Studies on polyoxymethylene dimethyl ethers production from dimethoxymethane and 1,3,5-trioxane over SO_(4)^(2-)/ZrO_(2)-TiO_(2)

Polyoxymethylene dimethyl ethers(OMEs)with physical properties similar to those of diesel has received significant attention as green additives for soot emission suppression.Herein,series of SO_(4)^(2-)/ZrO_(2)-TiO_(2)catalysts were developed for OMEs production from dimethoxymethane(DMM)and1,3,5-trioxane through sequential formaldehyde monomer insertion into C-O bond of DMM.Not Lewis but Bronsted acid sites were identified to be active for the decomposition of 1,3,5-trioxane into formaldehyde unit,however,both of them are effective for the chain propagation of DMM via formaldehyde unit insertion into C-O bond.Kinetic studies indicated each chain growth step exhibited the same parameters and activation barrier on corresponding Bronsted and Lewis acid sites due to the same reaction mechanism and very similar chemical structure of OMEs.Also,the catalytic stability investigation suggested the deactivation behavior was derived from the carbon deposition,and the decay factor could be exponentially correlated with the amount of coke accumulation.

Tracking gassing behavior in pouch cell by operando on-line electrochemical mass spectrometry

As the rapid development of more powerful and safer lithiumion batteries, the mechanism study of gases evolution is attacking more and more attention in recent years. Especially under overcharge/discharge and/or high-temperature working condition.

Cocoon Silk-Derived, Hierarchically Porous Carbon as Anode for Highly Robust Potassium-Ion Hybrid Capacitors

Potassium-ion hybrid capacitors(KIHCs) have attracted increasing research interest because of the virtues of potassium-ion batteries and supercapacitors.The development of KIHCs is subject to the investigation of applicable K+storage materials which are able to accommodate the relatively large size and high activity of potassium.Here,we report a cocoon silk chemistry strategy to synthesize a hierarchically porous nitrogen-doped carbon(SHPNC).The as-prepared SHPNC with high surface area and rich N-doping not only offers highly efficient channels for the fast transport of electrons and K ions during cycling,but also provides sufficient void space to relieve volume expansion of electrode and improves its stability.Therefore,KIHCs with SHPNC anode and activated carbon cathode afford high energy of 135 Wh kg-1(calculated based on the total mass of anode and cathode),long lifespan,and ultrafast charge/slow discharge performance.This study defines that the KIHCs show great application prospect in the field of high-performance energy storage devices.

A High Capacity and Working Voltage Potassium-Based Dual Ion Batteries

Potassium-based dual ion batteries(KDIBs)have attracted significant attention owing to high working voltage,high safety,low processing cost,and environmental friendliness.Nevertheless,one great challenge for practical KDIBs is to develop suitable anode materials with high specific capacity.Herein,we report an architecture of hierarchically porous antimony nanoparticles/carbon nanofibers(HPSb CNFs)as flexible,free-standing anode for high-performance KDIBs.The HPSb CNFs with hierarchically porous structure,and high-content nitrogen doping,not only offer sufficient free space to tolerate the repetitive volume expansion of Sb nanoparticles during long-term cycling,but also greatly facilitate the transport of electrons and ions within electrode,ensuring high material utilization ratio.Thus,the KDIBs,constituted by HPSb CNFs-700(calcined at 700°C)anode and graphite cathode,exhibited a high reversible capacity of 440 m Ah g^(-1)with high discharge medium voltage of 4.5 V at a specific current of 200 m A g^(-1)(the highest capacity for all KDIBs normalized by the mass of the anode),and excellent cyclic life.Outstanding electrochemical reversibility of the KDIBs was further demonstrated by ex situ XRD,ex situ Raman spectrum,and HRTEM.These results suggest the as-designed HPSb CNFs-700 with highcapacity and long-term cycling stability is a promising anode material for high-performance KDIBs.

四氢噻唑-2-硫酮-4-羧酸一步催化合成α-氨基膦酸酯类化合物

本文以四氢噻唑-2-硫酮-4-羧酸作为一种可循环的有机催化剂,在无溶剂条件下催化芳香醛、苯胺和亚磷酸三甲酯得到了一系列α-氨基膦酸酯类化合物。该方法具有环境友好、操作简单的特点。

Preliminary Study on Management of Agricultural Scientific Research Projects in the New Situation

Project management of agricultural scientific research institutions is an important section of agricultural scientific research plan management. It is of great significance for sustainable development of scientific research work of scientific research institutions. According to a series of opinions and notices about scientific and technological system reform issued by the state,and combining current situations of management of scientific research projects in scientific research institutions,this paper made a preliminary study on management of agricultural scientific research projects in the new trend. Finally,on the basis of the current situations of management of agricultural scientific research projects,it came up with pertinent recommendations,including strengthening communication and cooperation and actively declaring projects,strengthening preliminary planning of projects and establishing project information database,reinforcing project process management,ensuring on-time and high quality completion of projects,and strengthening learning and improving quality of management personnel.

Current Situations of Competitive Scientific Research Projects for Agri-scientific Research Institutions: A Case Study of Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences

This paper collected and arranged competitive scientific research projects undertaken by Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences in 2003-2014. Through statistical analysis on quantity of projects,funded amount,age of person responsible,professional title of person responsible,academic degree of person responsible,research object,it discussed relevant characteristics and rules. Finally,it came up with pertinent measures and recommendations,in the hope of providing services for decision-making and scientific and technological management.

