利用HHGS和OOCHAS评分评价兔前交叉韧带断裂后膝骨关节炎软骨损伤程度的研究

目的：研究两种软骨组织学评分方法 Histologic/Histochemical Grading System（HHGS）和OARSI Osteoarthritis Cartilage Histopathology Assessment System（OOCHAS）对兔前交叉韧带断裂后骨关节炎早期软骨损伤评价的不同,选择更适合早期软骨损伤评价的组织学评分标准。方法：取48只成年新西兰大白兔（2.5~3 kg）,切断左膝前交叉韧带建立骨关节炎（OA）模型（实验组）,右膝为假手术组（对照组）。分别于术后2、4、6、8周随机处死12只兔子,分别取实验组与对照组胫骨平台负重区软骨行大体观评分、核磁检查、HE和甲苯胺蓝染色,利用HHGS和OOCHAS对组织切片进行软骨损伤评价,并分析两种标准之间的差异。结果：大体观和核磁结果：术后第2周无明显软骨损伤,术后第4周出现早期OA软骨损伤,术后第6和8周出现中晚期OA软骨损伤。组织学评分结果：两种评分标准对实验组术后2、6和8周的软骨损伤程度评价一致,但对术后第4周的评价存在差异,HHGS评分结果显示,12膝中9膝为中期OA软骨损伤,3膝为早期OA软骨损伤;OOCHAS评分显示,1膝为中期OA软骨损伤,11膝为早期OA软骨损伤,配对卡方检验结果：P=0.021,表明两者构成比存在差异。kappa=-0.176（〈0.02为一致性差）,表明两种方法在评价早期软骨损伤时一致性较差。与HHGS评分相比,OOCHAS评分结果与大体观和核磁检查结果更一致。结论：本动物实验研究表明OOCHAS评分适合前交叉韧带断裂后早期骨关节炎软骨损伤的评价。

High harmonic generation in crystal SiO_(2) by sub-10-fs laser pulses

The high harmonic generation(HHG)by few-cycle laser pulses is essential for research in strong-field solid-state physics.Through comparison of high harmonic spectra of solids generated by laser pulses with varying durations,we discovered that lasers with good dispersion compensation are capable of producing a broad spectrum of high harmonics.As the pulse duration is further compressed,several interference peaks appear in the broad spectrum.Moreover,we conducted simulations using the semiconductor Bloch equation,considering the effect of Berry curvature,to better understand this process.Our work provides a valuable approach for studying HHG by few-cycle laser pulses in solid materials,expanding the application of HHG in attosecond physics.

经典相关系数及统计功效对比研究

本工作选取多种经典相关系数进行了对比研究,如Pearson相关系数、Spearman相关系数、距离相关系数、最大信息系数及HHG相关系数。具体地,在不同数据规模及噪声水平下,对线性、非线性单调、非单调、非函数等不同类型变量的相关性分别进行研究,得到各相关系数的统计功效。通过分析发现,Pearson相关系数、Spearman相关系数更适合衡量线性、非线性单调相关关系,最大信息系数则更适合衡量含有周期性的相关关系,HHG则更适合衡量非函数相关关系。本研究可为挖掘不同相关关系,提供相关系数选取依据。

关东172号陆稻糯米饼高度硬化的基因鉴定

2001年日本栽培了6380公顷陆稻，但是陆稻的粳型品种的米饭食味比水稻品种的明显较差，因此陆稻栽培面积的99％都是糯性品种。陆稻糯米饼的食味也比水稻糯米差，因此其用途只限于米糕原料，并且陆稻糯米饼的硬化速度也比水稻糯米饼慢，米饼的加工制作比较难。为了扩大陆稻糯米的需要，今后的主要课题是育成米饼硬化性优良的陆稻品种，提高米糕原料的适应性。

Broadband isolated attosecond pulse generation in a two-color laser field combined with an orthogonally polarized laser pulse

We present a method to generate broadband isolated attosecond pulses. Using a two-color laser field, which is synthesized by a mid-infrared （12.5 fs, 2000 nm） and a weaker （12 fs, 800 nm） pulse in the x direction, a modulated supercontinuum from 290 to 430 eV is obtainable. By properly adding a second-harmonic control field of the driving pulse in the y direction, the short quantum path is well selected and a smooth supercontinuum from 290 to 440 eV is generated. The bandwidth of the supercontinuum can be controlled by adjusting the electric field of the control pulse in the x direction. When the electric field increases to 0.051 a.u., a smooth supercontinuum from 295 to 520 eV is obtained. Using this method we expect that isolated 63-as attosecond pulses with tunable central wavelengths are straightforwardly obtained.We present a method to generate broadband isolated attosecond pulses. Using a two-color laser field, which is synthesized by a mid-infrared （12.5 fs, 2000 nm） and a weaker （12 fs, 800 nm） pulse in the x direction, a modulated supercontinuum from 290 to 430 eV is obtainable. By properly adding a second-harmonic control field of the driving pulse in the y direction, the short quantum path is well selected and a smooth supercontinuum from 290 to 440 eV is generated. The bandwidth of the supercontinuum can be controlled by adjusting the electric field of the control pulse in the x direction. When the electric field increases to 0.051 a.u., a smooth supercontinuum from 295 to 520 eV is obtained. Using this method we expect that isolated 63-as attosecond pulses with tunable central wavelengths are straightforwardly obtained.

A nonperturbative quantum electrodynamic approach to the theory of laser induced high harmonic generation

Using nonperturbative quantum electrodynamics, we develop a scattering theory for high harmonic generation （HHG）. A transition rate formula for HHG is obtained. Applying this formula, we cal- culate the spectra of high harmonics generated from different noble gases shined by strong laser light. We study the cutoff property of the spectra. The data show that the cutoff orders of high harmonics are greater than that predicted by the ＂3.17＂ cutoff law. As a numerical experiment, the data obtained from our repeated calculations support the newly derived theoretical expression of the cutoff law. The cutoff energy of high harmonics described by the new cutoff law, in terms of the ponderomotive energy Up and the ionization potential energy Ip, is 3.34Up 1.83Ip. The higher cutoff orders predicted by this theory are due to the absorption of the extra photons, which participate only the photon-mode up-conversion and do nothing in the photoionization process.

Isolated attosecond pulse generation combining propagation effects and a modulated chirped polarization gating technique

We propose a theoretical scheme to generate a broadband supercontinuum using a modulated chirped polarization gating technique. By this technique, a broadband continuum of 155 eV can be obtained at microscopic level. The modulations on the supercontinuum can be eliminated after propagation. Then a smooth broadband supercontinuum with the bandwidth of 155 eV can be generated. As a result, isolated sub-100-attosecond pulses with tunable central wavelengths could be obtained straightforwardly. Our simulations also reveal that an isolated attosecond pulse can still be generated by using multicycle driving laser pulses, and the central wave- length of isolated attosecond pulse can be controlled by adjusting the delay rj （ra is the delay of the two counter-rotating circularly polarized pulses.）.