How to promote cooperative innovation in environmentally friendly technology:a case of agricultural biotechnology in China

This study explored the factors influencing cooperative innovation in environmentally friendly agricultural biotechnology in China.First,we constructed an evolutionary game model comprising the factors of net income of cooperative innovation,net income of independent innovation,market constraints,and government subsidies.Using MATLAB simulation,we assigned different values to the aforementioned variables to explore the evolutionary trend of innovators’willingness to cooperate.Results showed that when the values of net income of cooperative innovation,net income of independent innovation,market constraints,and government subsidies exceeded the threshold,innovators’willingness to cooperate was significantly enhanced.Furthermore,the proportion of innovators who cooperated with others gradually increased to 100%;otherwise,it gradually decreased to 0%.Comparing the simulation curve with the real evolution curve of cooperative innovation in agricultural biotechnology in China,we found that the gradual decline in the willingness to cooperate could be due to insufficient subsidies for cooperative innovation,low income from cooperative innovation,weak profitability of innovators,and weak market constraints.

Characteristics and fate behavior of environmentally persistent free radicals in atmospheric particulate matter

Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H_(2)O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants.

Preparation of Phase Change Concrete Using Environmentally FriendlyMaterials and Its Performance Study

The control of carbon emissions and energy conservation,and environmental protection are hot spots of global concern.In this paper,phase change paraffin wax is applied to porous materials for adsorption and storage,and nature’s eco-friendly materials are selected as the porous matrix to propose an eco-friendly phase change concrete using eco-friendly materials as raw materials.It was obtained that the strength of the phase change concrete utilizing environmentally friendly materials was 25.4%to 36.8%lower than that of ordinary concrete,while some of the phase change light aggregates were found to produce slip damage with the cement paste in the damage study.By constructing a small-sized test room for thermal properties,we obtained a phase change concrete that utilizes environmentally friendly materials to control the temperature better than the commonly studied phase change concrete,with a peak temperature drop of up to 2.6℃ in the phase change test room compared to the normal test room and a delay in the peak temperature.

Decontamination of Cr(Ⅵ) from water using sewage sludge-derived biochar: Role of environmentally persistent free radicals

Biochar is a well-known material for pollutant removal owing to its low cost and rich surface functionality. A kind of highly active substance, called environmentally persistent free radicals(EPFRs), can be produced in the preparation process of biochar, playing an important role in the removal of pollutants.In this study, sludge-derived biochars(SBC_(120) and SBC_(270)) were prepared by the hydrothermal carbonization under two temperatures(120℃ and 270℃) to investigate their removal abilities of Cr(Ⅵ). The maximum removal amounts of Cr(Ⅵ) by SBC_(120) and SBC_(270) were 16.58 and 22.93 mg·g^(-1), respectively. It was further revealed that the appearance of Cr(Ⅲ), as a result of EPFRs on sludge-derived biochar(SBC) transferred electrons to Cr(Ⅵ) in neutral solutions. That is to say, oxygen-centered(O-centered) EPFRs on SBC_(120) and carbon-centered(C-centered) EPFRs on SBC_(270) all could be used as electron donors to Cr(Ⅵ) to make it become Cr(Ⅲ). This study not only provides a theoretical basis for the mechanism of pollutants removal by sludge-derived biochar but also offers a new perspective on the direct effect of EPFRs on pollutants.

Synthesis and mechanism of environmentally friendly high temperature and high salt resistant lubricants

With the exploration and development of deep and ultra-deep oil and gas,high torque and high friction during the drilling of deep and ultra-deep wells become one of the key issues affecting drilling safety and drilling speed.Meanwhile,the high temperature and high salt problem in deep formations is prominent,which poses a major challenge to the lubricity of drilling fluids under high temperature and high salt.This paper reports an organic borate ester SOP as an environmentally friendly drilling fluid lubricant.The performance evaluation results show that when 1%lubricant SOP is added to the fresh water-based mud,the lubrication coefficient decreases from 0.631 to 0.046,and the reduction rate of lubrication coefficient is 92.7%.Under the conditions of 210℃ and 30%NaCl,the reduction rate of lubricating coefficient of the base slurry with 1%SOP was still remain 81.5%.After adding 1%SOP,the wear volume decreased by 94.11%compared with the base slurry.The contact resistance experiment during the friction process shows that SOP can form a thick adsorption film on the friction surface under high temperature and high salt conditions,thus effectively reducing the friction resistance.Molecular dynamics simulation shows that lubricant SOP can be physically adsorbed on the surface of drilling tool and borehole wall through hydrogen bond and van der Waals force.XPS analysis further shows that SOP adsorbs on the friction surface and reacts with metal atoms on the friction surface to form a chemically reactive film.Therefore,under high temperature and high salt conditions,the synergistic effect of physical adsorption film and chemical reaction film effectively reduces the frictional resistance and wear of the friction surface.In addition,SOP is non-toxic and easy to degrade.Therefore,SOP is a highly effective and environmentally friendly lubricant in high temperature and high salt drilling fluid.

