Study on the optimal incident proton energy of ^(7)Li(p,n)^(7)Be neutron source for boron neutron capture therapy

Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.

基于石灰苛化法研究CaO在含草酸盐稀铝酸钠溶液中的反应动力学与机理（英文）

基于草酸盐石灰苛化法研究水合铝酸三钙和草酸钙分别在稀铝酸钠溶液和草酸钠溶液中的反应动力学和机理,并获得铝酸钠溶液去除草酸盐的最佳条件及其去除机理。水合铝酸三钙和草酸钙的生成分别受化学反应控制和内扩散控制,分别计算其反应速率方程和表观活化能。在含草酸盐的稀铝酸钠溶液中能够形成具有空间交错片状结构的水铝钙石相,其通过吸附大幅度降低溶液中草酸盐杂质。随着反应时间的延长,生成的草酸钙能够转化为水合铝酸三钙。在反应温度为50℃、搅拌速度为200r/min下,草酸盐苛化效率达到90%以上,氧化铝损失率在31%以下。

Pre-desilication and digestion of gibbsitic bauxite with lime in sodium aluminate liquor

The effect of lime on the pre-desilication and digestion of gibbsitic bauxite in synthetic sodium aluminate liquor at different tem- peratures was investigated. The bauxite is comprised of gibbsite, aluminogoethite, hematite, kaolin, quartz, and minor boehmite. Lime in- creases the desilication efficiency of the bauxite during the pre-desilication process by promoting the conversion of sodalite and cancrinite to hydrogamet. Desilication reactions during the digestion process promoted by lime result in the loss of A1203 entering the red mud, but the amount of aluminogoethite-to-hematite conversion promoted by lime leads to the increase of aluminogoethific A1203 entering the digested liquor. The alumina digestion rate at 245~C is higher than that at 145 C due to the more pronounced conversion of aluminogoethite to hema- tite. The soda consumption during the digestion process decreases due to lime addition, especially at higher temperatures.

Theoretical Study on Reaction Mechanism of Tautomerization of Indazole and 3-halogeno-indazole

indazole 和 3-halogeno-indazole tautomers 的分子的结构被 B3LYP 方法在 6-311G** 水平计算，两个在气体、水的阶段，与完整的几何学优化。几何学和 indazole， 3-halogeno-indazole 和他们的转变状态的 tautomers 的电子结构被获得。Onsager solvate 理论模特儿为水的答案计算被雇用。计算的结果显示学习分子的 N1-H 形式比 N2-H 形式的更稳定。几何学，精力，费用和激活精力上的不同 3-halogeno 和溶剂效果的影响被讨论。indazole 和 3-halogeno-indazole 的 tautomerization 的反应机制也被学习， tautomer 反应的一个三成员的周期的转变状态被获得了。

P含量对CaO-Al_2O_3-SiO_2体系在高温烧结过程中矿相转变的影响（英文）

采用XRF、XRD、SEM-EDS和DSC-TG等技术手段研究不同P含量下铝酸钙熟料在高温烧结过程中的矿相转变、显微组织、自粉性能及其氧化铝浸出性能。1350°C下烧结熟料主要由12CaO·7Al_2O_3、Ca O·Al_2O_3、β-2CaO·SiO_2和γ-2CaO·SiO_2等矿相组成;随着P含量的增加,β-2CaO·SiO_2含量逐渐升高,而γ-2CaO·SiO_2含量逐渐降低。熟料的自粉性能随着P含量的增加逐渐恶化。P在熟料中均匀分布,其存在抑制β-2CaO·SiO_2向γ-2CaO·SiO_2的转变。12Ca O·7Al_2O_3和CaO·Al_2O_3的晶胞体积随着P含量的增加分别降低和提高,且P能降低铝酸钙化合物的形成温度。铝酸钙熟料的氧化铝浸出率随着P含量的增加明显降低,当P含量从0提高到0.85%时,氧化铝浸出率从95.01%降低到83.84%。

Prevention against diffuse spinal cord astrocytoma: can the Notch pathway be a novel treatment target?

