The Al-5Cu alloys were prepared by different treatment methods,including adding a refiner Al-5Ti-1B,exerting a rotating magnetic field(RMF),and compound treatment of both refiner and RMF.The effects of treatment metho...The Al-5Cu alloys were prepared by different treatment methods,including adding a refiner Al-5Ti-1B,exerting a rotating magnetic field(RMF),and compound treatment of both refiner and RMF.The effects of treatment methods on the microstructure,properties,and solid solubility of the Al-5Cu alloy were investigated.The optimal magnetic field parameters and addition amount of refiner were confirmed by experiment.Results show that either RMF or adding refiner Al-5Ti-1B alone can refine the grain size,and the refining effect can be further improved by a compound refining treatment with optimized magnetic field parameters(120 A current and 8 Hz frequency) and 1.0wt.% Al-5Ti-1B refiner(RMF*+Al-5Ti-1B*).The average grain size is decreased to 68.1 μm,which is 60.8%,21.1%,and 83.5% lower than that of the alloy treated by the optimized rotating magnetic field,the Al-5Ti-1B refiner,and the alloy without any treatment,respectively.The tensile strength and elongation of the alloy reach 232.5 MPa and 18.6%,respectively,which are obviously higher than those of the alloys treated by rotating magnetic field,Al-5Ti-1B refiner,and the alloy without any treatment,respectively.Additionally,the solid solubility of the alloy is also obviously improved compared to the alloys treated by other methods.展开更多
In order to study the effect of electromagnetic compound treatment on the mechanical property, cutting performance and microstructure of cemented carbide, the samples were treated by a self-made electromagnetic compou...In order to study the effect of electromagnetic compound treatment on the mechanical property, cutting performance and microstructure of cemented carbide, the samples were treated by a self-made electromagnetic compound treatment device with different magnetic field strength(H=1, 1.25 and 1.5 T). The electromagnetic compound treatment method was proposed to couple pulsed magnetic field and pulsed current. The results show that after the pulsed magnetic field treatment, the values of the transverse rupture strength of the samples were respectively reduced by 21%, 20.6% and 20.1%;the cutting performance was decreased by about 4.5%, which means the tool life was decreased. After the electromagnetic compound treatment, the values of the transverse rupture strength of the rectangular samples were respectively increased by 8%, 8.6% and 9.5%, and the tool life was increased by 4.2%, 7% and 10.3%. After the electromagnetic compound treatment, the pulse current provided the driving force for dislocation motion. A strong pulse current driving force is more likely to make the dislocation multiply and slip. A high density dislocation cell is formed within the material, so the mechanical properties were significantly increased.展开更多
In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were...In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were conducted. The biodegradation pathways under the various operational conditions were identified from batch experiments： shortening of ethoxy-chains dominated under the anaerobic condition, whereas oxidizing of the terminal alcoholic group prevailed over the other routes under the aerobic condition. Results showed that the anoxic condition could accelerate the biodegradation rates of nonylphenolic compounds, but had no influence on the biodegradation pathway. The biodegradation rates of nonylphenol （NP） and short-chain nonylphenol polyethoxylates （NPnEOs, n： number of ethoxy units） increased from the anaerobic condition, then the anoxic, finally to the aerobic condition, while those of long-chain NPnEOs and nonylphenoxy carboxylates （NPECs） seemed similar under the various conditions. Under every operational condition, long-chain NPnEOs showed the highest biodegradation activity, followed by NPECs and short-chain NPnEOs, whereas NP showed relatively recalcitrant characteristics especially under the anaerobic condition. In addition, introducing sulfate and nitrate to the anaerobic condition could enhance the biodegradation of NP and short-chain NPnEOs by supplying more positive redox potentials.展开更多
