AlLi-LDH中Al-O八面体环吸附锂的机制

采用共沉淀法合成铝锂层状双氢氧化物(AlLi-LDH)并进行提锂试验。AlLi-LDH的空间群为P32或C2/m,微观形貌呈直径为5~10μm的规则球形。AlLi-LDH吸附Li^(+)后,空间群转化为P32。当Li^(+)浓度为95.4 mg/L时,1 h后锂吸附量为8.98 mg/g;吸附48 h后,吸附量增加到16.50 mg/g;根据二级吸附模型预测Li^(+)吸附总量为17.57 mg/g。当Mg^(2+)/Li^(+)的质量比为1067时,Mg^(2+)/Li^(+)分离系数为29536。空间群为P32时,Li-O的相互作用强度变弱,且相互作用属于静电效应。具有P32空间基团的AlLi-LDH更容易吸附和解吸Li^(+)。

Experimental Investigation of Wave-Current Loads on a Bridge Shuttle-Shaped Cap–Pile Foundation

To scrutinize the characteristics of wave-current loads on a bridge shuttle-shaped cap–pile foundation,a 1:125 test model was considered in a laboratory flume.The inline,transverse and vertical wave–current forces acting on the shuttle-shaped cap-pile group model were measured considering both random waves and a combination of random waves with a current.The experimental results have shown that the wave-current forces can be well correlated with the wave height,the wavelength,the current velocity,the incident direction and the water level in the marine environment.An increase in the current velocity can lead to a sharp increase in the inline and transverse wave-current forces,while the vertical wave-current force decreases.Moreover,the wave-current forces are particularly strong when a combination of high tide,strong wave and strong current is considered.

发酵茶渣对肉羊生长性能、瘤胃发酵参数和营养物质表观消化率的影响

本试验旨在研究发酵茶渣对肉羊生长性能、瘤胃发酵参数和营养物质表观消化率的影响,以确定发酵茶渣替代肉羊精料补充料的适宜比例。试验选取64只3月龄、体重(20.0±2.5)kg的健康湖羊,随机分为4组,每组16只。对照组饲喂基础饲粮,Ⅰ组、Ⅱ组、Ⅲ组在基础饲粮的基础上分别用发酵茶渣等比例替代5%、10%、20%的精料补充料。结果表明:1)各组之间肉羊的末重、平均日增重、干物质采食量和料重比均无显著差异(P>0.05)。2)Ⅱ组的瘤胃液丙酸(PA)比例显著高于对照组和Ⅲ组(P<0.05),Ⅰ组和Ⅱ组的瘤胃液乙酸/丙酸(AA/PA)显著低于对照组和Ⅲ组(P<0.05)。各组之间肉羊的瘤胃液pH和总挥发性脂肪酸(TVFA)、氨态氮(NH3-N)、微生物蛋白(MCP)含量以及乙酸(AA)、丁酸(BA)比例均无显著差异(P>0.05)。3)对照组和Ⅰ组的粗脂肪表观消化率显著高于Ⅲ组(P<0.05)。各组之间肉羊的有机物、粗蛋白质、干物质、中性洗涤纤维和酸性洗涤纤维表观消化率均无显著差异(P>0.05)。4)与对照组相比,Ⅰ组、Ⅱ组、Ⅲ组的饲料成本和饲料增重成本均有所降低,其中,Ⅲ组的降低幅度最大。由此可见,本试验条件下,发酵茶渣替代5%、10%、20%的精料补充料对肉羊的生长性能以及大部分瘤胃发酵参数、营养物质表观消化率均无显著影响,从经济效益考虑,建议发酵茶渣替代肉羊精料补充料的适宜比例为20%。

