漫卷的打工潮──国有企业人才流失聚焦

漫卷的打工潮──国有企业人才流失聚焦梅雨霖九十年代，真是多彩的年代，多彩到最本分的专业技术人员也心猿意马、坐卧不宁，最听党话的职工也心活手痒、拳拳欲动，在去与留的问题上矛盾重重。这不，一向凭服务完善、收入稳定而吸引人的国营企业，近日已叠起波澜。职工们...

腐植酸聚失肥的研制与开发

利用黄腐酸为载体研制开发腐植酸聚失肥是在低碳经济、可持续农业、有机农业、生态农业大环境下发展的新肥源和新型肥料产业。该肥料的主要特点和功能:聚合土壤中养分,控制养分流失;提高肥料利用率,补充化肥的不足;改良土壤,增强作物抗逆性;提高作物产量,改善产品品质;科技含量高,生产工艺先进。

用水分散性胶体共聚物制药物微囊

用水分散性胶体共聚物制药物微囊郭建平节译周全校本文研究了用水分散性胶体共聚物为包料将具不同溶解度的药物（布洛芬、茶碱、愈创木酚甘油醚、盐酸伪麻黄碱）制成缓释微囊的制备工艺。这种制备工艺改变了有机溶剂溶解非水溶性共聚物载体包微囊的传统方法（溶剂蒸发或有...

Synthesis of Chiral Polyaniline Induced by Modified Hemoglobin

The synthesis of chiral polyaniline （PANI） induced by modified hemoglobin （Hb） was pro- foundly explored for the first time. Results revealed that after being separated, inactivated or immobilized, Hb can still induce the formation of chiral PANI successfully, suggesting that Hb can be used as the chiral inducers regardless of harsh reaction conditions. By examining the properties of PANI induced by modified Hb, it was found that Hb（inactivated）-PANI possessed excellent chirality, stability, and crystalline structure. The globin separated from Hb was demonstrated to have the ability of inducing the production of chiral PANI whereas the hematin from Hb had no capacity to direct enantio specificity for the PANI chains. Results indicated that Hb（immobilized）-PANI exhibited poor yield, doping state, and crys- talline structure, indicating that the immobilization of Hb by entrapment was not beneficial to the polymerization reaction. Results also showed that the structure of Hb may have significant effects on the morphologies of chiral PANI.

Understanding the deactivation behavior of Pt/WO3/Al2O3 catalyst in the glycerol hydrogenolysis reaction

The selective hydrogenolysis of glycerol to 1,3-propanediol is a highly important reaction for both improving the profitability of biodiesel and valorization of biomass.While intensive research efforts have been devoted to enhancing the catalytic activity and selectivity,little is focused on the stability although the latter is of paramount importance to practical applications.In this work,we investigated the stability of Pt/WO3/Al2O3 and observed a continuous deactivation trend during a 700 h time-on-stream run.Neither the leaching of active W nor the coking was responsible for the deactivation.Instead,XRD,HAADF-STEM and CO chemisorption results clearly showed the occurrence of significant aggregation of Pt particles,which caused a remarkable decrease of Pt-WOx interfacial sites.As a consequence,strong Br?nsted acid sites which were in situ formed by H2 dissociation at the Pt-WOx interfacial sites were reduced,leading to the deactivation of the catalyst.

Deletions in the genomes of fifteen inbred mouse lines and their possible implications for fat accumulation

Copy number variants (CNVs) are pieces of genomic DNA of 1000 base pairs or longer which occur in a given genome at a different frequency than in a reference genome. Their importance as a source for phenotypic variability has been recognized only in the last couple of years. Chromosomal deletions can be seen as a special case of CNVs where stretches of DNA are missing in certain lines when compared to the reference genome of the mouse line C57BL/6, for example. Based upon more than 8 million single nucleotide polymorphisms (SNPs) in the fifteen inbred mouse lines which were determined in a whole genome chip based resequencing project by Perlegen Sciences, we detected 20166 such long chromosomal deletions. They cover altogether between 4.4 million and 8.8 million base pairs, depending on the mouse line. Thus, their extent is comparable to that of SNPs. The chromosomal deletions were found by searching for clusters of missing values in the genotyping data by applying bioinformatics and biostatistical methods. In contrast to isolated missing values, clusters are likely the consequence of missing DNA probe rather than of a failed hybridization or deficient oligos. We analyzed these deletion sites in various ways. Twenty-two percent of these deletion sites overlap with exons; they could therefore affect a gene's functioning. The corresponding genes seem to exist in alternative forms, a phenomenon that reminds of the alternative forms of mRNA generated during gene splicing. We furthermore detected statistically significant association between hundreds of deletion sites and fat weight at the age of eight weeks.

