摘要：The rise of antibiotic resistance as one of the most serious global public health threats has necessitated the timely clinical diagnosis and precise treatment of deadly bacterial *** identify which types and doses of antibiotics remain effective for fighting against multi-drug-resistant pathogens,the development of rapid and accurate antibiotic-susceptibility testing(AST)is of primary *** methods for AST in well-plate formats with disk diffusion or broth dilution are both labor-intensive and operationally *** microfluidic chip provides a versatile tool for evaluating bacterial AST and resistant *** this paper,we develop an operationally simple,3D-printed microfluidic chip for AST which automatically deploys antibiotic concentration gradients and fluorescence intensity-based reporting to ideally reduce the report time for AST to within 5 *** harnessing a commercially available,digital light processing(DLP)3D printing method that offers a rapid,high-precision microfluidic chip-manufacturing capability,we design and realize the accurate generation of on-chip antibiotic concentration gradients based on flow resistance and diffusion *** further demonstrate the employment of the microfluidic chip for the AST of *** to representative clinical antibiotics of three classes:ampicillin,chloramphenicol,and *** determined minimum inhibitory concentration values are comparable to those reported by conventional well-plate *** proposed method demonstrates a promising approach for realizing robust,convenient,and automatable AST of clinical bacterial pathogens.

摘要：High enzymatic activity is required for laccase *** composite design(CCD)-based response surface methodology(RSM)can effectively increase the enzymatic activity of Pleurotus ostreatus P40 in liquid substrate *** screening of the nutritional components was performed using a Plackett-Burman *** variables,namely,bran,bagasse,Tween 80,and yeast extract,were found to have statistically significant effects on laccase *** variables were further optimized using CCD-based *** concentrations for the maximum laccase activity were 8.144 2 g/L bran,50 g/L bagasse,0.424 1 mL/L Tween 80,and 2.832 5 g/L yeast *** optimized conditions,the maximum measured laccase activity reached 96 480 U/L,which was close to the predicted value(104 830 U/L)by ***,RSM can be used to optimize culture components for laccase activity from Pleurotus ostreatus P40.

摘要：An investigation into the effect of several novel well-designed guanidinium salt ionic liquids（GILs） on inhibitting tumor growth is described. The GILs which have longer alkyl chain（6-18 carbon atoms） exhibit the high cytotoxicity to Hela299, B16 and SMMC-7721 cells so as to inhibit their proliferation. The inhibitory effect of the most effective GILl2 is about 10-fold higher than that of MMC（a common chemotherapy drug in clinic）.

摘要：光催化废水产氢技术是缓解日益严峻的能源和环境危机的有效方法.然而,由于载流子复合率较高、太阳光利用率较低,目前光催化活性仍然难以满足工业发展的需要.基于以上问题,本文设计了具有全谱太阳光响应的黑磷敏化的金/氮化碳(BP/Au/CN)异质结光催化剂,该三元异质结可以在实现降解双酚A的同时,将水分解为氢气,其光催化产氢活性可达到195.8μmol h^(−1)g^(−1).此外,在紫外-可见光照射下,BP/Au/CN的光催化产氢活性可以达到1400.8μmol h^(−1)g^(−1),是CN或BP/CN样品的近70倍,Au/CN异质结的2倍.光催化活性的提高表明异质结中三种元素具有良好的协同作用.本文将一系列实验表征与理论计算相结合,对BP/Au/CN的光催化机理进行了系统研究.结果表明,黑磷的全谱太阳光吸收能力、金的电子传输介质作用以及三种材料匹配的功函数是其光催化活性提高的关键因素.此外,通过金和黑磷的欧姆接触以及Au/CN杂化体系中肖特基异质结的构筑,实现了电子从黑磷到金,再到氮化碳的单向转移,从而提高了载流子的传输性能.

摘要：目的:针对硝酸盐氮氧同位素新型预处理方法——细菌反硝化法尚存在的氧同位素测试精度低和两种标准物质间的δ^(18)O差值会收缩等问题进行优化试验和机理探究。创新点:首次深入探究纯培养时的溶解氧浓度和硝酸盐进样量对同位素测试结果的影响及原因,可为氧同位素测试精度的提高提供方法和参考。方法:通过控制培养瓶内的气液比(1:5、3:10、2:5和3:5)和摇床转速(60和120 r/min)来调节纯培养时的溶解氧浓度,并设计不同的硝酸盐进样量(0.05～1.00μmol),由硝酸盐标准物质的测试结果判断适宜的溶解氧浓度和硝酸盐进样量。结论:标准物质间的δ^(18)O差值收缩主要受溶解氧浓度的影响。根据氧同位素测试结果的精度和δ^(18)O差值收缩率的大小,得出以下结论:当普通三角瓶内的气液比为3:10,摇床转速为120r/min时的溶解氧浓度最佳(1.9～2.6mg/L),0.2～0.4nmol的硝酸盐进样量最适宜。

