In this article, we firstly analyze the referencing process and the citation process of a scientific journal in theory, and
find that the observed referencing or citation process includes the diffusing process and the aging process of cited literature
and the publishing process of citing literature, thereby it is illuminated why the identified average publication delay
was longer than the observed value. Secondly, we compare the transfer function model of the observed citing process with
other classical citation distribution models and find that the model is superior to others. Finally, using the model, we identify
parameters of actual referencing and citation processes from data of age distributions of references and citations of 38 journals
of neurology and applied mathematics in JCR, respectively; and then compare differences of identified parameters and obtain
some interesting conclusions.
Based on the transfer function model of the observed citation distribution and the expression of the cumulative citation probability
distribution, parameters of 12 citation distributions are identified from statistical data of age distributions of references
of 10 journals in JCR using the parameter optimization fitting method. At same time, based on the steady state solution of
differential equations of the publication delay process and data of publication delays of 10 journals, the publication delay
parameters of every journal are identified using the fitting method. Identified parameters of every journal citation distribution
are compared with the journal’s publication delay parameters and some valuable conclusions are deduced.
Based on the transform
function model of the observed citing process, the analytical expression of the
age distribution of citations is deduced, and it is theoretically proved that
the peak value of the citation distribution curve would fall and shift backward
along with increasing the average publication delay and the peak age has a
direct proportion relation with the pure delay and would be prolonged along
with increasing the delay or decreasing the aging rate. The influence of the
average publication delay on three ISI indicators impact factor, immediacy
index and cited half-life are studied; in one subject discipline, the bigger
the delay, the lower the three indicators of journals. Using the sensitivity
theory, sensitivity formulae of the three indicators to publication delay
parameters are deduced and it is found that responses of these indicators to
changes of publication delays are different according to different time
constant of the aging process; The faster the aging rate of a discipline
literature is, the worse the influence of publication delays on the indicators
of journals in the discipline.
The steady state solution of differential equations of periodical publication process is deduced, and based on this, the indicator of periodical publication delay, which reflects the degree of information ageing in editorial board of a periodical, is established. The indicator is proved to be the sum of two items: the pure publication delay, which reflects the editing rapidity of a periodical, and the ratio of deposited contribution quantity to the publishing quantity in one year, which reflects the waiting period of adopted papers deposited in editorial board. As a demonstration, the delay indicators of seven periodicals are calculated. Finally, the application of this indicator is discussed.
In this paper, the internal law of delay in the secondary literature publishing process is presented. The process is demonstrated
to abide by the partial differential equation of periodical literature publishing process. A definite solution of the publishing
delay process is derived. Accordingly, the expression of average publication delay indicator based on the particular solution
is deduced. Then the problem is studied that some information of primary literatures is missed in information retrieval, and
the relationship is established between the average delay indicator and the miss ratio of primary literatures in the index
periodicals or databases. Also it is proposed that the primary literature should be used as a supplemental tool in information
retrieval to guarantee the recall ratio.
Summary According to the discrete model of periodical publication process, recurrence formulae of parameters of the process are gained and the initial conditions of control process parameters from one steady state to another are deduced. Using the variable separation approach, which is used generally to solve the partial differential equation, the recurrence computing formula of the publication probability function is deduced. First the publication delay increasing process caused by the accepted contribution flux increase is simulated, and then the publication delay decreasing processes under four different control means are simulated too. Finally it is demonstrated that the periodical publishing process is a strong inertia system and it is found that reducing the quantity of deposited contributions can shorten the publication delay.
Authors:Huan Zhang, Pan Wang, Ai-Jun Zhang, Xuan Li, Ji-Hong Zhang, Qi-Lian Qin, and Yi-Jun Wu
The housefly is an important resource insect and the housefly larvae are ideal source of food additives. The housefly larvae protein hydrolysates were obtained by enzymatic hydrolysis by alcalase and neutral proteinase. Their antioxidant activities were investigated, including the superoxide and hydroxyl radicalscavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and metal chelating activity. The antioxidant activities of both hydrolysates increased with their increasing concentrations. The alcalase hydrolysate (AH) showed higher scavenging activities against hydroxyl radical and superoxide anion radical at low concentrations and higher metal-chelating activity than the neutral proteinase hydrolysate (NPH). The NPH exhibited higher scavenging activity against DPPH free radical and higher reducing power than the AH. Both hydrolysates showed more than 50% superoxide anion radical-scavenging activity at 10 μg/mL. These results indicate that both housefly larvae protein hydrolysates display high antioxidant activities and they could serve as potential natural antioxidant food additives.