Failure load prediction of adhesive joints under different stress states over the service temperature range of automobiles

To predict the failure loads of adhesive joints under different stress states over the service temperature range of automobiles,adhesively bonded carbon fiber reinforced plastic( CFRP)/aluminum alloy joints under shear stress state( thickadherend shear joints,TSJ),normal stress state( butt joints,BJ) and combined shear and normal stress states( scarf joints with scarf angle 45°,SJ45°) were manufactured and tested at-40,-20,0,20,40,60 and 80 ℃,respectively. The glass transition temperature Tgof the adhesive and CFRP,failure loads and fracture surfaces were used to analyze the failure mechanism of CFRP/aluminum alloy joints at different temperatures. A response surface,describing the variations of quadratic stress criteria with temperature,was established and introduced into the cohesive zone model( CZM) to carry out a simulation analysis. Results show that the failure of CFRP/aluminum alloy joints was determined collectively by the mechanical performances of adhesive and CFRP. Besides,reducing temperature or increasing the proportion of normal stress of adhesive layer was more likely to cause fibre tear or delamination of CFRP,resulting in a more obvious effect of CFRP. The validity of the prediction method was verified by the test of scarf joints with the scarf angle of 30°( SJ30°) and 60°( SJ60°) at-10 and 50 ℃.

Strength failure and crack coalescence behavior of sandstone containing single pre-cut fissure under coupled stress, fluid flow and changing chemical environment

In order to study the strength failure and crack coalescence characteristics of cracked rocks, uniaxial compression experiments were conducted on cylindrical sandstone specimens, sampled from Longyou Grottoes of Zhejiang Province, China, with a single pre-cut crack soaking in different chemical solutions. Based on the results of uniaxial compressive test under different chemical solutions and velocities of flow, the effect of strength and deformation characteristics and main modes of crack coalescence for cracked rocks under chemical corrosion were analyzed. The results show that the pH value and velocity of the chemical solutions both have great influence on the sandstone sample's uniaxial compressive strength and deformation characteristics. Cracked sandstone samples are tension-destructed under uniaxial compression, and the crack propagation directions are consistent with the loading direction. The phenomena of crack initiation, propagation and coalescence of sandstone are well observed. Four different crack types are identified based on the crack propagation mechanism by analyzing the ultimate failure modes of sandstone containing a single pre-cut fissure. The failure process of specimen in air is similar with the specimen under chemical solutions, however, the initial time of crack occuring in specimen under chemical solutions is generally earlier than that in the natural specimen, and the crack propagation and coalescence process of specimen under chemical solutions are longer than those of the natural specimen due to softening of structure of rock caused by hydro-chemical action. Immersion velocity of flow and chemical solutions does not have influence on the ultimate modes of crack coalescence.

Detection of mitochondrial DNA deletion by a modified PCR method

Objective: To develop a simple and efficient method for detecting small populations of mitochondrial DNA deletion. Methods: Peripheral blood cell DNA was obtained from a victim who was accidently exposed to a 60Co radiation source 11 years ago. Using the DNA as template, PCR was performed to generate multiple products including true deletions and artifacts. The full length product was recovered and used as template of secondary PCR. The suspicious deletion product of mtDNA could be confirmed if it was only yielded by first PCR. Using either original primers or their nested primers, the suspicious deletion product was amplified and authenticated as true deletion product. The template was recovered and determined to be a deletion by sequencing directly. Results: A new mtDNA deletion, spanning 889 bp from nt11688 to nt12576, was detected in the peripheral blood cells of the victim. Conclusion: The new PCR-based method is more efficient in detecting small populations of mtDNA deletion than other routine methods. MtDNA deletion is found in the victim, suggesting there is relationship between the deletion and phenotypes of the disease.

