资金困境与晚清(1896—1901)书院改革成效——以令德堂、莲池、求是三书院为中心的考察

以往学界在探究晚清时期书院改制为学堂的原因时,多从书院外部因素着眼,对其内部因素的考察,仅仅集中在书院教学陈旧,难以适应社会发展方面,对书院变通自身章程以兼容西学的改革历程关注不多。甲午战后,败于日本的创痛使国人掀起了变通书院章程以兼容西学的热潮,具体方式有在旧书院中添设西学课程、附设学堂和新建书院兼容中西实学三种。虽然书院改革者对改革过程中的师资聘请、生徒待遇、设施配置等均有着正确的认识,但在经费的制约下,能够保证改革成效的规划却大多难以付诸实施,改革也最终失败。而书院改革在长达六年时间里的难见成效,则成为庚子国难后,清廷在急于革新自强时,决心废书院以兴学堂的现实判断依据。

Catalytic cracking of light diesel over Au/ZSM-5 catalyst for increasing propylene production

The catalytic cracking of light diesel oil （235–337 ＆#176;C） over gold‐modified ZSM‐5 was investigated in a small confined fluidized bed at 460 ＆#176;C and ambient pressure. Different Au/ZSM‐5 catalysts were prepared by a modified deposition‐precipitation method by changing the preparation procedure and the amount of gold loading and were characterized by X‐ray diffraction, N2 adsorp‐tion‐desorption, temperature‐programmed desorption of NH3, transmission electron microscopy and inductively coupled plasma spectrometer. It was found that a small amount of gold had a posi‐tive effect on the catalytic cracking of light diesel oil and increased propylene production at a rela‐tively low temperature. The maintenance of the ZSM‐5 MFI structure, pore size distribution and the density of weak and strong acid sites of the Au/ZSM‐5 catalysts depended on the preparation pa‐rameters and the Au loading. Simultaneous enhancement of the micro‐activity and propylene pro‐duction relies on a synergy between the pore size distribution and the relative intensity of the weak and strong acid sites. A significant improvement in the micro‐activity index with an increase of 4.5 units and in the propylene selectivity with an increase of 23.2 units was obtained over the Au/ZSM‐5 catalyst with an actual Au loading of 0.17 wt%.

In vitro corrosion and biocompatibility of phosphating modified WE43 magnesium alloy

Phospahting coated WE43 magnesium alloy was prepared by an immersion method. The microstructure, corrosion resistance and biocompatibility of the coated alloy were investigated. Scanning electron microscopy （SEM） and X-ray diffraction （XRD） were used to examine the microstructure and the composition of the coated alloy. The corrosion resistance was studied by means of potentiodynamic polarization method and the biocompatibility of the surface modified WE43 alloy was evaluated by （3-（4,5）-Dimethylthiazol-2, yl）-2,5-diphenyltetrazolium bromide （MTT） and hemolysis test. The results show that the phosphating coating can enhance the corrosion resistance of WE43 alloy and can be a good candidate to increase the biocompatibility of WE43 alloy.

Research on Phytoremediation of Heavy Metal Pollution in River Sediment by Medicago sativa L.

