Some variants of SAT and their properties

A new model for the well-known problem, the satisfiablility problem of boolean formula (SAT), is introduced. Based on this model, some variants of SAT and their properties are presented. Denote by NP the class of all languages which can be decided by a non-deterministic polynomial Turing machine and by P the class of all languages which can be decided by a deterministic polynomial-time Turing machine. This model also allows us to give another candidate for the natural problems in ((NP-NPC)-P), denoted as NPI, under the assumption P≠NP, where NPC represents NP-complete. It is proven that this candidate is not in NPC under P≠NP. While, it is indeed in NPI under some stronger but reasonable assumption, specifically, under the Exponential-Time Hypothesis (ETH). Thus we can partially solve this long standing important open problem.     

用ETH1001钙离子选择电极研究钙与胆汁酸根的作用

比较了ETH1001钙离子选择电极(Ca ISE)与磷酸酯Ca ISE抗表面活性剂干扰的能力。ETH1001 Ca ISE不受胆盐的干扰,而磷酸酯Ca ISE受干扰造成电位负移。因此用ETH1001 Ca ISE重新研究了钙与一些胆汁酸根的作用。     

乙烯利对降香黄檀生长和光合生理特性的影响

【目的】探究不同浓度乙烯利对降香黄檀生长、光合生理特性的影响,为后期心材形成提供参考。【方法】以胸径6~8 cm的降香黄檀为研究对象,设置CK、E0.1%(乙烯利质量分数0.1%,后同)、E0.5%、E2.5% 4个乙烯利处理,研究各处理对降香黄檀生长指标增长量、叶绿素含量(SPAD值)、比叶面积(SLA)、水分利用效率(WUE)和光合参数的影响。【结果】在3个乙烯利处理中,E0.1%、E0.5%处理胸径增长量(ΔD)均高于对照,分别增加了8.97%、6.07%;E2.5%处理的树高增长量(ΔH)和材积增长量(ΔV)均较对照低,分别减少了67.39%和59.33%。各乙烯利处理对降香黄檀叶绿素含量(SPAD值)有显著影响,大小顺序为E0.1%>E0.5%>CK>E2.5%。E0.1%、E0.5%处理叶干质量、叶面积显著高于E2.5%处理,各处理比叶面积(SLA)大小顺序为E0.1%>E0.5%>CK>E2.5%。Pearson相关分析表明,E0.1%、E0.5%、E2.5%处理下SLA和WUE都具有显著负相关关系。光响应曲线所得光合参数显示,最大净光合速率(P_n,max)随乙烯利浓度的增加先升高后下降,E0.1%、E0.5%处理分别较CK增加了38%、26.22%。光饱和点(P_Lsp)随注射乙烯利的浓度先增加后略微降低但均高于对照,E0.5%处理最高。乙烯利各处理光补偿点(P_Lcp)均低于对照,E0.1%、E0.5%处理比CK降低了16.37%、20.92%。【结论】低浓度乙烯利可提高降香黄檀的叶绿素含量、比叶面积、净光合速率等光合特征参数,E2.5%的乙烯利不利于降香黄檀树高和材积的增长。