杂交构树青贮对奶公牛生长性能、营养物质表观消化率和瘤胃发酵参数的影响

本试验旨在研究杂交构树青贮对奶公牛生长性能、营养物质表观消化率和瘤胃发酵参数的影响。选取12月龄左右、体重(330±35)kg的奶公牛30头,随机分成3组,每组10头牛。对照组饲喂基础饲粮,试验1、2组饲分别喂用杂交构树青贮替代基础饲粮中50%和100%苜蓿干草的试验饲粮。预试期14 d,正试期35 d。结果表明:各组之间奶公牛的生长性能、营养物质表观消化率和瘤胃发酵参数均无显著差异(P>0.05)。然而,对照组日饲料成本显著高于试验1、2组(P<0.05),试验2组日利润显著高于对照组(P<0.05)。由此可见,杂交构树青贮替代苜蓿干草不影响奶公牛生长性能、营养物质表观消化率和瘤胃发酵功能,并可降低饲料成本。

杂交构树半干青贮加工工艺参数研究

杂交构树‘中科1号构树’(Broussonetia papyrifera‘Zhongke No.1’)属桑科构属落叶灌木,具有生长迅速、产量高、蛋白含量丰富的特性,是一种极具开发价值的非常规蛋白质饲料资源。但其作为一种饲料原料,粗纤维含量高、蛋白质结构复杂,且含有抗营养因子。为了提高构树饲料适口性和营养物质消化率,降低其中纤维素含量,本试验选用植物乳杆菌(Lactiplantibacillus plantarum)、乳酸片球菌(Pediococcus acidilactici)、布氏乳杆菌(Lactobacillus buchneri)作为发酵菌种,对半干构树采用正交设计来优化菌种组合、物料组合、含水量、青贮时间等条件,以感官指标、化学指标以及营养指标为判定青贮质量优劣的依据,最终确定最优的构树半干青贮饲料工艺参数组合。结果表明,构树半干青贮最佳工艺参数为水分含量55%、植物乳杆菌꞉乳酸片球菌꞉布氏乳杆菌组合比例4꞉1꞉1、糖蜜添加量3%、纤维素酶添加量9×10^(3)U·kg^(−1)、青贮时间60 d。该条件下有氧稳定性为226.33~245.67 h,粗蛋白含量为16.27%~16.62%,酸性洗涤纤维含量为32.25%~32.61%,中性洗涤纤维含量为44.17%~44.81%。本研究确定了杂交构树半干青贮饲料适宜工艺参数,为构树青贮饲料在畜牧养殖业的应用提供依据。

柴胡皂苷对热诱导的奶牛乳腺上皮细胞抗氧化能力和热休克蛋白基因表达的影响

本试验旨在研究柴胡皂苷a(SSa)和柴胡皂苷d(SSd)对热诱导的奶牛乳腺上皮细胞(BMECs)抗氧化能力和热休克蛋白基因表达的影响。以38℃培养的BMECs作为阴性对照组;高温42℃分别培养BMECs 1、4、8、12和24 h,建立热应激模型(阳性对照组);BMECs培养基中分别添加0.1、1.0μmol/L SSa和0.01、0.10μmol/L SSd,38℃培养4 h(SSa和SSd作用细胞时间)后,42℃分别处理1、4、8、12和24 h(处理组)。测定各组BMECs中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)活性及培养液中丙二醛(MDA)含量,并检测细胞中热休克转录因子-1(HSF-1)和热休克蛋白70(HSP70)mRNA相对表达量。结果表明:与阴性对照组相比,阳性对照组BMECs中SOD和GSH-Px活性显著降低(P<0.05),培养液中MDA含量在热诱导4 h时显著升高(P<0.05),HSF-1和HSP70 mRNA相对表达量显著上调(P<0.05)。与阳性对照组相比,任意浓度的SSa均能够显著提高热诱导1 h时BMECs中SOD活性(P<0.05);热诱导4、8和24 h时,0.1μmol/L SSa组BMECs中CAT活性显著提高(P<0.05);0.01μmol/L SSd在热诱导1、4、8、12和24 h时能显著提高BMECs中GSH-Px的活性(P<0.05);但在热诱导12和24 h时,1.0μmol/L SSa和0.1μmol/L SSd对BMECs中SOD、GSH-Px和CAT活性无显著改善作用(P>0.05),或者显著降低了以上抗氧化酶的活性(P<0.05),且在热诱导12 h时0.1μmol/L SSd组培养液中MDA含量显著升高(P<0.05),表明SSa和SSd对BMECs氧化应激的缓解作用存在剂量和时间依赖性。在热诱导1 h时,各处理组BMECs中HSP70 mRNA相对表达量较阳性对照组显著上调(P<0.05);在热诱导4 h时,0.1μmol/L SSa处理组BMECs中HSF-1和HSP70 mRNA相对表达量较阳性对照组显著上调(P<0.05);在热诱导12和24 h时,0.01μmol/L SSd处理组BMECs中HSP70 mRNA相对表达量较阳性对照组显著上调(P<0.05)。综上所述,42℃热处理可诱导BMECs氧化应激,适宜浓度的SSa和SSd能够缓解热诱导BMECs的氧化应激,其中0.1μmol/L SSa和0.01μmol/L SSd对42℃热诱导条件下BMECs的氧化应激有较好的缓解作用,并可提高HSF-1和HSP70基因的表达,保护BMECs免受高温诱导的损伤。

