Appropriate Supply of Ammonium Nitrogen and Ammonium Nitrate Reduces Cadmium Content in Rice Seedlings by Inhibiting Cadmium Uptake and Transport

Reasonable nitrogen(N) application is a promising strategy for reducing crop cadmium(Cd) toxicity. However, the specific form of N and the required amount that affect Cd tolerance and accumulation in rice remain unclear. This study explored the influence of different N-fertilizer forms(NH_(4)NO_(3), NH_4Cl, and KNO_(3)) and dosages on Cd tolerance and uptake in Cd-stressed N-sensitive and N-insensitive indica rice accessions. The results indicated that the Cd tolerance of N-sensitive indica accessions is more robust than that of N-insensitive ones. Furthermore, the shoot Cd content and Cd translocation rate in both N-sensitive and N-insensitive indica accessions decreased with an appropriate supply of NH_(4)NO_(3) and NH_4Cl, whereas they were comparable or slightly increased with increased KNO_(3). Unfortunately, we did not find significant and regular differences in Cd accumulation or translocation between N-sensitive and N-insensitive rice accessions. Consistent with the reduction of shoot Cd content, the addition of NH_(4)NO_(3) and NH_4Cl also inhibited the instantaneous root Cd^(2+) uptake. The expression changes of Cd transport-related genes under different N forms and dosages suggested that the decreased shoot Cd content, caused by the increased supply of NH_(4)NO_(3) and NH_4Cl, is likely achieved by reducing the transcription of OsNRAMP1 and OsIRT1. In summary, our findings reveal that an appropriate supply of NH_(4)NO_(3) and NH_4Cl could reduce Cd uptake and transport in rice seedlings, suggesting that rational N management could reduce the Cd risk in rice production.

Solid-liquid phase equilibrium for the system ammonium polyphosphate-urea ammonium nitrate-potassium chloride-water at 273.2 K

Based on the dynamic method,a quaternary system of ammonium polyphosphate (APP)-urea ammonium nitrate (UAN,CO(NH_(2))_(2)-NH_(4)NO_(3))-potassium chloride (KCl)-H_(2)O and its subsystems (APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O,KCl-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O and APP-KCl-H_(2)O) were systematically investigated at the temperature of 273.2 K.Each ternary phase diagram contains one invariant point and three crystallization regions.The crystallization regions are:(1)(NH_(4))_(3)HP_(2)O_(7),(NH_(4))_(4)P_(2)O_(7)and ((NH_(4))_(3)HP_(2)O_(7)+(NH_(4))_(4)P_(2)O_(7)) for APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O diagram;(2) KCl,KNO_(3)and(KCl+KNO_(3)) for KCl-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O diagram and (3)(NH_(4))_(3)HP_(2)O_(7),KCl and((NH_(4))_(3)HP_(2)O_(7)+KCl) for APP-KCl-H_(2)O diagram.The quaternary phase diagram of APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-KCl-H_(2)O has no quaternary invariant point but includes four solid phase crystallization regions,i.e.,(NH_(4))_(3)HP_(2)O_(7),(NH_(4))_(4)P_(2)O_(7),KNO_(3)and KCl,in which the KNO_(3)region occupies the largest area.The maximum total nutrient content (N+P_(2)O_(5)+K_(2)O) existing as ionic forms in the APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O,KCl-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O,APP-KCl-H_(2)O and quaternary systems is 44.70%,32.86%,45.56%and 46.23%(mass),respectively,indicating that the maximum nutrient content can be reached using raw materials of the corresponding systems to prepare liquid fertilizer.In the quaternary system,the content of NH_(4)~+-N ascends with the increase of the total nutrient content,while the contents of NO_(3)^(-)-N and CO(NH_(2))_(2)-N increase with elevated total N.This work can help optimize the operating parameters for the production,storage and transportation of liquid fertilizers.

Ultrasound-assisted one-pot synthesis of 2,4,5-triarylimidazole derivatives catalyzed by ceric (Ⅳ) ammonium nitrate in aqueous media

2,4,5-Triarylimidazoles could be obtained in excellent yields by the one-pot three-component condensation of benzil/benzoin, aldehydes and ammonium acetate in the presence of catalytic amount of the inexpensive, readily available and non-toxic ceric （IV） ammonium nitrate （CAN） in aqueous media under ultrasound at room temperature. In this reaction the products were obtained in short reaction time and easy operation under mild conditions.