The effects of heat treatment on the microstructure and mechanical properties of intermetallic compounds in the interface of stainless steel 321 explosively bonded to aluminum 1230 were investigated in this study. Exp...The effects of heat treatment on the microstructure and mechanical properties of intermetallic compounds in the interface of stainless steel 321 explosively bonded to aluminum 1230 were investigated in this study. Experimental investigations were performed by optical microscopy, scanning electron microscopy, and microhardness and shear tensile strength testing. Prior to heat treatment, increasing the stand-off distance between samples from 1 to 2.5 mm caused their interface to become wavy and the thickness of intermetallic layers to increase from 3.5 to 102.3 μm. The microhardness increased from HV 766 in the sample prepared at a stand-off distance of 1 mm to HV 927 in the sample prepared at a stand-off distance of 2.5 mm; in addition, the sample strength increased from 103.2 to 214.5 MPa. Heat treatment at 450°C for 6 h increased the thickness of intermetallic compound layers to 4.4 and 118.5 μm in the samples prepared at stand-off distances of 1 and 2.5 mm, respectively. These results indicated that increasing the duration and temperature of heat treatment decreased the microhardness and strength of the interface of explosively welded stainless steel 321-Al 1230 and increased the thickness of the intermetallic region.展开更多
Oil storage is a source of volatile organic compounds( VOCs). Volatile organic compounds can cause different damages to the environment,animals and plants. Therefore, it is important to control the discharge of VOCs i...Oil storage is a source of volatile organic compounds( VOCs). Volatile organic compounds can cause different damages to the environment,animals and plants. Therefore, it is important to control the discharge of VOCs in oil storage. In this paper,the control technology of sources of VOCs pollution in oil storage was analyzed from the source,process and end treatment,and measures for the prevention and control of VOCs pollution in oil storage were proposed.展开更多
The advanced treatment using integrated Fenton＇s reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreat...The advanced treatment using integrated Fenton＇s reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreated by UASB （upflow anaerobic sludge bed） and a SBR （sequencing batch reactor） process. The residual recalcitrant compounds, measured by gas chromatographymass spectrometry （GC-MS）, mainly consisted of alcohols, phenols, and nitrogenous and sulfur compounds. The experimental results indicated that when the Fenton＇s reaction was conducted at pH=3.0, H2O2CODOcr=0.27, H2O2/Fe^2＋=3：1 and 30 min of reaction time, and the coagulation process operated at a sulfate aluminum concentration of 800 mg/L and pH value of 5.0, the color and COD in the wastewater decreased by 94% and 73%, respectively; with a finale COD concentration of 267 mg/L and color level of 40 units, meeting the secondary standard of GB8978-1996 for industrial wastewater.展开更多
Volatile organic compounds (VOCs) are an atmospheric pollutant with a boiling point of 50˚C - 260˚C at room temperature and pressure. They are precursors of sulfur dioxide and ozone, which can seriously pollute the at...Volatile organic compounds (VOCs) are an atmospheric pollutant with a boiling point of 50˚C - 260˚C at room temperature and pressure. They are precursors of sulfur dioxide and ozone, which can seriously pollute the atmosphere and endanger human health. After the “14th Five-Year Plan”, VOCs, instead of SO2, became one of the five indicators of China’s atmospheric governance. As a result, the government’s efforts to control VOCs have increased significantly. VOCs governance mustn’t be delayed. This paper provides a comprehensive summary and analysis of VOCs governance, covering the classification of VOCs, analysis of VOC governance technology (with a focus on end-of-pipe governance technology), national policy regulations, current governance shortcomings, and a forward-looking perspective on the future direction of VOCs governance, emphasizing healthy and sustainable development.展开更多
[Objective] An approach of stress relaxation was proposed in present work to investigate the interactions among the waterproof agent,preservative and wood.[Method] Paraffin emulsion waterproof using natural surfactant...[Objective] An approach of stress relaxation was proposed in present work to investigate the interactions among the waterproof agent,preservative and wood.[Method] Paraffin emulsion waterproof using natural surfactants was prepared at different concentrations of 0.5% and 2.0%,which were added into two concentrations（0.3%,0.5%） of copper azole（CA） to obtain compound systems,and one-time fullcell process was applied to treat the sapwood of Pinus spp.with a size of 10 mm（L） ×10 mm（R） ×10 mm（T）.[Result] Compressive stress relaxation behaviors at two moisture levels and room temperature were measured and the results were as follows：1） compared with control group,the stress relaxation of compound system treated groups reduced,whether at oven-dried state or air-dried state.2） Under oven-dried condition,CA could weaken the relaxation of treated samples and this effect became greater with increasing concentration of preservative,but an increase in the concentration of paraffin emulsion would slightly promote the relaxation of compound system treated samples.While under air-dried condition,both CA and paraffin wax emulsion lowered the relaxation which was inversely related to the concentrations of both agents.[Conclusion] The results were expected to shed new light on the various macroscopic properties of the compound system treated wood at a microscopic level,and to provide favorable scientific evidences and theoretical supports for the manufacture of waterproofing preservative-treated wood.展开更多
