PIC mode simulation of solenoid collimation channel

A new SSC (Separated Sector Cyclotron)-Linac is being designed to serve as an injector for the SSC at the HIRFL (Heavy Ion Research Facility Lanzhou). The beam intensity at the LEBT (Low Energy Beam Transport) for the heavy ions after the selection is typically low and the space charge effects are inconspicuous. The space charge effects become obvious when the beam current increases to a few hundred microamperes. The emittance growth deriving from the space charge effects may be particularly troublesome for the following linac and cyclotron. An optical system containing three solenoids has been designed for the LEBT to limit the beam emittance and to avoid the unnecessary beam loss in the cyclotron, as well as for the purpose of immunizing the LEBT emittance growth due to the space charge effects. The results of the PIG (Particle-In-Cell) mode simulation illustrate that this channel could limit the beam emittance growth and increase the beam brightness.

我国水土流失危害及防御对策

分析了我国水土流失对国民经济造成的危害 ,因地制宜地提出了防治水土流失的对策 ;( 1 )良化生态环境 ;( 2 )坚持土地的综合治理 ;( 3)坚持小流域治理 ;( 4 )提高江河湖海的防洪能力 ;( 5 )加大水土保持的执法力度 ;6 )增强保水保土意识

Self-assembly of a hydrophobic polypeptide containing a short hydrophilic middle segment: Vesicles to large compound micelles

This report describes a facile route to prepare the vesicles and large compound micelles (LCMs) from a series of poly(epsilon-benzyloxycarbonyl L-lysine)-block-poly[diethylene glycol bis(3-amino propyl) ether]-block-poly(epsilon-benzyloxycarbonyl L-lySine) (PZLL-DGBE-PZLL) in their water solution, depending on molecular weight of the polypeptides. A pyrene probe is used to demonstrate the aggregate formation of PZLL-DGBE-PZLL in solution, and also to measure their critical micelle concentration as a function of molecular weight of the polymer.

Selection for variables in quantitative structure-activity/property relationship studies - Comparison between methods of orthogonal descriptors and leaps-and-bounds regression analysis

In this paper, the comparison of orthogonal descriptors and Leaps-and-Bounds regression analysis is performed. The results obtained by using orthogonal descriptors are better than that obtained by using Leaps-and-Bounds regression for the data set of nitrobenzenes used in this study. Leaps-and-Bounds regression can be used effectively for selection of variables in quantitative structure-activity/property relationship(QSAR/QSPR) studies. Consequently, orthogonalisation of descriptors is also a good method for variable selection for studies on QSAR/QSPR.

Bright green organic electroluminescent devices based on a novel thermally stable terbium complex

A navel thermally stable terbium carboxylate complex, Tb(MTP)(3)(phen) (MTP=monotetradecyl phthalate, phen=1,10-phehanthroline), was synthesized and characterized. The device structure of glass substrate/indium-tin-oxide/poly(p-phenylenevinylene) (PPV)/poly (N-vinycarbazole) (PVK):Tb(MTP)(3)(phen): 1,3,4-oxadizole derivative (PBD)/tris(8-hydroxyquinoline) (Alq(3))/aluminum (Al) was employed to study the electroluminescent properties of Tb(MTP)(3)(phen). A green emission with extremely sharp spectral band of less than 10 nm at 544 nm peak wavelength was observed. A maximum luminance of 152 cd/m(2) and an external quantum efficiency of 0.017% were achieved at a drive voltage of 24 V. A possible mechanism of energy transfer based on the polymer doped with lanthanide organic complex was also proposed.

Studies on the fusion heat of poly(ether ether ketone ketone)-poly(ether biphenyl ether ketone ketone) copolymers

On the basis of DSC measurements, the Delta H-f(0) values of the fusion heat for PEEKK-PEBEKK copolymers with various biphenyl contents were obtained by using thermodynamics statistical theory proposed by Flory and graphical method of the specific volume-fusion heat. The results reveal that Delta H-f(0) values determined by these two methods for PEEKK-PEBEKK copolymers with various biphenyl content are nearly the same, and that Delta H-f(0) values are closely dependent on biphenyl content. Delta H-f(0) value is minimum at n(B)=0.35.