Efficiency and Effectiveness Thermal Analysis of the Shell and Helical Coil Tube Heat Exchanger Used in an Aqueous Solution of Ammonium Nitrate Solubility (<i>ANSOL</i>) with 20% H₂O and 80% <i>AN</i>

The case study is about obtaining the flow rate and saturation temperature of steam that makes it possible to heat a solution of water and ammonia nitrate (ANSOL) in a shell and helical coil tube heat exchanger, within a time interval, without that the crystallization of the ANSOL solution occurs. The desired production per batch of the solution is 5750 kg in 80 minutes. The analysis uses the concepts of efficiency and effectiveness to determine the heat transfer rate and temperature profiles that satisfy the imposed condition within a certain degree of safety and with the lowest possible cost in steam generation. Intermediate quantities necessary to reach the objective are the Reynolds number, Nusselt number, and global heat transfer coefficient for the shell and helical coil tube heat exchanger. Initially, the water is heated for a specified period and, subsequently, the ammonium nitrate is added to a given flow in a fixed mass flow rate.

Preparation of ammonium nitrate-based solid composite propellants supplemented with polyurethane/nitrocellulose blends binder and their thermal decomposition behavior

To improve the performance of solid composite propellants(SCPs)supplemented with ammonium nitrate(AN)as an oxidizer,the incorporation of energetic ingredients such as explosives,energetic binders or catalysts is a common effective approach.For this purpose,polyurethane(PU),a typical inert binder,was mixed with nitrocellulose(NC)as an energetic polymer.Numerous composite solid propellant compositions based on AN and NC-modified polyurethane binder with different NC ratios were prepared.The prepared formulations were characterized using Fourier transform infrared spectroscopy(FTIR),RAMAN spectroscopy,X-ray diffraction(XRD),electron densimetry,thermogravimetric(TG)analysis,and differential scanning calorimetry(DSC).A kinetic study was then performed using the iterative KissingerAkahira-Sunose(It-KAS),Flynn-Wall-Ozawa(It-FWO),and non-linear Vyazovkin integral with compensation effect(VYA/CE)methods.The theoretical performances,such as theoretical specific impulse,adiabatic flame temperature,and ideal exhaust gaseous species,were also determined using the NASA Lewis Code,Chemical Equilibrium with Application(CEA).Spectroscopic examinations revealed the existence of NC and full polymerization of PU in the prepared propellants.According to density tests,the density of the propellant increases as the nitrocellulose component increases.According to the thermal analysis and kinetics study,the increase in NC content catalyzed the thermal decomposition of the AN-based composite solid propellants.Based on the theoretical study,increasing the amount of NC in the propellant increased the specific impulse and,as a result,the overall performance.

Ceric Ammonium Nitrate-mediated Oxidative Cycloaddition of 1,3-Dicarbonyls to β-Aryl-α, β-unsaturated Ketones

Regio and stereoselective synthesis of substituted dihydrofurans were accomplished by eeric ammonium nitrate mediated oxidative cycloaddition of 1,3-dicarbonyls to β-aryl-α,β-unsaturated ketones in moderate yields.

A New Method for the Cleavage of Carbohydrate Benzylidene Acetal by Ceric (IV) Ammonium Nitrate in CH_3CN-H_2O (10: 1)

A new method for the cleavage of carbohydrate benzylidene acetal has been developed using Ceric (YV) ammonium nitrate (CAN) [(NH4)2Ce(NO3)6] in CH3CN-H2O (10/1, v/v).

Thermal stability assessment of anti-explosive ammonium nitrate

The explosivity experiment of anti-explosive ammonium nitrate (AEAN) shows that the explosive characteristic of AEAN is eliminated. The adiabatic decompositions of ammonium nitrate and AEAN were investigated with an accelerating rate calorimeter (ARC). The curves of thermal decomposition temperature and pressure versus time, self-heating rate and pressure versus temperature for two systems were obtained. The kinetic parameters such as apparent activation energy and pre-exponential factor were calculated. The safety of AEAN was analyzed. It was indicated that AEAN has a higher thermal stability than AN. At the same time, it can be shown that the elimination of its explosive characteristic is due to the improvement on the thermal stability of AEAN.

