检索结果-南通市图书馆

Efficient and simple synthesis of B_(2)O_(3)-Al_(2)O_(3)nanocomposites assisted by deep eutectic solvent for production of 5-hydroxymethylfurfural from glucose

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2025年第1期18卷 236-248页

作者： Yuchen Wang Kai rong Shanlei Chang Youxing Fang Shaojun Dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China College of Chemistry Jilin UniversityChangchun 130012China

The catalytic conversion of glucose to high valueadded platform chemical 5-hydroxymethylfurfural(HMF)is a promising biorefinery process,and alumina-boria catalysts are considered to be green and mild solid acid catalysts for this catalytic ***,compared to the common synthesis methods with complicated steps,we reported a simple and efficient strategy to prepare B_(2)O_(3)-Al_(2)O_(3)nanocomposites by calcining cost-effective glucose-urea deep eutectic solvent(DES)solution containing the *** prepared B_(2)O_(3)-Al_(2)O_(3)nanocomposites exhibited an open three-dimensional skeleton and two-dimensional porous lamellar substructure,endowing them with a high specific surface area(228.27 m2/g).The introduction of boron changed the ratios of different aluminum species(AlⅣ,AlⅤ,and AlⅥ)and borate species(BO3 and BO4),thus further affecting the acidity and the types of acid sites of the *** prepared B_(2)O_(3)-Al_(2)O_(3)bifunctional acid catalysts possessing abundant Lewis acid sites and adjustable Brønsted acid sites showed complete glucose conversion and 55.38%of HMF yield under the optimum *** study proposed a concise method to synthesize alumina-boria solid acid catalysts assisted by glucose-urea *** hope to extend the application and prospect of this efficient and simple synthesis strategy.

关键词： 5-hydroxymethylfurfural(HMF) deep eutectic solvent glucose alumina-boria acid catalyst

A calculation method for friction coefficient and meshing efficiency of plastic line gear pair under dry friction conditions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2021年第6期9卷 1420-1435页

作者： yangzhi CHEN Yifan LIN School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510640China

A calculation method for the friction coefficient and meshing efficiency of plastic line gear(LG)pair under dry friction conditions was studied theoretically and experimentally,taking a polyoxymethylene parallel line gear pair(POM PLGP)as an ***,the geometric and mechanical models of PLGP were built by considering the effects of misalignment and loaded deformation under the actual operating ***,the friction coefficient of POM specimens was obtained via the ball-on-disk experiment,of which the value varies between 0.35 and 0.45 under the experimental *** calculation formula for the friction coefficient of POM LG pair was obtained by fitting the friction coefficient of the POM specimens,and the meshing efficiency of POM LG pair was calculated based on the calculation formula for friction coefficient and the meshing efficiency calculation ***,the meshing efficiency of POM PLGP specimens was measured using a homemade gear meshing efficiency test *** experimental results validated the feasibility of the proposed calculation method for the friction coefficient and meshing efficiency of the plastic LG *** study provides a method for the calculation of the friction coefficient and meshing efficiency of plastic gear pairs under dry friction *** also provides the basis for the wear calculation of plastic LG pair under dry friction conditions.

关键词： line gear(LG)pair friction coefficient meshing efficiency dry friction polyoxymethylene(POM)

Upstream-downstream cooperation approach in Guanting Reservoir watershed

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2005年第4期17卷 676-680页

作者： yangzhi-feng ZHANGWen-guo StateKeyJointLaboratoryofEnvironmentalSimulationandPollutionControl BeijingNormalUniversityBeijing100875China. StateKeyJointLaboratoryofEnvironmentalSimulationandPollutionControl BeijingNormalUniversityBeijing100875China.／／DepartmentofNatureandEcologyConservationofSEPABeijing100035China

A case study is introduced and discussed concerning water dispute of misuse and pollution between up\| and down\|stream parts. The relations between water usage and local industrial structures are analyzed. Results show it is important to change industrial structures of the target region along with controlling water pollution by technical and engineering methods. Three manners of upstream-downstream cooperation are presented and discussed based on the actual conditions of Guangting Reservoir watershed. Two typical scenarios are supposed and studied along with the local plan on water resources development. The best solution for this cooperation presents a good way to help the upstream developing in a new pattern of eco-economy.

关键词： watershed cooperation upstream-downstream industrial structures Guanting Reservoir

Influence of the Haizhou Open Pit Coal Mine on the atmospheric flow over Fuxin, China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第6期16卷 978-980页

作者： CHENHe yangzhi-feng WANGXuan StateKeyLaboratoryofEnvironmentSimulationandPollutionControl SchoolofEnvironmentBeijingNormalUniversityBeijing100875China

The influence of the Haizhou Open Pit Mine on the atmospheric flow in nearby Fuxin City in China was analyzed with the aid of the steady-state Navier-Stokes equations. The finite element method was used to obtain numerical solutions to these equations. The results showed that the Haizhou Open Pit Coal Mine contributes to the turbulent flow in the Fuxin City and its surroundings. However, when compared with the climatic effects, the open pit mine has a relatively small impact on the atmospheric flow over Fuxin.