[Objectives]This study was conducted to effectively prolong the shelf life of Hongxiangsu pear and maintain its excellent quality.[Methods]The fruit of Hongxiangsu pear were treated with 1.5%sodium alginate,0.4 g/L na...[Objectives]This study was conducted to effectively prolong the shelf life of Hongxiangsu pear and maintain its excellent quality.[Methods]The fruit of Hongxiangsu pear were treated with 1.5%sodium alginate,0.4 g/L natamycin and 2%chitosan for 3 min,respectively.Taking soaking treatment as control,the effects of different treatments on the weight loss rate,firmness,color difference,soluble solid content,titratable acid content,catalase activity and peroxidase activity of Hongxiangsu pear fruit during postharvest storage were studied at 25℃.[Results]The results showed that compared with the control group,single or compound treatments all delayed the decline of fruit firmness and color difference,better inhibited the increase of weight loss rate,and maintained higher soluble solids and total acid content.Physiologically,single and compound treatments all maintained the activities of peroxidase and catalase.Among them,the compound treatment of three reagents could improve the storage and fresh-keeping ability of Hongxiangsu pear.After 15 d of storage,the weight loss rate of the fruit treated with three reagents was lower than that of the blank group by 2.47%,and the color difference was lower than that of the blank group by 3.79.In terms of soluble solids,firmness,and other qualities,the fruit treated with the combination of the three reagents was superior to that treated with singe reagent or two reagents in pair.[Conclusions]Different compound coating treatments all showed positive effects on the preservation of Hongxiangsu pear,but before practical application and promotion,it is necessary to further explore the appropriate coating methods and proportions.展开更多
Endocrine disrupting compounds（EDCs） and pharmaceuticals pose a challenge for water and wastewater treatment because they exist at very low concentrations in the presence of substances at much higher concentrations ...Endocrine disrupting compounds（EDCs） and pharmaceuticals pose a challenge for water and wastewater treatment because they exist at very low concentrations in the presence of substances at much higher concentrations competing for adsorption sites.Sub-micron sized resin particles（approximately 300 nm in diameter）（SMR） were tested to evaluate their potential as a treatment for EDCs including：17-β estradiol（E2）,17-α ethinylestradiol（EE2）,estrone（E1）,bisphenol A（BPA）,and diethylstilbestrol（DES） as well as 12 pharmaceuticals.SMR were able to remove 98%of spiked E2,80%of EE2,87%of BPA,and up to 97%of DES from water.For a 0.5 ppm mixture of E2,EE2,E1,BPA and DES,the minimum removal was24%（E2） and the maximum was 49%（DES）.They were also able to remove the pharmaceuticals from deionized water and wastewater.Overall,SMR are a promising advanced treatment for removal of both EDCs and pharmaceuticals.展开更多
文摘The Al-5Cu alloys were prepared by different treatment methods,including adding a refiner Al-5Ti-1B,exerting a rotating magnetic field(RMF),and compound treatment of both refiner and RMF.The effects of treatment methods on the microstructure,properties,and solid solubility of the Al-5Cu alloy were investigated.The optimal magnetic field parameters and addition amount of refiner were confirmed by experiment.Results show that either RMF or adding refiner Al-5Ti-1B alone can refine the grain size,and the refining effect can be further improved by a compound refining treatment with optimized magnetic field parameters(120 A current and 8 Hz frequency) and 1.0wt.% Al-5Ti-1B refiner(RMF*+Al-5Ti-1B*).The average grain size is decreased to 68.1 μm,which is 60.8%,21.1%,and 83.5% lower than that of the alloy treated by the optimized rotating magnetic field,the Al-5Ti-1B refiner,and the alloy without any treatment,respectively.The tensile strength and elongation of the alloy reach 232.5 MPa and 18.6%,respectively,which are obviously higher than those of the alloys treated by rotating magnetic field,Al-5Ti-1B refiner,and the alloy without any treatment,respectively.Additionally,the solid solubility of the alloy is also obviously improved compared to the alloys treated by other methods.