This study was designed to investigate whether the Notch pathway is involved in the develop-ment of diffuse spinal cord astrocytomas. BALB/c nude mice received injections of CD133＋and CD133？ cell suspensions prepared using human recurrent diffuse spinal cord astrocytoma tissue through administration into the right parietal lobe. After 7–11 weeks, magnetic resonance imaging was performed weekly. Xenografts were observed on the surfaces of the brains of mice receiving the CD133＋ cell suspension, and Notch-immunopositive expression was observed in the xenografts. By contrast, no xenografts appeared in the identical position on the surfaces of the brains of mice receiving the CD133？ cell suspension, and Notch-immunopositive expres-sion was hardly detected either. Hematoxylin-eosin staining and immunohistochemical staining revealed xenografts on the convex surfaces of the brains of mice that underwent CD133＋ astro-cytoma transplantation. Some sporadic astroglioma cells showed pseudopodium-like structures, which extended into the cerebral white matter. However,it should be emphasized that the sub-cortex xenograft with Notch-immunopositive expression was found in the fourth mouse received injection of CD133？ astrocytoma cells. However, these ifndings suggest that the Notch pathway plays an important role in the formation of astrocytomas, and can be considered a novel treat-ment target for diffuse spinal cord astrocytoma.

Mineral transition and formation mechanism of calcium aluminate compounds in CaO-Al2O3-Na2O system during high-temperature sintering

The mineral transition and formation mechanism of calcium aluminate compounds in CaO-Al2O3-Na2O system during the hightemperature sintering process were systematically investigated using DSC-TG,XRD,SEM-EDS,FTIR,and Raman spectra,and the crystal structure of Na4Ca3(AlO2)10 was also simulated by Material Studio software.The results indicated that the minerals formed during the sintering process included Na4Ca3(AlO2)10,CaO·Al2O3,and 12 CaO·7 Al2O3,and the content of Na4Ca3(AlO2)10 could reach 92 wt%when sintered at 1200°C for 30 min.The main formation stage of Na4Ca3(AlO2)10 occurred at temperatures from 970 to 1100°C,and the content could reach82 wt%when the reaction temperature increased to 1100°C.The crystal system of Na4Ca3(AlO2)10 was tetragonal,and the cells preferred to grow along crystal planes(110)and(210).The formation of Na4Ca3(AlO2)10 was an exothermic reaction that followed a secondary reaction model,and its activation energy was 223.97 kJ/mol.

Experimental Investigation on Springback Performance of Transformation-induced Plasticity Steel Sheet during Cyclic Bending Process

In order to investigate the springback performance of a cold-rolled transformation-induced plasticity( TRIP) steel sheet during cyclic bending,three-points bending experiments were performed. The specimen was firstly forward bended and then reversed bended according to three basic punch strokes,10 mm,20 mm and 30 mm,respectively. The outlines of the deformed specimens,punch load and crosshead displacement were obtained. The experimental procedures and the method of determining the springback displacement were reported in detail. The contribution of the strain hardening and decrease of elastic modulus to the overall springback was explained. The results demonstrated that springback increases both with the cycles and with the punch stroke during the cyclic bending process. Furthermore,springback in forward bending is larger than that in the corresponding reverse bending. This may be helpful to understand the complex springback behavior of the complicated sheet metal panels.

Regulation by hydrogen sulfide on thyroid cancer

To explore the role in of hydrogen sulfide(H2S)in the occurrence and development of thyroid cancer,through the literature,this paper comprehensively analyzes the physical and chemical characteristics of H2S and the composition of endogenous hydrogen sulfide enzymes,as well as the thyroid cancer pathogenesis of cancer genes and the related signal pathways,discusses its mechanisms in the development of hydrogen sulfide in thyroid carcinoma,and exogenous hydrogen sulfide donor regulation function of thyroid cancer cell growth.In order to further reveal the pathogenesis of thyroid cancer,for the development of new anti-tumor drugs to bring new clinical ideas and value.

