacrificial reagents on the present ZnO suspension were investigated, photocatalytic H2 evolution efficiency from the The experimental results indicate that ZnO rianoparticles calcined at 400℃ exhibit the best photoactivity for the H2 production in comparison with the samples calcined at 300 and 500℃, and the photoeatalytie H2 production efficiency from a methanol solution is much higher than that from a triethanolamine solution. It can be ascribed to the oxidization of methanol also contributes to the H2 production during the photochemical reaction process. Moreover, the photocatalytic mechanism for the H2 production from the present ZnO suspension system containing methanol solution is also discussed in detail.

用Lipofectin Reagent转染猪子宫上皮细胞

本文用Lipofectin Reagent作为转染细胞的间型脂质,使Liposome与SV40 ts A209 DNA形成一种混合物转染猪子宫上皮细胞。此法比用磷酸钙和二乙氨乙基葡聚糖转染细胞的方法简单,高效、重复性好。转染后的猪子宫上皮细胞形状和大小略有改变;对温度敏感,用相同培养液培养7天,在33℃条件下细胞的生长速度是在40℃时的5倍.

Mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes from stone coal

The mechanisms of aid-leaching reagent calcium fluoride in the extracting vanadium processes were researched by comparing the blank extraction with the extraction with calcium fluoride as aid-leaching reagent. The leaching experiments were carried out under the conditions of 95 ~C, 6 h, 1.5 ml.g-1, 15 vol % H2SO4, and 5 % calcium fluoride （mass ratio of CaF2 to stone coal）. The concentrations of hydrogen ion were adjusted from initial 1.82 and 4.79 mol.L-1 to the pH of 1.80 4- 0.05 by 200 g.L-1 lime milk, respectively. The solvent extraction experiments were carded out under the organic phase using 15 vol% D2EHPA, 5 vol% TBP, and 80 vol% sulfonated kerosene and O/A phase ratio of 1/4. The leaching rate of vanadium and six-stage countercurrent solvent extraction rate of vanadium can be remarkably improved from 66.71 to 92.97 % and 81.15 to 98.81%, respectively, when calcium fluoride was added as aid-leaching reagent. In the leaching process, fluorine can enhance the breakage of the structure of vanadium-bearing minerals. Meanwhile, fluoride ion can combine with iron ion to generate acid-insoluble iron fluoride hydrate （Fe2Fs.7H20） and consume all ferric ions and a portion of ferrous ions. In adjusting pH value process, the massive impurities are decreased to form KA1SO4 and FeA1Fs. In solvent extraction process, fluorine can prevent the formation of ferric hydroxide colloids and eliminate the formed unstable ferric hydroxide colloids and the silicon-containing colloids to promote the sufficient contact between the aqueous phase and the organic phase and the sufficient reaction.

Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning

The use of Fenton＇s reagent （Fe^2＋/H2O2） and Fenton-like reagents containing transition metals of Cu（Ⅱ）, Zn（Ⅱ）, Co（Ⅱ）, and Mn（Ⅱ） for an alum sludge conditioning to improve its dewaterability was investigated. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton＇s reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time （CST） reduction efficiency of 47% can be achieved under test conditions of Fe^2＋/H2O2 = 20/125 mg/g DS （dry solid） and pH 6.0. The observation of floc-like particles after Fenton＇s reagent conditioning of alum sludge suggested that the mechanism of Fenton＇s reagent conditioning was different from that of polymer conditioning. In spite of the lower efficiency in the CST reduction of Fenton＇s reagent in alum sludge conditioning compared to that of polymer conditioning, Fenton＇s reagent offers a more environmentally safe option. Tiffs study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.

Reagent types and action mechanisms in ilmenite flotation:A review

Ilmenite is an essential mineral for the extraction of titanium.Conventional physical separation methods have difficulty recovering fine ilmenite,and dressing plants have begun applying flotation to recover ilmenite.The interaction of reagent groups with Ti and Fe sites on the ilmenite surface dramatically influences the ilmenite flotation.However,the investigation on Fe sites has received more attention because the activity of Ti is lower than that of Fe.For the activators on ilmenite flotation,most are metal ions but typically lead ions.The metal ions of activators promote ilmenite flotation by increasing the active sites on the ilmenite surface.Combined reagents have a better selective separation of ilmenite than single reagents due to their synergistic effect.Combining the lead ion(Pb^(2+))and the benzyl hydroxamic acid(BHA)into a Pb-BHA complex has a marked effect on ilmenite flotation,which puts forward a new idea of developing combined reagents for ilmenite flotation.This review considers reagent types and action mechanisms in ilmenite flotation.On the basis of the analysis of previous research,a brief future outlook of reagent types and action mechanisms in ilmenite flotation is also proposed in this study.

Diagnosis of spontaneous bacterial peritonitis: An update on leucocyte esterase reagent strips

Ascites remain the commonest complication of decompensated cirrhosis. Spontaneous bacterial peritonitis (SBP) is defined as the infection of ascitic fluid (AF) in the absence of a contiguous source of infection and/or an intraabdominal inflammatory focus. An AF polymorphonuclear (PMN) leucocyte count ≥ 250/mm 3 -irrespective of the AF culture resultis universally accepted nowadays as the best surrogate marker for diagnosing SBP. Frequently the results of the manual or automated PMN count do not reach the hands of the responsible medical personnel in a timely manner. However, this is a crucial step in SBP management. Since 2000, 26 studies (most of them published as full papers) have checked the validity of using leukocyte esterase reagent strips (LERS) in SBP diagnosis. LERS appear to have low sensitivity for SBP, some LERS types more than others. On the other hand, though, LERS have consistently given a high negative predictive value (> 95% in the majority of the studies) and this supports the use of LERS as a preliminary screening tool for SBP diagnosis. Finally, an AF-tailored dipstick has been developed. Within the proper setting, it is set to become the mainstream process for handling AF samples.