摘要：目的:揭示双季杂交稻系统中硅(Si)养分补充对水稻养分利用率与对土壤养分有效性影响的相应关系及其生态机制。创新点:发现一定量的Si养分补充可提高稻田土壤氮(N)和磷(P)养分的有效性,并促进水稻根系对养分的吸收,从而提高水稻产量及肥料利用率。其核心生态机制是补充Si养分可显著增加稻田土壤的微生物总量,从而促进土壤养分同化固定,提高土壤中N和P的矿化以及易矿化的土壤微生物量氮(MBN)和土壤微生物量磷(MBP)的储备。方法:2017和2018连续两年,在双季稻作区设计了系列田间试验,统一常规养分管理,于早稻和晚稻种植期间设置五个有效Si用量梯度处理(即0(对照)、7.8、15.6、23.4和31.2 kg/ha Si),分析收获后的水稻生长性状(株高、籽粒产量、植株生物量等),水稻根、茎、叶和籽粒中N和P的含量,土壤有效态N和P的含量以及土壤微生物量碳(MBC)、MBN和MBP的含量,最后统计分析Si的供应与对水稻N和P养分利用率、土壤养分有效性、MBC、MBN和MBP的影响及其相互关系。结论:Si养分补充可增加双季杂交稻系统土壤微生物总量,促进土壤养分同化固定,提高土壤养分的有效性以及易矿化的有机养分的储备,使得土壤养分易于被水稻根系吸收利用,从而提高水稻肥料利用率,促进水稻的生长发育,提高水稻产量。其中Si施用量为23.4 kg/ha时双季水稻产量及N和P肥利用率均达到最大值,此时土壤有效态氮与总氮比(AN/TN)、有效态磷与总磷比(AP/TP)以及MBN和MBP也均达到最大值。上述结果表明,通过Si养分补充可适当削减双季杂交稻系统因过多化学肥料投入带来的面源污染问题。

摘要：设计廉价和高效的双功能催化剂应用于CO_(2)还原和O_(2)还原反应(CO_(2)RR和ORR)是实现碳中和的理想选择.因此,本文研制出铌原子分散固定在氮掺杂有序介孔碳(Nb-N-C)上的双功能CO_(2)RR和ORR催化剂用于锌-空气电池(ZAB)自驱动CO_(2)RR.得益于高铌原子利用率和有序介孔结构,Nb-N-C催化剂展现出高达90%的CO法拉第效率,ORR的半波电位活性为0.84 V,ZAB的峰值功率活性为115.6 mW cm-2.此外,采用两个串联的ZABs单元作为自供能CO_(2)RR系统的电源,能够连续将C O_(2)转化为C O.该自供能系统前10小时的C O平均产率为3.75μmol h-1mg-1cat.理论计算表明,铌原子分散固定在氮掺杂的碳上形成Nb–N配位键,从而有效地降低CO_(2)RR的决速中间体*COOH和ORR的决速中间体*O的生成能垒.

摘要：太阳能驱动光催化分解水制氢是实现可持续制氢气的一种有效策略.硫化镉半导体光催化剂基于其较强的可见光响应、适宜的氧化还原反应带边位置以及优异的电荷传输性能而备受关注.本文综述了近年来国内外在提高硫化镉基光催化剂制氢性能的设计、改性和制备等方面的研究进展.首先简要介绍了光催化制氢的基本概念和机理,阐述了硫化镉光催化制氢的基本性质、重要进展和瓶颈,综述了该材料的发展前景.随后,重点讨论了硫化镉基光催化剂光催化分解水产氢的各种改性策略,其中有效的策略是产生更多的载流子,促进电荷的有效分离,促进界面电荷转移,加速电荷利用,以及抑制电荷诱导的自光腐蚀.针对每一种改性策略,都详细讨论了影响光催化剂性能的重要因素和未来潜在的研究方向.最后介绍了纳米结构硫化镉和硫化镉基纳米复合材料在光催化分解水产氢中的发展前景和面临的挑战.本综述将为开发镉基半导体光催化剂提供重要和及时的理论指导,并促进其在太阳能氢气生产中的应用.