The Loss of Weight and Release of Formaldehyde in Acid Treatment of Basofil Fiber

The Basofil fiber is a new type of high-temperature fiber. Its Limiting Oxygen Index (LOI) value reaches 32. It does not melt, drop down or smolder when it contacts fire. The fiber is condensed from melamine and formaldehyde into a cross-linked with methylene-ether and methylene bridge bond. This thesis discusses the change of fiber structure and performance after the acid treatment.

Causes of Land Loss in Tuvalu,a Small Island Nation in the Pacific

Studies on land loss in Tuvalu reveal the following findings. Although both sea level rise and coastal erosion can cause land loss in the tropic Pacific oceanic islands, their mechanisms are different. When sea level rises, the low elevation coastal zone submerges and the erosion datum plane rises, the beach process progresses normally as always, resulting in no beach sediment coarsening. When the sea level is stable, coastal erosion removes finer sediment from reef flat, beach and land, resulting in beach sediment coarsening. The human-induced coastal erosion in the tropic Pacific oceanic islands has the following features. 1) Erosion occurs or intensifies immediately after inappropriate human activities. 2) It occurs near the places having human activities and places related to the above places in sediment supply. 3) It often occurs on original prograding or stable coasts (on lagoon coasts for atolls) because there are more coastal engineering projects and other human activities on such coasts. 4) It is chronic, covering a long period of time. The coastal geological events in Tuvalu islands do not accord with the features resulted from sea level rise but do accord with the features resulted from coastal erosion, particularly from human-induced erosion. The land loss in Tuvalu is mainly caused by inappropriate human activities including coastal engineering and aggregate mining, and partly caused by cyclones. Moreover, all recent measurements (satellite altimetry,thermosteric sea level data and tide observations) so far have not been able to verify any sea level rise around Tuvalu islands.

聚乙二醇修饰对苦瓜籽中RIP抗肿瘤活性及免疫学特性的影响

目的探讨苦瓜籽核糖体失活蛋白(RIP)经聚乙二醇(PEG)修饰后的体外及动物体内免疫学特性的变化。方法用MTT法测定RIP和RIP-PEG结合物对小鼠黑色素瘤细胞的抑制率;通过间接ELISA法测定RIP和RIP-PEG结合物在小鼠体内的免疫原性;以全身主动过敏实验(ASA)和被动皮肤过敏实验(PCA)来比较二者在豚鼠和大鼠体内的过敏毒性。结果RIP-PEG结合物对小鼠黑色素瘤细胞B16的抑制率约为RIP的70%,产生的特异性IgG与RIP比较显著下降(P<0.01),诱发的过敏反应也显著降低。结论苦瓜籽RIP经PEG修饰后,其抗肿瘤活性、免疫原性和过敏毒性均显著降低。

耳穴疗法治疗原发性失眠的现代文献研究

Objective By sorting and analyzing pertinent modern studies targeting auricular point therapy treating primary insomnia(PI),to summarize the point selection rules and clinical efficacy of using auricular points alone or combining it with other therapies in treating PI.Methods A search on China National Knowledge Infrastructure(CNKI),Wanfang Academic Journal Full-text Database(Wanfang),Chongqing VIP Database(CQVIP),PubMed,Springer and Ovid were conducted from January 1,1998 till January 31,2020.Point selection,diagnostic criteria and Pittsburgh sleep quality index(PSQI)in the eligible studies were analyzed and summarized.Results The difference in PSQI before and after using auricular point therapy alone was more significant than that of using Chinese medication alone(P<0.05),but less significant than that of combining auricular point therapy and acupuncture-moxibustion and Chinese therapeutic massage(tuina)(P<0.05).In the included studies,Shenmen(TF_(4))was the most commonly used(370 times),followed by Heart(CO_(15)),which was 344 times,and Subcortex(AT_(4)),which was 325 times.In terms of auricular points distribution,points in the auricular concha were the most commonly used(1500 times),followed by those in the antitragus(474 times)and triangular fossa(387 times).Correlation analysis showed that Shenmen(TF_(4))and Liver(CO_(12)),Sympathetic(AH6a)and Heart(CO_(15))were used together more often,followed by Shenmen(TF_(4)),Liver(CO_(12)),Spleen(CO_(13)),Kidney(CO_(10))and Subcortex(AT_(4)),and then Shenmen(TF_(4)),Liver(CO_(12)),Sympathetic(AH6a),Subcortex(AT_(4))and Heart(CO_(15)).Cluster analysis showed that the auricular points used for PI can be divided into 6 clusters in 2 major groups.One group was Heart(CO_(15)),Subcortex(AT_(4)),Shenmen(TF_(4)),Sympathetic(AH6a),Spleen(CO_(13)),Kidney(CO_(10)),Liver(CO_(12))and Endocrine(CO_(18));the other was Occiput(AT3),Stomach(CO_(4)),Pancrease-gallbladder(CO_(11)),Chuiqian(LO_(4)),Small Intestine(CO_(6)),Central Rim(AT_(2,3,4i))and Sanjiao(CO_(17)).In terms of patterns in traditional Chinese medicine,the pattern of dual deficiency of heart and spleen accounted for the largest proportion in the studies of using auricular points alone or combining it with other treatments to treatment PI,and then it was the pattern of liver depression transforming into fire.Conclusion In treatment of PI with auricular points alone or combo therapy involving auricular points,Shenmen(TF_(4))was commonly used,and the commonly used point group consisted of Shenmen(TF_(4)),Liver(CO_(12)),Sympathetic(AH_(6a))and Heart(CO_(15)).Auricular point therapy can be taken as a complementary therapy in treating PI.

