Characteristics of Central Heating Cinder and Its Influence on Soil Properties

[Objective]The research was designed to explore the effect of long-term stacking of solid waste produced in the coal-burning process of central heating enterprises on physical and chemical properties of soil.[Method]This study took the heating enterprises in Shenyang City as the research object.The morphological structure and element composition of coal cinder were determined by continuously collecting coal and cinder samples in different periods.At the same time,the original soil and cinder soil of the stacking site were collected to determine the changes of soil morphological structure,element composition and physical and chemical properties,so as to provide reference for the resource utilization of local cinder waste and the potential pollution risk of the stacking site.[Result]The contents of C,H,O,N,and S non-metallic elements in coal cinder decreased by 69.5%,71.2%,76.0%,74.5%,and 34.6%,respectively when compared with raw coal;while the content of Si increased significantly by 95.7%.The contents of Al,K,and Fe in cinder decreased by 4.3%,60.2%,and 33.3%,respectively,while the contents of Mg and Na increased by 36.1%and 130.9%,respectively.Compared with the original soil,the contents of C,H,and O in shallow cinder soil and deep cinder soil increased by 126.5%,67.9%,80.93%,and 21.3%,25.0%and 42.3%,respectively.The residual carbon existed in the form of activated carbon.The contents of Mg,Al,K,Na,Ca,and Fe in shallow cinder soil and deep cinder soil increased by 61.6%,5.4%,46.1%,35.8%,32.5%,6.3%and 22.3%,12.3%,12.2%,15.6%,5.8%and 2.8%,respectively compared with the original soil.The content of heavy metal elements in coal cinder did not reach the detection limit.Under the scanning electron microscope,the raw coal is mainly block structure,while the cinder is honeycombed and porous and dust.[Conclusion]Cinder stacking can significantly improve the content of organic matter and available K in shallow cinder soil,and improve the porosity and permeability of soil.In addition,cinder waste has high pH and pore structure,which can be used as acid soil conditioner,seedling flower matrix and compound fertilizer filler to take full advantage of cinder waste,improve soil structure and supply nutrients.

Co-composting of Chinese milk vetch with rice straw and using the compost as a peat substitute of seeding substrate of vegetables

Chinese milk vetch(Astragalussinicus L.)is an environment-friendly green manure used for rice with low carbon/nitrogen(C/N)ratio and high moisture.To improve the added values of milk vetch,the feasibility of co-composting of milk vetch with rice straw was evaluated.The probability of using the milk vetch-based compost as a peat substitute in seeding substrate of vegetable was further tested.The changes in physicochemical properties during co-composting of milk vetch and rice straw were evaluated,depending on three treatments:(1)milk vetch alone(MV),(2)co-composting of milk vetch and rice straws with 4:1 ration(w/w)(MV+S)and(3)MV+S with the addition of 3%(w/w)microbial inoculation(MV+S+M).The entire composting durations were 15 d,24 d,and 24 d in MV,MV+S,MV+S+M composts.Compare to MV compost,both the MV+S,MV+S+M composts increased the temperature,pH,organic C,total nitrogen(N),total potassium(K)and the germination index(GI)(over 100)during the cooling/mature phase,and decreased total N loss,and generally,the improvements or reductions were greater in the MV+S+M compost than in the MV+S compost.Additionally,the MV+S+M compost was added at a peat substitute rates of 0%,20%,40%,80%and 100%in a pot experiment to testify the utilization of milk vetch-based compost in substrates.The results showed that the substrate with 40%substitute rate increased the cabbage seeding growth,and that the electrical conductivity was the limiting factor of preventing the substitute rate increase.Another pot experiment demonstrated that the substrate with 40%peat substitute increased the cucumber growth as compared to the substrate without compost.In conclusion,the co-composting milk vetch with rice straw was feasible and quick,and microbial inoculation accelerated the composting process and improved the compost quality.The milk vetch-based composts were nutrient-rich and safe,and thus,can replace part of peat in vegetable seeding substrate.

Two-dimensional beam shaping and homogenization of high power laser diode stack with rectangular waveguide

In this paper, the research work of twodimensional beam shaping and homogenization of high power laser diode (LD) stack by a rectangular waveguide is presented. Both the theoretical simulation and experiment results have shown that the diode stack beam can be shaped into a uniform square spot with a dimension of 10 mm×10 mm and the non-uniformity less than 5% along both directions of slow axis and fast axis, the shaped beam has a uniform pumping depth over 10 mm, which is well to be used for a rectangular laser medium end pumping.

Small extracellular vesicles secreted by urine-derived stem cells enhanced wound healing in aged mice by ameliorating cellular senescence

Regeneration of chronic skin wounds in tissue is still a key challenge in regenerative medicine because of the accumulation of senescent cells and increasing secretion of s¨enescence-associated secretory phenotype(SASP)in the wound site.Recently,some studies have reported that small extracellular vesicles(sEVs)derived from stem cells can alleviate cellular senescence with very low risk of tumorigenesis and immune responses.As our previous studies have shown that urine-derived stem cells(USCs)can be obtained easily and noninvasively and sEVs derived from USCs(USC-sEVs)have capabilities of regenerating tissue injuries,using USC-sEVs to enhance chronic skin wound healing in aged tissue might be a feasible and efficient strategy.Therefore,in this study,the USC-sEVs were collected and firstly loaded in a human acellular amniotic membrane(HAAM)for controlled releasing and locating the USC-sEVs in the wound site before they were implanted into a chronic skin wound in aged mice.In vivo results showed that the USC-sEVs in HAAM could effectively accelerate the wound healing by ameliorating cellular senescence and reducing the secretion of SASP in the aged skin wounds.To elucidate the mechanism,USC-sEVs were used to in vitro culture human dermal fibroblasts(HDFs)and results showed that USC-sEVs could rejuvenate senescent fibroblasts by reversing the aging phenotypes of senescent HDFs and efficiently reducing the secretion of SASP after they activated the Sirt1 pathway.Therefore,USC-sEVs are efficient for enhancing wound healing in aged mice by ameliorating cellular senescence.

Biomechanical thrombosis: the dark side of force and dawn of mechano-medicine

Arterial thrombosis is in part contributed by excessive platelet aggregation,which can lead to blood clotting and subsequent heart attack and stroke.Platelets are sensitive to the haemodynamic environment.Rapid haemodynamcis and disturbed blood flow,which occur in vessels with growing thrombi and atherosclerotic plaques or is caused by medical device implantation and intervention,promotes platelet aggregation and thrombus formation.In such situations,conventional antiplatelet drugs often have suboptimal efficacy and a serious side effect of excessive bleeding.Investigating the mechanisms of platelet biomechanical activation provides insights distinct from the classic views of agonist-stimulated platelet thrombus formation.In this work,we review the recent discoveries underlying haemodynamic force-reinforced platelet binding and mechanosensing primarily mediated by three platelet receptors:glycoprotein Ib(GPIb),glycoprotein IIb/IIIa(GPIIb/IIIa)and glycoprotein VI(GPVI),and their implications for development of antithrombotic‘mechano-medicine’.