基金Funded by the National Natural Science Foundation of China(Nos.51575369&51675357)
文摘In order to study the effect of electromagnetic compound treatment on the mechanical property, cutting performance and microstructure of cemented carbide, the samples were treated by a self-made electromagnetic compound treatment device with different magnetic field strength(H=1, 1.25 and 1.5 T). The electromagnetic compound treatment method was proposed to couple pulsed magnetic field and pulsed current. The results show that after the pulsed magnetic field treatment, the values of the transverse rupture strength of the samples were respectively reduced by 21%, 20.6% and 20.1%;the cutting performance was decreased by about 4.5%, which means the tool life was decreased. After the electromagnetic compound treatment, the values of the transverse rupture strength of the rectangular samples were respectively increased by 8%, 8.6% and 9.5%, and the tool life was increased by 4.2%, 7% and 10.3%. After the electromagnetic compound treatment, the pulse current provided the driving force for dislocation motion. A strong pulse current driving force is more likely to make the dislocation multiply and slip. A high density dislocation cell is formed within the material, so the mechanical properties were significantly increased.
基金supported by the National Natural Science Foundation of China (No. 51138009)
文摘In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were conducted. The biodegradation pathways under the various operational conditions were identified from batch experiments： shortening of ethoxy-chains dominated under the anaerobic condition, whereas oxidizing of the terminal alcoholic group prevailed over the other routes under the aerobic condition. Results showed that the anoxic condition could accelerate the biodegradation rates of nonylphenolic compounds, but had no influence on the biodegradation pathway. The biodegradation rates of nonylphenol （NP） and short-chain nonylphenol polyethoxylates （NPnEOs, n： number of ethoxy units） increased from the anaerobic condition, then the anoxic, finally to the aerobic condition, while those of long-chain NPnEOs and nonylphenoxy carboxylates （NPECs） seemed similar under the various conditions. Under every operational condition, long-chain NPnEOs showed the highest biodegradation activity, followed by NPECs and short-chain NPnEOs, whereas NP showed relatively recalcitrant characteristics especially under the anaerobic condition. In addition, introducing sulfate and nitrate to the anaerobic condition could enhance the biodegradation of NP and short-chain NPnEOs by supplying more positive redox potentials.