[Objective] The aim was to study the phytoremediation of heavy metal pollution in river sediment by Medicago sativa L.,so as to provide reliable references for the phytoremediation of heavy metal pollution in river sediment.[Method] The air-dried,screened and mixed sediment was put in rectangular PVC box（0.6 m×0.5 m×0.4 m） with seepage vent at the bottom,and the water holding capacity（WHC） of sediment was kept at 30%-60% by deionized water.The seeds of Medicago sativa L.were sown in April 2010,and seedlings were thinned after 7 d.Samples were collected from rhizosphere soil every 30 d,and were used to determine the content of heavy metals,bacteria quantity and enzyme activity in sediment.In addition,the accumulation of heavy metals in the roots,stems and leaves of plant was measured after harvest in October.[Result] Different parts of Medicago sativa L.varied in accumulation capacity to different heavy metals.The accumulation amount of Zn in Medicago sativa L.was the highest,especially in roots.Meanwhile,the accumulation amount of heavy metals like Ni,Cr,Cu and Pb in roots was higher than that of stems and leaves.In contrast,Mn was mainly accumulated in leaves and its amount accounted for 42.47% of the total amount in plant.Besides,the accumulation amount of all heavy metals was the lowest in stems.Ni,Cr,Cu and Pb could be degraded more effectively than Mn,and increasing the planting time and sowing times of crop was beneficial to the degradation of heavy metals.After planted Medicago sativa L.,the quantity of microorganisms in sediment went up obviously,and dehydrogenase activity also showed an increaseing trend.[Conclusion] Medicago sativa L.has certain restoring effect on Zn,Ni,Cr,Cu and Pb,and could be used to restore heavy metal pollution in river sediment.

Hot deformation behavior and microstructure evolution of 1460 Al-Li alloy

The hot deformation behavior and microstructure evolution of 1460 Al-Li alloy were investigated by isothermal compression test conducted at various strain rates（10-3-10 s-1） and temperatures（573-773 K）. The flow stress curves were corrected by considering the friction at the platen/specimen interface and the temperature change due to the deformation heating. The effects of strain, strain rate and temperature on the deformation behavior were characterized by the Zener-Hollomon parameter in a hyperbolic-sine equation, and the constitutive equations were established according to the peak flow stress associated with dynamic recovery, dynamic recrystallization and the dissolution of T1 phases. In the entire strain rate and temperature range, the prediction capabilities of the developed constitutive equation are proved to be feasible and effective with a linear correlation coefficient and an average absolute relative error coefficient of 0.9909 and 6.72%, respectively.

Study Progress in Remediation of Soil Contaminated by Heavy Metals and Its Application Prospect

Flax is an ideal crop for remedying soil contaminated by heavy metals. It has high tolerance to heavy metals and strong adsorption to heavy metals. Through properly using or adjusting external conditions such as regulator, moisture, fertilizer, microorganisms, and pH value, it is able to improve ability of flax to absorb, trans- fer, and accumulate heavy metals. To improve the ability of flax in remediating heavy metal contaminated soil, it is recommended to strengthen cultivation of flax varieties and screening of germplasm resources, actively carry out studies on tech- nologies of fax remedying heavy metal contaminated soil, implement large-scale and mechanized planting of flax, and promote control of heavy metal contaminated soil.

Effects of Red Mud on the Remediation of Pb, Zn and Cd in Heavy Metal Contaminated Paddy Soil

[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contaminated soil. [Method] The soil incubation experiment was conducted to study the effect of red mud on the pH values and electrical conductivity （EC）, and the remediation efficiency of red mud on lead （Pb）, zinc （Zn） and cadmium （Cd） in heavy metal contaminated soil. [Result] Red mud addition reduced the content of exchangeable Pb, Zn and Cd in the soil significantly. Compared with the control, when incubated for 30, 60 and 90 d with the red mud dosage of 4% （W/W）, the exchangeable Pb content was decreased by 39.25%, 41.38% and 50.19%; exchangeable Zn content was decreased by 49.26%, 57.32% and 47.16%; and exchangeable Cd content was decreased by 19.53%, 24.06% and 25.70%, respectively. The application of red mud had significant impact on the share of Pb, Zn and Cd contents in five forms, and different amounts of red mud application all reduced the proportion of exchangeable Pb, Zn and Cd to the total Pb, Zn and Cd. In addition, the proportion of exchangeable Pb, Zn and Cd to total Pb, Zn and Cd decreased with the increasing amount of red mud addition. [Conclusion] The study provided references for reasonable application of red mud and reduction of heavy metal pollution in paddy soil.