Electrospun Poly(p-dioxanone)/Poly(ester-urethane)ureas Composite Nanofibers for Potential Heart Valve Tissue Reconstruction

Electrospun nanofibrous mats represent a new generation of medical textiles with promising applications in heart valve tissue reconstruction. It is important for biomaterials to mimic the biological and mechanical microenvironment of native extracellular matrix(ECM). However, the major challenges are still remaining for current biomedical materials, including appropriate mechanical properties,biocompatibility, and hemocompatibility. In the present work, the novel composite nanofibrous mats of poly(p-dioxanone)(PDO) and poly(ester-urethane)ureas(PEUU) are fabricated by electrospinning system. The optimal combination ratio of PDO to PEUU may balance the mechanical properties and cellular compatibility to match the newly formed tissue. In PDO/PEUU composite nanofibrous mats, PEUU can provide the biomimetic elastomeric behavior, and PDO could endow the excellent biocompatibility. In comparison to nanofibrous mat of neat PDO, the composite showed significantly improved mechanical properties, with 5-fold higher initial elongation at break.Furthermore, human umbilical vein endothelial cells(HUVECs) were cultured on the composite to evaluate its ability to rapidly endothelialize as heart valve tissue engineering. The results revealed that PDO/PEUU composite nanofibrous mats could promote cell adhesion and proliferation, especially for the ratio of 60/40. Overall, PDO/PEUU composite nanofibrous mats(60/40) show the excellent mechanical properties, appropriate biocompatibility and hemocompatibility which meet the necessary norm for tissue engineering and may be suitable for potential heart valve tissue reconstruction.

Effect of Iron Oxides on Activity of Calcium Aluminate Clinker in CaO-Al_2O_3-SiO_2 System

The sintering characteristics at 1350℃ and leaching property at 80℃ of calcium aluminate clinkers in the CaO-Al2O3-SiO2 （C-A-S） system with different additions of FeO and Fe2O3 were investigated. FeO inhibits the conversion of β-Ca2SiO4 to γ-Ca2SiO4 and makes the clinker not pulverizable. FeO and Fe2O3 inhibit the formation of CaAl2O4, but promote the formation of Ca12Al14O33. The interplanar spacing at （2 1 1） crystal face of Ca12 Al14O33 in the clinker increases with the increase of FeO addition, which indicates that FeO forms solid solutions in Ca12Al14O33. The clinkers with Fe2O3 addition form a new phase Ca2Fe2O5, and the amount of Ca2Fe2o5 increases with the in crease of Fe2O3 addition. Both FeO and Fe2O3 do not affect the Al2O3 leaching rate of calcium aluminate clinker in sodium carbonate solution, but they increase the molar ratio of caustic Na2O to Al2O3 in the leached liquor.

A two-stage heuristic method for vehicle routing problem with split deliveries and pickups

The vehicle routing problem(VRP) is a well-known combinatorial optimization issue in transportation and logistics network systems. There exist several limitations associated with the traditional VRP. Releasing the restricted conditions of traditional VRP has become a research focus in the past few decades. The vehicle routing problem with split deliveries and pickups(VRPSPDP) is particularly proposed to release the constraints on the visiting times per customer and vehicle capacity, that is, to allow the deliveries and pickups for each customer to be simultaneously split more than once. Few studies have focused on the VRPSPDP problem. In this paper we propose a two-stage heuristic method integrating the initial heuristic algorithm and hybrid heuristic algorithm to study the VRPSPDP problem. To validate the proposed algorithm, Solomon benchmark datasets and extended Solomon benchmark datasets were modified to compare with three other popular algorithms. A total of 18 datasets were used to evaluate the effectiveness of the proposed method. The computational results indicated that the proposed algorithm is superior to these three algorithms for VRPSPDP in terms of total travel cost and average loading rate.