杂交构树适宜收割高度与青贮加工工艺参数研究

[目的]确定杂交构树的适宜收割高度以及利用微生物菌种发酵加工构树青贮的工艺参数。[方法]通过分析不同生长高度构树的营养成分和生物产量确定适宜的收割高度;选用植物乳杆菌、乳酸片球菌、布氏乳杆菌作为发酵菌种,以适宜生长高度的构树为原料制作构树青贮;采用正交试验设计优化菌种组合、糖蜜添加量、纤维素酶添加量、青贮时间等加工参数,以现场感官指标、化学成分指标、有氧稳定性指标以及营养成分指标作为判定青贮质量的依据,确定最优的构树青贮加工工艺参数组合。[结果]构树收割高度为1.2 m时,其生物产量和营养价值最高;经正交试验设计优化得到的构树青贮最佳工艺参数:菌种组合植物乳杆菌∶乳酸片球菌∶布氏乳杆菌比例为4∶1∶1,糖蜜添加量为3%,纤维素酶添加量为9×10^(3)U/kg、青贮时间60 d。[结论]研究确定了杂交构树的适宜收割高度及青贮加工工艺参数,为构树饲料化利用提供了参考。

Electrochemical behavior and electrolytic preparation of lead in eutectic NaCl−KCl melts

A novel molten salt extraction process consisting of chlorination roasting and molten salt electrolysis was proposed to develop a more efficient and environmental friendly technology for recovering lead from spent lead acid batteries(LABs).The feasibility of this process was firstly assessed based on thermodynamics fundamentals.The electrochemical behavior of Pb(II)on a tungsten electrode in the eutectic NaCl−KCl melts at 700℃ was then investigated in detail by transient electrochemical techniques.The results indicated that the reduction reaction of Pb(II)in NaCl−KCl melts was a one-step process exchanging two electrons,and it was determined to be a quasi-reversible diffusion-controlled process.Finally,potentiostatic electrolysis was carried out at−0.6 V(vs Ag/AgCl)in the NaCl−KCl−PbCl2 melts,and the obtained cathodic product was identified as pure Pb by X-ray diffraction analysis.This investigation demonstrated that it is practically feasible to produce pure Pb metal by electrochemical reduction of PbCl2 in eutectic NaCl−KCl melts,and has provided important fundamental for the further study on lead recovery from spent LABs via molten salt extraction process.