文摘The effects of heat treatment on the microstructure and mechanical properties of intermetallic compounds in the interface of stainless steel 321 explosively bonded to aluminum 1230 were investigated in this study. Experimental investigations were performed by optical microscopy, scanning electron microscopy, and microhardness and shear tensile strength testing. Prior to heat treatment, increasing the stand-off distance between samples from 1 to 2.5 mm caused their interface to become wavy and the thickness of intermetallic layers to increase from 3.5 to 102.3 μm. The microhardness increased from HV 766 in the sample prepared at a stand-off distance of 1 mm to HV 927 in the sample prepared at a stand-off distance of 2.5 mm; in addition, the sample strength increased from 103.2 to 214.5 MPa. Heat treatment at 450°C for 6 h increased the thickness of intermetallic compound layers to 4.4 and 118.5 μm in the samples prepared at stand-off distances of 1 and 2.5 mm, respectively. These results indicated that increasing the duration and temperature of heat treatment decreased the microhardness and strength of the interface of explosively welded stainless steel 321-Al 1230 and increased the thickness of the intermetallic region.
文摘Oil storage is a source of volatile organic compounds( VOCs). Volatile organic compounds can cause different damages to the environment,animals and plants. Therefore, it is important to control the discharge of VOCs in oil storage. In this paper,the control technology of sources of VOCs pollution in oil storage was analyzed from the source,process and end treatment,and measures for the prevention and control of VOCs pollution in oil storage were proposed.
文摘The advanced treatment using integrated Fenton＇s reaction and coagulation process was investigated in this study. Before the advancement, the pharmaceutical wastewater containing lincomycin hydrochloride was pretreated by UASB （upflow anaerobic sludge bed） and a SBR （sequencing batch reactor） process. The residual recalcitrant compounds, measured by gas chromatographymass spectrometry （GC-MS）, mainly consisted of alcohols, phenols, and nitrogenous and sulfur compounds. The experimental results indicated that when the Fenton＇s reaction was conducted at pH=3.0, H2O2CODOcr=0.27, H2O2/Fe^2＋=3：1 and 30 min of reaction time, and the coagulation process operated at a sulfate aluminum concentration of 800 mg/L and pH value of 5.0, the color and COD in the wastewater decreased by 94% and 73%, respectively; with a finale COD concentration of 267 mg/L and color level of 40 units, meeting the secondary standard of GB8978-1996 for industrial wastewater.
文摘Volatile organic compounds (VOCs) are an atmospheric pollutant with a boiling point of 50˚C - 260˚C at room temperature and pressure. They are precursors of sulfur dioxide and ozone, which can seriously pollute the atmosphere and endanger human health. After the “14th Five-Year Plan”, VOCs, instead of SO2, became one of the five indicators of China’s atmospheric governance. As a result, the government’s efforts to control VOCs have increased significantly. VOCs governance mustn’t be delayed. This paper provides a comprehensive summary and analysis of VOCs governance, covering the classification of VOCs, analysis of VOC governance technology (with a focus on end-of-pipe governance technology), national policy regulations, current governance shortcomings, and a forward-looking perspective on the future direction of VOCs governance, emphasizing healthy and sustainable development.
文摘[Objective] An approach of stress relaxation was proposed in present work to investigate the interactions among the waterproof agent,preservative and wood.[Method] Paraffin emulsion waterproof using natural surfactants was prepared at different concentrations of 0.5% and 2.0%,which were added into two concentrations（0.3%,0.5%） of copper azole（CA） to obtain compound systems,and one-time fullcell process was applied to treat the sapwood of Pinus spp.with a size of 10 mm（L） ×10 mm（R） ×10 mm（T）.[Result] Compressive stress relaxation behaviors at two moisture levels and room temperature were measured and the results were as follows：1） compared with control group,the stress relaxation of compound system treated groups reduced,whether at oven-dried state or air-dried state.2） Under oven-dried condition,CA could weaken the relaxation of treated samples and this effect became greater with increasing concentration of preservative,but an increase in the concentration of paraffin emulsion would slightly promote the relaxation of compound system treated samples.While under air-dried condition,both CA and paraffin wax emulsion lowered the relaxation which was inversely related to the concentrations of both agents.[Conclusion] The results were expected to shed new light on the various macroscopic properties of the compound system treated wood at a microscopic level,and to provide favorable scientific evidences and theoretical supports for the manufacture of waterproofing preservative-treated wood.