Optimization of efficient stable reagent of alkaline thiourea solution for gold leaching

Na2SiO3 and Na2SeO3 were chosen as stable reagents of alkaline thiourea solution substituting Na2SO3, according to the structure-property relationship between the stability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of the stable reagents on stability of alkaline thiourea was investigated. The results show that contrary to Na2SeO3, Na2SO3 and Na2SiO3 affect the stability of alkaline thiourea solution remarkably. The stable effect of Na2SiO3 on alkaline thiourea is obviously better than that of Na2SO3. The stable reagents Na2SO3 and Na2SiO3 decrease the decomposition rate of alkaline thiourea solution greatly, and the decomposition rate of alkaline thiourea reduces from （72.5%） to （33.8%） with addition of (0.3 mol·L-1) Na2SiO3. Dissolution currents of gold in the alkaline thiourea solution containing Na2SO3 and Na2SiO3 are （2.0） (mA·cm-2) and （3.5） (mA·cm-2) at the potential of 0.42 V, respectively, and Na2SO3 is consumed excessively due to the oxidation reaction of Na2SO3 occurring in the studied potential range. Na2SiO3 is an efficient stable reagent of alkaline thiourea solution, and gold dissolution is accelerated much more obviously by Na2SiO3 than by Na2SO3.

Novel Synthetic Method for the Vilsmeier-Haack Reagent and Green Routes to Acid Chlorides, Alkyl Formates, and Alkyl Chlorides

An environmentally benign and practical preparation method for the Vilsmeier-Haack reagent (VH) has been developed by using phthaloyl dichloride with DMF in toluene or 2-chlorotoluene. Phthalic anhydride as the byproduct was recovered in high yield by simple filtration. Some aromatic acids have been transformed into the corresponding acid chlorides in good yields by employing the isolated VH. Treatment of primary or secondary alcohols with VH gave alkyl formates or alkyl chlorides by depending on the reaction conditions.

Studies on New Additions to 5-Methoxy-2 (5H)-Furanone: 1, 4-Addition of Grignard Reagents, and 1,3-Dipolar Cycloaddition of Silyl Nitronates

1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.

Degradation of polyvinyl-alcohol wastewater by Fenton’s reagent: Condition optimization and enhanced biodegradability

The pretreatment of refractory polyvinyl-alcohol （PVA） wastewater with low value of CODcr by Fenton＇s reagent was investigated to enhance the biodegradabilily. The effects of operating conditions such as pH of the solution, Fe2＋ dosage, H2O2 dosage, reaction time and initial PVA concentration on the removal efficiency of CODCr were discussed. It is demonstrated that the optimum value of pH for removal of CODcr is 5 and the most suitable dosages of H2O2 （2%） and FeSO4 （10 mg/L） are 5% and 8.0%, respectively. When the initial CODcr value of the PVA water is 760 mg/L, the favorable reaction time is 110 min. Under these optimum conditions, the removal ratio of CODcr is 58.6% 61.4%, and the value of biodegradability （CODB/CODcr） increases markedly from 8.9% 9.7% to 62.6% 68.3%.

Quantitative Correlation between Group Connectivity Index and Property of Flotation Reagent

Topological method is applied firstly to calculate the group connectivity indexes of some flotation reagents for sulfide minerals and oxide minerals. The study reveals that some properties of flotation reagents, such as group electronegativity, energy criterion, solubility product of chemicals and maximum wavelength of ultraviolet absorbency, have linear correlation with the first order group connectivity index (GCI) of polar group, and the related coefficients are all larger than 0.900. The GCI can be used to characterize the structure of groups, and is a sort of new effective structural parameter to study the quantitative structure activity relationship of flotation reagents.

A novel method for the spectrophotometric determination of cefradine by using sodium nitroprusside as chromogenic reagent

A novel method is developed for the determination of cefradine by using sodium nitroprusside as chromogenic reagent. The experiment indicates that a russety product is formed by the reaction of cefradine with sodium nitroprusside in basic solution, and the maximum absorption wavelength （λmax） of russety product is 505 rim. And the sensitization of tetradecyl benzyl dimethyl ammonium chloride for the reaction of cefradine with sodium nitroprusside is remarkable, The apparent molar absorption coefficient （5505） is 2.81 × 103 L/mol cm. The linear equation isA = 0.0657 ＋ 0.00804C （μg/mL） in the range of 1.50-55.0μg/mL of cefradine with a correlation coefficient r = 0.9992, and the detection limit is 1.38 p,g/mL. This method has been applied to determine cefradine in capsule and tablet samples.

Stereoselective Addition of Organotitanium and Grignard Reagents to 3,5-O-isopropylidene-L-glucurono-γ-lactone

Substituted PhMgX and PhTi(OCHMe2)4MgX react with 3,5-O-isopropylidene-L-glucurono-γ-lactone 4 to give tetrads 5a-e and its stereoisomers 6a-e Tetrads 5a-e are the important intermediates in the synthesis of howiinol Al and its derivatives. The stereoselectivities of substituted PhTi(OCHMe2)4Mg (5a-e:6a-e ratio, 68-72:32-28) were better than those of substituted PhMgX(33-64:67-36) in the reaction. The effects of different substitUted groups and positions (p-Me, m-Me, o-MeO, p-Cl) of the phenyl ring on their stereoselectivies were not significant.