聚醚醚酮酮和含联苯聚醚醚酮酮共聚物的熔融热

根据Ｆｌｏｒｙ热力学统计理论和比容－熔融热作国法，由ＤＳＣ结果得到了不同联苯含量的聚醚醚酮酮－含联苯聚醚醚酮酮（ＰＥＥＫＫ－ＰＥＢＥＫＫ）共聚物的熔融热，两种方法获得的结果吻合。在此基础上给出了ＰＥＥＫＫ－ＰＥＢＥＫＫ共聚物不同联苯含量的熔点计算表达式。结果还表明，随着联苯含量ｎＢ，的变化，明显改变；当ｎＢ＝０．３５时，ＰＥＥＫＫＰＥＢＥＫＫ共聚物的值最小。

DIELS-ALDER REACTION CATALYZED BY RARE-EARTH CHLORIDES

Rare earth chlorides were used to catalyze the synthesis of 2-butoxy-3, 4-dihydro-2H-pyran using equimolar acrolein and vinyl butyl either. The cycloadduct is unstable which undergoes catalytic ring opening oligomerization. The way to stabilize the cyclo adduct has been studied, thus high yields of 90-95% were obtained.

稀土氯化物催化的Diels—Alder反应

本文提出以稀土氯化物作催化剂,催化等摩尔比的丙烯醛和乙烯基丁醚进行环加成反应,生成2-丁氧基-3,4-二氢-2H-吡喃。实验表明,环加成产物是不稳定的中间物,它可以进一步开环聚合构成一个催化的连串反应。找到了稳定中间物的反应条件,以90—95％产率得到环加成产物。

亚历山大藻对海产贝类胚胎和蒙古裸腹溞的影响及致毒机制研究

本文研究了典型有毒赤潮藻——亚历山大藻(Alexandrium)对海湾扇贝(Argopecten irradians Lamarck)、文蛤(Meretrix meretrix Linnaeus)和太平洋牡蛎(Ostrea gigas Thunberg)受精卵孵化的影响和致毒机制以及对蒙古裸腹溞(Moina mongolica Daday)生命活动的影响。此外，还针对我国赤潮发生特点，模拟研究了我国东海大规模赤潮对菲律宾蛤仔（Ruditapes philippinarum (Adams et Reeve)）受精卵孵化和蒙古裸腹溞种群数量的影响。 结果发现：8株产PSP毒素的亚历山大藻：塔玛亚历山大藻( ATHK, AT5-1, AT5-3, ATCI02, ATCI03)，链状亚历山大藻, A. lusitanicum、微小亚历山大藻和2株不产PSP毒素的相关亚历山藻(AC-1, AS-1)对海湾扇贝受精卵的孵化均有显著抑制作用，说明在亚历山大藻属中，这种抑制作用具有一定的普遍性，并与PSP毒素的产生无直接关系，表明存在非PSP毒素的其它毒性物质。一种PSP标准毒素STX也没有这种抑制作用，进一步证明该抑制作用与PSP毒素不直接相关。 相关亚历山大藻AC-1对海湾扇贝、文蛤和太平洋牡蛎受精卵孵化的有显著的毒害作用，其藻液、重悬液、去藻液和内容物均显著影响受精卵的孵化。相关亚历山大藻AC-1对海湾扇贝、文蛤和太平洋牡蛎担轮幼虫细胞的超微结构有显著破坏作用，破坏膜结构和胞内结构，影响细胞内的功能器官如溶酶体的稳定性，使卵黄颗粒萎缩变形；对文蛤和太平洋牡蛎的受精卵显示出极强的毒害作用： 3000cells•ml-1时，使二者胚胎完全溶掉消失；在2000cells•ml-1的藻液中培养2h后，担轮幼虫的外膜发生溶解，整个幼体呈葡萄串样。相关亚历山大藻AC-1产生的这种毒性物质可能对贝类胚胎细胞的结构和功能有影响。 亚历山大藻对蒙古裸腹溞的毒性效应与不同藻种/藻株密切有关：塔玛亚历山大藻（AT-6, ATCI02）、链状亚历山大藻、A. lusitanicum和微小亚历山大藻不影响蒙古裸腹溞的存活，而塔玛亚历山大藻（ATHK、ATCI03和AT5-1）和相关亚历山大藻(AC-1, AS-1)有显著影响。蒙古裸腹溞能摄食塔玛亚历山大藻(AT-6, ATHK, ATCI02, ATCI03, AT5-1)，链状亚历山大藻, A. lusitanicum和微小亚历山大藻，很少或基本不摄食相关亚历山大藻。亚历山大藻影响蒙古裸腹溞的RNA/DNA比值和蛋白质含量以及Na+,K+-ATP酶活性。相关亚历山大藻AC-1对蒙古裸腹溞的存活有极强的毒性作用，藻液、重悬液、内容物和碎片均有显著影响；即使与3×106cells•ml-1小球藻混合，10和50cells•ml-1的相关亚历山大藻AC-1仍能使蒙古裸腹溞的产幼数和存活时间显著下降。亚历山大藻对蒙古裸腹溞生命活动的影响不仅与PSP毒素有关，还与非PSP毒素有关；蒙古裸腹溞可能也是研究有害藻急性和慢性毒性的一种理想生物。 应用菲律宾蛤仔胚胎和蒙古裸腹溞评价我国东海特大规模赤潮对海洋生物资源的潜在危害时发现：单种链状亚历山大藻对菲律宾蛤仔受精卵的孵化和蒙古裸腹溞的种群增长均有显著不利影响；单种东海原甲藻（1~10×104cells•ml-1）对菲律宾蛤仔受精卵的孵化没有影响；较低密度的东海原甲藻能维持蒙古裸腹溞（2~5×104cells•ml-1）的种群增长；较高密度的东海原甲藻对蒙古裸腹溞（10×104cells•ml-1）种群有显著的抑制作用。两种藻以赤潮密度混合后，适当密度的东海原甲藻能在一定程度上减轻链状亚历山大藻对菲律宾蛤仔受精卵和蒙古裸腹溞的毒性。可见，东海连年爆发的大规模赤潮不仅对浮游生态系统有不利影响，若同时爆发亚历山大藻赤潮，则对海洋浮游生态系统和贝类资源的恢复产生更加不利的影响。