New insights into the formation of ammonium nitrate from a physical and chemical level perspective

High levels of fine particulate matter(PM_(2.5))is linked to poor air quality and premature deaths,so haze pollution deserves the attention of the world.As abundant inorganic components in PM_(2.5),ammonium nitrate(NH_(4)NO_(3))formation includes two processes,the diffusion process(molecule of ammonia and nitric acid move from gas phase to liquid phase)and the ionization process(subsequent dissociation to form ions).In this study,we discuss the impact of meteorological factors,emission sources,and gaseous precursors on NH4NO3 formation based on thermodynamic theory,and identify the dominant factors during clean periods and haze periods.Results show that aerosol liquid water content has a more significant effect on ammonium nitrate formation regardless of the severity of pollution.The dust source is dominant emission source in clean periods;while a combination of coal combustion and vehicle exhaust sources is more important in haze periods.And the control of ammonia emission is more effective in reducing the formation of ammonium nitrate.The findings of this work inform the design of effective strategies to control particulate matter pollution.

Ceric Ammonium Nitrate Catalyzed Oxidation of Aldehydes and Alcohols

A variety of aromatic, aliphatic and conjugated aldehydes and alcohols were transformed to the corresponding carboxylic acids and ketones with a quantitative conversion in high yields with 70% t-BuOOH solution in water in the presence of catalytic amounts of ceric ammonium nitrate [Ce（NH4）2（NO3）6] （CAN） under room temperature conditions. The scope of our catalytic system is applicable for a wide range of aromatic, conjugated and aliphatic substrates. These aldehydes were converted to the corresponding carboxylic acids in good isolated yields in reason- able times. This method possesses a wide range of capabilities since it can be used with other functional groups which may not tolerate oxidative conditions, involves fairly simple method for work-up, exhibits chemoselectivity and proceeds under ambient conditions. The resulting products are obtained in good yields within reasonable time.

A Mild Procedure for the Preparation of o-Nitrophenols by Nitro Urea or Ammonium Nitrate in the Presence of Silica Sulfuric Acid （SiO2-OSO3H）

A mixture of ammonium nitrate or nitro urea and silica sulfuric acid was found to be efficient and environmentally friendly nitrating media for the preparation of orto-nitro phenols in dichloromethane at room temperature.

Ceric ammonium nitrate supported HY-zeolite:An efficient catalyst for the synthesis of 1,8-dioxo-octahydroxanthenes

Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.

Study on Modification and Test Technology of Nonexplosive and Irrestorable Fertilizer-grade Ammonium Nitrate

Based on a study of the relationship of ammonium nitrate （AN） explosion and its thermal stability, inert agents were added to AN for eliminating the explosive characteristic of AN and in order to be irrestorable. The results of using a large quantity of experiments and various testing technologies show that the improvement on thermal stability of modified AN is the basic reason for eliminating explosive characteristic of AN. The modification scheme was considered to have the following features： reliable and stable technology, market-demanded product, low investment and good economic returns. And during the revamping period, the normal production of AN will not be af- fected, and the economic, social and environmental benefits are good.

Cerium(Ⅳ) ammonium nitrate(CAN) initiated O-alkylation of oximes with N-vinyl lactams

O-Alkylation of oximes with N-vinylpyrrolidin-2-one or N-methyl-N-vinylacetamide was efficiently initiated by a catalytic amount of cerium（Ⅳ） ammonium nitrate（CAN）,giving the corresponding oxime ether derivatives in good yield.

Field measurements of dissociation of ammonium nitrate at a Beijing site

The atmospheric nitric acid, ammonia and ammonium nitrate aerosol were determined simultaneously in a Beijing site to test the equilibrium prediction. Rather good agreement between measurements and theory was found at ambient temperature above 9℃ at relative humidity below 70%. Below 9 ℃ the kinetic constraints preventing rapid attainment equilibrium were observed. A procedure for calculation of dependence of NH_4NO_3 aerosol dissociation constants on temperature and relative humidity was given. The seasonal variation of concentrations of NH_3, total NH_4^+ and HNO_3 was observed. The seasonal variation of concentrations of HNO_3 was caused by dissociation of NH_4NO_3 aerosol. The concentrations of NH_3 were 1-2 order higher than those of HNO_3. For formation of NH_4NO_3 aerosol the HNO_3 was the control reagent. Any increase of HNO_3 formed from NO_x would react with NH_3 to form NH4NO_3 aerosol in Beijing area except for someday in summer time.