Water-Based Environmentally Friendly Pesticide Formulations Based on Cyclodextrin/Pesticide Loading System

Difenoconazole(DIF)is a representative variety of broad-spectrum triazole fungicides and liposoluble pesticides.However,the water solubility of DIF is so poor that its application is limited in plant protection.In addition,the conventional formulations of DIF always contain abundant organic solvents,which may cause pollution of the environment.In this study,two DIF/cyclodextrins(CDs)inclusion complexes(ICs)were successfully prepared,which were DIF/β-CD IC and DIF/hydroxypropyl-β-CD IC(DIF/HP-β-CD IC).The effect of cyclodextrins on the water solubility and the antifungal effect of liposoluble DIF pesticide were investigated.According to the phase solubility test,the molar ratio and apparent stability constant of ICs were obtained.Fourier transform infrared spectroscopy,thermal gravity analysis,X-ray diffraction and scanning electron microscopy were used systematically to characterize the formation and characteristics of ICs.The results noted that DIF successfully entered the cavities of two CDs.In addition,the antifungal effect test proved the better performance of DIF/HP-β-CD IC,which exceeded that of DIF emulsifiable concentrate.Therefore,our study provides informative direction for the intelligent use of liposoluble pesticides with cyclodextrins to develop water-based environmentally friendly formulations.

Synthesis and Kinetics of Hydrogenated Rosin Dodecyl Ester as an Environmentally Friendly Plasticizer

The plasticizer is an important polymer material additive.Non-toxic and environmentally friendly plasticizers are developed recently in order to decrease fossil fuel reserves,serious environmental pollution and the toxicity of phthalate esters.In this study,a new,efficient and environmentally friendly plasticizer of hydrogenated rosin dodecyl ester was prepared by an esterification reaction of hydrogenated rosin and dodecanol.The influences of different reaction conditions(including different catalysts,the catalyst concentration,the ratio of the reactants,reaction temperature,and reaction time)on the esterification yield are examined and discussed.Hydrogenated rosin dodecyl ester with 71.8%yield was synthesized under the optimized reaction conditions(1:0.8 molar ratio of rosin to dodecanol,1 mol%tetrabutyl titanate concentration,and 210℃for 6 h).The esterification reaction is a second-order reaction,and kinetic calculations showed that the activation energy is 39.77 KJ·mol^(−1).The structure of the hydrogenated rosin dodecyl ester was confirmed by FT-IR spectroscopy and^(13)C NMR spectrum.Besides,the thermal stability of target product(hydrogenated rosin dodecyl ester)was also tested by thermal gravimetric analysis(TGA),which showed a good thermal stability.

Notoginsenoside as an environmentally friendly shale inhibitor in water-based drilling fluid

The demand for non-toxic and biodegradable shale inhibitors is growing in the drilling industry.In this paper,the effect of notoginsenoside(NS)as a new,environmentally friendly inhibitor of shale hydration is systematically studied for the first time.The inhibition performance of NS was evaluated via inhibition evaluation tests,including mud ball immersion tests,linear expansion tests,shale rolling recovery tests,and compressive strength tests.The inhibition mechanism of NS was analyzed using Fourier transform infrared spectroscopy(FTIR),contact angle measurements,particle size distribution determination,thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The experimental results demonstrate that NS is able to adhere to the clay surface,forming a hydrophobic film that prevents the entry of water molecules and inhibiting the hydration dispersion of the clay.Because of this,NS can maintain the original state of bentonite pellets in water,which can effectively reduce the swelling rate of bentonite,increase the recovery rate of shale drill cuttings,maintain the strength of the shale,and therefore maintain the stability of the borehole wall during drilling.In addition,NS is non-toxic,degradable,and compatible with water-based drilling fluids.The above advantages make NS a promising candidate for use as an environmentally friendly shale inhibitor.