Ti对N80-1油管冲击性能的影响

36Mn2V是生产N80-1钢级油管的常用材料,一般采用在线常化或离线正火的生产工艺保证其强韧性。分析了不同化学成分N80-1钢级油管的力学性能和显微组织,用热力学软件模拟得到了过冷奥氏体连续冷却转变曲线,研究了Ti对N80-1油管冲击性能的影响。结果表明:由于微合金元素Ti的添加使过冷奥氏体连续冷却转变曲线右移,降低了贝氏体和马氏体开始转变的冷却速度,使热轧后的组织中有较多的贝氏体和马氏体,从而造成强度和硬度升高及冲击功降低。

Study on primary carbides precipitation in H13 tool steel regarding cooling rate during solidification

This study aims to investigate the primary carbides precipitation in H13 steel solidified at relatively high cooling rates,ranging from 300 to 6,000℃·min^-1,based on in situ observations with a high temperature confocal laser scanning microscope.In the cooling rate range investigated,the solidification microstructure becomes more refined as cooling rate increases and the relationship between the secondary dendrite arm spacing(SDAS),λ2,and cooling rate,.T,can be expressed asλ2=128.45.T-0.124.Regardless of cooling rates,two kinds of primary carbides,i.e.,the Mo-Cr-rich and V-rich carbides,are precipitated along the interdendritic region and most of them are the Mo-Cr-rich carbides.The morphology of Mo-Cr-rich carbide is not obviously influenced by the cooling rate,but that of V-rich carbide is obviously affected.The increasing cooling rate markedly refines the primary carbides and reduces their volume fractions,but their precipitations cannot be inhibited even when the cooling rate is increased to 6,000℃·min^-1.Besides,the segregation ratios(SRs)of the carbides forming elements are not obviously affected by the cooling rate.However,compared with the conventionally cast ingot,the SDAS and primary carbides in the steel solidified at the investigated cooling rates are much finer,morphologies of the carbides have changed significantly,and SRs of the carbides forming elements are markedly greater.The variation of primary carbide characteristics with cooling rate is mainly due to the change in SDAS.

Density Functional Theory Study of Selectivity of Crown Ethers to Li^+ in Spent Lithium-Ion Batteries Leaching Solutions

It is a challenge to recover lithium from the leaching solution of spent lithium-ion batteries,and crown ethers are potential extractants due to their selectivity to alkali metal ions.The theoretical calculations for the selectivity of crown ethers with different structures to Li ions in aqueous solutions were carried out based on the density functional theory.The calculated results of geometries,binding energies,and thermodynamic parameters show that 15C5 has the strongest selectivity to Li ions in the three crown ethers of 12C4,15C5,and 18C6.B15C5 has a smaller binding energy but more negative free energy than 15C5 when combined with Li^+,leading to that the lithium ions in aqueous solutions will combine with B15C5 rather than 15C5.The exchange reactions between B15C5 and hydrated Li^+,Co^2+,and Ni^2+were analyzed and the results show that B15C5 is more likely to capture Li^+from the hydrated ions in an aqueous solution containing Li^+,Co^2+,and Ni^2+.This study indicates that it is feasible to extract Li ions selectively using B15C5 as an extractant from the leaching solution of spent lithium-ion batteries.

美丽俏佳人之花青素篇

在当今社会,随着消费的升级,美容和减肥逐渐成为一种全民的时尚潮流,不仅如此,人们更加追求一种健康的抗衰老和保持身材的方式。于是,花青素出现在千家万户的视野中,享有“皮肤维生素”的花青素为大家带来了福音,帮助身体消除自由基的同时,又有很多保健作用。本文用拟人化的手法,从花青素的结构开始分析,生动形象地揭秘了花青素还原美貌的神奇功效,并科学地解释了花青素抗氧化和帮助减肥的机理,无疑是人如其名的天然营养补充剂。