The S190R mutation in the hemagglutinin protein of pandemic H1N1 2009 influenza virus increased its pathogenicity in mice

Human influenza viruses preferentially bind to sialic acid-α2,6-galactose (SAα2,6Gal) receptors, which are predominant in human upper respiratory epithelia, whereas avian influenza viruses preferentially bind to SAα2,3Gal receptors. However, variants with amino acid substitutions around the receptor-binding sites of the hemagglutinin (HA) protein can be selected after several passages of human influenza viruses from patients’ respiratory samples in the allantoic cavities of embryonated chicken eggs. In this study, we detected an egg-adapted HA S190R mutation in the pandemic H1N1 virus 2009 (pdmH1N1), and evaluated the effects of this mutation on receptor binding affinity and pathogenicity in mice. Our results revealed that residue 190 is located within the pocket structure of the receptor binding site. The single mutation to arginine at position 190 slightly increased the binding affinity of the virus to the avian receptor and decreased its binding to the long human α2,6-linked sialic acid receptor. Our study demonstrated that the S190R mutation resulted in earlier death and higher weight loss in mice compared with the wild-type virus. Higher viral titers at 1 dpi (days post infection) and diffuse damage at 4 dpi were observed in the lung tissues of mice infected with the mutant virus.

Materialization of strained CVD-graphene using thermal mismatch

Theoretical physics foretells that ＂strain engineering＂ of graphene could hold the key to finding treasures still hidden in two-dimensional （2D） condensed matter physics and commercializing graphene-based devices. However, to produce strained graphene in large quantities is not an easy task by any means. Here, we demonstrate that thermal annealing of graphene placed on various substrates could be a surprisingly simple method for preparing strained graphene with a large area. We found that enhanced graphene-substrate interfacial adhesion plays a critical role in developing strained graphene. Creative device architectures that consider the thermal mismatch between graphene and the target substrate could enable the resulting strain to be intentionally tailored. We believe that our proposed method could suggest a shortcut to realization of graphene straintronics.

Controlling the surface buckling wrinkles by patterning the material system of hard-nano-film/soft-matter-substrate

Wrinkling and buckling of nano-films on the compliant substrate are always induced due to thermal deformation mismatch.This paper proposes effective means to control the surface wrinkling of thin film on the compliant substrate,which exploits the curvatures of the curve cracks designed on the stiff film.The procedures of the method are summarized as:1)curve patterns are fabricated on the surface of PDMS(Polydimethylsiloxane)substrate and then the aluminum film with the thickness of several hundred nano-meters is deposited on the substrate;2)the curve patterns are transferred onto the aluminum film and lead to cracking of the film along the curves.The cracking redistributes the stress in the compressed film on the substrate;3)on the concave side of the curve,the wrinkling of the film surface is suppressed to be identified as shielding effect and on the convex side the wrinkling of the film surface is induced to be identified as inductive effect.The shielding and inductive effects make the dis-ordered wrinkling and buckling controllable.This phenomenon provides a potential application in the fabrication of flexible electronic devices.