一种新蛋白源──青海钩虾（Gammarus suifunensis,Ueno,1940）营养价值的初步研究

对青海钩虾的营养价值进行了初步的研究。首先分析三种不同品级的青海钩虾，一般营养成分及氨基酸含量，并同两种鱼粉比较；第二，养鸡试验的结果表明，钩虾组在平均增量和总增重量等方面都优于鱼粉；第三，真鲷Pagrosomusmajor（Temminck＆Schlegel）的实验是按照逐次降低钩虾的含量的方法，分为4组。Ⅰ．钩虾：鱼粉＝6：4，Ⅱ．钧虾：鱼粉＝4：6，Ⅲ．钩虾：鱼粉＝2：8，Ⅳ．钩虾：鱼粉＝0：10。实验结果显示在其鲷的成活率、体长平均增长率、增重率和饲料系数等方面，含钩虾组较无钩虾（Ⅳ）为佳，而Ⅱ组具有最好的促增重效果和最经济的特点。最后，根据上述分析和实验结果，作者认为青海钩虾是一种可以代替鱼粉的新蛋白源，值得开发利用和推广。

改进叠前深度偏移的计算效率＆叠前高分辨率成像

An high-resolution prestack imaging technique of seismic data is developed in this thesis. By using this technique, the reflected coefficients of sheet sands can be gained in order to understand and identify thin oil reservoirs. One-way wave equation based migration methods can more accurately model seismic wave propagation effect such as multi-arrivals and obtain almost correct reflected energy in the presence of complex inhomogeneous media, and therefore, achieve more superiorities in imaging complex structure. So it is a good choice to apply the proposed high-resolution imaging to the presatck depth migration gathers. But one of the main shorting of one-way wave equation based migration methods is the low computational efficiency, thus the improvement on computational efficiency is first carried out. The method to improve the computational efficiency of prestack depth migration is first presented in this thesis, that is frequency-dependent varying-step depth exploration scheme plus a table-driven, one-point wavefield interpolation technology for wave equation based migration methods; The frequency-dependent varying-step depth exploration scheme reduces the computational cost of wavefield depth extrapolation, and the a table-driven, one-point wavefield interpolation technology reconstructs the extrapolated wavefield with an equal, desired vertical step with high computational efficiency. The proposed varying-step depth extrapolation plus one-point interpolation scheme results in 2/3 reduction in computational cost when compared to the equal-step depth extrapolation of wavefield, but gives the almost same imaging. The frequency-dependent varying-step depth exploration scheme is presented in theory by using the optimum split-step Fourier. But the proposed scheme can also be used by other wave equation based migration methods of the frequency domain. The proposed method is demonstrated by using impulse response, 2-D Marmousi dataset, 3-D salt dataset and the 3-D field dataset. A method of high-resolution prestack imaging is presented in the 2nd part of this thesis. The seismic interference method to solve the relative reflected coefficients is presented. The high-resolution imaging is obtained by introducing a sparseness- constrained least-square inversion into the reflected coefficient imaging. Gaussian regularization is first imposed and a smoothed solution is obtained by solving equation derived from the least-square inversion. Then the Cauchy regularization is introducing to the least-square inversion , the sparse solution of relative reflected coefficients can be obtained, that is high-resolution solution. The proposed scheme can be used together with other prestack imaging if the higher resolution is needed in a target zone. The seismic interference method in theory and the solution to sparseness-constrained least-square inversion are presented. The proposed method is demonstrated by synthetic examples and filed data.