Redox behavior of indium in molten chlorides

An electrochemical study on the redox behavior of indium in the eutectic LiCl-KCl system at 450 ℃ was carried out with the transient techniques of cyclic voltammetry and chronopotentiometry on an inert molybdenum electrode. The reduction of In(Ⅲ) was found to be a two-step process involving In(Ⅲ)/In(Ⅰ) and In(Ⅰ)/In couples at the potentials of about-0.4 and-0.8 V versus Ag/AgCl, respectively. The redox mechanism was further confirmed by the theoretical evaluation of the number of transferred electrons based on cyclic voltammetry and characterizations of the precipitates generated by the potentiostatic electrolysis. The diffusion coefficients of indium ions in the eutectic LiCl-KCl melt at 450 ℃ were estimated by cyclic voltammetry and chronopotentiometry. The results obtained through the two methods are in fair agreement, delivering an average diffusion coefficient of approximately 1.8×10^(-5)cm^(2)/s for In(Ⅲ), and 1.4×10^(-4)cm^(2)/s for In(Ⅰ).

Numerical Analysis of the Hydrodynamic Behavior of a Remotely Operated Vehicle in Multi-Directional Flow

In recent years,Remotely Operated Vehicles(ROVs)have played an increasingly important role in the construc-tion and monitoring of underwater pile foundations.However,due to the open frame structure of such vehicles,a gap of knowledge still exists with regard to their hydrodynamic behavior.In this study,the hydrodynamic stability of such vehicles is investigated numerically by means of a multiple reference frame method.The hydrodynamic characteristics of the ROV when it moves horizontally and upward in the vertical plane are examined.It is found that there is interference between the horizontal and vertical thrusters of the ROV.There is also interference between the propeller thrust and drag(or lift).The effect of the vertical thrusters can increase the horizontal thrust by about 5%.The horizontal thrusters create a low-pressure area below the body,which can make vertical drag experienced by the ROV significantly higher.

基于葫芦[8]脲主客体化学的双客体组分动态交联水凝胶的制备和性能研究

基于超分子主客体作用的动态交联在构筑用于生物大分子和细胞载体的可注射水凝胶输送材料方面具备很多优势,但单一性质交联点的动态快慢程度固定,无法进行调节,难以实现水凝胶动态可调的性能.本研究利用葫芦[8]脲(CB[8])能够与它的客体分子以摩尔比为1/2的比例形成同种三元复合物主客体的相互作用,设计了一种双组分超分子动态交联水凝胶系统.在水凝胶聚合物骨架的侧链上同时引入偶氮苯与苯基吡啶盐2种客体基团,其中偶氮苯客体与CB[8]的结合较弱,呈现较快的动态可逆性质;苯基吡啶盐客体与CB[8]的结合较强,呈现较慢的动态可逆性质.设计不同比例的2种动态交联,得到了系列网络结构相同,但交联点性质动态可调的水凝胶材料.水凝胶性能研究结果显示,得到的材料能够在流变学机械性能、自修复、剪切变稀、应力松弛、大分子药物释放等生物医用关键性质上随客体比例变化而进行调控,具备良好的应用前景.

CEPC Technical Design Report

The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.

A compact route for efficient production of high-purity β-Ga_(2)O_(3) powder

The present study has proposed a compact process for the production of high-purity β-Ga_(2)O_(3)powder by simply using gallium metal and water as the raw materials.The process basically consists of two essential steps including hydrothermal synthesis of Ga OOH and calcination of Ga OOH for the production of the target product of β-Ga_(2)O_(3).Thermodynamic evaluation and systematic experiments were conducted for process parameter optimization.X-ray diffractometer(XRD),scanning electron microscopy(SEM),thermogravimetryDdifferential scanning calorimetry(TG-DSC)and X-ray photoelectron spectroscopy(XPS)were utilized to clarify the reaction mechanisms of the hydrothermal synthesis and transformation of Ga OOH to β-Ga_(2)O_(3)by calcination.Chemical analysis of the final product of β-Ga_(2)O_(3)obtained under the optimal conditions was carried out with inductively coupled plasma mass spectrometry(ICP-MS),and the results showed that the contents of the representative impurities such as Ni,Cu,In,Mn,Co,Zn and Cr are obviously lower than the requirement of 5N β-Ga_(2)O_(3)standard,exhibiting excellent application prospect of the proposed process to produce high-purity β-Ga_(2)O_(3).