Fertigation for Environmentally Friendly Fertilizers Application: Constraints and Opportunities for Its Application in Developing Countries

There is an increasing concern about agriculture’s role in polluting the environment which makes farmers feel guilty about using fertilizers. Fertigation is proposed as a panacea to this dilemma, which by this practice reaffirms the principles of 4Rs which are the right source, at the right rate, right time and right place. The aim of this study was to explore constraints and opportunities for its application in developing countries for environmentally friendly fertilizers application. It is a review of literature from government reports, legislature and published material on fertilization and irrigation initiatives of developing countries which include Rwanda, Nepal, Suriname, Zambia, Panama, Tanzania, Sri Lanka and South Sudan in addition to the case presented of China during the “2016 Environmentally Friendly Fertilizer Production, Application and Demonstration from Developing Countries” training course. The study found that in developing countries there is potential to apply fertigation as a way of environmentally friendly fertilizers application as it has been adopted in China. These opportunities include the following: Abundant natural resources like land and water, less polluted environment, conducive agricultural policies, zero duties levied on imported irrigation equipment. However, a number of limitations also are highlighted including: Lack of investment, lack of infrastructure, lack of information, requires expertise on plant nutrition and management of fertigation system, require soil analysis and proper interpretation which is done by experts. This study provides relevant information for fertigation planning and application in respective developing countries.

Synthesis and Evaluation of Environmentally Friendly Calcium Isostearate Detergent with Excellent Oil Solubility

This article describes a method for synthesizing an excellent oil soluble calcium isostearate detergent using isostearic acid and calcium hydroxide as main starting materials. Reaction conditions, including the molar ratios of calcium hydroxide to isostearic acid, methanol to calcium hydroxide and water to calcium hydroxide, the carbonation temperature, the CO_2 flow rate, and the volume of injected CO_2, were optimized. Under the optimized conditions, a high alkalinity calcium isostearate detergent with a total base number(TBN) of 358 mg KOH/g and an overbased calcium isostearate detergent with a value of TBN equating to 406 mg KOH/g could be obtained. Finally, the properties of the calcium isostearate detergent were evaluated by the size distribution analysis, the thermogravimetric analysis(TGA) and the coking tendency tester.

Synthesis of 3-(1-Cyclohexenyl)-2-butanone via Environmentally Friendly Catalysts

We substituted several environmentally friendly catalysts which included HY and H- β zeolites, various cation-exchanged β zeolites, and solid-supported ferric chloride for conventional catalysts for the synthesis of 3-(1-cyclohexenyl)-2-butanone from the reaction of ethylidenecyclohexane with acetic anhydride at room temperature. HY zeolite was found to be the most effective for this reaction, and gave the acylated product in a 72% yield under the conditions of n (ethylidenecyclohexane)/ n (acetic anhydride)/ m (HY zeolite)=1 mmol/10 mmol/0 100 g, reaction temperature 25 ℃ and reaction time 2 h. The used HY zeolite can be recovered, regenerated and gave almost the same yield as the fresh one. The lifetime of the HY zeolite is over 80 h. The effect of different factors on the reaction has also been investigated.

Development of Environmentally Friendly and Energy Efficient Refrigerants for Refrigeration Systems

This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems.The novel azeotropic refrigerant mixtures of HFCs and HCs can replace refrigeration systems,and using the R134,R32,R125,and R1270 refrigerants in several compositions found using the decision tree function of the RapidMiner software(which camefirst in the KDnuggets annual software poll).All refrigerant results are mixed of POE,which is A1 classification refrigerant,non-flammable,and innocuous refrigerant,and using REFPROP software and CYCLE_D-HX software are under the CAN/ANSI/AHRI540 standards.The boiling point of the new refrigerant mix R-No.595 is 4.58%,lower than that of R404A,with a higher refrigerant effect and 50.34%lower GWP value than R404A.The proposed mix R-No.595 can be operated in hot environmental country and has high critical temperature and heat-rejection effects,due to the presence of R32 and R1270.The COPc of R463A is 13.49%,higher than R404A in freeze condition.The novel refrigerant mixes provide alternate refrig-erant options mixed of 1%R1270,and which are related with the development of current refrigerants,containing a compose of HFOs and eco refrigerants for producing low-GWP,zero ODP,high-refrigerant effect,low-operating pressure,and innocuous refrigerants.