Construction and Establishment of Sci-tech Platform for Agricultural Scientific Research Institutions: A Case Study of Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences

Taking Tropical Crops Genetic Resources Institute( TCGRI) of Chinese Academy of Tropical Agricultural Sciences( CATAS) as an example,this paper discussed current situation of construction of sci-tech platform,analyzed existing problems,and finally came up with pertinent recommendations.

Management of Official Overseas Trips of Staff in Agri-scientific Research Institutions

Taking Tropical Crops Genetic Resources Institute( TCGRI) of Chinese Academy of Tropical Agricultural Sciences( CATAS) as an example,this paper discussed current situation of management of official overseas trips of staff in agric-scientific research institutions,analyzed existing problems,and finally came up with pertinent recommendations.

High‑resolution silicon photonic sensor based on a narrowband microwave photonic flter

Microwave photonic sensors are promising for improving sensing resolution and speed of optical sensors.In this paper,a high-sensitivity,high-resolution temperature sensor based on microwave photonic flter(MPF)is proposed and demonstrated.A micro-ring resonator(MRR)based on silicon-on-insulator is used as the sensing probe to convert the wavelength shift caused by temperature change to microwave frequency variation via the MPF system.By analyzing the frequency shift with high-speed and high-resolution monitors,the temperature change can be detected.The MRR is designed with multi-mode ridge waveguides to reduce propagation loss and achieves an ultra-high Q factor of 1.01×10^(6).The proposed MPF has a single passband with a narrow bandwidth of 192 MHz.With clear peak-frequency shift,the sensitivity of the MPF-based temperature sensor is measured to be 10.22 GHz/℃.Due to higher sensitivity and ultra-narrow bandwidth of the MPF,the sensing resolution of the proposed temperature sensor is as high as 0.019℃.

The long-term effectiveness of ferromanganese biochar in soil Cd stabilization and reduction of Cd bioaccumulation in rice

The application of Fe-Mn-modified biochar for the remediation of Cd-contaminated soil over long time periods has been little studied.In this paper,we describe the performance of coconut-shell-derived biochar modified with ferromanganese in relation to soil Cd stabilization and rice Cd bioaccumulation during a 3-year laboratory study.Different application dosages(0.05-0.5 wt%)and different rice varieties(the early and late rice)are also considered.The results show that ferromanganese is mainly loaded in biochar pores as MnFe_(2)O_(4),and that it decreases the specific surface area(SSA)and total pore volume of biochar.Ferromanganese biochar(0.5 wt%)applied to paddy soil is more effective than the same dose of pristine biochar in decreasing the soil-exchangeable Cd fraction(27.42-41.92%vs 22.56-33.85%),predominantly by decreasing soil Eh and increasing root Fe plaques.Ferromanganese biochar application helps to reduce Cd bioaccumulation in rice,especially in the grain(up to 48.6%-61.0%),and grain Cd levels(0.2 mg/kg)are all within the acceptable limit for food security in China.It is shown that ferromanganese modification and application can maintain soil at low redox status,keep root Fe plaques at a high level,and may also increase the stability of pristine biochar.All of these effects contribute to maintaining its high remediation efficiency over a 3-year inoculation period.The results presented in this paper demonstrate the potential appli-cations of ferromanganese biochar in soil remediation and the improvement of food safety.

miRNA-let-7i modulates status epilepticus via the TLR4 pathway

Background:Status epilepticus(SE)is a neurological emergency associated with high mortality and morbidity.Many SE episodes cannot be quickly and effectively terminated with current medications.miRNA-Let-7i,a member of the miRNA-Let-7 family,has been found to be associated with a variety of brain pathophysiological and neurological diseases.However,its role in SE remains elusive and requires further clarification.Methods:The expression of miRNA-Let-7i was detected in temporal lobe epilepsy(TLE)patients and SE model rats using the real-time quantitative polymerase chain reaction(RT-qPCR)method.Behavioral assays were performed in pilocarpine-induced SE model,and a whole-cell current clamp technique was employed to examine neuronal excitability.Neuronal apoptosis was evaluated by Nissl staining and terminal deoxynucleotidyl transferase-mediated dUTP end-labeling(TUNEL)assays.Results:The expression of miRNA-Let-7i was significantly reduced in the cortex and hippocampus of SE rats.The miRNA-Let-7i agomir and antagomir effectively regulated the levels of miRNA-Let-7i.In particular,the agomir significantly reduced the degree of SE and prolonged the latent period of SE,whereas the antagomir increased the degree of seizures and shortened the latent period.In addition,the agomir significantly decreased the frequency of action potentials,while the antagomir significantly increased it.Nissl staining and TUNEL assays demonstrated that the agomir increased the survival and decreased the apoptosis,while the antagomir had the opposite effects.In addition,a Toll-like receptor 4(TLR4)inhibitor rescued the effects of antagomir on SE behavior and expression of IL-6 and TNF-α.Similar results on miRNA-Let-7i expression and effects of TLR4 inhibition were found in brain tissues of TLE patients.Conclusions:The miRNA-Let-7i−TLR4 regulatory pathway is involved in SE,which provides insights into the pathogenesis of SE.