Temporal expression of c-kit in spermatogenesis of two grasshopper species

Two species of grasshoppers, Calliptamus abbreviatus （Ikonn.） and Shirakiacris shirakii （I. Bol.）, were collected randomly in the Siping area of Jilin Province, China. By using immunohistochemical methods and statistical analysis, we observed and compared the temporal expression of c-kit protein in four representative stages of spermatogenesis of the two grasshoppers, namely： spermatogonia; primary spermatocyte; secondary spermatocyte; and mature sperm. Results showed that there was c-kit positive temporal expression at each stage of spermatogenesis, but there were different positive expression levels： （i） weak positive expression of c-kit protein appeared in spermatogonia and the positive granules were thinner; （ii） strong positive expression of c-kit protein existed in primary spermatocyte and positive granules became biggest among all developmental stages; （iii） c-kit positive expression stayed stronger in secondary spermatocyte while positive granules became thinner; （iv） there was a strong positive expression of c-kit and thinner positive granules in mature sperm, which distributed on head and tail; （v） the biggest c-kit positive granules had been found massing at the end of spermary; and （vi） significant differences of c-kit positive expression existed in spermatogenesis between two species of grasshoppers. The results indicated that c-kit protein may play a crucial role in spermatogenesis and even retain the physiological action of sperms and fertilization in grasshoppers.

HIV-1 Vif suppresses antiviral immunity by targeting STING

HIV-1 infection-induced cGAS–STING–TBK1–IRF3 signaling activates innate immunity to produce type I interferon(IFN).The HIV-1 nonstructural protein viral infectivity factor(Vif)is essential in HIV-1 replication,as it degrades the host restriction factor APOBEC3G.However,whether and how it regulates the host immune response remains to be determined.In this study,we found that Vif inhibited the production of type I IFN to promote immune evasion.HIV-1 infection induced the activation of the host tyrosine kinase FRK,which subsequently phosphorylated the immunoreceptor tyrosine-based inhibitory motif(ITIM)of Vif and enhanced the interaction between Vif and the cellular tyrosine phosphatase SHP-1 to inhibit type I IFN.Mechanistically,the association of Vif with SHP-1 facilitated SHP-1 recruitment to STING and inhibited the K63-linked ubiquitination of STING at Lys337 by dephosphorylating STING at Tyr162.However,the FRK inhibitor D-65495 counteracted the phosphorylation of Vif to block the immune evasion of HIV-1 and antagonize infection.These findings reveal a previously unknown mechanism through which HIV-1 evades antiviral immunity via the ITIM-containing protein to inhibit the posttranslational modification of STING.These results provide a molecular basis for the development of new therapeutic strategies to treat HIV-1 infection.

The accelerator control system of CSNS

The China Spallation Neutron Source is an accelerator-based user facility for neutron,proton,muon applications and so on.The designed proton beam power is 100 kW for the first phase.Overall,the scope of accelerator control system covers four parts,the global systems,the device layer local controls and remote controls,the high-level applications and services and the integration of conventional facilities.The principle guideline is to adopt as many as possible matured technologies and commercial products in the design and implementation.The control system is based on Experimental Physics and Industrial Control System.VME64x bus is chosen for timing system and fast protection system.PLCs and embedded industrial computers are used in the device layer slow controls.Control System Studio is adopted as the high-level applications.Blade server-based virtualization platform is deployed for the computer system.The accelerator control system was completed in September 2017 and then transited to routine operations.The design,implementation and operation of the accelerator control system are described in this paper.