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program of Guangdong Province(S202010580073)Undergraduate Innovation and Entrepreneurship Training Program of Zhaoqing University(X202210580139,X202210580143)Zhaoqing Science and Technology Innovation Guidance Project(202304038003).
文摘[Objectives]This study was conducted to effectively prolong the shelf life of Hongxiangsu pear and maintain its excellent quality.[Methods]The fruit of Hongxiangsu pear were treated with 1.5%sodium alginate,0.4 g/L natamycin and 2%chitosan for 3 min,respectively.Taking soaking treatment as control,the effects of different treatments on the weight loss rate,firmness,color difference,soluble solid content,titratable acid content,catalase activity and peroxidase activity of Hongxiangsu pear fruit during postharvest storage were studied at 25℃.[Results]The results showed that compared with the control group,single or compound treatments all delayed the decline of fruit firmness and color difference,better inhibited the increase of weight loss rate,and maintained higher soluble solids and total acid content.Physiologically,single and compound treatments all maintained the activities of peroxidase and catalase.Among them,the compound treatment of three reagents could improve the storage and fresh-keeping ability of Hongxiangsu pear.After 15 d of storage,the weight loss rate of the fruit treated with three reagents was lower than that of the blank group by 2.47%,and the color difference was lower than that of the blank group by 3.79.In terms of soluble solids,firmness,and other qualities,the fruit treated with the combination of the three reagents was superior to that treated with singe reagent or two reagents in pair.[Conclusions]Different compound coating treatments all showed positive effects on the preservation of Hongxiangsu pear,but before practical application and promotion,it is necessary to further explore the appropriate coating methods and proportions.
文摘化疗后周围神经病变(chemotherapy-induced peripheral neuropathy,CIPN)是癌症患者接受化疗过程中常见的严重并发症,严重影响患者的生活质量和治疗依从性。近年来,中医在缓解CIPN症状方面展现出独特优势,针灸与中药复方在减轻疼痛、改善感觉障碍以及促进神经再生等方面展现出良好潜力。文章通过系统检索PubMed、Web of Science和CNKI等数据库,综述了近五年中医治疗CIPN的研究进展,重点探讨其作用机制、疗效评价及多学科融合的研究方向。研究表明,中医治疗通过抗炎、抗氧化、调节神经生长因子及肠道菌群等多途径、多靶点机制显著缓解CIPN症状。此外,神经影像学和分子生物学技术的应用为揭示针灸和中药的作用机制提供了新的视角。尽管中医治疗在安全性和患者接受度方面具有优势,但研究设计质量不足、样本量较小及中药制剂标准化不足等问题限制了其国际化推广。文章提出构建“中医-现代科学”整合模型,探索肠-脑轴调节机制,并推动中药制剂的标准化和疗效评价体系的完善,为CIPN的治疗策略优化及中医治疗的国际化应用提供科学依据。
基金funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) (RGPIN0326978-2011) under the Discovery Grant program
文摘Endocrine disrupting compounds（EDCs） and pharmaceuticals pose a challenge for water and wastewater treatment because they exist at very low concentrations in the presence of substances at much higher concentrations competing for adsorption sites.Sub-micron sized resin particles（approximately 300 nm in diameter）（SMR） were tested to evaluate their potential as a treatment for EDCs including：17-β estradiol（E2）,17-α ethinylestradiol（EE2）,estrone（E1）,bisphenol A（BPA）,and diethylstilbestrol（DES） as well as 12 pharmaceuticals.SMR were able to remove 98%of spiked E2,80%of EE2,87%of BPA,and up to 97%of DES from water.For a 0.5 ppm mixture of E2,EE2,E1,BPA and DES,the minimum removal was24%（E2） and the maximum was 49%（DES）.They were also able to remove the pharmaceuticals from deionized water and wastewater.Overall,SMR are a promising advanced treatment for removal of both EDCs and pharmaceuticals.