关键词： numerical simulation turbulence finite element method open pit coal mine

Valuing health effects from the industrial air pollution in rural Tianjin,China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第1期16卷 157-160页

作者： yangzhi-feng XULin-yu StateKeyJointLaboratoryofEnvironmentalSimulationandPollutionControl InstituteofEnvironmentalSciencesBeijingNormalUniversityBeijing100875China

High concentrations of air pollutants such as total suspended particulates(TSP) and sulfur dioxide(SO_2) have serious impacts on nearby populations. In this paper, a survey of rural Tianjin residents' willingness-to-pay for health improvement was reported on, and the MBDC(multiple bounded discrete choice) model was adopted to study the respondents' willingness-to-pay to prevent respiratory illnesses. The results showed that the willingness-to-pay for health improvement was affected by respondents' health condition, work situation and environmental awareness, but not by personal habits, such as smoking. If person's willingness-to-pay to avoid respiratory diseases can be considered equal to the cost to personal health caused by air pollution, the total cost will reach 538×10 6 RMB Yuan(RMB, equal to 65 million USD) per year.

关键词： health loss MBDC willingness-to-pay TVIE Tianjin City

(188)~Re-labeled McAb 3H11 used as preventive for the peritoneal micrometasis of gastric cancer

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 1999年第4期10卷 203-206页

作者： yangzhi ZHANGMeiying 等 SchoolofClinicalOncology BeijingMedicalUniversityandBeijingCancerHospitalBeijing100036 SchoolofClini

In advancing gastric cancer,especially when the serous is invaded,the plantation of cancer cells in peritoneal is common and it affects patients' survival time *** on sucessfully labeled McAb(monoclonal antibody) 3H11 with ^188Re,we investigated the effect of RIT(Radioimmuno-Therapy) with ^188Re-3H11 on preventing the survival time,After 1×10^6 BGC-823 gastric cancer cells were injected into the peritoneal cavity of each mouse,45MABL/C nude mice were divided into 9 *** group received different doses of ^188Re-3Hll or 188Re-IgG,or saline I.P.16 hours *** injected volume of each mouse was *** results showed that the survival time depended on the injected doses during 0 to *** survival time was 170±25.3d after 37MBq 188^Re-3H11 were *** was over 5 times more than that for the saline gro9up and about 3 times more than that for 37MBq 188-Re IgG group(P<0.05),The mice hemogram were reduced to lowest 14days after injection,but they recovered after ***:with proper injection doses,early postoperative ^188Re-3H11 *** effective and safe for the prevention of intra-peritoneally injected gastric cancer cells from surviving,growing and disseminating in nude mice.

关键词：胃癌 188Re示踪单克隆抗体

Quantitative structure-property relationship of aromatic sulfur-containing carboxylates

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2003年第6期15卷 721-727页

作者： LIUXin-hui yangzhi-feng WANGLian-sheng StateKeyLaboratoryofEnvironmentalSimulationandPollutionControl InstituteofEnvironmentalSciencesBeijingNormalUniversityBeijing100875China. SchooloftheEnvironment NanjingUniversityNanjing210093China

Based on quantum chemical calculations, TLSER model(theoretical linear solvation energy relationships) and atomic charge approach were applied to model the partition properties(water solubility and octanol/water partition coefficient) of 96 aromatic sulfur-containing carboxylates, including phenylthio, phenylsulfinyl and phenylsulfonyl carboxylates. In comparison with TLSER models, the atomic charge models are more accurate and reliable to predict the partition properties of the kind of compounds. For the atomic charge models, the molecular descriptors are molecular surface area(S), molecular shape(O), weight(M W), net charges on carboxyl group(Q OC), net charges of nitrogen atoms(Q N), and the most negative atomic charge(q -) of the solute molecule. For water solubility(log S W) and octanol/water partition coefficient(log K OW), the correction coefficients r 2 adj(adjusted for degrees of freedom) are 0.936 and 0.938, and the standard deviations are 0.364 and 0.223, respectively.

关键词： octanol/water partition coefficient water solubility atomic charge model TLSER quantum chemical descriptor

Projection pursuit cluster model and its application in water quality assessment

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第6期16卷 994-995页

作者： WANGShun-jiu yangzhi-feng DINGJing SchoolofEnvironment BeijingNormalUniversityBeijing100875China. TheStateKeyLaboratoryofWaterEnvironmentSimulation BeijingNormalUniversityBeijing100875China SchoolofHydropowerEngineering SichuanUniversityChengdu610065China

One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must be used. In order to overcome this issues the projection pursuit principle is introduced into water quality assessment, and projection pursuit cluster(PPC) model is developed in this study. The PPC model makes the transition from high dimension to one-dimension. In other words, based on the PPC model, multifactor problem can be converted to one factor problem. The application of PPC model can be divided into four parts: (1) to estimate projection index function Q(); (2) to find the right projection direction ; (3) to calculate projection characteristic value of the i th sample z-i, and (4) to draw comprehensive analysis on the basis of z-i. On the other hand, the empirical formula of cutoff radius R is developed, which is benefit for the model to be used in practice. Finally, a case study of water quality assessment is proposed in this paper. The results showed that the PPC model is reasonable, and it is more objective and less subjective in water quality assessment. It is a new method for multivariate problem comprehensive analysis.

关键词： projection pursuit cluster model water quality assessment

A distributed non-point source pollution model: calibration and validation in the Yellow River Basin

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第4期16卷 646-650页

作者： HAOFang-hua ZHANGXue-song yangzhi-feng InstituteofEnvironmentalSciences BeijingNormalUniversityBeijing100875China

The applicability of a non-point source pollution model—SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database, which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage “Brute Force' optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998—1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.

关键词： Yellow River SWAT sediment flow non-point source pollution