Research Progress of Phytoremediation Technology on Soils Polluted by Heavy Metals in Mining Areas

Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant absorption in soils polluted with heavy metals in metal mines were summarized, including the characteristics and status quo of phytoremediation and selection method of hyperaccumulator. In addition, further research was proposed as well.

Effect of amendments on growth and metal uptake of giant reed(Arundo donax L.) grown on soil contaminated by arsenic,cadmium and lead

The effects of five amendments such as acetic acid（AA）, citric acid （CA）, ethylenediamine tetraacetic acid （EDTA）, sepiolite and phosphogypsum on growth and metal uptake of giant reed （Arundo donax L.） grown on soil contaminated by arsenic （As）, cadmium （Cd） and lead （Pb） were studied. The results showed that the shoot biomass of giant reed was enhanced by 24.8% and 15.0%, while superoxide mutase and catalase activities slightly varied when adding 5.0 mmol/kg CA and 2.5 mol/kg EDTA to soil as compared to the control, respectively. The concentrations of As, Cd and Pb in shoots were remarkably increased by the addition of 2.5 mmol/kg AA and CA, 5.0 mmol/kg EDTA, and 4.0 g/kg sepiolite as compared to the control. The accumulations of As and Cd were also significantly enhanced in the above condition, while the shoot Pb accumulation was noticeably enhanced by amending with 4.0 g/kg sepiolite and 8.0 g/kg phosphogysum, respectively. The results suggested that AA, CA and sepiolite could be used as optimum soil amendments for giant reed remediation system.

Magnetostriction and microstructure of melt-spun Fe_(77)Ga_(23) ribbons prepared with different wheel velocities

A set of stacked ribbons with the composition of Fe77Ga23 were prepared with different wheel velocities of 7 m/s, 12.5 m/s and 25 m/s（named as S7, S12.5 and S25, respectively）. High resolution X-ray diffraction patterns of these ribbons show that all the ribbons present the disordered A2 structure, whereas an additional modified-DO3 phase is detected in S12.5 and S25. S25 has stronger（100） texture than other two samples. Ga K-edge extended X-ray absorption fine structure results indicate that both bond distance and the number of Ga atoms in the second neighbor shell around Ga decrease with increasing wheel velocity. No Ga cluster is detected in the studied ribbons. A short-range ordering Ga-rich phase and large local strain have no obvious influence on magnetostriction of S7. It is believed that both the（100） texture and the additional modified-DO3 phase play a positive role in magnetostrictive properties of Fe77Ga23 ribbons.

Advances in Microbial Remediation on the Application of Heavy Metal Pollution in Agricultural Water Resources

Heavy metal pollution in agricultural water resources is very serious in re- cent years, resulting in large losses of the agricultural economy and endangering human life and health. Due to the advantages of low cost, high efficiency and less secondary pollution, microbial ramediation technology is widely used in the treatment of heavy metal pollution in agricultural water resources. At present, with the progress of modern biotechnology, microbial remediation of heavy metals in agricul- tural water resources has grown rapidly. The sources and status quo of heavy met- al pollution in agricultural water resources at home and aboard, and the principles of microbial remediation of heavy metals pollution in agricultural water resources were reviewed in this paper, as well as the several common microbial remediation technology of heavy metals in agricultural water resources. Additionally, the further research work of heavy metal contaminated agricultural water resources by microbial ramediation were prospected.

Effects of acid pretreatment on Fe-ZSM-5 and Fe-beta catalysts for N_2O decomposition

Two series of ZSM-5 and beta zeolites were pretreated in 1.0 mol/L HNO3 solution at room temper-ature for various time periods. The catalytic performances of their Fe-exchanged products in N2O decomposition were evaluated. The Fe-zeolite catalysts were characterized using N2 adsorp-tion-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, ultra-violet-visible spectroscopy, temperature-programmed desorption of NH3, and scanning and trans-mission electron microscopies. For the ZSM-5 zeolite, acid leaching primarily takes place on the crystal surface and the particle size is reduced, therefore the pore channels are shortened. However, because of the good stability of MFI zeolites, the acid does not greatly penetrate the pore channels and new mesopores are not created. For the beta zeolite, because the amorphous material is in-clined to dissolve（deagglomerate）, some of the micropores are slightly dilated. The improved cata-lytic activities can be explained by the increased active Fe loading as a result of structural changes.