Environmentally Smart Nitrogen (ESN)——Potential for Improving Modern Crop Production and N-Use Efficiency

Environmentally smart nitrogen(ESN)is polymer coated urea that is designed to release N in synchrony with crop requirements.Research on ESN was initiated in field crops in Ontario,Canada in 2006,initially on timothy,spring wheat and winter wheat and later(till date)on bromegrass,grass mixtures(timothy,bromegrass,orchardgrass),other forages(barley,silage corn,oat,MasterGraze corn and sorghum Sudangrass)and canola.In winter wheat,in three out of six years ESN gave^0.6 MT/ha higher grain yield than urea.In spring wheat,in a relatively warm year with well-distributed rainfall,ESN produced 1 MT/ha higher grain yield than urea;averaged over three years,two-thirds N from urea and one-third N from ESN could be recommended.Two-thirds N from urea and one-third N from ESN gave^0.75 MT/ha extra seed yield as compared to urea alone at 180 kg N/ha in canola during 2016 to 2018.The entire N in winter/spring wheat could be applied in seed rows at seeding as ESN without any detrimental effect.The highest barley forage yields were recorded by urea at 50 kg N/ha+ESN at 20 kg N/ha which produced 1.2 MT/ha more forage yield than urea at 70 kg N/ha.Partial substitution of N from urea with ESN improved forage dry matter yield of timothy and MasterGraze corn.In MasterGraze corn 100 kg N/ha from urea+ESN(3:1 on N basis)equaled that with urea at 150 kg N/ha in dry matter yield,%protein and relative feed value(RFV),but not in silage corn and sorghum Sudangrass.At equal rates of N,single/fall application of ESN in timothy and bromegrass gave equal yield to urea applied in two splits in spring/summer.Spring wheat grain yields were the same with fall/spring application of ESN.ESN/urea+ESN(3:1 on N basis)increased the grain/forage protein content in almost all crops by 1%-2%points at an extra cost of only$6.0-10.5/ha(with urea+ESN in 3:1 ratio on N basis).The results indicate that ESN could improve both crop yields and quality,make better use of N/or increase N-use efficiency.The paper summarizes results from over 10 years and the results could be applicable globally under situations of high N losses from readily available N sources such as urea.

Activity test and mechanism study of an environmentally friendly wheat seed coating agent

This novel environmentally friendly wheat seed coating agent which has been made with natural polymer as the primary material could increase yield by about 9% compared with the conventionally virulent wheat seed coating agent. In the premise of this production, the content of malondialdehyde (MDA) and peroxidase (POD) was determined. The results show that, after treated by the self-made wheat seed coating agent, the contents of the MDA were less than traditional group and the blank control group and POD contents were higher than traditional group and blank control group, this provides a good foundation on the further research of self-control wheat seed coating agent.

Development of an Environmentally Friendly in-situ Pack-Cyaniding Technique

A safe and environmentally friendly cyaniding method has been developed to mitigate the toxic impacts of cyanide salts on the environment during conventional cyaniding. The method entails in-situ diffusion of nascent cyanide from mature cassava leaves into the surface of mild steel components via pack-cyaniding. Both high-temperature in-situ diffusion into austenite and low-temperature in-situ diffusion into ferrite were explored. Results from light and scanning electron microscopic studies showed that surface hardness of the steel components was substantially increased. The waste product was a harmless biodegradable organic compound that posed no disposal threats. This study is important for increasing the wear resistance of ferrous parts for a longer service life in application without polluting the environment.

Fluidized mining and in-situ transformation of deep underground coal resources: a novel approach to ensuring safe, environmentally friendly, low-carbon, and clean utilisation

Traditional coal mining and utilisation patterns are severely detrimental to natural resources and environments and significantly impede safe, low-carbon, clean, and sustainable utilisation of coal resources. Based on the idea of in situ fluidized coal mining that aims to transform solid coal into liquid or gas and transports the fluidized resources to the ground to ensure safe mining and low-carbon and clean utilisation, in this study, we report on a novel in situ unmanned automatic mining method. This includes a flexible, earthworm-like unmanned automatic mining machine (UAMM) and a coal mine layout for in situ fluidized coal mining suitable for the UAMM. The technological and economic advantages and the carbon emission reduction of the UAMM-based in situ fluidized mining in contrast to traditional mining technologies are evaluated as well. The development trends and possible challenges to this design are also discussed. It is estimated that the proposed method costs approximately 49% of traditional coal mining costs. The UAMM-based in situ fluidized mining and transformation method will reduce CO2 emissions by at least 94.9% compared to traditional coal mining and utilisation methods. The proposed approach is expected to achieve safe and environmentally friendly coal mining as well as lowcarbon and clean utilisation of coal.