A numerical simulation of kinetic constraint on evaporation of ammonium nitrate in diffusion denuder

A numerical simulation model has been developed to investigate the diffusion and reaction in diffusion denuder for reactive gases and aerosols. The analytical equation for equilibrium and kinetic equations of NH 4NO 3, NH 3 and HNO 3 system were presented. The model results of sampling efficiencies were agree with those calculated by Gormley Kennedy equation and other models. The evaporation of NH 4NO 3 aerosol has a kinetic constraint. The kinetic constant can be estimated from evaporation data. The model results showed that an annular denuder can separate reactive gases and aerosols.

Cerium(Ⅳ)ammonium nitrate(CAN)-mediated regioselective synthesis and anticancer activity of 6-substituted 5,8-dimethoxy-1,4-naphthoquinone

6-Substituted 5,8-O-dimethyl-1,4-naphthoquinones（6-DMNQ）,the promising anticancer scaffolds,were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN in EtOAc/H2O in comparatively high yields.An interesting finding was that apart from the reported electron-withdrawing effects of substituents on position 2 of naphthalene ring,regioselective synthesis of 6-DMNQ was largely dependent on the steric effects in CAN-mediated oxidation.The selective cytotoxicities of 6-DMNQ from the in vitro cell-based assays were exhibited between the cancer cells and normal cells.Moreover,most of sulfur-containing 6-DMNQ derivatives displayed better anticancer activities than the corresponding oxygen-containing ones,which could provide an available strategy for the design of 6-DMNQ derivatives as potential anticancer agents.

Reduction of Nitrate to Ammonium in Selected Paddy Soils of China *1

Three paddy soils were examined for their capacities of dissimilatory reduction of nitrate to ammonium (DRNA). 15 N labelled KNO 3 was added at the rate of 100 mg N kg -1 . Either glucose or rice straw powder was incorporated at the rate of 1.0 or 2.0 mg C kg -1 respectively. Three treatments were designed to keep the soil saturated with water: A) a 2 cm water layer on soil surface (with beaker mouth open); B) a 2 cm water layer and a 1 cm liquid paraffin layer (with beaker mouth open); and C) water saturated under O 2 free Ar atmosphere. The soils were incubated at 28 oC for 5 days. There was almost no 15 N labelled NH + 4 N detected in Treatment A. However, there was 1.4 to 3.4 mg N kg -1 15 N labelled NH + 4 N in Treatment B and 2.1 to 13.8 mg N kg -1 in Treatment C. Glucose was more effective than straw powder in ammonium production. Because there was sufficient amount of non labelled NH + 4 N in the original soils, 15 N labelled NH + 4 N produced as such should be the result of dissimilatory reduction. Studies on microbial population showed that there were plenty of bacteria responsible for DRNA process (DRNA bacteria) in the soils examined, indicating that number of DRNA bacteria was not a limiting factor for ammonium production. However, DRNA bacteria were inferior in number to denitrifiers. DRNA process in soil suspension seemed to start after 5 days of incubation. Glycerol and sodium succinate, though both are readily available carbon sources to organisms,did not facilitate DRNA process. DRNA occurred only when glucose was available and at the C/NO 3 - N ratio of over 12. It seemed that both availability and quality of the carbon sources affected DRNA.

Denitrification and Nitrate Reduction to Ammoniumin Taihu Lake and Yellow Sea Inter-Tidal MarineSediments

Denitrification and nitrate reduction to ammonium in Taihu Lake and Yellow Sea inter-tidal marinesediments were studied. The sediment samples were made into slurry containing 150 g dry matter per liter.Various amounts of glucose and 5 mmol L-1 of potassium nitrate were added in order to achieve differentratios of glucose-C to nitrate-N. Acetylene inhibition technique was applied to measure denitrification in theslumes. All samples were incubated anaerobically under argon atmosphere. Data showed that Taihu Lakesediment produced more N2O than marine sediment. Denitrification potential was higher in Taihu Lakesediment than in marne one. Glucose added increased denitrification activity but not the denitrification po-tential of the sediments. Dissimilatory nitrate reduction to ammonium seemed to occur in marine sediment,but not in freshwater one. When the marine sediment was treated with 25 mmol L-1 glucose, its denitrification poteatial, as indicated by maximum N2O production by acetylene blockage, was lower than that treatedwith no or 2.5 mmol L-l glucose. Acetylene was suspected to have inhibitory effect on dissimilatory nitratereduction to ammonium.