Microencapsulation of UV-Curable Self-healing Agent for Smart Anticorrosive Coating

UV-curable polyurethane prepolymer and photoinitiator 1173 were facilely encapsulated in a poly（urea-formaldehyde） shell, which was in situ formed by the polymerization of formalde-hyde and urea in an oil-in-water emulsion. The diameters of the microcapsules ranged from 118 μm to 663 μm depending on agitation speed, and were obtained via optical mi-croscopy and scanning electron microscopy analyses. The encapsulation percent and the yield of microcapsules prepared at the agitation speed of 600 r/min can reach 97.52wt% and 65.23wt%, respectively. When the water-borne polyurethane （WPU） coating embedded with the prepared microcapsules were scratched, the healing agent could be released from rup-tured microcapsules and lled the scribed region. The excellent anticorrosion properties of the WPU coating embedded with the prepared microcapsules were con rmed by the results obtained from both electrochemical impedance spectroscopy and Tafel curves.

Influence of transition metal modification of oxide-derived Cu electrodes in electroreduction of CO_2

The modification of oxide-derived Cu electrode with Ni, Zn, and Au was examined to improve the catalytic activity of COz electroreduction. The experimental results showed that Ni modification increased the Faraday efficiency of the formation of formic acid and n-propanol. The Faraday effi- ciency relating to the formation of the liquid products was as high as 34.3% at -1.5 V versus the saturated calomel electrode reference potential. In contrast, modification with Zn reduced the for- mic acid formation efficiency but enhanced the alcohol formation efficiency. Finally, modification with Au suppressed the selectivity toward the formation of both formic acid and alcohols.

Amine-grafted on lanthanide metal-organic frameworks:Three solid base catalysts for Knoevenagel condensation reaction

A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.55（H20）0.45 （3, PP = piperazine）, and Er（btc）（DABCO）0.15（H2O）0.85 （4, DABCO = 1,4- diazabicyclo[2.2.2]octane）, by grafting three different diamines onto the coordinatively unsaturated Er（III） ions into the channels of the desolvated lanthanide metal-organic framework （Er（otc））. The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4- for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests.

Nitrogen Mineralization of Prunings of Six N_2-Fixing Hedgerow Species in a Dry Valley of the Jinsha River

A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or used as mulch. The results indicated thatpruning N of the six hedgerow species was mineralized fast in thefirst week and then decreased slowly in the rest of the study period.When prunings were incorporated into soil, the amount of nitrogenmineralized by the end of the first week accounted for 69.9/100,58.2/100, 54.5/100, 43.0/100, 29.6/100 and 20.6/100 of the total N inprungins of Desmodium rensonii, Tephrosia candida, Leucaenaleucoephala, Albizia yunnanensis, Acacia dealbata, and Acaciamearnsii, respectively.

Effects of organic acids on heavy metal release or immobilization in contaminated soil

In order to explicit the environmental activity of heavy metals affected by different organic acids in soil,a batch incubation experiment was explored to investigate the influence of high relative molecular mass organic acid(HMWOA)(humic acid and fulvic acid)and low relative molecular mass organic acid(LMWOA)(threonic acid and oxalic acid)on the release or immobilization of Pb,Cu and Cd in soils.Results showed that LMWOA,especially threonic acid,had a good performance in the release of Pb,Cu and Cd from soils,and decrease in the fractions of HOAc-extractable,reducible and oxidable Pb,Cu and Cd.Conversely,HMWOA,especially humic acid,decreased the release of Pb,Cu and Cd,while it increased the fractions of HOAc-extractable,reducible and oxidable Pb,Cu and Cd,indicating that HMWOA can immobilize heavy metals.The release of Pb,Cu and Cd caused by LMWOA was attributed to the dissociation of soil organic matter and amorphous iron oxides since the total organic carbon and the water-soluble iron increased.The immobilization of Pb,Cu and Cd by HMWOA was attributed to the adsorption onto HMWOA followed by amorphous iron since HMWOA resulted in a significant decrease of zeta potential and an increase of amorphous iron oxide.It can be concluded that LMWOA has a potential application in soil washing remediation,while HMWOA can be used in the immobilization remediation for heavy metals contaminated soils.