Using lean methodologies for economically and environmentally sustainable foundries

Lean manufacturing is often seen as a set of tools that reduce the total cost and improve the quality of manufactured products.The lean management philosophy is one which targets waste reduction in every facet of the manufacturing business;however,only recently have studies linked lean management philosophies with improving environmental sustainability.These studies suggest that lean manufacturing is more than a set of lean tools that can optimize manufacturing efficiencies;it is a process and mindset that needs to be integrated into daily manufacturing systems to achieve sustainability.The foundry industry,as well as manufacturing in general,has significant challenges in the current regulatory and political climate with developing an economically and environmentally sustainable business model.Lean manufacturing has proven itself as a model for both economic sustainability and environmental stewardship.Several recent studies have shown that both lean and green techniques and "zero-waste" policies also lead to reductions in overall cost.While these strategies have been examined for general manufacturing,they have not been investigated in detail for the foundry industry.This paper will review the current literature and describe how lean and green can provide a relevant framework for environmentally and economically sustainable foundries.Examples of lean and green technologies and techniques which can be applied to foundries in a global context will be described.

Biomass-Derived Carbon Heterostructures Enable Environmentally Adaptive Wideband Electromagnetic Wave Absorbers

Although advances in wireless technologies such as miniature and wearable electronics have improved the quality of our lives,the ubiquitous use of electronics comes at the expense of increased exposure to electromagnetic(EM)radiation.Up to date,extensive efforts have been made to develop high-performance EM absorbers based on synthetic materials.However,the design of an EM absorber with both exceptional EM dissipation ability and good environmental adaptability remains a substantial challenge.Here,we report the design of a class of carbon heterostructures via hierarchical assembly of graphitized lignocellulose derived from bamboo.Specifically,the assemblies of nanofibers and nanosheets behave as a nanometer-sized antenna,which results in an enhancement of the conductive loss.In addition,we show that the composition of cellulose and lignin in the precursor significantly influences the shape of the assembly and the formation of covalent bonds,which affect the dielectric response-ability and the surface hydrophobicity(the apparent contact angle of water can reach 135°).Finally,we demonstrate that the obtained carbon heterostructure maintains its wideband EM absorption with an effective absorption frequency ranging from 12.5 to 16.7 GHz under conditions that simulate the real-world environment,including exposure to rainwater with slightly acidic/alkaline pH values.Overall,the advances reported in this work provide new design principles for the synthesis of high-performance EM absorbers that can find practical applications in real-world environments.

Spatial distributions of tropical tree species in northern Vietnam under environmentally variable site conditions

Ecological interactions of species and thus their spatial pat- terns may differ between homogeneous and heterogeneous forests. To account for this, techniques of point pattern analysis were implemented on mapped locations of tree individuals from two 1-ha tropicalforest plots in Vietnam. We analyzed the effect of environmental heterogeneity on tree distributions; spatial distribution patterns of dominant species; inter-specific associations; and conspecific associations between life stages. Our analyses showed that： environmental conditions were homo- geneous at plot 1 but heterogeneous at plot 2; in both plots, all six domi- nant species were aggregated at various scales up to 30 m, and tree spe- cies were aggregated at larger scales in the homogeneous site than in the heterogeneous site; attraction between pairs of species was remarkably higher at the homogeneous site while negative associations were more frequent in the heterogeneous site; some species, H. kurzii, T. ilicifolia （homogeneous plot） and D. sylvatica, S. wightianum （heterogeneous plot） showed a lack of early life-stage individuals near conspecific adults. Moreover, additional clustering of young individuals was independent from conspecific adults, except D. sylvatica in both sites. These findings are consistent with the Janzen-ConneU hypothesis. Overall, habitat het- erogeneity influences spatial patterns and inter-specific associations of the tree species and evidences of self-thinning are shown in most species.

Synthesis of propylene glycol ethers from propylene oxide catalyzed by environmentally friendly ionic liquids

A series of acetate ionic liquids were synthesized using a typical two‐step method.The ionic liquids were used as environmentally benign catalysts in the production of propylene glycol ethers from propylene oxide and alcohols under mild conditions.The basic strengths of the ionic liquids were evaluated by determination of their Hammett functions,obtained using ultraviolet‐visible spectroscopy,and the relationship between their catalytic activities and basicities was established.The catalytic efficiencies of the ionic liquids were higher than that of the traditional basic catalyst NaOH.This can be attributed to the involvement of a novel reaction mechanism when these ionic liquids are used.A possible electrophilic‐nucleophilic dual activation mechanism was proposed and confirmed using electrospray ionization quadrupole time‐of‐flight mass spectrometry.In addition,the effects of significant reaction parameters such as concentration of catalyst,molar ratio of alcohol to propylene oxide,reaction temperature,and steric hindrance of the alcohol were investigated in detail.