不同保鲜液对切花月季保鲜的影响

以切花月季粉玫为试验材料,研究不同组合保鲜液对切花月季粉玫保鲜效果的影响。结果表明,通过对月季瓶插寿命、鲜质量变化率和花径变化3个指标的比较,筛选出一个较为理想的保鲜液配方为500 m L水中添加柠檬酸25 mg+抗坏血酸25 mg,该保鲜液可以延长切花的观赏期。

Co-application of energy uncoupling and ultrafiltration in sludge treatment:Evaluations of sludge reduction,supernatant recovery and membrane fouling control

Energy uncoupling is often used for sludge reduction because it is easy to operate and does not require a significant amount of extra equipments(i.e.no additional tank required).However,over time the supernatant extracted using this method can deteriorate,ultimately requiring further treatment.The purpose of this study was to determine the effect of using a low-pressure ultrafiltration membrane process for sludge water recovery after the sludge had undergone an energy uncoupling treatment(using 3,3’,4’,5-tetrachlorosalicylanilide(TCS)).Energy uncoupling was found to break apart sludge floe by reducing extracellular polymeric substances(EPS)and adenosine triphosphate(ATP)content.Analysis of supernatant indicated that when energy uncoupling and membrane filtration were coapplied and the TCS dosage was below 30 mg/L,there was no significant deterioration in organic component removal.However,ammonia and phosphate concentrations were found to increase as the concentration of TCS added increased.Additionally,due to low sludge concentrations and EPS contents,addition of 30-60 mg/L TCS during sludge reduction increased the permeate flux(two times higher than the control)and decreased the hydraulic reversible and cake layer resistances.In contrast,high dosage of TCS aggravated membrane fouling by forming compact fouling layers.In general,this study found that the co-application of energy uncoupling and membrane filtration processes represents an effective alternative method for simultaneous sludge reduction and sludge supernatant recovery.

Metabolic uncoupler,3,3’,4’,5-tetrachlorosalicylanilide addition for sludge reduction and fouling control in a gravity-driven membrane bioreactor

The gravity-driven membrane bioreactor(MBR)system is promising for decentralized sewage treatment because of its low energy consumption and maintenance requirements.However,the growing sludge not only increases membrane fouling,but also augments operational complexities(sludge discharge).We added the metabolic uncoupler 3,3’,4f,5-tetrachlorosalicylanilide(TC$)to the system to deal with the mentioned issues.Based on the results,TCS addition effectively decreased sludge ATP and sludge yield(reduced by 50%).Extracellular polymeric substances(EPS;proteins and polysaccharides)decreased with the addition of TCS and were transformed into dissolved soluble microbial products(SMPs)in the bulk solution,leading to the break of sludge floes into small fragments.Permeability was increased by more than two times,reaching 60-70 L/m2/h bar when 10-30 mg/L TCS were added,because of the reduced suspended sludge and the formation of a thin cake layer with low EPS levels.Resistance analyses confirmed that appropriate dosages of TCS primarily decreased the cake layer and hydraulically reversible resistances.Permeability decreased at high dosage(50 mg/L)due to the release of excess sludge fragments and SMP into the supernatant,with a thin but more compact fouling layer with low bioactivity developing on the membrane surface,causing higher cake layer and pore blocking resistances.Our study provides a fundamental understanding of how a metabolic uncoupler affects the sludge and bio-fouling layers at different dosages,with practical relevance for in situ sludge reduction and membrane fouling alleviation in MBR systems.

A V_(2)O_(3)@N-C cathode material for aqueous zinc-ion batteries with boosted zinc-ion storage performance

The discontinuity of new types of clean energy,such as wind power and solar cells, has promoted the development of large-scale energy storage systems(EES).Rechargeable aqueous zinc-ion batteries(ZIBs) have received extensive attention due to their inherent safety and low cost. At this stage, the performance of ZIBs is still limited by cathode materials. In this work, we have constructed a ZIBs cathode material-V_(2)O_(3)@N–C, through surface coating and N atom doping. The N-doped carbon coating endows V_(2)O_(3)@N–C with excellent structural stability and enhances its electrical conductivity. As a result,V_(2)O_(3)@N–C cathode delivers exceptional reversible of Zn^(2+) intercalation/deintercalation. The fabricated Zn/V_(2)O_(3)@N–C batteries exhibit high capacity of 274.6 mAh·g^(-1) at 5 A·g^(-1) and excellent capacity retention of 94% after 2000 cycles. The reversible intercalation/deintercalation of Zn^(2+) in the V_(2)O_(3)@N–C cathode is proved by ex-situ testing methods. It is believed that this work should inject new vitality into the development of ZIBs cathode.

Dynamic interaction of neutrophils and RFP-labelled Vibrio parahaemolyticus in zebrafish(Danio rerio)

Vibrio parahaemolyticus(Vp)is an aquatic zoonotic pathogen that causes vibriosis in marine animals as well as sepsis,gastroenteritis and wound infection in human.In vertebrates,the innate immune system plays a critical defense mechanism against Vp infection including transmigration of neutrophils.In this study,we have examined the genetic recombination and infectious process of Vp in the zebrafish(Danio rerio),a vertebrate model system extensively used for studying host-pathogen interactions.A pathogenic Vp strain,Vp57,tagged with red fluorescent protein(RFP)(Vp57^(RFP))was introduced into larval zebrafish at 3 days post fertilization(dpf),in which the innate immunity is present whereas the adaptive immunity has not yet developed.Vp57 and Vp57^(RFP)showed similar LD50 and induced similar symptoms and pathological changes in the hosts.We microinjected 579 colony-forming units(CFU)Vp57^(RFP)into the zebrafish caudal vein,and observed that neutrophils were recruited to the injection site and within 3 h post infection(hpi)Vp57^(RFP)were mainly distributed in the tail,eyes,heart and optic vesicle.After 3 hpi,the fish died with slight spine bending.Several Vp57^(RFP)were also detected in somites,the phagocytosis of neutrophils was activated through the progress of bacterial infections.We found that chemotaxis and phagocytosis of neutrophils occurs when zebrafish is infected by Vp57^(RFP),whereas Vp57^(RFP)can escape from neutrophils and colonize other remote regions using the blood circulation system.