Hot Issues in and Directions for Plant Root Research in Ecological Remediation

The mining activities destroy the natural vegetation and the land, pollute the environment in many aspects, and more and more attention has been paid to the ecological restoration in the mining area. Phytoremediation is the greenest tech- nical means of ecological restoration and reconstruction in the mining area. The root system is a direct organ that absorbs nutrients and water dudng phytoremediation, which is of great significance to ecological restoration. In order to explore the hot issues of plant root system in phytoremediation, the current situation of root system under the stress of heavy metal pollution and drought stress and geotechnical stress was reviewed, and the improvement effect of root exudates on rhizosphere environment was briefly introduced. The future direction of root system in ecological restoration and environmental protection was proposed on the basis of the existing research and existing problems.

Development of gold catalysts supported by unreducible materials:Design and promotions

Gold catalysis had been considered a highly efficient candidate for heterogeneous catalysis.It is well established that reducible-material-supported Au NPs are more reactive than the unreducible materials,unless specific modifications are carried out.However,unreducible materials such as carbon materials,silica,and alumina have particular advantages,including the easily controlled surface property,adjustable microscopic structure,earth-abundant reserves,and facile industrial manufacture.New strategies,influences,and mechanisms of modification to enhance the catalytic performance and thermal stability of unreducible-material-supported gold catalysts are among the most attractive research topics in gold catalysis.However,to the best of our knowledge,reports and reviews focused on unreducible-material-supported gold catalysts are lacking.Herein,the above concept will be thoroughly discussed regarding several typical unreducible supports,including the commonly used silica,alumina,carbon materials,and hydroxyapatite.The currently prevailing modification strategies will be summarized in detail from the aspects of theoretical conceptualization and practical methodology,including the ingenious synthesis method for catalyst with a specific structure,the currently prosperous electrostatic adsorption,colloid immobilization,and the applicative thermal gaseous treatment.The influences of physical and chemical modifications on the surface chemistry,electronic structure,interaction/synergy between Au-support/promoter,catalyst morphology and water precipitation will be also summarized.It is assumed that the review will shed light on significant studies on unreducible support in gold catalysis with the purpose of catalytic promotion and the promotion of the potential industrial demands in advance.Furthermore,the review will provide new insights into unreducible supports that can be potentially applied in gold catalysis.

Compatibility research of laser additive repairing TA15 forgings with Ti6Al4V-xTA15 alloy

The application of mixed powders with different mass fraction on laser additive repairing(LAR)can be an effective way to guarantee the performance and functionality of repaired part in time.A convenient and feasible approach is presented to repair TA15 forgings by employing Ti6Al4V-xTA15 mixed powders in this paper.The performance compatibility of Ti6Al4V-xTA15 powders from the aspects of microhardness,tensile property,heat capacity,thermal expansion coefficient and corrosion resistance with the TA15 forgings was fully investigated.The primaryαlaths were refined and the volume fraction of the secondaryαphase was increased by increasing the mass fraction of TA15 in the mixed Ti6Al4V-xTA15 powders,leading to varied performances.In conclusion,the mixed Ti6Al4V-70%TA15(x=70%)powders is the most suitable candidate and is recommended as the raw material for LAR of TA15 forgings based on overall consideration of the compatibility calculations of the laser repaired zone with the wrought substrate zone.